Date of Award:
Master of Science (MS)
Plants, Soils, and Climate
Mark W. Brunson
Sagebrush plant communities are among the most threatened in North America. This project had two goals: to test how increased temperature affects native and nonnative forb species common to the Western sagebrush region and to evaluate land manager beliefs about changes in their ecosystems, including those affecting forb species.
Native forbs Sphaeralcea munroana, Crepis acuminata, Linum lewisii, Penstemon palmeri, and Oenothera pallida and non-natives Erodium cicutarium and Lactuca serriola were each subjected to two treatments: experimental warming using open-top chambers and a control. Knowing how forbs used in restoration might respond to future conditions is both practical and economical information for land managers. Responses to an open-top chamber treatment suggest that S. munroana, L. lewisii, and P. palmeri may be resilient to predicted increases in temperature, while C. acuminata and O. pallida should be used with caution. As expected, temperature did not affect E. cicutarium fitness but did lead to earlier germination. This result supports the concept that competitive interactions between non-natives and natives could be compounded by increased temperature. Transplanted L. serriola was negatively affected by warming.
Semi-structured phone interviews of range managers in Utah, Idaho, Nevada, Wyoming, Oregon, and Montana addressed demographics, local climate and land changes, and forb knowledge. Additionally, local long-term climate data sets were compared to responses. Most states respondents were evenly split about beliefs of climate change in their area (half said there were no changes, and have said they thought there were some changes). Montana was the exception; Montana’s recent increases in climate-related events may explain most of the managers noting changes. Managers that had more years at their job gave more qualified, but also more accurate climate answers. Managers saying there was no change tended to base their answers on recent weather conditions, while managers that said they did notice changes tended to base their answers on long-term patterns. Forbs typically were not viewed as an important indicator of ecosystem health or resilience. This study indicates restoration organizations might benefit from more specified outreach to managers which focuses on local climate, forbs (especially those known to be used by Greater sage-grouse), and solutions.
Whitcomb, Hilary Louise, "Temperature Increase Effects on Sagebrush Ecosystem Forbs: Exprimental Evidence and Range Manager Perspectives" (2011). All Graduate Theses and Dissertations. 1044.
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