Assessing effects of global change by geographical analysis of population-level persistence data

• Camille Parmesan

Abstract
I have developed an extensive dataset on extinctions of populations of Edith's checkerspot butterfly throughout this species' range from Mexico to Canada. A significant latitudinal trend in extinctions appears to support predictions of northward range movement from global warming scenarios. However, such a conclusion is premature in the absence of information on latitudinal gradients of other ecological factors independent of climate. Spatially-explicit analyses, via a GIS, of a series such factors, as well as specific climatic variables, are proposed. The elimination of non-climatic factors as causes of the observed geographical trend would comprise evidence that biological effects of climate warming are starting to occur. Proposed collaboration with European researchers on their local databases will help assess the generality of the trends described.