My general research focus has been documentation of biotic responses to climate change, particularly on shifts in species ranges. Specifically, my time at NCEAS since beginning in June 1996 has been spent on the following projects:
1) Continuation of a NASA project started as a graduate student. The first part was published in Nature in 1996. I have been exploring in more detail possible causes for the population extinction patterns which I had documented for one species of Western North American butterfly, Edith's Checkerspot, and which had resulted in a northward and upward range shift consistent with regional warming trends. This is split into two sub-projects:
i) I have now explored several theoretically important non-climatic factors and found them unrelated to the extinction patterns. In particular, I completed analyses of land-use change and urban proximity that clearly show that the natural pattern of extinctions I found was not the result of indirect effects of urbanization or agriculture. In addition, I analyzed the patterns of extinctions due directly to human habitat destruction compared to patterns of natural extinction and show how these two processes interact in their impact on regional species stability. This manuscript will be submitted to Science by summer 1998.
ii) I spent a week visiting the National Climatic Data Center (NOAA) and am now in collaboration with Tom Karl (Scientific Director) and colleagues to generate climatic analyses specific to the biology of Edith's Checkerspot. These analyses will be life-stage specific for each of eight E. editha ecotypes. Preliminary results support the initial hypothesis that climatic change has been a strong influence on population peristence. Work is in progress and this is slated to be completed by Fall '98.
2) To complement these detailed studies on one species, and to verify whether poleward and upward range shifts are a general phenomena during this century, I have been gathering data on multiple species, principally European butterflies. In under a year, I have built up a team of 12 collaborators from Spain, France, Britain, Holland, Finland, Sweden and Columbia to analyze distributional changes in an unbiased sample of species. Almost all the data are now in computer databases and preliminary analyses show significant northward and upward movement of species' ranges of a magnitude consistent with the documented warming trends in Europe and the Americas. The e.t.a. for this manuscript is Fall, '98.
Both these projects have received considerable public interest. I was an invited speaker in the White House sponsored Global Change seminar series on Capitol Hill, DC in Fall '96. My work has gone on to be highlighted in an upcoming (May '98) National Geographic article on climate change and was included in an RSPB/WWF report that was formally presented to delegates at the Kyoto Convention on Global Warming in December. In addition, the following media have profiled my work: BBC, NPR, Radio Canada Montreal, NY Times, Science News, LA Times & affiliates, New Scientist, London Times, Atlantic Constitution, Science et Vie, Die Zeit, Earth, National Wildlife, Weerspiegel, Vancouver Sun, Natur Wissenschaft Umwelt, Seoul daily, Veja Revista, Santa Barbara News Press, WBEZ Chicago, and the Rush Limbaugh Show.
I was invited to speak about my NCEAS work at the RSPB/WWF Climate Change workshop (NCAR, Boulder) and the California Regional Climate Change Workshop, as well as at CNRS (Montpellier, France), UC Santa Cruz, UC Davis and San Francisco State.
The RSPB workshop has been approved for a special issue in Climate Change. I am lead author on a review of species' distributional changes in terrestrial systems. E.t.a. for submission is Nov. '98.
3) I am also participating in the Species' Borders working group and am lead author of a review and concepts paper on how cross-systems comparisons can be used to elucidate causal mechanisms determining species' boundaries.
4) I have submitted one paper from my dissertation (to J of Ecology), with one more due to be submitted in June '98.