Research Interests

I work on both basic and applied problems in population ecology, community ecology, and conservation biology.  My research program addresses these two 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. Cascading (or 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 and midwestern 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.

2. 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.  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.  Explanations at a single scale or level of analysis can be misleading, so I combine information about species composition, management history, and landscape context within a "natural experiment" framework to identify key processes.  Questions that interest me include: (1) How are native and exotic species changing in abundance within and among sites through time, and how might management history and landscape context contribute to observed patterns?  (2) How can we objectively quantify the quality of natural areas and detect degradation through time? (3) How does biotic homogenization occur, how does homogenization influence ecosystem function, and how can our understanding of homogenization advance conservation strategies?

Representative Publications:

Waller, DM and TP Rooney, eds. The vanishing present: Wisconsin's changing lands, waters, and wildlife. The University of Chicago Press. forthcoming book.

Rooney TP, JD Olden, MK Leach, DA Rogers. 2007. Biotic homogenization and conservation prioritization. Biological Conservation 134:  447-450.

Olden, JD and TP Rooney. 2006. On defining and quantifying of biotic homogenization. Global Ecology and Biogeography 15: 113-120.

Rooney, TP. 2005. Distribution of ecologically-invasive plants along off-road vehicle trails in the Chequamegon National Forest, Wisconsin. Michigan Botanist 44: 169-173.

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.

Rooney, TP and DM Waller. 2003. Direct and indirect effects of deer in forest ecosystems. Forest Ecology and Management 181: 165-176.

Rooney, TP and K Gross. 2003. A demographic study of deer browsing impacts on Trillium grandiflorum. Plant Ecology 168: 267-277.

Rooney, TP and DA Rogers. 2002. The modified Floristic Quality Index. Natural Areas Journal 22: 340-344.

Rooney, TP 2001. Impacts of white-tailed deer on forest ecosystems: a North American perspective. Forestry 74: 201-208.

Rooney, TP, RJ McCormick, SL Solheim and DM Waller. 2000. Regional variation in recruitment of hemlock seedlings and saplings in the upper Great Lakes, USA. Ecological Applications 10: 1119-1132.

Rooney, TP, C Antolik and MD Moran. 2000. The impact of salamander predation on Collembola abundance. Proceedings of the Entomological Society of Washington 102: 308-312.