preview

The Impact of Invasive Species on Ecosystems Essay

Good Essays

Influence on ecosystems range from human causes like the bulldozing of a forest to natural causes like a fire or a flood. In recent times, the introduction and spread of invasive species has transformed native communities rapidly and, in some cases, created irreversible damages. In the Earth’s history, changes have often occurred in the ecosystems. For example, glaciers and the retreat of glaciers cause wide-spread changes. However, although change is a constant in ecosystems, animals and habitats often cannot adapt to the rapid alterations of non-natural stresses. Harm to the environment from the introduction of invasive species occurs through changes in the habitat and declines in the native species. Invasive species …show more content…

According to Van Driesche, nonnative species are more likely to establish if they invade habitats with lowered biotic resistance, encounter prey with poorly developed mechanisms of self-defense, or invade habitats unaccompanied by their specialized natural enemies or when their invasion is facilitated by earlier invaders (2000). Damage to these communities, then, can be seen both in cumulative effects and in a cycle of self-reinforcement. Although pristine environments are still at risk from invasion, this positive feedback loop makes habitats already with a disturbance by exotics even more vulnerable to other invasions. With the increasing amount of disturbed habitats, invasive species could soon become the leading cause of ecological degradation (Soulé & Orians, 2001). Invasive species can alter habitats in a number of ways. Changes in the physical structure of the land are the most visually obvious. Examples include narrowing stream channels, reducing sand supply to dunes, and stabilizing surfaces such as mudflats, and each invasive species goes about these changes in their own way. For instance, the burrowing activities of Australian isopods cause the banks of tidal channels to collapse, leading to the widening of channels and the loss of vegetated salt marsh (Cox, 1999). On the other hand, Japanese mussels that have invaded the San Diego area are stabilizing mudflats. Although reaching Southern California in the 1960s,

Get Access