| Species that are brought from their natural habitat and "introduced" into a new area by humans can be amazingly destructive. Sometimes these introduced species are types of grasses or shrubs that were transported accidentally as seeds, and upon arriving in a new habitat, manage to replace the native species. Other times, insects are introduced accidentally. With no natural enemies, they quickly multiply to almost epidemic populations, feeding heavily on the leaves of trees and other plants. When mammals are introduced, the native animal populations can suffer greatly. This has been repeated many times on small islands where humans intentionally brought familiar food and companion animals when first moving to the islands. Many native island animals evolved without any serious predators, and were quickly driven to extinction by the introduced livestock. Introduced animals such as goats also cause extensive damage to the land itself, by feeding on all the grasses and small plants, leaving the ground bare and very susceptible to erosion. |
threats to forests -- page 6 of 6
[1] [2] [3] [4] [5] [6]
sub-topics
[deforestation] [climate change] [loss of biodiversity] [pollution] [erosion] [fire]
related topics
[plants] [insects] [mammals] [humans & forests]
view the condensed version of the threats to forests article for faster printing/reading
return to the main menu