My students and I work on both basic and applied problems in population ecology, community ecology, and conservation biology. Research in my lab addresses these three broad questions:
1. How do deer shape community composition and structure? By foraging selectively, deer affect the growth and survival of many herb, shrub, and tree species. Knock-on effects extend through vegetation, potentially altering gastropod, arthropod, bird and mammal communities. Because white-tailed deer occupy a broad range of habitats and can reproduce rapidly under favorable conditions, their populations have increased sharply in recent decades throughout much of the eastern United States. High deer densities create management conflicts in many parks and natural areas, as large numbers of deer have severe and often irreversible impacts on plant communities. My research investigates the web of interactions that connect deer to other organisms through changes in resource availability and quality. I am a founding member of the Forest Ungulate Research Network--an international collaborative group seeking sustainable solutions in the management of wild ungulates and natural resources management.
2. What is the velocity of biodiversity loss, how is community composition changing through time, and to what extent can these changes be attributed to human activities? Both human population growth and natural resource overexploitation stress natural systems. My students, collaborators and I try to understand how community composition will respond to future stress by looking back in time, observing the types of changes that have occurred during past decades while identifying the putative drivers of these changes. We combine information about species composition, management history, and landscape context within a "natural experiment" framework to identify patterns and processes contributing to changes in biodiversity.
3. How do we restore forest ecosystems? Land use legacies, management history, emerging pathogens, invasive species, ecological complexity, and inadequate inventory and monitoring contribute to the challenge of sustainable forest management. For the past 10 years, I have worked with a forest landowner to face these challenges. I have written a long-term land stewardship plan, and am now working on invasive species eradiation projects on the 2500 ha property.
Fakhar-i-Abbas, KE Ruckstuhl, A Mian, T Akhtar, and TP Rooney 2012. Distribution, population size and structure of Himalayan grey goral Naemorhedus goral bedfordi (Certiodactyla: Bovidae) in Pakistan. Mammalia 76: 143-147.
Rooney TP and DA Rogers. 2011. Colonization and effects of Garlic Mustard (Alliaria petiolata), European Buckthorn (Rhamnus cathartica), and Bell’s Honeysuckle (Lonicera × bella) on understory plants after five decades in southern Wisconsin forests. Invasive Plant Science and Management 4: 317-325.
Rooney TP and MK Leach. 2010. Replacing hay-mowing with prescribed fire restores species diversity and conservation value in a tallgrass prairie sampled thrice: a 59-year study. American Midland Naturalist 164: 311-321
Ripple, WJ, TP Rooney, and RL Beschta. 2010. Large predators, deer, and trophic cascades in the mid-latitudes. Pages 141-161 in J Terborgh and JA Estes, eds. Trophic Cascades: Predators, Prey, and the Changing Dynamics of Nature. Island Press, Washington DC.
Rogers, DA, TP Rooney, TJ Hawbaker, VC Radeloff, and DM Waller. 2009. Paying the extinction debt in southern Wisconsin forest understories. Conservation Biology 23: 1497-1506.
Rooney, TP. 2009. High white-tailed deer densities benefit graminoids and contribute to biotic homogenization of forest ground-layer vegetation. Plant Ecology 202: 103-111.
Rogers, DA, TP Rooney, D Olson, and DM Waller. 2008. Fifty years of change in southern Wisconsin forests: Shifts in canopy and understory richness, composition and heterogeneity. Ecology 89: 2482-2492.
Olden, JD and TP Rooney. 2006. On defining and quantifying of biotic homogenization. Global Ecology and Biogeography 15: 113-120.
Rooney, TP, SM Wiegmann, DA Rogers, and DM Waller. 2004. Biotic impoverishment and homogenization in unfragmented forest understory communities. Conservation Biology 18: 787-798.
Cote, SD, TP Rooney, JP Tremblay, C Dussault, and DM Waller. 2004. Ecological impacts of deer overabundance. Annual Review of Ecology Evolution and Systematics 35: 113-147.
Waller, DM and TP Rooney, eds. 2008. The Vanishing Present: Wisconsinís changing lands, waters, and wildlife. University of Chicago Press, Chicago and London. 507 p.