Submitted to: Society for Range Management Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 8/17/2009
Publication Date: 2/8/2010
Citation: Harmon, D.N., Clements, C.D. 2010. Revegetation Potential of Great Basin Native Annuals and Perennial Grasses: Does Facilitation Occur? [abstract]. Society for Range Management. 63:64.
Technical Abstract: Revegetation of degraded Great Basin rangelands is a challenging task. In an already unforgiving environment the addition of exotic invasive annual weeds, such as cheatgrass (Bromus tectorum) have added to this challenge. Increasing interest in plant facilitation research has suggested using native annuals to facilitate in the establishment of desirable later successional perennial species. Our first question was what native annual species has the potential to establish in various habitats through common seeding techniques, and secondly does the establishment of annual species increase the establishment of desirable perennial species. We tested 25 native annuals at five sites with differing soils, plant communities and invasive plant presence. Six levels of seed mix diversities were used for comparisons including a perennial grass only mix and increasing diversities of native annuals. We included many novel native annuals to observe their role in revegetation and succession. Results yielded that perennial grasses established more than any of the native annuals seeded in this experiment, 1.3/m² compared to 0.7/m², respectfully. Very little native annual establishment occurred at all, which was observed similarly in naturally occurring stands in 2009, which indicates that even with artificial seeding the highly sporadic establishment of such annuals is likely. Only at the harshest sites that support very little perennial vegetation did the annuals establish more than the perennials, grass 0.67/m2, annual 4.0/m2, respectfully. Our results indicate no evidence of facilitation of increased grass establishment with and without annuals, 0.5/m2 and 1.3/m2, respectively.