Pests, Predators, and Multiple Stressors in Agroecosystems

EPA Grant Number: R834896
Title: Pests, Predators, and Multiple Stressors in Agroecosystems
Investigators: Lawler, Joshua J.
Institution: University of Washington
EPA Project Officer: Hahn, Intaek
Project Period: February 25, 2011 through February 24, 2013
Project Amount: $100,000
RFA: Pesticide Registration Improvement Renewal Act (PRIA 2) Partnership Grants (2010) RFA Text |  Recipients Lists
Research Category: Biodiversity


Exposure of non-target wildlife to second-generation anticoagulant rodenticides (SGARs) is a growing problem. These rodenticides, including brodifacoum, bromadiolone, difenacoum and difethialone, have been found in a variety of carnivorous and omnivorous mammals and birds, some of which have the potential to play key roles in integrated pest management strategies. 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 investigate the synergistic effects of alternative pesticide regimes, land-use change, and climate change on interacting populations of pests and their predators in agricultural landscapes. Our goal is to simulate the effects of pesticides on a target pest population and the non-target wildlife populations that prey upon those pests. We will investigate how these direct and indirect pesticide effects change with different land-use-change and climate-change scenarios. More specifically, we will parameterize a spatially-explicit population model to assess the effects of altered precipitation regimes, land-use change, and rodent control, on population size and distribution of rodent pests and a sensitive non-target species, the San Joaquin kit fox. We will use our models to evaluate scenarios of pesticide management under current conditions and plausible future climate and land-use scenarios to attempt to maximize the combined effect of rodenticide and foxes on rodent populations while minimizing fox exposure to rodenticides. These models will be parameterized for the Central Valley of California, an agricultural area with Mediterranean climate.

Expected Results:

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. Our model will provide a framework for making decisions about this particular system, but our approach will be more generally applicable to efforts to better control pesticides to minimize their effects on sensitive non-target wildlife. Our results will also have clear implications for the implementation of integrated pest management.

Progress and Final Reports:

  • 2011
  • Final