My current research is a comprehensive program focused on the long-term effects of disturbance (drought, disease, fire) on shortgrass steppe and desert grasslands, and pinyon-juniper woodlands. The studies are aimed at understanding how these unique and important systems function in the face of changing disturbance patterns and climate including large and devastating wildfires. Main studies include: (1) landscape-scale patterns of fire and drought in the Great Plains; (2) long-term experimental research on the effects of season and frequency of fire in shortgrass steppe in the southern Great Plains and Chihuahuan Desert grassland; (3) state-transition simulation modeling as a decision support tool for southern Great Plains managers; (4) long-term carbon dynamics in aridland ecosystems; and (5) global-change-type drought in piñon-juniper woodland ecosystems in the American Southwest.
My research interests focus on the role of disturbance, (i.e., fire, drought, infestations, pathogens), in structuring grassland, desert, and woodland communities; and ecosystem resilience.
• The effects of fire and mowing on expansion of re-established black-tailed prairie dog colonies in Chihuahuan Desert grasslands. • Black-tailed prairie dog (Cynomys ludovicianus) response to seasonality and frequency of fire in shortgrass steppe. • Habitat and breeding ecology of amphibians. • Fleas and lice of mammals in New Mexico. • Coccidia (Apicomplexa) from heteromyid rodents in the southwestern United States, Baja California, and northern Mexico with three new species from Chaetodipus hispidus.
• The American Southwest is characterized by extreme drought conditions accompanied by rising temperatures, causing widespread tree mortality in pinyon-juniper woodlands. This die-off occurred across millions of acres of the southwestern United States and killed up to 350 million pinyon pines. Because the region has continued to experience frequent droughts and high temperatures, on-going research examines whether even drought tolerant junipers may succumb to increased aridity and begin dying at increased rates, potentially significantly altering fire regimes.
• Climate change is a pressing environmental issue that requires measuring the exchange of greenhouse gases between terrestrial systems and the atmosphere. Reductions in atmospheric CO2 concentration through enhanced terrestrial carbon storage may help slow or reverse the rate of global climate change. As a result, Federal land management agencies, such as the US Forest Service, are now beginning to implement management policies to increase carbon storage.
• Fire is a key management tool in the southwestern US, yet fire management strategies must be designed within a context of global climate change, which includes a more variable climate with more frequent extreme events, and potentially a shift in winter/summer rainfall patterns. Given the uncertainty of future scenarios for climate change and climate variability in the southwestern US we need to know now how fire seasonality, and over the long-term fire frequency, interacts with climate variability to affect biodiversity and ecosystem functioning in these highly dynamic aridland ecosystems.
• The High Plains states are in the midst of ongoing extreme drought, experiencing below normal precipitation and above normal temperatures for the past several years. Drought is expected to persist or intensify. In addition, climate change is predicted to have multiple effects on fire regimes, including more large-scale fires that significantly exceed those of recent decades.