**Figure 4.**

*Ecological zones of West Africa.*

### **2.2 Geographical distribution**

The species is native to the Guinean forest-savannah mosaic ecoregion of West Africa (**Figure 3**), which lies between the Guinean rainforest and the Sudanian

*Challenges of Conservation and Sustainable Management of African Rosewood… DOI: http://dx.doi.org/10.5772/intechopen.88796*

**Figure 4.** *Ecological zones of West Africa.*

4–7 cm in diameter and straw yellow in color and persists for a long time on the tree. It contains one–two seeds of often very different sizes [22]. The young fruits are light green and turn light brown when dry (**Figure 1C**). The seeds are flat to slightly thick, about 10 5 mm, smooth, and red to dark brown. The seedling has an epigeal

The species is native to the Guinean forest-savannah mosaic ecoregion of West Africa (**Figure 3**), which lies between the Guinean rainforest and the Sudanian

*Distribution de P. erinaceus in West Africa (Source: Ligneux du Sahel V.1.0, 2008).*

germination and leafy cotyledons [17].

*Natural Resources Management and Biological Sciences*

**2.2 Geographical distribution**

**Figure 2.**

**Figure 3.**

**292**

*Flowering tree of P. erinaceus.*

savannah [23]. It has been listed throughout the region, including Senegal, the Gambia, Guinea-Bissau, Guinea, Mali, Côte d'Ivoire, Burkina Faso, Ghana, Niger, Benin, Togo, Nigeria, and Cameroon (**Figure 3**). It is present up to the latitude of 14°N, but at this latitude the individuals are small and stunted. From this latitude, the species *P. lucens* dominates and is more abundant. To the south, the range of *P. erinaceus* extends to the moist forest limit in Côte d'Ivoire and the humid coastal savannas in Guinea, Togo, and Benin, where a gallery species, *P. santalinoides*, is common along rivers and temporary streams.

According to [24] classification, based on the total annual classes of rainfall, the species is distributed through three ecological zones, namely, Guinean zone, Sudanian zone, and Sahelian zone (**Figure 4**). *P. erinaceus* grows in dry open forests of semiarid and subhumid soils with an average annual rainfall of 600–1200 mm and a moderate or very long dry season that can last from 8 to 9 months. The average annual temperature in its range is 15–32°C, but the species tolerates high temperatures exceeding 40°C. The tree grows at low altitude (0–600 m) and also grows on shallow soils. Individuals tolerate drought and, once rooted, withstand different annual dry seasons.

#### **3. Socioeconomic status and perceptions of** *Pterocarpus erinaceus* **in West Africa**

Socioeconomic survey carried out in three countries (Burkina Faso, Niger, and Togo) allowed to collect data on uses and perceptions of *P. erinaceus* in West Africa [13]. Results indicate that *P. erinaceus* organs (leaves, barks, roots, sap) are used in the treatment of more than 33 diseases or pathologies in these countries. According to [25], *P. erinaceus* contains a high level of protein (19%) which makes it a very good agroforestry species [26]. The individuals in the farms, the fallows, and the classified forests are frequently pruned to feed the cattle. The leaves of the species are also sold in urban centers in Burkina Faso and Mali, as fodder.

In Burkina Faso, where the resource is relatively more abundant, 30 different local products from *P. erinaceus* wood have been identified including the balafon, the djembe, the mask, the statuettes, etc.:

The socio-professional category of the populations and the availability of the resource strongly influence the uses of the species in West Africa. The species is highly sought after by craftsmen for making musical instruments such as "balafon" and "djembe" (**Figure 6A** and **B**) especially among para-Gourma people in Burkina Faso, Niger, and Togo.

> problems, anemia, fever, sexual weaknesses, etc. These uses are similar to those observed in Hausa (Tchanga) located in the same geographical area. In contrast, the organs of *P. erinaceus* are used very little in traditional medicine

*Musical instruments manufactured from P. erinaceus for sale on the Bobo-Dioulasso market in Burkina Faso:*

• In Togo, Para-Gourma, Kabyè, and Tem use the species in the treatment of more than 18 diseases, including impotence, anemia, menstrual periods in women, and dermatoses such as skin scurf, intestinal wounds, and white losses in women. In Kabyè and Tem communities, the organs of the species are also used to facilitate delivery in pregnant women, cure ringworm and scorpion

among the Zarmas, Tuaregs and Peulhs communities of Niger.

*Challenges of Conservation and Sustainable Management of African Rosewood…*

*DOI: http://dx.doi.org/10.5772/intechopen.88796*

**4.** *Pterocarpus erinaceus* **stands' patterns in West Africa**

cantly from one climate zone to another (P < 103

from 0.30 0.10 (Sahelian zone) to 3.15 1.30 m2

zones is statistically significant (P < 0.001) (**Table 1**).

Sudanian zone, it is 2.46 2.88 m2

**295**

**4.1 Trees' characteristic variability according to ecological gradient**

three climate zones indicates that the average tree density ranges between

the values range between 22.07 8.98 (Guinean zone) and 49.63 19.44 cm

(Sahelian) at the Sudanian zone. In this zone, the average diameter is

The analysis of the main characteristics of the *P. erinaceus* forest stands in the

1.17 0.75 trees/ha (Sahelian zone) and 74.9 1.44 trees/ha (Guinean zone). In the Sudanian zone, it is 35.05 41.2 trees/ha. The values of the densities vary signifi-

29.02 15.44 cm. A significant difference was also noted for this parameter within the three zones (P < 0.001). Regarding the basal area, the values obtained range

The analysis of the total average height and the average stem height of *P. erinaceus* stands shows various values depending on whether it is in the Sahelian zone, in Sudanian zone, or Guinean zone. For the average total height, the stands of the Sudanian zone (9.51 2.75 m) are significantly different (P < 0.001) from the other two zones (10.18 2.27 m for the Sahelian zone and 10.09 2.88 m for the

). For the trees average diameter,

/ha (Guinean zone). In the

/ha in average. The difference among the three

bites, etc.

**Figure 6.**

*(A) balafon and (B) djembe.*

In addition, the endogenous knowledge of sociocultural communities is quite often contrasted with *P. erinaceus*:

**Figure 5.** *P. erinaceus logs being loaded into vehicles for export.*

*Challenges of Conservation and Sustainable Management of African Rosewood… DOI: http://dx.doi.org/10.5772/intechopen.88796*

#### **Figure 6.**

• In Niger, *P. erinaceus* is the only green fodder during the lean season (April– June). The fodder collection is generally focused on young leaves and flowers. Under the current effect of climate change, stands of *P. erinaceus* are in sharp decline and are tending toward extinction in Niger, which marks the northern

• In Togo, it is essentially the exploitation and export of lumber in the form of squares, logs, boards, and other carpentry products that are more developed [27]. Logging is based on the selective collection of key timber and fuel wood in natural habitats [10]. *P. erinaceus* is broadly used as first-class timber wood (**Figure 5**) and fuelwood [10, 28]. These selective collections pose a serious

The socio-professional category of the populations and the availability of the resource strongly influence the uses of the species in West Africa. The species is highly sought after by craftsmen for making musical instruments such as "balafon" and "djembe" (**Figure 6A** and **B**) especially among para-Gourma people in Burkina

In addition, the endogenous knowledge of sociocultural communities is quite

• In Burkina Faso, Nouné and Dioula communities use the parts of *P. erinaceus* especially in measles treatments, spider bites, low back pain, foot pimples, cough, etc. The Dioula communities use the plant for, among other things, cases of general tiredness, heart problems, dermatoses, dysentery, hemorrhoids, diarrhea to provoke menstruation in women, for magico-therapeutic treatments, etc. Diseases treated by Dioula communities are close to those treated by Fulani communities in Burkina Faso. Lele, Mossi, and Komono communities also show almost the same practices of using *P. erinaceus* organs in

• In Niger, the Dandy are distinguished from other ethnic groups with a larger number of diseases treated with the species, including among others gastric

threat to the country's plant genetic resources [29].

limit of its natural range.

*Natural Resources Management and Biological Sciences*

Faso, Niger, and Togo.

often contrasted with *P. erinaceus*:

the treatment of diseases.

*P. erinaceus logs being loaded into vehicles for export.*

**Figure 5.**

**294**

*Musical instruments manufactured from P. erinaceus for sale on the Bobo-Dioulasso market in Burkina Faso: (A) balafon and (B) djembe.*

problems, anemia, fever, sexual weaknesses, etc. These uses are similar to those observed in Hausa (Tchanga) located in the same geographical area. In contrast, the organs of *P. erinaceus* are used very little in traditional medicine among the Zarmas, Tuaregs and Peulhs communities of Niger.

• In Togo, Para-Gourma, Kabyè, and Tem use the species in the treatment of more than 18 diseases, including impotence, anemia, menstrual periods in women, and dermatoses such as skin scurf, intestinal wounds, and white losses in women. In Kabyè and Tem communities, the organs of the species are also used to facilitate delivery in pregnant women, cure ringworm and scorpion bites, etc.

#### **4.** *Pterocarpus erinaceus* **stands' patterns in West Africa**

#### **4.1 Trees' characteristic variability according to ecological gradient**

The analysis of the main characteristics of the *P. erinaceus* forest stands in the three climate zones indicates that the average tree density ranges between 1.17 0.75 trees/ha (Sahelian zone) and 74.9 1.44 trees/ha (Guinean zone). In the Sudanian zone, it is 35.05 41.2 trees/ha. The values of the densities vary significantly from one climate zone to another (P < 103 ). For the trees average diameter, the values range between 22.07 8.98 (Guinean zone) and 49.63 19.44 cm (Sahelian) at the Sudanian zone. In this zone, the average diameter is 29.02 15.44 cm. A significant difference was also noted for this parameter within the three zones (P < 0.001). Regarding the basal area, the values obtained range from 0.30 0.10 (Sahelian zone) to 3.15 1.30 m2 /ha (Guinean zone). In the Sudanian zone, it is 2.46 2.88 m2 /ha in average. The difference among the three zones is statistically significant (P < 0.001) (**Table 1**).

The analysis of the total average height and the average stem height of *P. erinaceus* stands shows various values depending on whether it is in the Sahelian zone, in Sudanian zone, or Guinean zone. For the average total height, the stands of the Sudanian zone (9.51 2.75 m) are significantly different (P < 0.001) from the other two zones (10.18 2.27 m for the Sahelian zone and 10.09 2.88 m for the

**Table 1.**

*Main forest characteristics of the three climatic zones.*

Guinean zone). Regarding the merchantable height, it ranges between 4.08 1.35 m (Sahelian zone) and 2.58 2.63 m (Guinean zone). For this parameter, the difference observed among the three zones is statistically significant (P < 0.001; **Table 1**). For the height of Lorey, the values obtained for the three zones range between 10.91 m (Sahelian zone) and 11.73 m (Guinean zone) and indicate a significant difference (P < 0.001).

The analysis of the structures shows a modal distribution of height classes for all the three climate zones. The individuals with heights ranging between 8 and 12 m are the most represented. These structures in height fit well with the theoretical distribution of Weibull (P > 0.05) with shape parameters c ranging between 2.1 and

*Demographic structures of the stands of P. erinaceus in Guineo-Sudano-Sahelian zone: (A) diameter*

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*DOI: http://dx.doi.org/10.5772/intechopen.88796*

*P. erinaceus* has a good regeneration capacity in seed, stump, and roots [16, 25]. Germination tests in Burkina Faso, Côte d'Ivoire, and Mali have shown that the species has a good germination capacity, with rates up to 95% if the seeds are shelled [17, 25, 30]. This should present good prospects for the production of seedlings for reforestation. Unfortunately, if the germination rate is very encouraging, this is not the case for the initial growth of seedlings. The main difficulties associated with the plantation of *P. erinaceus* are precisely the weak growth of young seedlings and their young flexible stem [17, 25]. This makes young seedlings vulnerable to wildfires, pests, trampling of animals, and adverse climatic conditions, preventing most of

In fact, the dynamics of natural regeneration of *P. erinaceus* show that the young plants come almost exclusively from underground stumps [9]. In natural conditions, the best regeneration technique for this species appears to be the regeneration

Studies carried out on *P. erinaceus* wood properties show that it could be classi-

**5.** *P. erinaceus* **wood technology and ecological variability in West**

fied in heavy and very hard wood with a density of 0.80 0.07 g/cm3 and an

2.9 (**Figure 7B1, B2**, and **B3**).

*distribution and (B) height distribution.*

**Figure 7.**

*4.2.2 Natural regeneration capacity of P. erinaceus*

them from crossing the first years of life [9, 31].

**5.1 General characteristics of** *P. erinaceus* **wood**

of cut stems at 10 cm from the soil [17, 25].

**Africa**

**297**

#### **4.2 Demographic structures**

#### *4.2.1 Distribution of trees in diameter and height classes*

The analysis of the demographic structure (distribution of trees in diameter classes and height classes (dbh ≥ 10 cm) of the *P. erinaceus* stands indicates a different situation depending on the climate zone considered (**Figure 7A** and **B**):

*Challenges of Conservation and Sustainable Management of African Rosewood… DOI: http://dx.doi.org/10.5772/intechopen.88796*

#### **Figure 7.**

Guinean zone). Regarding the merchantable height, it ranges between

indicate a significant difference (P < 0.001).

*Main forest characteristics of the three climatic zones.*

*Natural Resources Management and Biological Sciences*

*4.2.1 Distribution of trees in diameter and height classes*

**4.2 Demographic structures**

Average merchantable height

*NB: Avg, average; SE, standard error.*

*No significant differences for these values.*

(m)

*a*

**Table 1.**

Basal area (m2

of the stand (**Figure 7A2**).

