Photo credit: Heather Bell, USFWS


Land-use Change

Sources and Sinks

Research team:  Julie Heinrichs, Lauren Walker, Josh Lawler, John Marzluff, David Cimprich, Paul Leberg
Populations are often spatially structured.  Understanding the effects of spatial structures such as sources and sinks, metapopulations, patchy networks, and isolated populations on population dynamics is critical for successful management.  We are exploring the relative importance of the factors that influence source-sink dynamics in general as well as the implications of source-sink dynamics for the management of an at-risk species—the Black-capped Vireo.  The study has three, more specific objectives: 1) identify attributes of species, landscapes, and ecological systems that promote source-sink dynamics, 2) identify sources and sinks for Black-capped Vireos on and around Ft. Hood, and 3) explore the potential contribution of different sources and sinks—as well as the effects of differential management of these sources and sinks—to the population dynamics of the Black-capped Vireo throughout its range.

Pests, Predators, and Multiple Stressors in Agroecosystems

Research team: Theresa Nogeire, Josh Lawler
The EPA has identified exposure of non-target wildlife to second-generation anticoagulant rodenticides (SGARs) as a problem and has set regulations to reduce such exposures. Designing efficient integrated pest management strategies that maximize pest control while minimizing the impacts on non-target wildlife requires an understanding of the effects of these rodenticides on interacting target and non-target wildlife populations in dynamic environments. Given that climate change and land-use change are likely to be the two largest drivers of environmental change in this century, it will be necessary to assess the potential effects of pesticides in light of these two factors. We will parameterize a spatially-explicit population model (HexSim) to assess the effects of altered precipitation regimes, land-use change, and rodent control on population size and distribution of a sensitive non-target species, the San Joaquin kit fox. The results of these simulations will inform decisions about where, when, and how to apply pesticides to best take advantage of both wildlife- and pesticide-based pest control while minimizing the effects of pesticides on non-target populations.

Amphibians, landscape patterns, and urbanization

Research team: Jorge Ramos
Rapid population growth in King County, WA has led to the disappearance, alteration, and isolation of seasonally flooded wetlands that provide breeding habitat for a number of amphibian species. We are exploring the effects of landscape pattern on amphibian distributions in these seasonally flooded wetlands. We are sampling wetlands for amphibians and relating species occurrences to landscape patterns as measured from remotely sensed data. Using those relationships, in conjunction with projected future urbanization patterns in King County, we will predict potential future changes in amphibian distributions as driven by future land development.