Read at : Google Alert – desertification
http://www.turf.arizona.edu/OALS/ALN/aln60/kurc.pdf
Extreme makeovers: Crossing critical thresholds into desertification
by Shirley Kurc1
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Implications for Management
Currently, two primary management strategies are being used to eradicate buffelgrass in southeastern Arizona: herbicides and manual removal. Herbicides are only used when a majority of the plant is green and actively growing, whereas manual removal of the plants can be effective year round. Both of these management strategies rely heavily on knowing the locations of existing buffelgrass patches, and often the good will of citizen volunteers, thus limiting their impact. While the development of remote sensing techniques (e.g. Franklin et al. 2006) may be able to help locate current stands, making these management strategies more effective, they still focus more on removal than on prevention.
A better understanding of pre‐threshold states can benefit these management efforts (Friedel 1991; Kolar and Lodge 2001). Preventing new invasions is the most successful and economical management strategy, whether in the Sonoran Desert or elswhere around the globe (Dale et al. 2005; Vitelli and Pitt 2006). Insights into mechanisms and patterns of invasive plant establishment are fundamental to forecasting their spread (Pysek and Hulme 2005). Spatially explicit predictive models based on ecological theory are needed to direct limited local and regional resources to monitor and manage those portions of the landscapes most likely to be invaded (Hastings et al. 2005; King and With 2002; Marone et al. 1998). Given the potential for rising global temperatures to turn exotic grasses and other invasive species into agents of irreversible desertification around the globe, the development of such tools and insights is of the utmost importance.
