about 35 species are different types of spruce trees.
about 35 species are different types of spruce trees.
how many different types of spruce trees are there?
about 35 species
Na
Na
spruce broom rust is an interesting pathogen in terms of its importance in forest management programs. many spruce trees do not exhibit any symptoms of disease upon infection by "chrysomyxa arctostaphyli", and still many others display effects of a merely cosmetic nature. besides obviously impacting visual quality, spruce broom rust can also have major, more economically important impacts on timber productivity. nutrients that were originally sequestered for growth in spruce are redirected to the brooms, which can lead to a reduction in height and radial tree growth. for example, a 1963 us forest service study found that trees infected by "chrysomyxa arctostaphyli" showed a 30 percent reduction in growth over the course of ten years as compared to healthy trees. the extent of this damage depends on the number and size of brooms, as well as their location. when brooms occur upon the primary bole of the spruce, this can lead to a phenomenon known as top kill, in which the portion of the spruce above the brooms dies. as the infection continues to grow and more sections of the tree die, new entrance ways open up for wood decaying fungi, such as red ring rot ("phellinus pini"). these fungi are capable of devastating the volume of usable wood obtained from spruce trees, and in turn greatly reducing the trees’ marketable value, because they are highly specialized in removing the wood’s structural compounds. additionally, this internal wood decay causes spruce trees to become structurally unstable, posing relevant hazards in residential and recreational areas. finally, although tree death is not common in infected trees, "chrysomyxa arctostaphyli" may weaken the spruce and cause it to become highly vulnerable to other potential killers such as other fungi, bark beetles, or simply by increasing the tree’s susceptibility to intense wind, water, and snow. the same 1963 us forest service study found that infected trees had a three times greater mortality rate over a ten-year period than healthy trees. nevertheless, "chrysomyxa arctostaphyli" may indeed play an ecologically vital role in the yukon. oftentimes squirrels, fishers, and other forest animals utilize cavities within brooms, especially those carved out by other wood decaying fungi, as sources of shelter and dens.
spruce broom rust