As principal investigator with U.S. Geological Survey - Biological Resources Division at Northern Prairie Wildlife Research Center, I am interested in effects of anthropogenic disturbance on native plant and animal communities in the northern Great Plains. My primary research focus is on the ecology of invasion of exotic plants in natural areas. Ultimately, my work must be relevant to resource managers; my goal is to use basic ecological principles to address applied questions.

Prairies are one of the most endangered of North American ecosystems, and invasions of non-indigenous plants pose a most insidious threat. When the exotic plant, yellow sweetclover, is the sixth most commonly encountered plant in randomized vegetation transects throughout a National Park, as it was at the south unit of Theodore Roosevelt National Park in North Dakota, and only 13% of those 847 transects were free of exotic plants, what has become of the prairie? Large, fragrant stands of flowering leafy spurge attract a wide array of insect pollinators. What does this mean for increasingly thin populations of native flowering plants in the vicinity that rely on these same insects for pollination? Managing invasive plants in natural areas is a complex issue, but what has become clear is that simply killing weeds is not an adequate management goal. How can we use the principles of ecological succession to favor native mixed-grass prairie, rather than weedy invaders? These are the questions of primary concern in my current research.

Larson, D.L., J.B. Grace, P.A. Rabie, and P. Andersen. In press. Short-term disruption of a leafy spurge (/Euphorbia esula/) biocontrol program following herbicide application. Biological Control: In press. Electronic pre-publication copy available at Elsevier web site.

Larson, D.L., R.A. Royer and M.R. Royer. 2006. Insect visitation and pollen deposition in an invaded prairie plant community. Biological Conservation 130: 148-159.

Larson, D.L. and J.B. Grace. 2004. Temporal dynamics of leafy spurge (/Euphorbia esula/) and two species of flea beetles (/Aphthona/ spp.) used as biological control agents. Biological Control 29: 207-214.

Larson, D.L. 2003. Native weeds and exotic plants: relationships to disturbance in mixed-grass prairie. Plant Ecology 169: 317-333.

Fahnestock, J.T., D.L. Larson, G.E. Plumb and J.K. Detling. 2003. Effects of ungulates and prairie dogs on seed banks and vegetation in a North American mixed-grass prairie. Plant Ecology 167: 255-268.

Larson, D.L., P.J. Anderson, and W.E. Newton. 2001. Alien plant invasion in mixed-grass prairie: effects of vegetation type and anthropogenic disturbance. Ecological Applications 11: 128-141.