**296**

4.08 1.35 m (Sahelian zone) and 2.58 2.63 m (Guinean zone). For this parameter, the difference observed among the three zones is statistically significant (P < 0.001; **Table 1**). For the height of Lorey, the values obtained for the three zones range between 10.91 m (Sahelian zone) and 11.73 m (Guinean zone) and

Height of Lorey (m) Average 11.34 10.91 11.73 <0.001

**Structural parameters Ecological zones Probability**

Density (trees/ha) Avg SE 1.17 0.75 35.05 41.2 74.9 1.44 <0.001 Average diameter (cm) Avg SE 49.63 19.44 29.02 15.44 22.07 8.98 <0.001 Average height (m) Avg SE 10.18 2.27a 9.51 2.75 10.09 2.88a <0.001

**Sahelian Soudanian Guinean**

Avg SE 4.08 1.35 3.63 1.49 2.58 2.63 <0.001

/ha) Avg SE 0.30 0.10 2.46 2.88 3.15 1.30 <0.001

The analysis of the demographic structure (distribution of trees in diameter classes and height classes (dbh ≥ 10 cm) of the *P. erinaceus* stands indicates a different situation depending on the climate zone considered (**Figure 7A** and **B**):

• In the Sahelian zone, the distribution of the *P. erinaceus* diameter classes reveals a predominance of the individuals with diameter classes ranging between 30 and 65 cm, that is, 55.09% of the entire stand. The young individuals with diameter class ranking between 10 and 30 cm and larger individuals with diameter ranging between 65 and 100 cm are very poorly represented, that is,

predominance of the individuals with diameter class ranging between 15 and 40 cm, that is, 74.4% of the stand. The young individuals with a diameter ranging between 10 and 15 cm and larger individuals with diameter ranging between 40 and 95 are poorly represented, that is, 17.11 and 8.4%, respectively,

• The Guinean zone is characterized by a preponderance of individuals with diameter class ranging between 10 and 25 cm, that is, 69.10% of the stand. The individuals with diameter class higher than 25 cm are poorly represented, that is, 30.8% of the stand. All the structures in diameter are fit (P > 0.05) with the theoretical distribution of Weibull and shape parameters c > 1, characteristics of the stand with predominance of middle-aged individuals (**Figure 7A3**).

11.13, and 29.77%, respectively, of the stand (**Figure 7A1**).

• In the Sudanian zone, the distribution of diameter classes indicates a

*Demographic structures of the stands of P. erinaceus in Guineo-Sudano-Sahelian zone: (A) diameter distribution and (B) height distribution.*

The analysis of the structures shows a modal distribution of height classes for all the three climate zones. The individuals with heights ranging between 8 and 12 m are the most represented. These structures in height fit well with the theoretical distribution of Weibull (P > 0.05) with shape parameters c ranging between 2.1 and 2.9 (**Figure 7B1, B2**, and **B3**).

#### *4.2.2 Natural regeneration capacity of P. erinaceus*

*P. erinaceus* has a good regeneration capacity in seed, stump, and roots [16, 25]. Germination tests in Burkina Faso, Côte d'Ivoire, and Mali have shown that the species has a good germination capacity, with rates up to 95% if the seeds are shelled [17, 25, 30]. This should present good prospects for the production of seedlings for reforestation. Unfortunately, if the germination rate is very encouraging, this is not the case for the initial growth of seedlings. The main difficulties associated with the plantation of *P. erinaceus* are precisely the weak growth of young seedlings and their young flexible stem [17, 25]. This makes young seedlings vulnerable to wildfires, pests, trampling of animals, and adverse climatic conditions, preventing most of them from crossing the first years of life [9, 31].

In fact, the dynamics of natural regeneration of *P. erinaceus* show that the young plants come almost exclusively from underground stumps [9]. In natural conditions, the best regeneration technique for this species appears to be the regeneration of cut stems at 10 cm from the soil [17, 25].

#### **5.** *P. erinaceus* **wood technology and ecological variability in West Africa**

#### **5.1 General characteristics of** *P. erinaceus* **wood**

Studies carried out on *P. erinaceus* wood properties show that it could be classified in heavy and very hard wood with a density of 0.80 0.07 g/cm3 and an

#### *Natural Resources Management and Biological Sciences*

#### **Table 2.**

*Main physical and mechanical characteristics of P. erinaceus wood.*

average hardness of 12 3.7 g/cm3 (**Table 2**). In terms of dimensional stability, radial shrinkage and tangential shrinkage are yielding, respectively, 3.2 0.7 and 5.7 1.0%, making *P. erinaceus* wood a stable wood with shrinkage anisotropy of <2. This high stability of *P. erinaceus* wood can be attributed to the high content of extracts (15.50–19.46%) of *P. erinaceus* wood [32]. Various studies on tropical

species such as *Pterocarpus soyauxii*, *Pterocarpus vernalis*, and *Swietenia macrophylla* confirm the close links between wood stability and extractable content [33]. Indeed, the presence of extracts enhances the stability of the wood by reducing the sensi-

The average compressive and static bending fracture stresses are, respectively,

14,500 1922 MPa [13]. The physical and mechanical characteristics of *P. erinaceus* wood confirm that certain uses of this wood in several African countries are quite appropriate, notably the manufacture of acoustic materials [13]. Empirically, the wood of *P. erinaceus* is known and sought, among other things, for making xylophone in West Africa and Sahel. Mostly wood used to produce xylophones are of

range of 14–20 GPa [34]. Moreover, [35, 36] have shown that the use of wood in

Analysis of *P. erinaceus* wood density according to phytogeographic zones indicates significant variability (P < 0.05). This variability results in an increase in the

) and a high modulus of elasticity in the

70 10 and 140 2.5 MPa, and the modulus of elasticity is in the order of

*Variation of radial and tangential shrinkage and FSP according to phytogeographic zones.*

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*DOI: http://dx.doi.org/10.5772/intechopen.88796*

tivity to thermodynamic variations of the environment.

such case requires a high insensitive to humidity variations.

**5.2 Variability of properties of** *P. erinaceus* **wood**

high density (between 0.80 and 0.95 g/cm3

**Figure 9.**

**299**

*5.2.1 Variability of physical properties*

**Figure 8.** *Variation of basic density according to phytogeographic zones.*

*Challenges of Conservation and Sustainable Management of African Rosewood… DOI: http://dx.doi.org/10.5772/intechopen.88796*

#### **Figure 9.**

average hardness of 12 3.7 g/cm3 (**Table 2**). In terms of dimensional stability, radial shrinkage and tangential shrinkage are yielding, respectively, 3.2 0.7 and 5.7 1.0%, making *P. erinaceus* wood a stable wood with shrinkage anisotropy of <2. This high stability of *P. erinaceus* wood can be attributed to the high content of extracts (15.50–19.46%) of *P. erinaceus* wood [32]. Various studies on tropical

Monnin hardness 12 3.7 5.8 23.8 28.6

*Main physical and mechanical characteristics of P. erinaceus wood.*

**deviation**

Radial shrinkage (%) 3.2 0.7 1.6 5.3 21.6 Anisotropy 1.8 0.2 1.2 2.2 12 FSP (%) 19.1 2.7 15.3 25 14 MOE (MPa) 14,500 1922 9717 19,127 13 MOR (MPa) 140 26.5 85.8 206.5 18.9

) 0.80 0.06 0.61 0.92 8

5.7 1 3.2 8.7 17.7

70 10 49 95 14.5

**Minimum Maximum Coefficient of variation**

**(%)**

**Properties Mean Stand**

*Natural Resources Management and Biological Sciences*

Basic density (g/cm3

Tangential shrinkage

Compressive strength

(MPa)

**Table 2.**

**Figure 8.**

**298**

*Variation of basic density according to phytogeographic zones.*

(%)

*Variation of radial and tangential shrinkage and FSP according to phytogeographic zones.*

species such as *Pterocarpus soyauxii*, *Pterocarpus vernalis*, and *Swietenia macrophylla* confirm the close links between wood stability and extractable content [33]. Indeed, the presence of extracts enhances the stability of the wood by reducing the sensitivity to thermodynamic variations of the environment.

The average compressive and static bending fracture stresses are, respectively, 70 10 and 140 2.5 MPa, and the modulus of elasticity is in the order of 14,500 1922 MPa [13]. The physical and mechanical characteristics of *P. erinaceus* wood confirm that certain uses of this wood in several African countries are quite appropriate, notably the manufacture of acoustic materials [13]. Empirically, the wood of *P. erinaceus* is known and sought, among other things, for making xylophone in West Africa and Sahel. Mostly wood used to produce xylophones are of high density (between 0.80 and 0.95 g/cm3 ) and a high modulus of elasticity in the range of 14–20 GPa [34]. Moreover, [35, 36] have shown that the use of wood in such case requires a high insensitive to humidity variations.

#### **5.2 Variability of properties of** *P. erinaceus* **wood**

#### *5.2.1 Variability of physical properties*

Analysis of *P. erinaceus* wood density according to phytogeographic zones indicates significant variability (P < 0.05). This variability results in an increase in the

according to the phytogeographic zones does not indicate a significant difference (P > 0.05) for the MOE, the hardness, and the static bending strength (MOR) (**Figure 10**). Indeed, the MOE indicates, respectively, 14,150 1900 and

*Challenges of Conservation and Sustainable Management of African Rosewood…*

14,100 2300 MPa for the Guinean and Sudanian zones. For Monnin hardness, the values indicate on average 13.09 3.87 in the Sudanian zone and 12.08 3.33 in the Guinean zone. As regards static bending fracture stresses, it gives an average of 137.5 25.5 MPa in the Guinean zone and 145 27.5 MPa in the Sudanian zone. Only the values of the compressive strength vary significantly from one zone to another (P < 0.05). It is 66.5 9.4 MPa in the Guinean zone and 73.5 10.3 MPa in

In terms of the variability of properties according to the age, the analysis of the mechanical properties according to the number of rings counted from pith to bark showed that only the compressive and static bending strength were correlated with the cambial age [13]. The juvenile wood zone appears slightly more "resistant" in compressive strength and MOR than the adult wood zone. But this correlation remains weak, as shown by the coefficients of determination obtained (compressive strength: R2 = 0.09, MOR: R2 = 0.13). Age would therefore have very little influence

**6. Restoration and conservation of** *P. erinaceus stands in West Africa*

The production strategies of *P. erinaceus*, like all plant species, are based on the use of classical cultural methods of sexual propagation (seedling germination) and

Several studies indicate that natural regeneration is often abundant and that the species may be somewhat invasive enough to be preserved for a few years from grazing, bush fires, vegetation, and pruning [17, 38]. For germination, all the seeds extracted from fruits can be used. It is essential to ensure the good health of these two organs and to avoid taking those who have suffered attacks (animals, insects, fungi, etc.), mechanical damage (breakage, injury, and holes), etc. Germination rates (70–90%) can be obtained with seeds extracted from fruit collected directly on the trees or collected on the ground. With healthy seeds from fruit hulling, sown without pretreatment on cotton soaked in distilled water, average germination rates

The substrate used during these trials was composed of vermiculite, vermiculite + earth (1v/1v) and vermiculite + compost (1v/1v), with cotton or paper as support (**Figure 11**). The seedlings of *P. erinaceus* are quite fragile at germination and are not able to support the weight and opacity of a compact substrate. There is no specific pretreatment to apply to seeds, but they can be soaked in water for 24 h before sowing to hasten their hydration and promote homogenous germination. The first germinations are observed 24 h after sowing [38, 39]. The advantage of the use of seedlings lies in the fact that they lead to variability in the monitored seedlings.

The influence of seed storage period on their germination capacity shows greatly

variable germination capacities, with a maximum of 93.75% and a minimum of 10.71%, with general decrease in the germination rate between the fifth and the ninth month. The germination capacity varies according to the origin of the seeds.

**6.1 Large-scale plant production strategies of** *P. erinaceus* **for restoration**

the Sudanian zone.

*6.1.1 Sexual propagation*

**301**

on the mechanical properties of wood.

*DOI: http://dx.doi.org/10.5772/intechopen.88796*

**programs of degraded forest ecosystems**

vegetative propagation (horticultural cuttings, layering, etc.).

were recorded at 84% for of 2 days of germination trials.

#### **Figure 10.**

*Variation of mechanical properties according to phytogeographic zones.*

density following the decreasing rainfall gradient in North–South [37]. The highest value of density is obtained in the Sahelian zone (0.78 0.01 g/m3 ) and the lowest in the Guinean zone (0.68 0.01 g/m3 ; **Figure 8**).

Like wood density, radial and tangential shrinkage and FSP vary significantly from one phytogeographic zone to another (P < 0.05). Indeed, the trees of *P. erinaceus* from the Sahelian zone present radial (2.7%) and tangential (4.1%) shrinkages significantly lower than those of the Sudanian and Guinean zones. The radial shrinkage gives an average of 2.8 and 2.95% for trees from the Guinean and Sudanian zones, respectively. As for shrinkages, the trees of the Sahelian zone have a FSP (17.1%) significantly lower than the other (**Figure 9**). In other words, the trees of *P. erinaceus* in the Sahelian zone have a more stable wood than the trees in the Guinean and Sudanian zones [37].

Regarding the influence of the radial position, only the FSP is negatively related to the cambial age [13]. This is consistent with the results of [36], which showed the influence of the level of extract, especially with benzene alcohol, on the PSF. For wood density, the work of [37] showed a very small decrease in density as a function of cambial age (R2 = 0.11). This generally shows that the physical properties of *P. erinaceus* wood remain very little, if any, influenced by cambial age.

#### *5.2.2 Variability of mechanical properties*

The climatic variability of the mechanical properties was analyzed according to two phytogeographic zones (Guinean and Sudanian; data on the Sahelian zone are not available). The analysis of the average values of the mechanical properties

*Challenges of Conservation and Sustainable Management of African Rosewood… DOI: http://dx.doi.org/10.5772/intechopen.88796*

according to the phytogeographic zones does not indicate a significant difference (P > 0.05) for the MOE, the hardness, and the static bending strength (MOR) (**Figure 10**). Indeed, the MOE indicates, respectively, 14,150 1900 and 14,100 2300 MPa for the Guinean and Sudanian zones. For Monnin hardness, the values indicate on average 13.09 3.87 in the Sudanian zone and 12.08 3.33 in the Guinean zone. As regards static bending fracture stresses, it gives an average of 137.5 25.5 MPa in the Guinean zone and 145 27.5 MPa in the Sudanian zone. Only the values of the compressive strength vary significantly from one zone to another (P < 0.05). It is 66.5 9.4 MPa in the Guinean zone and 73.5 10.3 MPa in the Sudanian zone.

