Ecological adaptation likely to influence impacts of climate change

University of Wisconsin-Madison: Animals' capacity to adapt is a factor in how they are likely to respond to changing climate conditions. This conclusion of a new study published Mar. 2 in the Proceedings of the Royal Academy B is not especially surprising, says author Brandon Barton, but confirms the importance of accounting for local adaptation when determining the likely ecological effects of climate change.

The work shows that the ability of the top predator in a well-studied food web to adapt to local temperatures can preserve the ways the species in the web influence one another across a range of climate conditions. Barton, a postdoctoral fellow at the University of Wisconsin-Madison, completed the work while a graduate student at Yale University.

Barton focused on a food web composed of a predatory spider, a grasshopper, and the plants the grasshopper eats. The spider's predatory behavior is temperature-sensitive: if things get too warm, it retreats to the shade and does not hunt, freeing the grasshoppers to eat more plants. Thus, in warm weather the spiders exert a larger — though indirect — effect on the plants.

…The new work overcomes a common limitation of many climate change experiments, in which an organism is suddenly exposed to a new set of conditions to see how it fares. Such an experimental design does not account for the ability of the species to adapt to changing conditions gradually over time.

Instead, Barton studied populations that already live in different climes. The spiders and grasshoppers he studies thrive along most of the eastern seaboard, so he compared populations in Vermont, Connecticut, and New Jersey, using the warmer temperatures farther south as a proxy for the changing conditions expected in Vermont over the next 100 years as projected by common global climate models.

…"Species do adapt to their local environment, and in this system that all worked out okay," he says. "But that does not mean that adaptation will completely eliminate the negative effects of climate change."…

A lovely shot of dew on a spider's web, by Luc Viatour, Wikimedia Commons, under the Creative Commons Attribution-Share Alike 3.0 Unported license