There has been much attention paid in recent times to the problem of invasive species and the potential harm that they cause. As a result, we have employed a variety of strategies to control the spread of non-native plants and animals that, in many instances, can disrupt local ecosystems and cause both ecological and economic damage.
As the climate changes, a vexing problem is arising. What exactly is a native species? Species move around on their own when conditions change in their native habitats. With increasing temperatures, the habitat ranges of many North American species are moving northward in latitude and upward in elevation.Their lifecycles and patterns are changing. Are these immigrating species to be considered invaders?
Warming has led to changes in the nesting patterns and the migratory habits of bird species and butterflies and the annual cycles of plants. Such changes lead to mismatches in food availability that can ripple through an ecosystem.
In some instances, the climate-induced migrations of species are merely opportunistic, taking advantage of newly available resources. In other cases, species may be moving to a last refuge as their unique adaptations to a specific climate are no longer applicable in their native habitat.
We have a strong interest in protecting our native wildlife but the policies and strategies we have developed are being challenged by the impacts of climate change. These changes are creating difficult but fundamental questions about the definition of native species. How we answer such questions will have a major effect on how we deal with a changing world.
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Web Links
Ecosystems Impacts and Adaptation
http://www.epa.gov/climatechange/impacts-adaptation/ecosystems.html
Photo, taken on May 27, 2008, courtesy of J. Kelly/USFWS Mountain Prairie via Flickr.
Earth Wise is a production of WAMC Northeast Public Radio. Support for Earth Wise comes from the Cary Institute of Ecosystem Studies in Millbrook, NY, with partial support from the Field Day Foundation.