In terms of the variability of properties according to the age, the analysis of the mechanical properties according to the number of rings counted from pith to bark showed that only the compressive and static bending strength were correlated with the cambial age [13]. The juvenile wood zone appears slightly more "resistant" in compressive strength and MOR than the adult wood zone. But this correlation remains weak, as shown by the coefficients of determination obtained (compressive strength: R2 = 0.09, MOR: R2 = 0.13). Age would therefore have very little influence on the mechanical properties of wood.

#### **6. Restoration and conservation of** *P. erinaceus stands in West Africa*

#### **6.1 Large-scale plant production strategies of** *P. erinaceus* **for restoration programs of degraded forest ecosystems**

The production strategies of *P. erinaceus*, like all plant species, are based on the use of classical cultural methods of sexual propagation (seedling germination) and vegetative propagation (horticultural cuttings, layering, etc.).

#### *6.1.1 Sexual propagation*

density following the decreasing rainfall gradient in North–South [37]. The highest

; **Figure 8**). Like wood density, radial and tangential shrinkage and FSP vary significantly from one phytogeographic zone to another (P < 0.05). Indeed, the trees of *P. erinaceus* from the Sahelian zone present radial (2.7%) and tangential (4.1%) shrinkages significantly lower than those of the Sudanian and Guinean zones. The radial shrinkage gives an average of 2.8 and 2.95% for trees from the Guinean and Sudanian zones, respectively. As for shrinkages, the trees of the Sahelian zone have a FSP (17.1%) significantly lower than the other (**Figure 9**). In other words, the trees of *P. erinaceus* in the Sahelian zone have a more stable wood than the trees in

Regarding the influence of the radial position, only the FSP is negatively related to the cambial age [13]. This is consistent with the results of [36], which showed the influence of the level of extract, especially with benzene alcohol, on the PSF. For wood density, the work of [37] showed a very small decrease in density as a function of cambial age (R2 = 0.11). This generally shows that the physical properties of *P. erinaceus* wood remain very little, if any, influenced by cambial age.

The climatic variability of the mechanical properties was analyzed according to two phytogeographic zones (Guinean and Sudanian; data on the Sahelian zone are not available). The analysis of the average values of the mechanical properties

) and the lowest

value of density is obtained in the Sahelian zone (0.78 0.01 g/m3

*Variation of mechanical properties according to phytogeographic zones.*

*Natural Resources Management and Biological Sciences*

in the Guinean zone (0.68 0.01 g/m3

**Figure 10.**

**300**

the Guinean and Sudanian zones [37].

*5.2.2 Variability of mechanical properties*

Several studies indicate that natural regeneration is often abundant and that the species may be somewhat invasive enough to be preserved for a few years from grazing, bush fires, vegetation, and pruning [17, 38]. For germination, all the seeds extracted from fruits can be used. It is essential to ensure the good health of these two organs and to avoid taking those who have suffered attacks (animals, insects, fungi, etc.), mechanical damage (breakage, injury, and holes), etc. Germination rates (70–90%) can be obtained with seeds extracted from fruit collected directly on the trees or collected on the ground. With healthy seeds from fruit hulling, sown without pretreatment on cotton soaked in distilled water, average germination rates were recorded at 84% for of 2 days of germination trials.

The substrate used during these trials was composed of vermiculite, vermiculite + earth (1v/1v) and vermiculite + compost (1v/1v), with cotton or paper as support (**Figure 11**). The seedlings of *P. erinaceus* are quite fragile at germination and are not able to support the weight and opacity of a compact substrate. There is no specific pretreatment to apply to seeds, but they can be soaked in water for 24 h before sowing to hasten their hydration and promote homogenous germination. The first germinations are observed 24 h after sowing [38, 39]. The advantage of the use of seedlings lies in the fact that they lead to variability in the monitored seedlings.

The influence of seed storage period on their germination capacity shows greatly variable germination capacities, with a maximum of 93.75% and a minimum of 10.71%, with general decrease in the germination rate between the fifth and the ninth month. The germination capacity varies according to the origin of the seeds.

**Figure 11.** *Nursery of P. erinaceus on vermiculite in seedling cells.*

*6.1.2 Vegetative propagation of P. erinaceus*

#### *<IP_ADDRESS> Marcottage ability of Pterocarpus erinaceus*

#### *<IP_ADDRESS>.1 Rooting rate of marcots*

Ref. [40] revealed that from 100 marcots monitored, 97 were stripped. The rooting rate observed is 55.67%. In the apical part, 18 marcots were unpacked with an average diameter of 11.33 2.53 mm, and 9 of them rooted, which have a success rate of 50%. In the unattached middle part of 37 with an average diameter of 19.30 4.01 mm, 16 have rooted which gives a rate of 56.75%. Among the 42 marcots of the proximal part whose average diameter is 21.87 3.95 mm, 24 root coots have rooted with a success rate of 57.14%. In general, it was founded that the marcots made in the proximal part of the tree gave the highest success rate (**Table 3**; **Figure 12A, B,** and **C**).

of the branch toward the terminal buds with a rate of 50%. The evolution of this rate shows that the success of marcottage depends on the age of the marcotted branch part. Indeed, the level located near the main stem is the oldest and in addition has the highest average diameter capable of storing a large amount of sap

*Challenges of Conservation and Sustainable Management of African Rosewood…*

*DOI: http://dx.doi.org/10.5772/intechopen.88796*

*Marcots ingrained legend: (A) marcot unpacked, (B) marcot with clod of soil, and (C) roots produced and rid*

Experimental trials were conducted to evaluate the effect of the indoleacetic acid (IAA) dose, cutting diameter and soaking time on the budding, and degeneration and rooting of *P. erinaceus* cuttings (Appendix 2). With this, two sets of experiments were carried out to assess the effect of IAA dose, diameter of cuttings and soaking duration on budding, and degeneration and cutting rooting of *P. erinaceus*. The first experimental tests were designed on the basis of three factors that are diameter of the cuttings with two levels ([0–1.5 cm] and [1.6–3]), the dose of IAA with six levels (0, 500, 750, 1000, 1500, and 2000 mg/l), and soaking duration in

A total number of 48 (2 6 4) treatments, repeated 11 times, were established. The data collected were related to the number of cuttings budged and number of cuttings that degenerated after diameter of shoots as well as number of

Based on these tests, it was pointed out that the budding started on the fourth day after establishment of the tests. The budding rate of the cuttings is 79.8% after 8 weeks. The budding rates are statistically similar whatever the diameter class

developed in its liber and supporting rhizogenesis.

IAA with four levels (0, 10, 20, and 30 min).

leaves produced.

**303**

**Figure 12.**

*of clods of earth.*

*<IP_ADDRESS> Budding ability of Pterocarpus erinaceus stem cuttings*

**Table 3** illustrates the relationship between the success rate and the diameter classes of marcotted stems. Indeed, the rods' diameter between 20 and 30 mm followed by rods with a diameter of between 10 and 20 mm has the highest success rate. Stems with a diameter of between 5 and 10 mm have only a success rate of 20%.

#### *<IP_ADDRESS>.2 Ability of marcots' rooting*

The success rate observed is about 55.6% [40]. The analysis of the success rate, i.e., the rate of rooting of the layers, showed that the layers of the proximal part located near the main stem of the tree are more suitable for layering with a rate of 57.14% followed by middle-aged layers with a rate of 56.7%, at the center of the branch; the lowest marcotting ability is observed at the level of the apical layer, i.e., at the end

**Table 3.** *Rooting rate and number of rooted marcots.* *Challenges of Conservation and Sustainable Management of African Rosewood… DOI: http://dx.doi.org/10.5772/intechopen.88796*

**Figure 12.**

*6.1.2 Vegetative propagation of P. erinaceus*

*Nursery of P. erinaceus on vermiculite in seedling cells.*

*<IP_ADDRESS>.1 Rooting rate of marcots*

**Figure 11.**

(**Table 3**; **Figure 12A, B,** and **C**).

*<IP_ADDRESS>.2 Ability of marcots' rooting*

*Rooting rate and number of rooted marcots.*

**Table 3.**

**302**

*<IP_ADDRESS> Marcottage ability of Pterocarpus erinaceus*

*Natural Resources Management and Biological Sciences*

Ref. [40] revealed that from 100 marcots monitored, 97 were stripped. The rooting rate observed is 55.67%. In the apical part, 18 marcots were unpacked with an average diameter of 11.33 2.53 mm, and 9 of them rooted, which have a success rate of 50%. In the unattached middle part of 37 with an average diameter of 19.30 4.01 mm, 16 have rooted which gives a rate of 56.75%. Among the 42 marcots of the proximal part whose average diameter is 21.87 3.95 mm, 24 root coots have rooted with a success rate of 57.14%. In general, it was founded that the

marcots made in the proximal part of the tree gave the highest success rate

**Table 3** illustrates the relationship between the success rate and the diameter classes of marcotted stems. Indeed, the rods' diameter between 20 and 30 mm followed by rods with a diameter of between 10 and 20 mm has the highest success rate. Stems with a diameter of between 5 and 10 mm have only a success rate of 20%.

The success rate observed is about 55.6% [40]. The analysis of the success rate, i.e., the rate of rooting of the layers, showed that the layers of the proximal part located near the main stem of the tree are more suitable for layering with a rate of 57.14% followed by middle-aged layers with a rate of 56.7%, at the center of the branch; the lowest marcotting ability is observed at the level of the apical layer, i.e., at the end

**Levels Initial number Average diameter (mm) Rooted number Success rate (%)** Apical 18 11.33 2.53a 9 50.00 Median 37 19.30 4.01b 21 56.75 Proximal 42 21.87 3.95c 24 57.14

*Marcots ingrained legend: (A) marcot unpacked, (B) marcot with clod of soil, and (C) roots produced and rid of clods of earth.*

of the branch toward the terminal buds with a rate of 50%. The evolution of this rate shows that the success of marcottage depends on the age of the marcotted branch part. Indeed, the level located near the main stem is the oldest and in addition has the highest average diameter capable of storing a large amount of sap developed in its liber and supporting rhizogenesis.

#### *<IP_ADDRESS> Budding ability of Pterocarpus erinaceus stem cuttings*

Experimental trials were conducted to evaluate the effect of the indoleacetic acid (IAA) dose, cutting diameter and soaking time on the budding, and degeneration and rooting of *P. erinaceus* cuttings (Appendix 2). With this, two sets of experiments were carried out to assess the effect of IAA dose, diameter of cuttings and soaking duration on budding, and degeneration and cutting rooting of *P. erinaceus*. The first experimental tests were designed on the basis of three factors that are diameter of the cuttings with two levels ([0–1.5 cm] and [1.6–3]), the dose of IAA with six levels (0, 500, 750, 1000, 1500, and 2000 mg/l), and soaking duration in IAA with four levels (0, 10, 20, and 30 min).

A total number of 48 (2 6 4) treatments, repeated 11 times, were established. The data collected were related to the number of cuttings budged and number of cuttings that degenerated after diameter of shoots as well as number of leaves produced.

Based on these tests, it was pointed out that the budding started on the fourth day after establishment of the tests. The budding rate of the cuttings is 79.8% after 8 weeks. The budding rates are statistically similar whatever the diameter class

(78.89, 80.56, and 80.56%, respectively, for cuttings with diameter comprising [2– 2.5 cm], [2.6–3 cm], and [3.1–3.5 cm]). In contrast, levels of IAA dose and soaking duration of cuttings have statistically significant (P < 0.05) effects on the budding (**Table 4**). The chances of budding of the cuttings soaked in IAA at doses 750, 1500, and 2000 mg/l are, respectively, 5.70, 2.55, and 3.71 times higher than the control tests (without application of IAA). All cuttings treated with IAA showed a budding rate much higher (>80%) than the one in control tests (62.22%, **Figure 10**). Similarly, budding rates after 8 weeks range from 79.26% for cuttings soaked for 10 s to 89.63% for cuttings soaked for 1 h (**Figure 13**).

observed in the three diameter classes. This result corroborates perfectly those of [38, 41] revealing that diameter has a marginal effect on bud development. However, contrary to previous trials that concluded that stem cuttings of *P. erinaceus* cannot be rooted and degenerated after a while [38, 41], the results of the previous trial show that cuttings with diameters between 2 and 3 cm can root perfectly when soaked in IAA dose of 1500–2000 mg/l for 20 min to 1 h. In this experiment, cuttings with small diameter, non-soaked cuttings (control), and cuttings soaked in IAA for 10 s have not rooted. The cuttings that survived with leafy shoots until 24 weeks are those which made large amount of callus and rooted sufficiently as the callus formation is a necessarypreliminary for cutting rooting

*Challenges of Conservation and Sustainable Management of African Rosewood…*

Ref. [42] determined *P. erinaceus* minimum felling diameter to ensure a sustainable management of its natural stands in West Africa. The methodological approach was based firstly on the calculation of the restoration rates and the rotation cycles and secondly on the distribution of the stand basal area in diameter classes. The results show that for the Guinean and Sudanian zones, the best restoration percentage (P ≥ 50%) is obtained for 35 m in diameter. Percentages equivalent to 356.5% are therefore obtained for the Guinean zone and 53.4% for the Sudanian zone for a rotation period estimated at 20 years (Appendix 3). In the Sahelian zone, the best restoration percentage (P ≥ 50%) is only obtained when testing the 65 cm diameter.

*Rooted cuttings of Pterocarpus erinaceus: a: cutting with callus; b&d: rooted cuttings without clod of soil; c:*

(**Figure 14**).

