Deforestation and Biodiversity
While the loss of forests is clearly visible, a decline in biodiversity has a less apparent effect. The subtle loss of biodiversity fails to indicate the significance that fewer species in the ecosystem increases the fragility of life for all species. Despite the negative effects of deforestation and the consequential decline of biodiversity, trees are cut down for an economic and consumer benefit. Members of society need to determine how much economic cost they are willing to spend in order to preserve plant and animal species.
To reduce the degree of deforestation, tree harvesters may use selective logging, which involves only the removal of trees that are the most economically beneficial. Trees with lower economic value are left standing. This method still has problems intrinsic with any kind of deforestation and selective logging also introduces new environmental problems. Tree harvesters need to build roads into the forests to remove the timber (Vandermeer and Perfecto, 1995). The road construction means that a greater surface of land will be covered by asphalt, which increases the amount of rainwater runoff that is not filtered by the soil before entering a stream. These streams are polluted by sediment carried by the rainwater.
Vandermeer and Perfecto also say that selective logging introduces secondary damage when non-targeted trees are knocked down in the process of removing the desirable trees. In addition, selective logging over a long period of time leads to deterioration of the stand, which reduces the overall value of the forest when the loss of more valuable trees leaves lower grade timber behind (Vandermeer and Perfecto, 1995).
Another change related to the effect of selective logging is the changes that occur in the forest when a gap forms due to the loss of a tree. For tropical rainforests, the hole created by a fallen tree leads to changes that eventually affect the biodiversity of the habitat. The tree that previously occupied the space preserved a dark area of land within the forest. With the canopy of the tree to provide shade gone, light streams in and causes plants that do better in brighter conditions to force out low light plants that existed there previously. The loss of low light plants leads to a decline in biodiversity. Selective logging can bring about this change as well as the by the work of natural causes, such as storms (Vandermeer and Perfecto, 1995).
Deforestation can directly lead to biodiversity loss when animal species that live in the trees no longer have their habitat, cannot relocate, and therefore become extinct. Deforestation can lead certain tree species to permanently disappear, which affects biodiversity of plant species in an environment. The effect of deforestation can have the largest effect in tropical rainforests. According to the NASA Earth Observatory, half of all 5 to 80 million species live in the rainforests. Rainforests only make up seven...