Submitted to: Bioannual Workshop Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 4/1/1999
Publication Date: N/A
Citation: Anderson, G.L., C. W. Prosser, S. Hagar, and B Foster. 1999. Change detection of leafy spurge (Euphorbia esula) infestations Using aerial photography and geographic information systems. In: Proceedings: 20th Anniversary Leafy Spurge Symposium, Medora, ND. June 29 p. 11.
Interpretive Summary: INTERPRETIVE SUMMARY Leafy spurge infests over 5 million acres in the northern Great Plains. Herbicide use has been the most prevalent treatment, however, it has not controlled the expansion of the weed. Records from Theodore Roosevelt National Park indicate that the amount of leafy spurge in the park has doub bover the last five years. The doubling of leafy spurge has occurred durin period when the park is expending considerable resources to control the problem. The results of this study indicate that leafy spurge will only be controlled with aggressive and consistent application of imported insect predators (biological control), herbicides, and other cultural practices th are specifically designed for the degree of leafy spurge infestation and specific type of land use practices.
Technical Abstract: ABSTRACT Leafy spurge is a troublesome weed in the northern Great Plains of the Unit States that herbicides and grazing management have not consistently controlled. The objectives of this study were to use remote sensing and GIS technologies to map and quantify the extent, distribution, and spatial- temporal dynamics of leafy spurge within Theodore Roosevelt National Park between 1993 and 1998. Preliminary analysis of the data indicated that spu had doubled during the five year period. Leafy spurge extent was estimated be 591 ha in 1993 and 1,194 ha in 1998. Most infestations were restricted t drainage channels, creek bottoms, and river bottoms. The extent of leafy spurge increased across all aspects and slopes, however, the rate of increa was slower on south facing aspects and flatter slopes. The faster rate of increase on slopes ranging from 6 to 20 % indicate that leafy spurge is slo omoving out of the relatively flat drainage channels and butte tops unto steeper slopes. The difference in the rate of increase between the north a south facing aspects combined with the slope and proximate to drainage chan data indicate that water is likely the driving variable for spurge establishment in the badlands. Doubling the extent of leafy spurge in five years is impressive because the increase was accomplished under an aggressi weed management plan. Leafy spurge will only be controlled with aggressive consistent application of IPM tools specifically chosen to meet the individ requirements of each situation.