**Figure 14.**

**305**

*rooted cuttings with clod of soil.*

**6.2 Minimum felling diameter of** *P. erinaceus*

*DOI: http://dx.doi.org/10.5772/intechopen.88796*

#### *<IP_ADDRESS> Cutting diameter and IAA appropriate dose for successful rooting in P. erinaceus stem cuttings*

The efficiency of cutting success is largely related to rooting. Indeed the budding alone does not explain the chances of survival of the young shoots because it is based on the reserves stored by the cuttings to occur. So after the depletion of these reserves in the absence of a root system that can take over to feed the young shoot, it dries up and dies. This explains the favorable budding and bud bursting response

**Table 4.** *Effect of diameter class, IAA dose, and soaking time on the budding of P. erinaceus after 8 weeks.*

#### **Figure 13.**

*Budding rates of the cuttings according to doses of IAA (a) and time of soaking (b) after 8 weeks.*

*Challenges of Conservation and Sustainable Management of African Rosewood… DOI: http://dx.doi.org/10.5772/intechopen.88796*

observed in the three diameter classes. This result corroborates perfectly those of [38, 41] revealing that diameter has a marginal effect on bud development.

However, contrary to previous trials that concluded that stem cuttings of *P. erinaceus* cannot be rooted and degenerated after a while [38, 41], the results of the previous trial show that cuttings with diameters between 2 and 3 cm can root perfectly when soaked in IAA dose of 1500–2000 mg/l for 20 min to 1 h. In this experiment, cuttings with small diameter, non-soaked cuttings (control), and cuttings soaked in IAA for 10 s have not rooted. The cuttings that survived with leafy shoots until 24 weeks are those which made large amount of callus and rooted sufficiently as the callus formation is a necessarypreliminary for cutting rooting (**Figure 14**).

#### **6.2 Minimum felling diameter of** *P. erinaceus*

(78.89, 80.56, and 80.56%, respectively, for cuttings with diameter comprising [2– 2.5 cm], [2.6–3 cm], and [3.1–3.5 cm]). In contrast, levels of IAA dose and soaking duration of cuttings have statistically significant (P < 0.05) effects on the budding (**Table 4**). The chances of budding of the cuttings soaked in IAA at doses 750, 1500, and 2000 mg/l are, respectively, 5.70, 2.55, and 3.71 times higher than the control tests (without application of IAA). All cuttings treated with IAA showed a budding rate much higher (>80%) than the one in control tests (62.22%, **Figure 10**). Similarly, budding rates after 8 weeks range from 79.26% for cuttings soaked for 10 s to

*<IP_ADDRESS> Cutting diameter and IAA appropriate dose for successful rooting in P. erinaceus*

alone does not explain the chances of survival of the young shoots because it is based on the reserves stored by the cuttings to occur. So after the depletion of these reserves in the absence of a root system that can take over to feed the young shoot, it dries up and dies. This explains the favorable budding and bud bursting response

**Treatments Odds ratio STD P > |z|** IAA dose (mg/l) 5.70 1.95 0.000 2.55 0.72 0.001 3.71 1.13 0.000 Soaking duration (s) 2.32 0.64 0.002 4.86 1.59 0.000 4.86 1.59 0.000

*Effect of diameter class, IAA dose, and soaking time on the budding of P. erinaceus after 8 weeks.*

*Budding rates of the cuttings according to doses of IAA (a) and time of soaking (b) after 8 weeks.*

The efficiency of cutting success is largely related to rooting. Indeed the budding

89.63% for cuttings soaked for 1 h (**Figure 13**).

*Natural Resources Management and Biological Sciences*

*STD, standard error; P, budding probability at 5%.*

**Table 4.**

**Figure 13.**

**304**

*stem cuttings*

Ref. [42] determined *P. erinaceus* minimum felling diameter to ensure a sustainable management of its natural stands in West Africa. The methodological approach was based firstly on the calculation of the restoration rates and the rotation cycles and secondly on the distribution of the stand basal area in diameter classes. The results show that for the Guinean and Sudanian zones, the best restoration percentage (P ≥ 50%) is obtained for 35 m in diameter. Percentages equivalent to 356.5% are therefore obtained for the Guinean zone and 53.4% for the Sudanian zone for a rotation period estimated at 20 years (Appendix 3). In the Sahelian zone, the best restoration percentage (P ≥ 50%) is only obtained when testing the 65 cm diameter.

For this diameter, a restoration rate is obtained at 111.9% for a rotation period estimated at 20 years (Appendix 3).

In addition, the distribution of the basal areas per trees diameter classes recorded in each of the three climate zones indicates a curve which is similar to a bell-shaped distribution. Therefore, for the Guinean and Sudanian zones, the maximum value of the basal area is obtained for the center with diameter class equal to 35 cm (**Figure 15**). As for the Sahelian zone, the maximum value of the basal area is obtained for the center of the diameter class equal to 65 cm.

bans. However, these regulations were routinely violated. Chinese custom data showed continuous rosewood export from producer countries under timber/log

Faced with these situations, some countries have placed a moratorium prohibiting its exploitation (the case of Togo where a moratorium has been put in place since June 2016). This decision of the Ministry of the Environment and Forest Resources of Togo was largely based on the results of our studies and warnings of the status of the species in the country. In 2016, the African Union organized a symposium on the illegal exploitation of the species in Guinea-Bissau. During this symposium, it was clearly pointed out that the abusive exploitation and the bush

The increased rate of unsustainable exploitation and illegal logging of *P. erinaceus* is driven by noncompliance and ineffective enforcement of regulatory framework governing timber exploitation and trade. Rosewood exploitation and trade have continued despite the ban in the affected countries and/or strict trade regulatory control such as CITES. National regulatory frameworks and law enforcers' endeavors within national territories have proved helpless against regional and intercontinental trade dynamics. The situation does not only deprive local communities (where the species is endemic) of due economic benefits but also deprives the state of huge revenue such as taxes and fees that could have been used for national development. For example, in 2013, it was estimated that Ghana lost 70% of the revenue that should have accrued to the state due to illegal exploitation of rosewood [12]. The limited effectiveness of the domestic measures against rosewood exploitation and the recent irregularities in the issuance of CITES permit in Nigeria call for a stronger regional collaboration and robust and technologically advanced timber tracking system and wood identification

*P. erinaceus* is also one of the priority species that focused the attention of number of scientists. Then several authors have pointed out the increased rate of illegal felling and over export of the species in African countries such as Benin, the Gambia, Ghana, Guinea-Bissau, Nigeria, and Mozambique [43–46]. Faced with this persistent threat, the domestication of this species is important to ensure its sustainability. Several actions have been carried out in favor of the species to reduce the pressure on it and make it an opportunity for the region. Assessing the impact of felling/export ban and CITES designation on the exploitation and trade of the species in Ghana [12] has concluded on the necessary ex situ conservation measures such as seed banking, field gene banking, tissue culture, and plantation development to conserve this endangered plant species in order to avoid the possibility of

The analysis of the state of knowledge on natural stands of *P. erinaceus* in West Africa has shown that different social and sociocultural categories know and use the products of the species. Approximately 46 uses have been identified by

fires make the renewal of the natural stands of *P. erinaceus* difficult.

Consequently, seeking stricter control of exploitation and trade of rosewood, Senegal and other range countries in West Africa listed the species on CITES Appendix III in 2016 and later up-listed it to Appendix II in 2017. In spite of the CITES Appendix listing, there are still incidences of illegal logging and trade in the exporting and importing countries. Due to incidence of illegal logging and irregularities in the issuance of CITES permit, Nigeria has recently (effective November 2018) been suspended from trading in *P. erinaceus* until it adequately addresses

export ban for well over 2–3 years under after the bans were imposed.

*Challenges of Conservation and Sustainable Management of African Rosewood…*

issues of forest law enforcement trade and governance.

*DOI: http://dx.doi.org/10.5772/intechopen.88796*

methods that can help stem illegalities.

commercial extinction.

**7. Conclusion**

**307**

In view of the foregoing results, two minimum felling diameters for Guineo-Sudano-Sahelian zone in West Africa are considered. This includes the diameter 35 cm for the Guinean and Sudanian zones (P = 356.5% for the Guinean zone and P = 53.4% for the Sahelian zone for a rotation of 20 years) and the diameter 65 cm for the Sahelian zone (P = 111.9% for a rotation period estimated at 20 years).

The analysis of the restoration percentages depending on the diameter classes and the time helps deducing that the *P. erinaceus* stands are restored in a relatively shorter time in Guinean zone. However, the Sahelian zone seems not to offer favorable conditions for the rapid restoration of this species stands (**Figure 13**). The high restoration rate of the species in the Guinean zone may be explained by the fact that the exploitation of the species there is frequently timber. This form of exploitation allows the selective cutting of the large-diameter trees and leaving behind the seedlings. Since the ecological conditions are favorable in this zone (high rainfall), there is a regeneration (usually in the form of stump sprouts), and seeds are produced. However, in the Sahelian zone, the pollarding for fodder is an important exploitation form of the species.

#### **6.3 Conservation measures to preserve** *P. erinaceus*

The intensity of the exploitation of the species sparked off concerns about its sustainability among a range of countries including Benin, Burkina Faso, Ghana, Senegal, and Togo. In order to curb the unrestrained exploitation of rosewood, countries (including Ghana and Togo) adopted harvesting and timber/log export

**Figure 15.** *Distribution of the basal area in terms of diameter classes across climatic zones.*

#### *Challenges of Conservation and Sustainable Management of African Rosewood… DOI: http://dx.doi.org/10.5772/intechopen.88796*

bans. However, these regulations were routinely violated. Chinese custom data showed continuous rosewood export from producer countries under timber/log export ban for well over 2–3 years under after the bans were imposed.

Consequently, seeking stricter control of exploitation and trade of rosewood, Senegal and other range countries in West Africa listed the species on CITES Appendix III in 2016 and later up-listed it to Appendix II in 2017. In spite of the CITES Appendix listing, there are still incidences of illegal logging and trade in the exporting and importing countries. Due to incidence of illegal logging and irregularities in the issuance of CITES permit, Nigeria has recently (effective November 2018) been suspended from trading in *P. erinaceus* until it adequately addresses issues of forest law enforcement trade and governance.

Faced with these situations, some countries have placed a moratorium prohibiting its exploitation (the case of Togo where a moratorium has been put in place since June 2016). This decision of the Ministry of the Environment and Forest Resources of Togo was largely based on the results of our studies and warnings of the status of the species in the country. In 2016, the African Union organized a symposium on the illegal exploitation of the species in Guinea-Bissau. During this symposium, it was clearly pointed out that the abusive exploitation and the bush fires make the renewal of the natural stands of *P. erinaceus* difficult.

The increased rate of unsustainable exploitation and illegal logging of *P. erinaceus* is driven by noncompliance and ineffective enforcement of regulatory framework governing timber exploitation and trade. Rosewood exploitation and trade have continued despite the ban in the affected countries and/or strict trade regulatory control such as CITES. National regulatory frameworks and law enforcers' endeavors within national territories have proved helpless against regional and intercontinental trade dynamics. The situation does not only deprive local communities (where the species is endemic) of due economic benefits but also deprives the state of huge revenue such as taxes and fees that could have been used for national development. For example, in 2013, it was estimated that Ghana lost 70% of the revenue that should have accrued to the state due to illegal exploitation of rosewood [12]. The limited effectiveness of the domestic measures against rosewood exploitation and the recent irregularities in the issuance of CITES permit in Nigeria call for a stronger regional collaboration and robust and technologically advanced timber tracking system and wood identification methods that can help stem illegalities.

*P. erinaceus* is also one of the priority species that focused the attention of number of scientists. Then several authors have pointed out the increased rate of illegal felling and over export of the species in African countries such as Benin, the Gambia, Ghana, Guinea-Bissau, Nigeria, and Mozambique [43–46]. Faced with this persistent threat, the domestication of this species is important to ensure its sustainability. Several actions have been carried out in favor of the species to reduce the pressure on it and make it an opportunity for the region. Assessing the impact of felling/export ban and CITES designation on the exploitation and trade of the species in Ghana [12] has concluded on the necessary ex situ conservation measures such as seed banking, field gene banking, tissue culture, and plantation development to conserve this endangered plant species in order to avoid the possibility of commercial extinction.

#### **7. Conclusion**

The analysis of the state of knowledge on natural stands of *P. erinaceus* in West Africa has shown that different social and sociocultural categories know and use the products of the species. Approximately 46 uses have been identified by

For this diameter, a restoration rate is obtained at 111.9% for a rotation period

obtained for the center of the diameter class equal to 65 cm.

In addition, the distribution of the basal areas per trees diameter classes recorded in each of the three climate zones indicates a curve which is similar to a bell-shaped distribution. Therefore, for the Guinean and Sudanian zones, the maximum value of the basal area is obtained for the center with diameter class equal to 35 cm (**Figure 15**). As for the Sahelian zone, the maximum value of the basal area is

In view of the foregoing results, two minimum felling diameters for Guineo-Sudano-Sahelian zone in West Africa are considered. This includes the diameter 35 cm for the Guinean and Sudanian zones (P = 356.5% for the Guinean zone and P = 53.4% for the Sahelian zone for a rotation of 20 years) and the diameter 65 cm for the Sahelian zone (P = 111.9% for a rotation period estimated at 20 years). The analysis of the restoration percentages depending on the diameter classes and the time helps deducing that the *P. erinaceus* stands are restored in a relatively shorter time in Guinean zone. However, the Sahelian zone seems not to offer favorable conditions for the rapid restoration of this species stands (**Figure 13**). The high restoration rate of the species in the Guinean zone may be explained by the fact that the exploitation of the species there is frequently timber. This form of exploitation allows the selective cutting of the large-diameter trees and leaving behind the seedlings. Since the ecological conditions are favorable in this zone (high rainfall), there is a regeneration (usually in the form of stump sprouts), and seeds are produced. However, in the Sahelian zone, the pollarding for fodder is an important

The intensity of the exploitation of the species sparked off concerns about its sustainability among a range of countries including Benin, Burkina Faso, Ghana, Senegal, and Togo. In order to curb the unrestrained exploitation of rosewood, countries (including Ghana and Togo) adopted harvesting and timber/log export

estimated at 20 years (Appendix 3).

