NPER Fellows

Fellows > 2005 | 2004 | 2003 | 2002 | 2001 | 2000

Besty Von Holle

Betsy Von Holle Betsy Von Holle received her B.S. degree in Ecology, Behavior and Evolutionary Biology at the University of California, at San Diego. She then received her Ph.D. from the University of Tennessee in 2002, in the Department of Ecology and Evolutionary Biology. Her dissertation research with Dr. Daniel Simberloff concerned ecological resistance to biological invaders. Dr. Von Holle’s NPER Fellowship project focused on disturbance histories as a predictor of habitat invasibility in a mosaic landscape at Cape Cod National Seashore. Dr. Von Holle and her team employed multi-scale techniques to determine landscape-level influences on nonnative plant invasion. Betsy collaborated with Dr. David Foster and Glenn Motzkin of Harvard Forest in a landscape study of nonnative plant distribution that pairs historical, environmental, and biotic properties of Cape Cod National Seashore to determine habitat invasibility. This research revealed that nonnative species distributions and abundances in this largely invasion-resistant landscape are largely driven by soil nutrient conditions, rather than current biota or historical disturbances. Models that emerge from this study were tested for their generality by applying them to the rest of the Cape Cod/ Long Island coastal ecoregion. In a smaller-scale field-based study, nonnative species richness and abundance values decreased away from typical natural disturbances (wind, salt spray) of the outer Cape, while native species richness and abundance values typify the 'intermediate disturbance' response to natural disturbances. Betsy and her team have documented that the invasive, nitrogen-fixing black locust tree, Robinia pseudoacacia, facilitates invasion by other nonnative plant species, most likely owing to the nutrient-rich soils found beneath this nonnative species. They investigated nutrient cycling properties of locust and native forests, initiating a restoration ecology experiment of heathland invasibility, and conducted manipulative experiments to investigate the factors that promote invasion into heathlands. For more information regarding Betsy’s research interests and activities, please see http://harvardforest.fas.harvard.edu/profiles/vonholle.html

Kristina M. Hufford

Kristina M. Hufford Kristina M. Hufford's NPER Fellowship project investigated the hypothesis that widespread, common plant species distributed among heterogeneous environments are likely to form different races or "ecotypes." Dr. Hufford's team examined both ecological and genetic variation of populations of three native grass species on the California Channel Islands. They compared data collected at the park with data collected from representative mainland sites in Santa Barbara County. A unique combination of genetic analyses and ecological field studies allowed them to characterize local adaptation within populations of a single species, and the extent to which breeding systems affect levels of local adaptation among species. As a result, this research provided new insights in ecological genetics and the island biogeography of plant populations. Dr. Hufford received a B.A. in Environmental Sciences from the University of California, Berkeley and a Ph.D. in Botany from the University of Georgia. She conducted her dissertation research at the Smithsonian Tropical Research Institute on Barro Colorado Island in the Republic of Panama. Her Ph.D. project examined temporal variation in selection across life stages of a population of tropical rainforest trees. Dr. Hufford is currently conducting postdoctoral research with Dr. Susan Mazer in the Department of Ecology, Evolution, and Marine Biology at the University of California in Santa Barbara.

Fellows > 2005 | 2004 | 2003 | 2002 | 2001 | 2000