Submitted to: Ecological Society of America Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 8/6/2000
Publication Date: 8/6/2000
Citation: GOSLEE, S., PETERS, D.C., HAVSTAD, K.M., SCHLESINGER, W. RECONNAISSANCE SATELLITE PHOTOS SHOW THE RECENT HISTORY OF SHRUB RECRUITMENT AND SURVIVAL IN DESERT GRASSLANDS. 85TH ANNUAL MEETING, ECOLOGICAL SOCIETY OF AMERICA. 2000. ABSTRACT P. 280. Interpretive Summary: Interpretive summary not required.
Technical Abstract: Certain shrub species, particularly Prosopis glandulosa and Larrea tridentata, have increased dramatically in the southwestern U.S. during the past few decades, replacing the original grassland vegetation. We obtained a temporal series of high-resolution military satellite images beginning in the early 1960s with the goal of monitoring shrub invasion over a large area to determine the topographic and climatic controls on shrub seedling establishment and the rate of expansion of shrub cover. Although the total area of shrub cover increased over time, both the number of shrubs and their size distributions were highly variable. Mortality in small shrubs was high, but once shrubs reached a threshold size, they were likely to persist for long periods. Shrub establishment and survival were related to both climatic factors and topographic features, particularly precipitation and drainage. Our results provide valuable information for those interested in the management and restoration of the desert grasslands of the southwestern U.S.