How will increasing climate variability change plant species diversity?
To most people, global climate change means increases in average temperatures. But scientists are also predicting that climate change will cause increases in rainfall variability-more severe storms and very wet years, but also more extreme droughts. Such changes in rainfall variability might have significant impacts on arid and semi-arid ecosystems. In fact, mathematical theory predicts that climate variability can be important in maintaining species diversity by allowing species to “time-share” one habitat. This theory implies that a change in variability could alter species diversity, but it has been difficult to test due to a lack of appropriate data. A remarkable dataset from grasslands in western Kansas, USA provides an opportunity to test theory about climate variability and species diversity. For over thirty years starting in the 1930’s, all individual plants in permanent quadrats were mapped each year. We can use these data to create a statistical model that describes how each
