**3. Methods**

A field survey was carried out from June, 2015 to May, 2017 in FA, DA and plantation (P). One hundred and fifty quadrats of 20 m 20 m in sizes were laid down randomly at FA to obtain data on the composition and phytosociological attributes of tree species. In each quadrat, trees (≥ 30 cm GBH) such as girth at breast height (137 cm above ground), height, canopy height, canopy width and regeneration (plants <10 cm GBH) were recorded [24]. Tree height and canopy height were measured from the ground to the tree tip and up to the height from where the branching of canopy starts, respectively using a height-measuring rod.

To measure the canopy width each tree was viewed below from all sides to identify the longest axis. The diameter 'd1' or length of the longest axis passing through the center of the canopy/crown was measured followed by the length of the shortest axis or diameter 'd2' perpendicular to the longest (first) axis. The two diameters were then averaged to determine the canopy width (in meter) as:

$$\mathbf{CW} = \mathbf{d}\_1 + \mathbf{d}\_2/2\tag{1}$$

Where, d1 = length of the longest axis of each tree canopy and d2 = Length of the shortest axis of each tree canopy perpendicular to the longest axis.

Shrub species from the FA were analyzed by placing two quadrats of 5 m � 5 m sizes nested within each quadrat laid down for tree species. The density and frequency of each shrub species enumerated from the FA were calculated as:

Density ¼ Total number of individuals of a species*=*Total number of quadrats studied (2)

$$\begin{aligned} \text{Frequency} &= \text{Number of quadrats in which species occur} \\ &\text{Total number of quadrats studied} \end{aligned} \tag{3}$$

The selection of shrub species from FA for restoration practice was recognized using relative index (RI) calculated as a sum of relative density (RD) and relative frequency (RF) [14]. Relative density (RD) is the study of the numerical strength of a species to the total number of individuals of all species and calculated as:

$$\begin{aligned} \text{Relative Density (RD)} &= (\text{Number of individuals of a species}) \\ &\text{Number of individuals of all species}) \times 100 \end{aligned} \tag{4}$$

Formulae to calculate the relative frequency (RF) as:

Relative Frequency RF ð Þ¼ Frequency of a species*=*Frequency of all species � 100 (5)

Unlike shrub and tree species, herbaceous species were analyzed by placing 300 numbers of 1 m � 1 m size quadrats each at FA and DA. Only abundance (A) was calculated for herbaceous species. The abundance which is an appreciation of the number of individuals of different species in a community is calculated as [25]:

Abundance Að Þ¼ Total number of individuals of a species*=*

Total number of quadrats in which the species occurred

(6)

In both FA and DA abundance of herbaceous species was estimated at regular intervals and categorized as rare, common and abundant. Further abundance rating (AR) was given to each herbaceous species. The rare species were rated as 1, while the common and abundant species were given a score of 2 and 3, respectively [26].

#### **3.1 Species selection from forest**

Tree species for restoration were selected in two phases. In the first phase, the top 15 species were selected based on the Importance Value Index (IVI). Remarking *Ecological Restoration of Degraded Habitats of Jajang Iron and Manganese Ore Mines… DOI: http://dx.doi.org/10.5772/intechopen.99584*

was given to each species based on the IVI. IVI was calculated as a sum of relative density (RD), relative frequency (RF), and relative dominance (RDo) [27, 28]. Formulae for measurement of RD and RF of tree species is similar to that of RD and RF of shrub species, but the relative dominance (RDo) of tree species was calculated as:

Relative Dominance RDo ð Þ¼ ð Þ Basal area of a species*=*Basal area of all the species

� 100

(7)

The basal area which is regarded as an index of dominance of a species was calculated as:

> Basal area BA ð Þ¼ πr 2 m2 (8)

$$\text{Importance Value Index (IVI)} = \text{RD} + \text{RF} + \text{RDo} \tag{9}$$

During the second phase of selection, regeneration potential was included. Tree species represented by more than 15 individuals per m2 in the regeneration (seedling) stage (GBH ≤ 10 cm) were ranked 1, species having less than five number of individuals in the regeneration stage were ranked 3 and species having individuals in between 5 and 15 in the regeneration stage were ranked 2 [29]. Adding IVI and regeneration ranks, the top twelve tree species were selected for restoration. Shrub species were selected using relative index (RI) and herbaceous species on abundance ranking (AR).

#### **3.2 Species selection from plantation**

Tree species in "P" were selected based on their growth, productivity and adaptation. The growth was estimated using the size index [14] as:

$$\text{Size Index (SI)} = \text{Tree height (cm)} \times \text{gbh (cm)}.\tag{10}$$

Productivity potential of tree species was estimated using canopy index [14] as:

$$\begin{array}{l} \textbf{Canopy Index (CI)} = \begin{pmatrix} \textbf{Average canopy height} + \textbf{Average canopy width} \end{pmatrix} \\ \times \text{no.of sample trees.} \end{array} \tag{11}$$

Adaptation potential of species was evaluated as; species grown on the slopes were ranked 1, species grown on flat terrain were ranked 2, while those species are grown in valleys, stream bed or river bed were ranked 3 and 4, respectively. The species growing on shallow soils were ranked 1, while those on medium and deep soil were ranked 2 and 3, respectively. Adding the ranks for growth, productivity, terrain and soil, the top ten species were selected. Some species were included based on their properties to enrich the soil.

#### **3.3 Economic rank (ER) of tree species selected for plantation**

The economic rank of tree species was considered as an additional criterion to strengthen the process of tree species selection from mining forest areas and plantation for plantation in the mining waste site of JIMOM. To analyze the economic rank of tree species selected from FA and P for plantation the local people and forest officials were consulted and interviewed during the field visit days. Based on local use types (food, animal feed, timber, gum, edible fruit, ethnomedicine, edible oil, etc.) of such plant species for livelihood subsistence of the local community and industrial purposes their economic rank was calculated. As ER was an ordinal variable, it took values >0 and varied from 1 to 3. Species having a maximum number of economic uses were ranked as 1 and those having a minimum number of economic uses were ranked as 3. The other ones of economic uses intermediate between maximum and minimum were ranked as 2.