*Natural Resources Management and Biological Sciences*

exploitation form of the species.

**Figure 15.**

**306**

**6.3 Conservation measures to preserve** *P. erinaceus*

*Distribution of the basal area in terms of diameter classes across climatic zones.*

the different sociocultural and socio-professional groups. In addition to using the species as lumber, fuel wood, and fodder, *P. erinaceus* is widely used as a medicinal plant.

• The "Agence Universitaire de la Francophonie (AUF)" for financing a part of

The study was also supported by the International Foundation for Science

We are also grateful to BioWooEB Research Unit of the French Agricultural Research Centre for International Development (CIRAD) for its material and

*P. erinaceus*, which is particularly appreciated for its wood and the quality of the fodder it provides, is threatened in several localities in western Burkina Faso [20]. Natural seedlings are very infrequent, and their survival after one or two dry seasons as well as that of young plantations is very low. The study of its regeneration by economic means such as "vegetative propagation" could then promote the regeneration of the species and increase the possibilities of its

exploitation and its valorization in Burkina Faso and Niger and in many other forest

Furthermore, the scientific and technical information necessary for good control of reproduction and vegetative propagation of this species is not yet available. In addition, in the field of low-cost vegetative propagation (PVFC), very few trials

Layering consists in inducing the appearance of roots on the stems of a woody species. This is done by contacting the stems with a suitable substrate (soil, sawdust, etc.). When the branch or stem of a woody species is placed directly against the ground to induce the root system, it is called layering. When the contact with the

Beforehand a mixture of earth and sawdust was prepared. The mixture consists of 40% sawdust and 60% earth. For each marcot, two annular incisions spaced from each other by 5 cm in height and without damaging the wood are applied to the branch. This results in a vertical incision of the bark from one annular incision to another. The portion of the bark is removed, leaving bare wood (**Figure A1A**). The consequence is the interruption of the circulation of the sap developed from the upper part to the lower part of the incised stem. The bare part of the bark is wrapped with a transparent plastic sheet containing the mixture of earth and saw-

Then seal the ends together with the tape while taking care not to trap the air. This support covers up to 10 cm on either side of the incised part, that is to say, to create a sufficiently large substrate to allow the possible roots to grow normally (**Figure A1B**). The supply of water is provided by injection with the aid of a syringe. In general, watering was done weekly. If the marcot is dry, a quantity of 20 ml can be injected or twice a 10 ml syringe. After the injection of water, the holes induced by the needle of the syringe are immediately closed with tape to minimize the

through a research grant provided to Dr. Kossi Novinyo Segla.

*Challenges of Conservation and Sustainable Management of African Rosewood…*

**A.1 Theoretical and methodological framework**

have been carried out in the world and especially in Africa [22].

substrate is above ground, it is called air layering.

**A.2 Experimental protocol**

dust that serves as a support for the roots.

evaporation of water.

**309**

**Appendices: vegetative propagation protocol by air layering**

this research

*DOI: http://dx.doi.org/10.5772/intechopen.88796*

financial support.

subregions [22].

In terms of the forest characteristics of *P. erinaceus* stands, studies indicate a significant difference in density, average diameter, mean total height, and basal area between the three climatic zones. The Guinean and Sudanian zones seem to present more favorable environmental conditions for the development of *P. erinaceus* stands. Regarding the potential and strategies of natural regeneration, studies have shown that the species has a good capacity of natural regeneration by sowing, stump rejects, suckers, and marcots. This opens up prospects for the production of seedlings and planting trials with *P. erinaceus* for the restoration of degraded natural stands. The results also showed that *P. erinaceus* has a very high ecological plasticity allowing it to adapt in several different climates. This large ecological range of the species offers opportunities to set up conservation plots in reserved areas regardless of site conditions in West Africa.

Studies have shown a difference in the properties of *P. erinaceus* wood according to climatic zones. This difference is reflected in the superiority of the properties of trees from the Sahelian zone followed by those of the Sudanian zone. This result provides information to the West African forest services on the behavior of this species, which could be the subject of a plantation program. In addition, knowledge of the technological characteristics of *P. erinaceus* wood according to the conditions of the environment and the age contributes to the management of the forest resources to ensure a sustainable production of wood. Indeed, these characteristics are among the important criteria to be included in the selection. For a long time confined to the selection of the growth, survival of trees, the current strategy for the genetic improvement of forest species is to include wood quality criteria.

Finally, to promote the rapid restoration of *P. erinaceus* stands, two regionalized minimum felling diameters were proposed based on the results of the structural parameter evaluation and the reconstitution percentage calculations and rotation times. For the Guinean-Sudanian zones, the minimum felling diameter adopted was 35 cm for a restoration percentage of 366.6 (Guinean zone) and 53.4% (Sudanian zone) for a period of 20 years. In the Sahelian zone, the minimum felling diameter adopted was 65 cm for a rotation period of 20 years. These parameters are an essential tool to limit over-logging of forest tree species and to ensure their sustainable management. Various forest authorities will consequently have scientific tools to better protect forest resources through the enforcement of restrictive measures concerning the selective logging of valuable timber.

#### **Acknowledgements**

The authors are grateful to:

*Challenges of Conservation and Sustainable Management of African Rosewood… DOI: http://dx.doi.org/10.5772/intechopen.88796*

• The "Agence Universitaire de la Francophonie (AUF)" for financing a part of this research

The study was also supported by the International Foundation for Science through a research grant provided to Dr. Kossi Novinyo Segla.

We are also grateful to BioWooEB Research Unit of the French Agricultural Research Centre for International Development (CIRAD) for its material and financial support.

#### **Appendices: vegetative propagation protocol by air layering**

#### **A.1 Theoretical and methodological framework**

*P. erinaceus*, which is particularly appreciated for its wood and the quality of the fodder it provides, is threatened in several localities in western Burkina Faso [20]. Natural seedlings are very infrequent, and their survival after one or two dry seasons as well as that of young plantations is very low. The study of its regeneration by economic means such as "vegetative propagation" could then promote the regeneration of the species and increase the possibilities of its exploitation and its valorization in Burkina Faso and Niger and in many other forest subregions [22].

Furthermore, the scientific and technical information necessary for good control of reproduction and vegetative propagation of this species is not yet available. In addition, in the field of low-cost vegetative propagation (PVFC), very few trials have been carried out in the world and especially in Africa [22].

Layering consists in inducing the appearance of roots on the stems of a woody species. This is done by contacting the stems with a suitable substrate (soil, sawdust, etc.). When the branch or stem of a woody species is placed directly against the ground to induce the root system, it is called layering. When the contact with the substrate is above ground, it is called air layering.

#### **A.2 Experimental protocol**

Beforehand a mixture of earth and sawdust was prepared. The mixture consists of 40% sawdust and 60% earth. For each marcot, two annular incisions spaced from each other by 5 cm in height and without damaging the wood are applied to the branch. This results in a vertical incision of the bark from one annular incision to another. The portion of the bark is removed, leaving bare wood (**Figure A1A**). The consequence is the interruption of the circulation of the sap developed from the upper part to the lower part of the incised stem. The bare part of the bark is wrapped with a transparent plastic sheet containing the mixture of earth and sawdust that serves as a support for the roots.

Then seal the ends together with the tape while taking care not to trap the air. This support covers up to 10 cm on either side of the incised part, that is to say, to create a sufficiently large substrate to allow the possible roots to grow normally (**Figure A1B**). The supply of water is provided by injection with the aid of a syringe. In general, watering was done weekly. If the marcot is dry, a quantity of 20 ml can be injected or twice a 10 ml syringe. After the injection of water, the holes induced by the needle of the syringe are immediately closed with tape to minimize the evaporation of water.

the different sociocultural and socio-professional groups. In addition to using the species as lumber, fuel wood, and fodder, *P. erinaceus* is widely used as a medicinal

In terms of the forest characteristics of *P. erinaceus* stands, studies indicate a significant difference in density, average diameter, mean total height, and basal area between the three climatic zones. The Guinean and Sudanian zones seem to present more favorable environmental conditions for the development of *P. erinaceus* stands. Regarding the potential and strategies of natural regeneration, studies have shown that the species has a good capacity of natural regeneration by sowing, stump rejects, suckers, and marcots. This opens up prospects for the production of seedlings and planting trials with *P. erinaceus* for the restoration of degraded natural stands. The results also showed that *P. erinaceus* has a very high ecological plasticity allowing it to adapt in several different climates. This large ecological range of the species offers opportunities to set up conservation plots in

Studies have shown a difference in the properties of *P. erinaceus* wood according to climatic zones. This difference is reflected in the superiority of the properties of trees from the Sahelian zone followed by those of the Sudanian zone. This result provides information to the West African forest services on the behavior of this species, which could be the subject of a plantation program. In addition, knowledge of the technological characteristics of *P. erinaceus* wood according to the conditions of the environment and the age contributes to the management of the forest resources to ensure a sustainable production of wood. Indeed, these characteristics are among the important criteria to be included in the selection. For a long time confined to the selection of the growth, survival of trees, the current strategy for the

Finally, to promote the rapid restoration of *P. erinaceus* stands, two regionalized minimum felling diameters were proposed based on the results of the structural parameter evaluation and the reconstitution percentage calculations and rotation times. For the Guinean-Sudanian zones, the minimum felling diameter adopted was 35 cm for a restoration percentage of 366.6 (Guinean zone) and 53.4% (Sudanian zone) for a period of 20 years. In the Sahelian zone, the minimum felling diameter adopted was 65 cm for a rotation period of 20 years. These parameters are an essential tool to limit over-logging of forest tree species and to ensure their sustainable management. Various forest authorities will consequently have scientific tools to better protect forest resources through the enforcement of restrictive measures

• The commission of the West African Economic and Monetary Union (UEMOA) for financing a part of this research within the framework of the Project "Support

• The Economic Community of West African States (ECOWAS) for financing a part of this research within the ECOWAS research and innovation support

• The "Sud Expert Plantes et Développement Durable (SEP2D)" program for

for Higher Education in the member countries of UEMOA (PAES)"

genetic improvement of forest species is to include wood quality criteria.

reserved areas regardless of site conditions in West Africa.

*Natural Resources Management and Biological Sciences*

concerning the selective logging of valuable timber.

**Acknowledgements**

**308**

The authors are grateful to:

program (PROGRAMME PARI)

financing a part of this research

plant.

IAA with six levels (0, 500, 750, 1000, 1500, and 2000 mg/l), and soaking duration in IAA with four levels (0, 10, 20, and 30 min). A total number of 48 (2 6 4) treatments, repeated 11 times, were established. The data collected were related to the number of cuttings budged and number of cuttings that degenerated after

*Challenges of Conservation and Sustainable Management of African Rosewood…*

As all cuttings with a diameter comprising between 0 and 1.5 cm having budded (including the control) degenerated within 20 days after budding while some of those with diameter >2 cm rooted, another experimental test was settled in a split plot design based on the previous three factors, changing the modalities as followed: cutting diameter with three levels ([2–2.5 cm], [2.6–3 cm], and [3.1–3.5 cm]), the dose of IAA with three levels (750, 1500, and 2000 mg/l), and soaking duration in IAA with three levels (10 s, 20 min, and 1 h). A total number of 27 (3 3 3) treatments, repeated three times, were established. The main factor was the cutting diameter. The subsidiary factors were randomly distributed in the sub-blocks. There was one control in each sub-block exempt of IAA treatment. The experimental tests were conducted on 540 leafless stem cuttings and put in pots filled with forest soil substrate (**Figure A2**). The plots were manually watered one–two times per day. Data collected were related to the cutting budding, bud bursting, number of shoots, shoot diameter, and height. The number of budded cuttings and leafy shoots was noted weekly for 8 weeks. The number of rooted cuttings, diameter, and height of

**C. Minimum felling diameter of** *P. erinaceus* **in Guineo-Sudano-Sahelian**

Diameter classes (cm) 15 25 35 45 55 65 75 85 95 105 Transition time (years) 10 30 50 70 90 110 130 150 170 190

0 37.3 356.5 1589.3 4648.7 4694.9 ————

0 6.9 53.4 206.7 534.9 1064.1 1765.5 2312.7 5073.6 5063.5

0 0.3 3.1 14.6 41.9 111.9 235.6 626.6 1282.5 1316.3

diameter of shoots as well as number of leaves produced.

*DOI: http://dx.doi.org/10.5772/intechopen.88796*

leafy shoots was noted until 24 weeks.

Guinean zone

Sudanian zone

Sahelian zone

**zone**

Recovery percentage (%)

*Source: Segla et al. [38].*

**311**

**Figure A1.** *Aerial carving of P. erinaceus. (A) Annealing of the stem and (B) soil wrapped by a plastic sheet.*

#### **B. Experimental design and data collection for vegetative propagation of** *P. erinaceus* **by stem cuttings**

*Pterocarpus erinaceus* stems were harvested from healthy mature trees whose diameter at 1.30 m ranged from 15 to 35 cm, in the morning before periods of high temperatures to limit their dehydration. Cuttings were collected at approximately the same levels on young branches. Stem cuttings were 15 cm length and with 20 cm diameter. Two sets of experiments were carried out to assess the effect of indoleacetic acid dose, diameter of cuttings and soaking duration on budding, and degeneration and cutting rooting of *P. erinaceus.*

The first experimental tests were designed on the basis of three factors that are diameter of the cuttings with two levels ([0–1.5 cm] and [1.6–3 cm]), the dose of

**Figure A2.** *Experimental settlement in the nursery: Pterocarpus erinaceus cuttings.*

*Challenges of Conservation and Sustainable Management of African Rosewood… DOI: http://dx.doi.org/10.5772/intechopen.88796*

IAA with six levels (0, 500, 750, 1000, 1500, and 2000 mg/l), and soaking duration in IAA with four levels (0, 10, 20, and 30 min). A total number of 48 (2 6 4) treatments, repeated 11 times, were established. The data collected were related to the number of cuttings budged and number of cuttings that degenerated after diameter of shoots as well as number of leaves produced.

