Conservation
Fragmentation and connectivity
Recent estimates suggest that humans have transformed habitats on more than 40% of the earth's surface, making habitat conversion and fragmentation easily the largest source of landscape change on earth. Much of our research in this area focuses on the effects of habitat fragmentation on interactions between organisms and the consequences of changing interactions for populations. We have three main research questions related to this theme:
- Fragmentation and bird communities in the Western US - Effects of landscape fragmentation on nest predation, brood parasitism, and avian community health in the Western US
- Fragmentation, patch size, and small mammal life histories - Declines in small mammal species as a consequence of fragmentation may be predicted based on life-history characteristics. Andrew Van Eck is leading an investigating this through meta-analysis and studies of small-mammal decline in Lebanon and the US.
- Connectivity, Corridors, and plant-animal interactions - The establishment of wildlife corridors connecting habitats are the most-often used conservation tactic for reducing the negative effects of landscape fragmentation. In a collaborative project, we are investigating the efficacy of corridors, particularly as they affect plant-animal interactions, and the development and restoration of communities.
Conservation of wild-crop relatives:
10 crop species account for 85% of the world's food, and with the advent of modern agricultural practices, the genetic resources that form the foundation of these crops has narrowed considerably. Our lab is actively working to study and preserve the close relatives of our food crops, in their natural habitat. Our current focus is on chilies, the most popular spice in the world, and our research is both in-country, and international.
The Wild Chile Botanical Area - Our lab helped to establish and is a managing partner for the first federally recognized management unit dedicated to the preservation of wild crop relatives.
Conservation of wild chilies in Bolivia - We are in the beginning phase of an international effort to help preserve the wild Bolivian Capsicums and examine their importance for crop development.
Invasive Species and Trophic Cascades
21% of the world's bird species are prone to extinction and 6% are functionally extinct, contributing little to ecosystem processes (Sekercioglu et al. 2004). By 2100, it has been estimated that 7-25% of all birds will be functionally extinct, including 28-56% of birds on oceanic islands (Sekercioglu et al. 2004). The loss of these species, including entire avian fauna in some locations, will have reverberating effects that may impact entire ecosystems, but these cascading effects have rarely been studied. Haldre Rogers will be examining these impacts on the Islands of Guam, where introductions of the Brown Tree-snake has resulted in the virtual extinction of the entire avifauna on the island. Haldre will be examining the consequences of this loss on forest communities through a series of comparative projects between Guam and Rota, where the Brown Tree-snake has not invaded.
Organismal response to climate change
Recent global warming has altered species distributions, phenology, and persistence. The impact of future warming on species persistence has been difficult to predict, but projections place the largest impacts at higher latitudes, as temperature changes are predicted to be larger there, and most organismal responses have been detected at high-latitudes. These predictions may be misleading, as they do not account for organismal tolerance to climate change. In a collaborative project, we are investigating the links between physiological tolerance and temperature seasonality, and modeling this relationship globally, in an effort to provide predictive relationships that will allow researchers to better understand the impacts of climate change on populations as a function of latitude and altitude.
