TEN YEARS OF LEAFY SPURGE BIOLOGICAL CONTROL AT THEODORE ROOSEVELT NATIONAL PARK,MEDORA,NORTH DAKOTA(Abstract)

摘要

Remote sensing and geographic information system(GIS)technology have been used to detect and monitor numerous grassland-related problems.The objectives of this study were to use both technologies jointly to map and quantify the extent,distribution,and spatial-temporal dynamics of leafy spurge within Theodore Roosevelt National Park.Initial surveys quantified that the park had approximately 591 ha of spurge in 1993 and 1,194 ha in 1998.An aggressive biological control program started in 1998 moved millions of leafy spurge biological control agents in the area.By 2005 most leafy spurge communities had been reduced to less then 5%of the biologically active plant communities and some native species were moving back into the previously impacted area.