As all cuttings with a diameter comprising between 0 and 1.5 cm having budded (including the control) degenerated within 20 days after budding while some of those with diameter >2 cm rooted, another experimental test was settled in a split plot design based on the previous three factors, changing the modalities as followed: cutting diameter with three levels ([2–2.5 cm], [2.6–3 cm], and [3.1–3.5 cm]), the dose of IAA with three levels (750, 1500, and 2000 mg/l), and soaking duration in IAA with three levels (10 s, 20 min, and 1 h). A total number of 27 (3 3 3) treatments, repeated three times, were established. The main factor was the cutting diameter.

The subsidiary factors were randomly distributed in the sub-blocks. There was one control in each sub-block exempt of IAA treatment. The experimental tests were conducted on 540 leafless stem cuttings and put in pots filled with forest soil substrate (**Figure A2**). The plots were manually watered one–two times per day. Data collected were related to the cutting budding, bud bursting, number of shoots, shoot diameter, and height. The number of budded cuttings and leafy shoots was noted weekly for 8 weeks. The number of rooted cuttings, diameter, and height of leafy shoots was noted until 24 weeks.

#### **C. Minimum felling diameter of** *P. erinaceus* **in Guineo-Sudano-Sahelian zone**

**B. Experimental design and data collection for vegetative propagation**

*Aerial carving of P. erinaceus. (A) Annealing of the stem and (B) soil wrapped by a plastic sheet.*

*Pterocarpus erinaceus* stems were harvested from healthy mature trees whose diameter at 1.30 m ranged from 15 to 35 cm, in the morning before periods of high temperatures to limit their dehydration. Cuttings were collected at approximately the same levels on young branches. Stem cuttings were 15 cm length and with 20 cm

indoleacetic acid dose, diameter of cuttings and soaking duration on budding, and

The first experimental tests were designed on the basis of three factors that are diameter of the cuttings with two levels ([0–1.5 cm] and [1.6–3 cm]), the dose of

diameter. Two sets of experiments were carried out to assess the effect of

**of** *P. erinaceus* **by stem cuttings**

*Natural Resources Management and Biological Sciences*

**Figure A1.**

**Figure A2.**

**310**

degeneration and cutting rooting of *P. erinaceus.*

*Experimental settlement in the nursery: Pterocarpus erinaceus cuttings.*

**References**

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Lessons from economic models (English). The World Bank Research

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York, Washington, DC: Oxford University Press; 2002. p. 272

[3] Arcand J-L, Guillaumont P,

real exchange rate. Journal of

242-262

p. 139

**313**

du Climat; 2011

Guillaumont JS. Deforestation and the

Development Economics. 2008;**86**(2):

[4] Damette O, Delacote P. On the economic factors of deforestation: what can we learn from quantile analysis?. Working Papers 1110. Chaire Economie

[5] Lamien N. Fructification du Karité (*Vitellaria paradoxa* C. F. Gaertn.): Facteurs de déperdition, Amélioration

[6] Ouôba P. Flore et végétation de la forêt classée de Niangoloko, Sud-Est du Burkina-Faso. Thèse de doctorat. Université de Ouagadougou; 2005.

François HA, Akomian FA, Gbèlidji FV, Tina KJT, et al. Ethnic differences in use value and use patterns of the threatened

et prévision des rendements à Boundoukuy, Ouest Burkina-Faso. Thèse de doctorat. Université de Ouagadougou; 2006. p. 114

[7] Assogbadjo AE, Glèlè KR,

multipurpose scrambling shrub (*Caesalpinia bonduc* L.) in Benin. Journal of Medicinal Plant Research.

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2011;**5**(9):1549-1557

Observer. 1999;**14**(1):73-98

Rethinking the causes of deforestation:

*DOI: http://dx.doi.org/10.5772/intechopen.88796*

*Challenges of Conservation and Sustainable Management of African Rosewood…*

rhizobia nodulating *Pterocarpus erinaceus* and *P. lucens* in Senegal. Systematic and Applied Microbiology.

[9] Ouédraogo A, Adjima T, Hahn-Hadjali K, Guinko S. Diagnostic de l'état de dégradation des peuplements de quatre espèces ligneuses en zone soudanienne du Burkina Faso. Sécheresse. 2006;**17**(4):485-491

[10] Kokou K, Nuto Y, Atsri H. Impact of charcoal production on woody plant species in West Africa: A case study in Togo. Scientific Research and Essays.

[11] Fontodji JK, Atsri H, Adjonou K, Radji AR, Kokutse AD, Nuto Y, et al. Impact of charcoal production on biodiversity in Togo (West Africa). In: López-Pujol J, editor. The Importance of Biological Interactions in the Study of Biodiversity. Rijeka, Croatia; 2011. pp. 215-230. ISBN 978-953-307-751-2

[12] Dumenu WK. Assessing the impact of felling/export ban and CITES designation on exploitation of African rosewood (*Pterocarpus erinaceus*). Biological Conservation. 2019;

[13] Sègla KN, Adjonou K, Radji AR, Kokutse AD, Kokou K, Habou R, et al. Importance socio-économique de *Pterocarpus erinaceus* Poir. au Togo. European Scientific Journal. 2015;

[14] Petit S, Mallet B. L'émondage d'arbres fourragers: détail d'une pratique pastorale. Bois et Forêts des Tropiques. 2001;**270**(4):35-45

[15] Karou D, Dicko MH, Sanon S, Simpore J, Traore AS. Antimalarial activity of *Sida acuta* Burm f.

Poir. (Fabaceae). Journal of

(Malvaceae) and *Pterocarpus erinaceus*

Ethnopharmacology. 2003;**89**:291-294

2002;**25**:572-583

2009;**4**(9):881-893

**236**(2019):124-133

**11**(23):119-217

[2] World Bank. Sustainable development

#### **Author details**

Adjonou Kossi1 \*, Houetchegnon Towanou2 , Rabiou Habou3 , Segla Kossi Novinyo1 , Abotsi Komla Elikplim1 , Johnson Benziwa Nathalie1 , Alaba Pyoabalo1 , Ouinsavi Christine A.I. Nougbodé2 , Quashie Akossiwoa Marie-Luce1 , Kokutse Adzo Dzifa1 , Mahamane Ali3 and Kokou Kouami1

1 Faculty of Sciences, University of Lomé (Togo), Lomé, Togo

2 Faculty of Sciences and Technology, University of Parakou, Parakou, Benin

3 Faculty of Agronomic Sciences, University of Diffa, Diffa, Niger

\*Address all correspondence to<EMAIL_ADDRESS>
© 2019 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

*Challenges of Conservation and Sustainable Management of African Rosewood… DOI: http://dx.doi.org/10.5772/intechopen.88796*

#### **References**

[1] Angelsen A, Kaimowitz D. Rethinking the causes of deforestation: Lessons from economic models (English). The World Bank Research Observer. 1999;**14**(1):73-98

[2] World Bank. Sustainable development in a dynamic world: transforming institutions, growth, and quality of life. World Development Report 2003. New York, Washington, DC: Oxford University Press; 2002. p. 272

[3] Arcand J-L, Guillaumont P, Guillaumont JS. Deforestation and the real exchange rate. Journal of Development Economics. 2008;**86**(2): 242-262

[4] Damette O, Delacote P. On the economic factors of deforestation: what can we learn from quantile analysis?. Working Papers 1110. Chaire Economie du Climat; 2011

[5] Lamien N. Fructification du Karité (*Vitellaria paradoxa* C. F. Gaertn.): Facteurs de déperdition, Amélioration et prévision des rendements à Boundoukuy, Ouest Burkina-Faso. Thèse de doctorat. Université de Ouagadougou; 2006. p. 114

[6] Ouôba P. Flore et végétation de la forêt classée de Niangoloko, Sud-Est du Burkina-Faso. Thèse de doctorat. Université de Ouagadougou; 2005. p. 139

[7] Assogbadjo AE, Glèlè KR, François HA, Akomian FA, Gbèlidji FV, Tina KJT, et al. Ethnic differences in use value and use patterns of the threatened multipurpose scrambling shrub (*Caesalpinia bonduc* L.) in Benin. Journal of Medicinal Plant Research. 2011;**5**(9):1549-1557

[8] Sylla SN, Samba RT, Neyra M, Ndoye I, Giraud E, Willems A, et al. Phenotypic and genotypic diversity of rhizobia nodulating *Pterocarpus erinaceus* and *P. lucens* in Senegal. Systematic and Applied Microbiology. 2002;**25**:572-583

[9] Ouédraogo A, Adjima T, Hahn-Hadjali K, Guinko S. Diagnostic de l'état de dégradation des peuplements de quatre espèces ligneuses en zone soudanienne du Burkina Faso. Sécheresse. 2006;**17**(4):485-491

[10] Kokou K, Nuto Y, Atsri H. Impact of charcoal production on woody plant species in West Africa: A case study in Togo. Scientific Research and Essays. 2009;**4**(9):881-893

[11] Fontodji JK, Atsri H, Adjonou K, Radji AR, Kokutse AD, Nuto Y, et al. Impact of charcoal production on biodiversity in Togo (West Africa). In: López-Pujol J, editor. The Importance of Biological Interactions in the Study of Biodiversity. Rijeka, Croatia; 2011. pp. 215-230. ISBN 978-953-307-751-2

[12] Dumenu WK. Assessing the impact of felling/export ban and CITES designation on exploitation of African rosewood (*Pterocarpus erinaceus*). Biological Conservation. 2019; **236**(2019):124-133

[13] Sègla KN, Adjonou K, Radji AR, Kokutse AD, Kokou K, Habou R, et al. Importance socio-économique de *Pterocarpus erinaceus* Poir. au Togo. European Scientific Journal. 2015; **11**(23):119-217

[14] Petit S, Mallet B. L'émondage d'arbres fourragers: détail d'une pratique pastorale. Bois et Forêts des Tropiques. 2001;**270**(4):35-45

[15] Karou D, Dicko MH, Sanon S, Simpore J, Traore AS. Antimalarial activity of *Sida acuta* Burm f. (Malvaceae) and *Pterocarpus erinaceus* Poir. (Fabaceae). Journal of Ethnopharmacology. 2003;**89**:291-294

**Author details**

Adjonou Kossi1

**312**

Abotsi Komla Elikplim1

Kokutse Adzo Dzifa1

Ouinsavi Christine A.I. Nougbodé2

provided the original work is properly cited.

\*, Houetchegnon Towanou2

*Natural Resources Management and Biological Sciences*

1 Faculty of Sciences, University of Lomé (Togo), Lomé, Togo

3 Faculty of Agronomic Sciences, University of Diffa, Diffa, Niger

\*Address all correspondence to<EMAIL_ADDRESS>
, Johnson Benziwa Nathalie1

, Mahamane Ali3 and Kokou Kouami1

2 Faculty of Sciences and Technology, University of Parakou, Parakou, Benin

© 2019 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

, Rabiou Habou3

, Quashie Akossiwoa Marie-Luce1

, Alaba Pyoabalo1

, Segla Kossi Novinyo1

,

,

,

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[43] Treanor NB. China's Hongmu consumption boom: Analysis of the Chinese rosewood trade and links to illegal activity in Tropical Forested Countries. Forest Trends Series-Forest trade and finance. Forest Trends Series

[44] Dumenu WK, Bandoh WN. Exploitation of African rosewood (*Pterocarpus erinaceus*) in Ghana: A situation analysis. Ghana Journal of

[45] Jafaru MY. General news of 29 Mar 2017. MP alarmed at increased rate of illegal felling of rosewood. 2017. Retrieved from: https://www.graphic.

and UKAid. 2015

Forestry. 2016;**32**:1-15

Vegetative propagation by aerial layering of *Pterocarpus erinaceus*: In the Sudanian zone. International Journal of Recent Advances in Multidisciplinary Research. 2017;**4**(10):2902-2908

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indicators of interspecific variability in vibration damping of wood. Annales des Sciences Forestières. 2010;**67**:707

[34] Holz D. Acoustically important properties of xylophone-bar materials: Can tropical woods be replaced by European species? Acta Acustica. 1996;

[35] Yano H. The changes in the acoustic properties of Western red cedar due to methanol extraction. Holzforschung.

[36] Brémaud I, Minato K, Thibaut B. Mechanical damping of wood as related to species classification: A preliminary survey. In: 6th International Conference on Plant Biomechanics, Cayenne; 16-21

[37] Segla KN, Adjonou K, Rabiou H, Moussa MB, Radji AR, Kokutse AD, et al. Stand structures and minimum felling diameter of the *Pterocarpus erinaceus* Poir in arid and semi-arid habitats of West Africa. South African Journal of Botany. 2016;**103**:17-24

[38] Kokou K, Adjonou K, Segla KS, Rabiou H, Bationo AB. et al. *Pterocarpus erinaceus* (Poir) en Afrique de l'Ouest: Usages, structure des peuplements, qualités de bois, normes d'exploitation et sylviculture au Burkina Faso, Niger et

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[26] Ali N. *Pterocarpus erinaceus* (Fabaceae) dans la Région Centrale du Togo: usages et impacts de l'exploitation sur la distribution spatiale et caractéristiques structurales. Togo: Mémoire de technicien supérieur agricole de l'Infa de Tové; 2009. p. 43

[27] Segla KN, Adjonou K, Rabiou H, Radji AR, Kokutse AD, Bationo A, et al. Spatial distribution of *Pterocarpus erinaceus* Poir. (Fabaceae) natural stands in the Sudanian and Sudano-Guinean zones of West Africa: Gradient distribution and productivity variation across the five ecological zones of Togo. Annual Research & Review in Biology. 2015;**6**(2):89-102. DOI: 10.9734/ARRB/ 2015/14771

[28] Ouro Djer, E, Djagba T, Sewa AA, Ouro-Landjo S, Albada A. Situation des ressources génétiques forestières du Togo. Atelier sous-régional FAO/IPGRI/ ICRAF sur la conservation, la gestion, l'utilisation durable et la mise en valeur des ressources génétiques forestières de la zone sahélienne, note thématique sur les ressources génétiques forestières, document FGR/13F, Département des forêts. Rome, Italie: FAO; 2001. p. 25

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*Challenges of Conservation and Sustainable Management of African Rosewood… DOI: http://dx.doi.org/10.5772/intechopen.88796*

[31] Nacoulma BMI. Dynamique et stratégie de conservation de la végétation et de la phytodiversité du complexe écologique du Parc National du W du Burkina Faso [Thèse de doctorat]. Ouagadougou, Burkina Faso: 2012. p. 151

[16] Adjonou K, Ali N, Kokutse AD, Segla KN. Etude de la dynamique des peuplements naturels de *Pterocarpus ericaceus* Poir. (Fabaceae) surexploités au Togo. Bois et Forêts des Tropiques.

