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ARS Home » Plains Area » Las Cruces, New Mexico » Range Management Research » Research » Publications at this Location » Publication #329859
Title: Can ecological land classification increase the utility of vegetation monitoring data

Author
item WILLIAMSON, JEB - New Mexico State University
item Bestelmeyer, Brandon
item MCCLARAN, MITCHEL - University Of Arizona
item ROBINETT, DAN - Non ARS Employee
item BRISKE, DAVID - Texas A&M University
item WU, X. BEN - Texas A&M University
item FERNANDEZ-GIMENEZ, MARIA - Colorado State University

Submitted to: Ecological Indicators
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/18/2016
Publication Date: 10/1/2016
Citation: Williamson, J.C., Bestelmeyer, B.T., McClaran, M.P., Robinett, D., Briske, D.D., Wu, X., Fernandez-Gimenez, M.E. 2016. Can ecological land classification increase the utility of vegetation monitoring data. Ecological Indicators. 69:657-666.

Interpretive Summary: Vegetation dynamics in rangelands and other ecosystems are known to be mediated by soils. Vegetation monitoring programs, however, often do not consider the impact of soils on patterns observed. Ecological sites (ES) comprise a land classification system based on soil, topographic, and climate variations that can be readily applied by land managers to classify soil and climate properties at monitoring locations. We used a long-term (>40 y) vegetation record from southeastern Arizona, USA to test the utility of an ES classification for refining interpretations of monitoring data in an area of relatively subtle soil differences. We focused on two phenomena important to rangeland management in the southeastern Arizona region: expansion of the native tree velvet mesquite (Prosopis velutina Woot.) and spread of the introduced perennial grass Lehmann lovegrass (Eragrostis lehmanniana Nees). Specifically, we sought to determine if a quantitative, ES-specific analysis of the long-term record would (1) improve detection of changes in plant species having heightened ecological or management importance and (2) further clarify soil effects on vegetation change. We found that ES class membership was a significant factor explaining changes in velvet mesquite canopy cover, Lehmann lovegrass basal cover, and Lehmann lovegrass density measurements.

Technical Abstract: Vegetation dynamics in rangelands and other ecosystems are known to be mediated by topoedaphic properties. Vegetation monitoring programs, however, often do not consider the impact of soils and other sources of landscape heterogeneity on the temporal patterns observed. Ecological sites (ES) comprise a land classification system based on soil, topographic, and climate variations that can be readily applied by land managers to classify topoedaphic properties at monitoring locations. We used a long-term (>40 y) vegetation record from southeastern Arizona, USA to test the utility of an ES classification for refining interpretations of monitoring data in an area of relatively subtle soil differences. We focused on two phenomena important to rangeland management in the southeastern Arizona region: expansion of the native tree velvet mesquite (Prosopis velutina Woot.) and spread of the introduced perennial grassLehmann lovegrass (Eragrostis lehmanniana Nees). Specifically, we sought to determine if a quantitative, ES-specific analysis of the long-term record would (1) improve detection of changes in plant species having heightened ecological or management importance and (2) further clarify topoedaphic effects on vegetation trajectories. We found that ES class membership was a significant factor explaining spatiotem-poral variation in velvet mesquite canopy cover, Lehmann lovegrass basal cover, and Lehmann lovegrass density measurements. In addition, we observed that the potential magnitude of velvet mesquite and Lehmann lovegrass increases varied substantially among ES classes. Our study brings attention to a practical land management tool that might be called upon to increase the effectiveness of vegetation-based indicators of ecosystem change.