Invasive species

According to May’s issue of Discover, the species invasion has already begun: dandelions, purple loosestrife, Cuban tree frogs, etc. The success of an invading species depends on its ability to find and exploit a niche in a new ecosystem. When an alien species enters a new ecosystem, it can cause a stir by eating native species, spreading disease, competing better against local decease, or changing the environment in such a way that favors itself. But, most invasive species just take their place quietly. Purple loosestrife, for example, is taking over wetlands and backyards in the northeast. Although local ecologists are sounding the alarm, a zoological study concluded that there is little or no evidence that its invasion has any serious ecological consequences. We traditionally see invasive species as deceases that ruin natural ecosystems. But invasion biologists don’t see it that way. Invasions don’t cause ecosystems to collapse; in fact, invasive species can make an ecosystem healthier by increasing the local biodiversity. Although a new species may not be as useful or attractive to humans, the new, more competitive species will make the ecosystem stronger. (You might not be able to read the story without a password.) Link.