These are projects that I am actively working on.
This project is funded by a grant from the NSF Dimensions of Biodiversity program, awarded to Carl Schlichting and colleagues. The Greater Cape Floristic Region (GCFR) of South Africa is a region of incredible plant diversity, much of which is the result of evolutionary radiations in a relatively small number of lineages. The goal of this project is to investigate the phylogenetic, taxonomic, and functional diversity of the GCFR by focusing on two radiations - that of the genus Protea and that of Pelargonium. As part of this project we are also examining patterns of taxonomic and functional diversity of plant communities, as it is within these communities that radiations have occurred. More details on the project can be found at our website. My role in this project is to lead the investigation of the relationships between plant communities, the functional traits of the plants that make up these communities, and the environmental conditions where these communities occur. Ultimately, we are trying to better understand what ecological and evolutionary processes drive the observed patterns of biodiversity in this region.
Though the usefulness and value of distinguishing native and non-native species is currently a topic of lively debate, it is clear that some non-native species have substantial negative effects on biodiversity and human health. The seriousness of these threats justifies research into the ecological and evolutionary processes governing the establishment and spread of non-native species. Additionally, several researchers (e.g. Sax et al. 2007, Trends in Ecol. Evol. 22:465-471) have pointed out that studying species invasions may yield insights into ecological and evolutionary processes in general. With these two ideas in mind, I set out early in my graduate career to study a non-native species of concern in a geographic region and ecosystem of great importance to me, the deciduous forests of northeastern North America. Following discussions with researchers and land managers, I decided to focus my dissertation research on the non-native invasive species Frangula alnus (Glossy Buckthorn). For my Ph.D. research, I examined the temporal and spatial processes governing the invasion of F. alnus in a quantitative modeling framework that comprised (1) a demographic model based on data I am collecting during a multi-year field study; (2) a statistical model of the spread rate of F. alnus and the effects of land-use change, based on herbarium records and historical landscape reconstruction; and (3) a species distribution model (SDM), based on occurrence data from multiple sources. I integrated the results of these models, linking information on dynamic processes (e.g., results from the demographic model) with information on ecological patterns (e.g., results from the SDM), to gain an understanding of what processes contributed to the rapid spread of this species throughout northeast North America. This work is currently being prepared for publication. I am continuing to monitor the populations I began monitoring in 2009 and am working to further refine our understanding of this invasion, with the goal of applying what I have learned with F. alnus to other invasive plants.
These are projects I worked on in the past.
From 2009 to 2012 I worked with a collaborative research group that included scientists from the University of Florida and the Army Corp of Engineers to examine the effects of projected sea-level rise on shore-birds along the Gulf Coast of Florida. My primary role in this project was to gather relavent biological information on three bird species of interest (Snowy Plover, Piping Plover, and Red Knot), and to construct a demographic model for the Snowy Plover (Charadrius nivosus). We linked this demographic model to a spatial model of the effect sea-level rise is projected to have on shore-bird habitat along the Gulf Coast, and examined what impacts on the risk of population decline and extinction such changes may have for this species. Several publications have come out of this project, but my work on linking the demographic and spatial models was published late in 2011 in Global Change Biology (Aiello-Lammens et al. 2011). (Image of Snowy Plover under Creative Commons Attribution 2.0 Generic from Wikipedia; photo by Mike Baird, bairdphotos.com)
Another project I have worked on is a systematic review of the proximate causes of local extinction due to climate change. This review was in part the result of a seminar lead by Professor John J. Wiens at Stony Brook University. The key question we set out to address in this review was “for observed local extinctions connected to climate change, are the proximate causes of extinction related to abiotic or biotic factors?” The results of our systematic review support the idea that biotic interactions are more often involved in the proximate cause of local extinction than abiotic factors (i.e. physiological limits). I have discussed our findings and my thoughts on the literature review process in blog post at my previous blog site. The article, which I co-lead, can be found here Cahill et al. 2012, Proceedings of the Royal Society B.