*Natural Resources Management and Biological Sciences*

de la dégradation du couvert végétal. Thèse de Doctorat. Belgique: Université

[25] Cuny P, Sanogo S, Sommer N. Arbres du Domaine Soudanien. Leurs Usages et Leur Multiplication. Sikasso:

[26] Ali N. *Pterocarpus erinaceus* (Fabaceae) dans la Région Centrale du Togo: usages et impacts de l'exploitation

sur la distribution spatiale et caractéristiques structurales. Togo: Mémoire de technicien supérieur agricole de l'Infa de Tové; 2009. p. 43

[27] Segla KN, Adjonou K, Rabiou H, Radji AR, Kokutse AD, Bationo A, et al. Spatial distribution of *Pterocarpus erinaceus* Poir. (Fabaceae) natural stands in the Sudanian and Sudano-Guinean zones of West Africa: Gradient

distribution and productivity variation across the five ecological zones of Togo. Annual Research & Review in Biology. 2015;**6**(2):89-102. DOI: 10.9734/ARRB/

[28] Ouro Djer, E, Djagba T, Sewa AA, Ouro-Landjo S, Albada A. Situation des ressources génétiques forestières du Togo. Atelier sous-régional FAO/IPGRI/ ICRAF sur la conservation, la gestion, l'utilisation durable et la mise en valeur des ressources génétiques forestières de la zone sahélienne, note thématique sur les ressources génétiques forestières, document FGR/13F, Département des forêts. Rome, Italie: FAO; 2001. p. 25

[29] Adjonou K. Structure et indicateurs biologiques de gestion durable des reliques de forets sèches du Togo [Thèse de doctorat]. Togo: Université de Lomé;

[30] Louppe D, Ouattara N. Croissance en plantation de quelques espèces ligneuses locales. Korhogo (Côte d'Ivoire). Korhogo, Côte d'Ivoire,

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2011. p. 119

Idefor; 1993. p. 12

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Mali, Ier, Berne, Suisse, Intercoopération; 1997, 122 p

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[20] Touré Y. Etude des potentialités agroforestières, de la multiplication et des usages de *Pterocarpus erinaceus* Poir. en zone soudanienne du Burkina Faso. Burkina-Faso: Mémoire d'Ingénieur, Université Polytechnique de Bobo-

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[24] Hountodji YCH. Dynamique environnementale en zones sahélienne et soudanienne de l'Afrique de l'Ouest: Analyse des modifications et évaluation

[22] Ouédraogo H. Structure démographique et modes de régénération de *P. erinaceus* Poir. et autres espèces prioritaires utilisées dans l'artisanat à l'Ouest du Burkina faso. Université Polytechnique de Bobo-Dioulasso (IDR), Mém. Ing., 2007. p. 77

2010;**306**(4):45-55

Prota. 2008

[32] Traore B. Influence de la structure anatomique et des métabolites secondaires sur les propriétés physiques et la qualité acoustique du bois de Vène provenant du mali [Thèse de doctorat]. Université Laval; 2009. pp. 206

[33] Bremaud I, Minato K, Langbour P, Thibaut B. Physico-mechanical indicators of interspecific variability in vibration damping of wood. Annales des Sciences Forestières. 2010;**67**:707

[34] Holz D. Acoustically important properties of xylophone-bar materials: Can tropical woods be replaced by European species? Acta Acustica. 1996; **82**:878-884

[35] Yano H. The changes in the acoustic properties of Western red cedar due to methanol extraction. Holzforschung. 1994;**48**(6):491-495

[36] Brémaud I, Minato K, Thibaut B. Mechanical damping of wood as related to species classification: A preliminary survey. In: 6th International Conference on Plant Biomechanics, Cayenne; 16-21 November 2009. 2009

[37] Segla KN, Adjonou K, Rabiou H, Moussa MB, Radji AR, Kokutse AD, et al. Stand structures and minimum felling diameter of the *Pterocarpus erinaceus* Poir in arid and semi-arid habitats of West Africa. South African Journal of Botany. 2016;**103**:17-24

[38] Kokou K, Adjonou K, Segla KS, Rabiou H, Bationo AB. et al. *Pterocarpus erinaceus* (Poir) en Afrique de l'Ouest: Usages, structure des peuplements, qualités de bois, normes d'exploitation et sylviculture au Burkina Faso, Niger et Togo. Fiches Techniques. 2015. N° P-ZI-IAD-002 N° DON:<PHONE_NUMBER>376; p. 28

[39] Bamba N, Ouattara ND, Konan D, Bakayoko A, Tra Bi FH. Effets de cinq prétraitements Sur la germination du vène (*Pterocarpus erinaceus* Poir., Fabaceae) dans la Réserve du Haut Bandama (Côte d'Ivoire). European Scientific Journal. 2018;**14**:438

[40] Rabiou H, Diouf A, Bationo AB, Segla KN, Adjonou K, Kokutse AD, et al. Vegetative propagation by aerial layering of *Pterocarpus erinaceus*: In the Sudanian zone. International Journal of Recent Advances in Multidisciplinary Research. 2017;**4**(10):2902-2908

[41] Bodjrènou RT, Houètchégnon T, Kéita NT, Ouinsavi C. Effets de l'acide naphtalène acétique, du type de substrat et de la grosseur des boutures Sur le bouturage de tige de *Pterocarpus erinaceus* Poir. (Fabaceae). European Scientific Journal. 2018;**14**(27):297-316

[42] Segla NK, Rabiou H, Adjonou K, Mamoudou BM, Saley K, Radji RA, et al. Population structure and minimum felling diameter of *Pterocarpus erinaceus* Poir in arid and semi-arid climate zones of West Africa. South African Journal of Botany. 2015;**103**:17-24 ISSN: 0254-6299

[43] Treanor NB. China's Hongmu consumption boom: Analysis of the Chinese rosewood trade and links to illegal activity in Tropical Forested Countries. Forest Trends Series-Forest trade and finance. Forest Trends Series and UKAid. 2015

[44] Dumenu WK, Bandoh WN. Exploitation of African rosewood (*Pterocarpus erinaceus*) in Ghana: A situation analysis. Ghana Journal of Forestry. 2016;**32**:1-15

[45] Jafaru MY. General news of 29 Mar 2017. MP alarmed at increased rate of illegal felling of rosewood. 2017. Retrieved from: https://www.graphic.

**Chapter 17**

**Abstract**

resources.

**317**

**1. Introduction**

the wild plants products [7].

conservation methods, useful wild plants

The Utilization and Conservation

The knowledge pertaining to uses of indigenous wild plants and their conservation methods by the rural communities of the Limpopo Province (South Africa) is not fully reconnoitered. The available data highlighting these aspects are scattered in general ethnobotanical literatures. The current study therefore sought to collate, analyze, and describe such information. Search engines and local libraries were used to document information. A total of 50 useful wild plant species belonging to 32 botanical families, mainly the Fabaceae (28%, n = 9) and Cucurbitaceae (13%, n = 4), were harvested by rural communities inhabiting the Limpopo Province. These species were mainly exploited wholly for medicinal (62%, n = 31) and food (20%, n = 10) purposes. Leaves, bark, fruits, and roots, respectively, were the most commonly used plant parts. Overall, the traditional conservation approaches employed by the indigenous people to ensure continual supply of these organs for

different livelihoods encompass traditional beliefs and taboos, sustainable harvesting practices as well as domestication of plants. However, not all these approaches promote effective conservation and sustainable utilization of wild plant

**Keywords:** indigenous plants, Limpopo province, management, traditional

Throughout history, plant resources have supported human being, providing goods such as food in the form of fruits and vegetables, materials for a variety of utensils, fodder, construction timber, fuel wood, and medicinal plants [1–5]. In addition, plants have also provided man with a range of cultural services, including spiritual services, inspiration, and esthetic values [6]. Therefore, sustainable plants harvesting and uses are fundamental for human survival, especially since gathering activity continue to increase in importance, in response to a growing demand for

Globally, loss of habitat by deforestation and unsustainable harvesting methods, among other factors, threatens the survival of the plant resources in the

of Indigenous Wild Plant

Resources in the Limpopo

Province, South Africa

*Sebua S. Semenya and Matjutla J. Mokgoebo*

com.gh/news/generalnews/mpalarmed-at-increased-rate-of-illegalfelling-of-rosewood.html

[46] Futukpor A. Online news of August 9, 2018. Felling of rosewood increases. 2018. Retrieved from: http:// www.ghananewsagency.org/social/ felling-of-rosewoodincreases-136896

#### **Chapter 17**

com.gh/news/generalnews/mpalarmed-at-increased-rate-of-illegal-

*Natural Resources Management and Biological Sciences*

[46] Futukpor A. Online news of August 9, 2018. Felling of rosewood increases. 2018. Retrieved from: http:// www.ghananewsagency.org/social/ felling-of-rosewoodincreases-136896

felling-of-rosewood.html

**316**

## The Utilization and Conservation of Indigenous Wild Plant Resources in the Limpopo Province, South Africa

*Sebua S. Semenya and Matjutla J. Mokgoebo*

#### **Abstract**

The knowledge pertaining to uses of indigenous wild plants and their conservation methods by the rural communities of the Limpopo Province (South Africa) is not fully reconnoitered. The available data highlighting these aspects are scattered in general ethnobotanical literatures. The current study therefore sought to collate, analyze, and describe such information. Search engines and local libraries were used to document information. A total of 50 useful wild plant species belonging to 32 botanical families, mainly the Fabaceae (28%, n = 9) and Cucurbitaceae (13%, n = 4), were harvested by rural communities inhabiting the Limpopo Province. These species were mainly exploited wholly for medicinal (62%, n = 31) and food (20%, n = 10) purposes. Leaves, bark, fruits, and roots, respectively, were the most commonly used plant parts. Overall, the traditional conservation approaches employed by the indigenous people to ensure continual supply of these organs for different livelihoods encompass traditional beliefs and taboos, sustainable harvesting practices as well as domestication of plants. However, not all these approaches promote effective conservation and sustainable utilization of wild plant resources.

**Keywords:** indigenous plants, Limpopo province, management, traditional conservation methods, useful wild plants

#### **1. Introduction**

Throughout history, plant resources have supported human being, providing goods such as food in the form of fruits and vegetables, materials for a variety of utensils, fodder, construction timber, fuel wood, and medicinal plants [1–5]. In addition, plants have also provided man with a range of cultural services, including spiritual services, inspiration, and esthetic values [6]. Therefore, sustainable plants harvesting and uses are fundamental for human survival, especially since gathering activity continue to increase in importance, in response to a growing demand for the wild plants products [7].

Globally, loss of habitat by deforestation and unsustainable harvesting methods, among other factors, threatens the survival of the plant resources in the wilderness [8–11]. This situation is dire in various African countries wherein the majority of people depend heavily on plants to meet their livelihoods [12]. Consequently, the wild plant resources are rapidly diminishing, indicating a need to adopt the management techniques that promote a sustainable harvesting practice to ensure the continual supply of plant products to meet various human livelihoods.

**3. Results and discussion**

*DOI: http://dx.doi.org/10.5772/intechopen.89920*

to experiment with.

**319**

**3.2 Plant utilization categories**

nutri-medicinal value, and local cultural practices.

**3.1 Diversity of useful wild indigenous plant resources**

The present study documented a total of 50 useful plant species belonging to 32 botanical families, mainly the Fabaceae (28%, n = 9) and Cucurbitaceae (13%, n = 4), that are harvested by rural communities inhabiting the Limpopo Province of South Africa (**Table 1**). These families are repeatedly recorded in various ethnobotanical studies conducted in South Africa [45, 46] and elsewhere [46–48], as being highly represented with a greater number of plants exploited by indigenous people to meet their livelihoods. Cucurbitaceae and Fabaceae are not only widespread in communal lands of the Limpopo Province but they also comprise many plants commonly known as foods and natural medicine. Therefore, their predominance in this study came as no surprise. According to de Albuquerque [49], indigenous people highly value and experiments on plants that are more accessible or locally abundant. However, plant species from the rest of the botanical families were rarely harvested for their products, perhaps due to their less adaptation in a wide range of altitudes across the aforementioned province. As such, they are less susceptible targets of the local people

*The Utilization and Conservation of Indigenous Wild Plant Resources in the Limpopo Province…*

The consumption of wild plants is an ancient African tradition which serves multiple purposes. In the present study, analysis of ethnobotanical uses categories indicated that more taxa were exploited exclusively for medicinal (n = 32) and food (n = 10) purposes. Some of the commonly harvested medicinal plants documented include *Elaeodendron transvaalense* (Burtt Davy) R.H.Archer (HIV/AIDS), *Hypoxis hemerocallidea* Fisch., C.A.Mey. and Avé-Lall. (Gonorrhea and HIV/AIDS), *Leonotis leonurus* (L.) R.Br. (asthma and chest pain), and *Lippia javanica* (Burm.f.) Spreng. (asthma, rhinitis sinusitis, and tuberculosis), used as therapies for the mentioned ailments (**Table 1**). Therapeutic applications of these species are well supported by scientific studies [36, 50, 51], thus partly explaining their utilization by people of the Limpopo Province. Plant-based medicines such as *Alepidea amatymbica* Eckl. and Zeyh, *Brackenridgea zanguebarica* Oliv., *Celtis africana* Burm.f., *Encephalartos transvenosus* Stapf and Burtt Davy, *Mundulea sericea* (Willd.) A. Chev, *Rauvolfia caffra* Sond., and *Sclerochiton ilicifolius* A. Meeuse were considered as having mysterious and magical powers used to expel evil, fight opponents, and as luck charms (**Table 1**). For the food plant category, all the species were reported to be either eaten as leafy vegetable with porridge (*Momordica balsamina* L., *Momordica boivinii* Baill, and *Vigna unguiculata* L.) or exploited for their edible fruits (*Berchemia discolor* (Klotzsch) Hemsl, *Dovyalis caffra* (Hook. F. and Harv.) Hook. F, *Grewia bicolor* Juss., *Pappea capensis* Eckl. and Zeyh, *Vangueria infausta* Burch, and *Ximenia caffra* Sond.). The consumption of these plants by indigenous people in the Limpopo Province is primarily attributed to multiple factors including food scarcity,

Other categories that had explicit use were for provision of livelihoods such as firewood (n = 2; *Vachellia karroo* Hayne and *Vachellia rehmanniana* Schinz), water storage (n = 1; *Breonadia salicina* (Vahl) Hepper and J.R.I. Wood.). *Vachellia karroo* and *V. rehmanniana* are preferred as firewood species due to both their local availability and long burning period, which provide lasting heat and light [41].

