Rangeland Ecology & Management

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A COMPARISON OF TWO METHODS FOR SAMPLING HERBACEOUS COVER: A RICH COUNTY, UT CASE STUDY.
Author
Thomas, Katherine
Hulvey, Kristin
Thacker, Eric
Coleman, Robert
Publisher
Society for Range Management
Publication Year
2016
Body

Rangelands in the intermountain west provide multiple ecosystem services including sustainable forage for livestock and habitat for sage grouse. Livestock grazing systems that alter the timing and distribution of cattle across the landscape have the potential to affect such services by altering the abundance and composition of rangeland vegetation. One common way to asses such changes is by monitoring herbaceous species cover, although the method used can greatly affect the quality of the data collected and the ability of researchers to answer their identified research questions. In an effort to better understand the relationship between grazing and ecosystem services, we investigated the effects of season long grazing versus rotational grazing systems on the herbaceous vegetation in our study sites. To do this, we evaluated herbaceous species cover along 50 transects using two different methods: Daubenmire and Sample Point photo analysis. While Daubenmire estimates are calculated in the field, Sample Point analysis is performed via computer, by manually identifying species intersected by a one hundred pixel-grid on photos taken along transects. Preliminary data analysis suggests that Daubenmire and Sample Point differ in their ability to accurately assess herbaceous cover in the presence of shrubs. The Daubenmire method allowed us to avoid shrubs since herbaceous evaluation could be assessed beneath the shrub canopy. The photos used for Sample Point, however, were taken above shrub height, and shrub cover obstructs a portion of herbaceous cover during photo analysis. Our findings will enable us to evaluate which method is appropriate for future herbaceous sampling at our Rich County project. More broadly, our results emphasize the need to select cover sampling methods that are appropriate for a site's vegetative community.

Language
English
Resource Type
Text
Document Type
Conference Proceedings
Conference Name
SRM Corpus Christi, TX