Monday, February 14, 2011

Invasive species are not always bad for ecosystems

Invasive species have more often than not negative impact on native ecosystems, and can in extreme cases even lead to extinction of native species. This is because invasive species in most cases compete with native species for food an other resources, and this often results in negative environmental effects.

But as said in the title of the post not all invasive species are bad for native ecosystems, and this was showed by the team of scientists who introduced invasive species of plants which resulted in positive environmental effects.

Tomás Carlo, an assistant professor of biology at Penn State University, and Jason Gleditsch, a graduate student in the Department of Biology, have sectioned off an area of central Pennsylvania known as the Happy Valley region, where honeysuckle, a non-native invasive fruiting plant, grows in abundance. Afterwards they assessed the abundance of bird species and fruiting plants, including honeysuckle, within the area. The conclusion was that the honeysuckle and bird communities had formed a relationship known as mutualism, where two species interact by benefiting mutually from each other's existence. In this case, honeysuckle provided birds with the food in the fall while birds benefit honeysuckle by dispersing the plant's seeds across a wider geographical area.

This study just proves that nature is in the condition of constant change, and that eliminating non-native species isn't always the right solution to protect native ecosystems, in most cases yes, but not in all cases. This is because humans have already changed many ecosystems beyond the recognition point so many native species are already rare, and some have already gone extinct.

Observation and comprehensive studying is the key for conservation, and scientists should consider all possible options, not just sticking with one, no matter how right this option might appear. As this study proved, invasive species shouldn't be always treated as threat to native animals because in some cases invasive species can form positive connection with native species which benefits given ecosystem.

We have been taught many times that generalization isn't exactly the best scientific method, and invasive species are clear evidence of this.

The results of this study will soon be published in the journal Diversity and Distributions.