The remaining plants, namely, *Anthocleista grandiflora* Gilg (used to cover maize grains to encourage germination when malt is prepared, and female bodies during rituals, and as medicine for high blood pressure), *Boscia albitrunca* Gilg and

In Africa as is the case in other continents of the world [13–16], natural plant resource utilization and management has been in the traditions of local communities, expressed variously in the beliefs as well as practices employed in their conservation [17]. These practices includes among others, removal of few roots from plants, harvesting of a bark that is the size of the palm of one's hand, taboos and social controls promoting sustainable harvesting of plants [18]. Studies conducted in countries such as Kenya [19], Ghana [20], Lesotho [21], Zimbabwe [22], Nigeria [3], Tanzania [23], Uganda [24], Benin and Gabon [25], Rwanda [26], and Ethiopia [27] indicated that these practices are very common among the indigenous communities and have evolved through the historical interaction of people and their environment.

However, in South Africa, data on indigenous wild plant resource utilization and associated management/conservation practices are scattered in general ethnobotanical literatures [28–32]. This makes it difficult for policy makers and conservationists to realize the potential of traditional conservation and innovation techniques in wild indigenous plant resource conservation. The current study therefore sought to collate and describe uses of the indigenous wild plants by rural communities in the Limpopo Province (South Africa), and implemented practices contributing to the conservation as well as the management of these plants.

#### **2. Materials and methods**

Overall, the data set used in this study was created by selecting articles that focused on the utilization and conservation of indigenous wild plant resources in the Limpopo Province, South Africa. The search for these articles was obtained from the main online scientific sites including Science Direct, SciFinder, Pubmed, Google Scholar, Medline, and SCOPUS. Searches were also undertaken in the library, University of Venda, University of Limpopo, and the search engines like ProQuest, Open-thesis, OATD, and EThOS [33]. The species name, botanical families, plant authority, and synonyms were verified using books, journal articles, and Internet sources such as the International Plant Name Index (www.ipni.org).

The articles selected met the pre-determined criteria, namely, inclusion and exclusion. The inclusion criteria encompass: (1) the articles reporting on the studies conducted in the Limpopo Province that highlighted or focused on the use and conservation of indigenous wild plant resources, (2) the identity of the utilized species including use part/s and traditional value/application/s and associated conservation strategy implemented, (3) the articles published between 1950 and May 2019, and (4) the articles that are written in English. The exclusion criteria include articles published as abstract, letters, and data that could not be extracted or overlapped with data from other articles. Of 410 collected articles published in the period between 1950 and May 2019, 52 met the exclusion criteria, thus did not form part of this book chapter. The conservation status of the plants was determined via the South African National Red Data List of Plants [34]. Generally, data were independently evaluated for completeness and reliability. Descriptive statistics such as frequencies and percentages were used in the analysis.

*The Utilization and Conservation of Indigenous Wild Plant Resources in the Limpopo Province… DOI: http://dx.doi.org/10.5772/intechopen.89920*

#### **3. Results and discussion**

wilderness [8–11]. This situation is dire in various African countries wherein the majority of people depend heavily on plants to meet their livelihoods [12]. Consequently, the wild plant resources are rapidly diminishing, indicating a need to adopt the management techniques that promote a sustainable harvesting practice to ensure the continual supply of plant products to meet various human

*Natural Resources Management and Biological Sciences*

In Africa as is the case in other continents of the world [13–16], natural plant resource utilization and management has been in the traditions of local communities, expressed variously in the beliefs as well as practices employed in their conservation [17]. These practices includes among others, removal of few roots from plants, harvesting of a bark that is the size of the palm of one's hand, taboos and social controls promoting sustainable harvesting of plants [18]. Studies conducted in countries such as Kenya [19], Ghana [20], Lesotho [21], Zimbabwe [22], Nigeria [3], Tanzania [23], Uganda [24], Benin and Gabon [25], Rwanda [26], and Ethiopia [27] indicated that these practices are very common among the indigenous communities and have evolved through the historical interaction of people and their

However, in South Africa, data on indigenous wild plant resource utilization and associated management/conservation practices are scattered in general ethnobotanical literatures [28–32]. This makes it difficult for policy makers and conserva-

Overall, the data set used in this study was created by selecting articles that focused on the utilization and conservation of indigenous wild plant resources in the Limpopo Province, South Africa. The search for these articles was obtained from the main online scientific sites including Science Direct, SciFinder, Pubmed, Google Scholar, Medline, and SCOPUS. Searches were also undertaken in the library, University of Venda, University of Limpopo, and the search engines like ProQuest, Open-thesis, OATD, and EThOS [33]. The species name, botanical families, plant authority, and synonyms were verified using books, journal articles, and Internet sources such as the International Plant Name Index

The articles selected met the pre-determined criteria, namely, inclusion and exclusion. The inclusion criteria encompass: (1) the articles reporting on the studies conducted in the Limpopo Province that highlighted or focused on the use and conservation of indigenous wild plant resources, (2) the identity of the utilized species including use part/s and traditional value/application/s and associated conservation strategy implemented, (3) the articles published between 1950 and May 2019, and (4) the articles that are written in English. The exclusion criteria include articles published as abstract, letters, and data that could not be extracted or overlapped with data from other articles. Of 410 collected articles published in the period between 1950 and May 2019, 52 met the exclusion criteria, thus did not form part of this book chapter. The conservation status of the plants was determined via the South African National Red Data List of Plants [34]. Generally, data were independently evaluated for completeness and reliability. Descriptive statistics such

as frequencies and percentages were used in the analysis.

tionists to realize the potential of traditional conservation and innovation techniques in wild indigenous plant resource conservation. The current study therefore sought to collate and describe uses of the indigenous wild plants by rural communities in the Limpopo Province (South Africa), and implemented practices contributing to the conservation as well as the management of these plants.

livelihoods.

environment.

**2. Materials and methods**

(www.ipni.org).

**318**

#### **3.1 Diversity of useful wild indigenous plant resources**

The present study documented a total of 50 useful plant species belonging to 32 botanical families, mainly the Fabaceae (28%, n = 9) and Cucurbitaceae (13%, n = 4), that are harvested by rural communities inhabiting the Limpopo Province of South Africa (**Table 1**). These families are repeatedly recorded in various ethnobotanical studies conducted in South Africa [45, 46] and elsewhere [46–48], as being highly represented with a greater number of plants exploited by indigenous people to meet their livelihoods. Cucurbitaceae and Fabaceae are not only widespread in communal lands of the Limpopo Province but they also comprise many plants commonly known as foods and natural medicine. Therefore, their predominance in this study came as no surprise. According to de Albuquerque [49], indigenous people highly value and experiments on plants that are more accessible or locally abundant. However, plant species from the rest of the botanical families were rarely harvested for their products, perhaps due to their less adaptation in a wide range of altitudes across the aforementioned province. As such, they are less susceptible targets of the local people to experiment with.

#### **3.2 Plant utilization categories**

The consumption of wild plants is an ancient African tradition which serves multiple purposes. In the present study, analysis of ethnobotanical uses categories indicated that more taxa were exploited exclusively for medicinal (n = 32) and food (n = 10) purposes. Some of the commonly harvested medicinal plants documented include *Elaeodendron transvaalense* (Burtt Davy) R.H.Archer (HIV/AIDS), *Hypoxis hemerocallidea* Fisch., C.A.Mey. and Avé-Lall. (Gonorrhea and HIV/AIDS), *Leonotis leonurus* (L.) R.Br. (asthma and chest pain), and *Lippia javanica* (Burm.f.) Spreng. (asthma, rhinitis sinusitis, and tuberculosis), used as therapies for the mentioned ailments (**Table 1**). Therapeutic applications of these species are well supported by scientific studies [36, 50, 51], thus partly explaining their utilization by people of the Limpopo Province. Plant-based medicines such as *Alepidea amatymbica* Eckl. and Zeyh, *Brackenridgea zanguebarica* Oliv., *Celtis africana* Burm.f., *Encephalartos transvenosus* Stapf and Burtt Davy, *Mundulea sericea* (Willd.) A. Chev, *Rauvolfia caffra* Sond., and *Sclerochiton ilicifolius* A. Meeuse were considered as having mysterious and magical powers used to expel evil, fight opponents, and as luck charms (**Table 1**). For the food plant category, all the species were reported to be either eaten as leafy vegetable with porridge (*Momordica balsamina* L., *Momordica boivinii* Baill, and *Vigna unguiculata* L.) or exploited for their edible fruits (*Berchemia discolor* (Klotzsch) Hemsl, *Dovyalis caffra* (Hook. F. and Harv.) Hook. F, *Grewia bicolor* Juss., *Pappea capensis* Eckl. and Zeyh, *Vangueria infausta* Burch, and *Ximenia caffra* Sond.). The consumption of these plants by indigenous people in the Limpopo Province is primarily attributed to multiple factors including food scarcity, nutri-medicinal value, and local cultural practices.

Other categories that had explicit use were for provision of livelihoods such as firewood (n = 2; *Vachellia karroo* Hayne and *Vachellia rehmanniana* Schinz), water storage (n = 1; *Breonadia salicina* (Vahl) Hepper and J.R.I. Wood.). *Vachellia karroo* and *V. rehmanniana* are preferred as firewood species due to both their local availability and long burning period, which provide lasting heat and light [41].

The remaining plants, namely, *Anthocleista grandiflora* Gilg (used to cover maize grains to encourage germination when malt is prepared, and female bodies during rituals, and as medicine for high blood pressure), *Boscia albitrunca* Gilg and

**Botanical family and species name**

*Celtis africana* Burm.f.

Gilg and Gilg-Ben.

*transvaalense* (Burtt Davy) R. H.Archer *Gymnosporia senegalensis* (Lam.) Loes

*Citrullus lanatus* (Thunb.) Matsum. and Nakai

*Cucumis zeyheri* Sond.

*Momordica balsamina* L.

*Momordica boivinii* Baill.

*sylvatica* Eckl.

*Vachellia karroo* Hayne *Vachellia rehmanniana* Schinz.

**321**

**Used part**

*DOI: http://dx.doi.org/10.5772/intechopen.89920*

**Cannabaceae** Stem Used to make magical

**Celastraceae** Root HIV/AIDS Near

Leaf Edible vegetable eaten with porridge

Leaf Edible vegetable eaten

**Dioscoreaceae** Tuber Gonorrhea Vulnerable

Stem Firewood

during times of drought

gardens [38] *Dioscorea*

**Fabaceae** Stem Firewood Least concern Harvesting and felling of

**Traditional value Conservation**

*The Utilization and Conservation of Indigenous Wild Plant Resources in the Limpopo Province…*

sticks which are driven into the ground to protect against witchcraft

**Capparaceae** Root HIV/AIDS Least concern Cultivated in home gardens [38] *Boscia albitrunca*

gardens [38] *Elaeodendron*

**Cucurbitaceae** Fruit Headache Least concern Hand-picked and some

**status (red data list)**

Fruit Eaten as food Protected within dryland

Root Blood disorders Least concern Only small quantity of

Fruit Lack of appetite and TB Least concern Hand-picked and some

A2cd

threatened A4ad

**Traditional plant conservation practices**

the homestead. Taboos associated with the tree are enforced through beliefs such that violators or the community will experience

Least concern Tree cannot be planted in

illnesses [40]

agricultural farming system [39]

Cultivated in home

lateral roots are harvested

fruits with seeds are left behind to allow natural regrowth during favorable

fruits with seeds are left behind to allow natural regrowth during favorable

selected allowing the leaves to reach maturity [40]

selected allowing the leaves to reach maturity. Leaves must not be harvested or touched by menstruating women; otherwise, it is believed that the vegetable will shrink in size [40]

Cultivated in home

species from the graveyard are forbidden, because graveyards are believed to be the home of the ancestors [41]

[41]

season [36]

season [36]

Least concern Only the tender leaves are

Least concern Only the tender leaves are

*The Utilization and Conservation of Indigenous Wild Plant Resources in the Limpopo Province… DOI: http://dx.doi.org/10.5772/intechopen.89920*

**Botanical family and species name**

*Sclerochiton ilicifolius* A. Meeuse

*Tulbaghia violacea* Harv. var. violacea

*Alepidea amatymbica* Eckl. and Zeyh

Sond.

DC

*Aloe falcata* Baker

*Aloe marlothii* A. Berger subsp. *Marlothii*

*namaquensis* (Schonland) Oberm.

(A. Rich.) Hochst.

**320**

**Apocynaceae** Whole

**Used part**