Progress 07/01/06 to 09/30/11
Outputs
OUTPUTS: Work under this project has resulted in numerous talks. This is including local presentations to landowners and land management professionals as well as inclusion of the owrk in lcassroom discussions. The work was included in several national presentations as well. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
This project resulted in knowledge about the challenges and benefits of returning some diversity to near monocultures of invasives. The challenges were especially useful since most available methods for restoring natives to invaded lands do not work. Better specification of the challenges spawned other research.
Publications
- Stevens, J. and J.S. Fehmi. 2011 Early establishment of a native grass reduces the competitive effect of a non-native grass. Restoration Ecology, 19: 399-406.
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Progress 01/01/10 to 12/31/10
Outputs
OUTPUTS: Several efforts are under way to include removal of mesquites to determine those effects as well as the original planting efforts. The main outcomes have been recommendations to regional land managers and those in similar climates. The two main recommendations have been to start at a small scale if possible and to plan for multiple years of effort. These findings have been disseminated though public forums, conference presentations, and publications. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
The research appears to be having some impact. Several large local reclamation efforts have adopted the recomendations derived from the study. There are numerous publications in preparation which will increase the impact.
Publications
- No publications reported this period
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Progress 01/01/08 to 12/31/08
Outputs
OUTPUTS: The research plots were monitored again. This field work evaluated native density, invader density (mostly Lehman lovegrass - Eragrostis lehmanniana Nees), and overall plant cover. All plots were again photographed. An initial evaluation of the data showed that there was no significant difference between the treatment plots which were seeded with field collected natives and the control plots that were treated identically except no seeding was done. This was expected after the previous years evaluations but if natives had survived, they would be much more readily visible now than as 1 leaf seedlings on a 16 m2 plot. This project was featured in the Audubon Research Ranch Annual report. PARTICIPANTS: Partner organization: Appleton-Whittell Research Ranch of the National Audubon Society, HC 1 Box 44, 366 Research Ranch Rd., Elgin, Arizona 85611 TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: The approach and assessment of ecosystem services has been reduced due to lack of funding and failure of the treatment.
Impacts
A proposal for outside funding was submitted to evaluate ways of suppressing the Lehmann lovegrass seed bank to better be able to establish native species. Related work has show that the natives are able to compete with the invaders of given a small head start and adult plants show few effects of competition with seedling invaders. The critical factor seems to be the ability of Lehmann to quickly fill any available space. Some observational data indicated that there was some seed predation by ants as well.
Publications
- No publications reported this period
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Progress 01/01/07 to 12/31/07
Outputs
OUTPUTS: Danthonia californica seed and soil inoculum was collected 45 km south of Tucson, AZ at the Santa Rite Experimental Range and added to "Cone-Tainer" cells containing sterile soil. Soil was collected from under 5 separate canopies of mature D. californica. Cells were randomly inoculated with water sieved through the field soil or water sieved through sterile field soil. Cells were watered as needed to provide adequate moisture for germination and subsequent growth. Subsets of plugs were either transplanted into 3.7 gallon pots of pasteurized soil or at a field site in Tucson where watering was decreased to assess inoculation effects emergence, tiller recruitment, biomass, reproductive output, and water stress. Soil analysis showed 1 VAM (vesicular arbuscular mycorrhizae) spore/g soil inoculum, however a root colonization analysis showed that plants inoculated with field soil and plants inoculated with sterile field soil both had 0% root infection by VAM fungi. Greenhouse
results suggest that soil inoculation may improve seedling emergence and drought hardiness, but result in a decrease in tiller recruitment, above and below ground biomass, and reproductive output. In areas of sporadic, pulse-like rainfall events, inoculating D. californica may increase establishment as a result of faster germination times (figure 1). When time intervals between rainfall events increase, earlier germination and emergence allows seedling to take advantage of available moisture near the soil surface.
PARTICIPANTS: Stevens, J. Graduate Student Kennedy, L. The Appleton-Whittell Research Ranch (ARR) - a cooperative partnership among the National Audubon Society, U.S. Forest Service, Bureau of Land Management, The Nature Conservancy, and The Research Ranch Foundation.
PROJECT MODIFICATIONS: The project is moving away from using only blue grama and is now including other native perennial grass species.
Impacts
The information from this project was featured in the Tucson Plant Materials Center's (USDA-NRCS) Report of Activities. The work was also presented at the annual meeting of the Ecological Society of America (ESA).
Publications
- No publications reported this period
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Progress 01/01/06 to 12/31/06
Outputs
Blue Grama (Bouteloua gracilis), a palatable native, was planted into the treated plots with seed locally-harvested from a nearby site in the year prior to planting. The nearly homogenous matrix invasive grass, Lehmann Lovegrass (Eragrostis lehmanniana), was mowed, allowed to sprout, and sprayed with a systemic herbicide (glyphosate) to remove it from both the treated and control plots. The Blue Grama seeding rate was 4 times the normal recommendation and the rainfall year was sufficient to establish Blue Grama. Results - There was no effective Blue Grama establishment within any plot of any of the three sizes in any of the 4 replications. The average density of Lehmann Lovegrass seedlings was a little more than 1 per cm2 (which is very high). Plant restoration seeding failures are not uncommon and represent a research opportunity to look at all the potential factors that can cause this type of seeding failure. The experiment will be repeated again in the coming
growing season with an effort to determine if seed predators or seedling herbivory were the cause of the planting failure. Local residents suggested that ants consume much of the seeds of natives since native seed is a highly preferred food compared to the Lehmann seed. While it seems somewhat less likely as a full explanation because the planted seed was raked into the soil, this hypothesis will be tested for this site along with tracking the fate of germinated plants. The impacts of soil microorganisms on germination and drought tolerance are also being tested for the locally collected Blue Grama seeds. The Lehmann dominated sites may lack symbiotic organisms important for Blue Grama success.
Impacts
This project may allow the reestablishment of native grasses into otherwise invader dominated grasslands.
Publications
- No publications reported this period
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