|DE SOYZA, AMRITA|
|Van Zee, Justin|
|Herrick, Jeffrey - Jeff|
Submitted to: Journal of Arid Environments
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/30/2000
Publication Date: 8/1/2000
Citation: DE SOYZA, A.G., VAN ZEE, J.W., WHITFORD, W.G., NEALE, A., TALLENT-HALLSEL, N., HERRICK, J.E., HAVSTAD, K.M. INDICATORS OF GREAT BASIN RANGELAND HEALTH. JOURNAL OF ARID ENVIRONMENTS. 2000. V. 45. P. 289-304.
Interpretive Summary: This study was undertaken to evaluate indicators of rangeland health that were robust indicators in Chihuahuan Desert rangeland in Great Basin rangelands. The most useful indicators of rangeland health in the Chihuahuan Desert rangelands were size of bare patches, vegetation cover and average height of the vegetation and species composition of the vegetation. These indicators were less useful in Great Basin rangelands. The most useful indicator was cover of native bunch grasses, which was an indicator of the potential for livestock production. Because of the potential for exotic weeds such as Bromus tectorum (cheat grass) to flourish following winters with good snowfall it is recommended that, in the Great Basin, measurement of indicators of rangeland health include cover of exotic grasses and weeds as an indictor of the potential for devastating range wild fires. It was also recommended that soil indicators include some measure of the stability of cryptogamic (algal and lichen) crusts because cryptogamic crusts are so important to the stability and fertility of Great Basin soils.
Technical Abstract: Early-warning indicators of rangeland health can be used to estimate the functional integrity of a site and may allow sustainable management of desert rangelands. The utility of several vegetation canopy-based indicators of rangeland health at 32 Great Basin rangeland locations was investigated. The indicators were originally developed in rangelands of the Chihuahuan Desert. Soil resources are lost through wind and water-driven erosion mainly from areas unprotected by plant canopies (i.e. bare soil). Study sites in Idaho had the smallest bare patches, followed by sites in Oregon. The more arid Great Basin Sagebrush Zone sites in Utah had the largest bare patches. Several vegetational indicators including percent cover by vegetation, percent cover by life-form, percent cover by sagebrush, and percent cover by resilient species were negatively related to mean bare patch size and are potential indicators of Great Basin rangeland condition. Plant community composition and the range of bare patch sizes were different at sites in the three locations in Idaho, Oregon and Utah. Therefore, expected indicator values are location specific and should not be extrapolated to other locations. The condition of study sites were often ranked differently by different indicators. Therefore, the condition of rangeland sites should be evaluated using several indicators.