Progress 08/21/06 to 11/30/09
Outputs
OUTPUTS: Our results suggest that while herbicide application is effective at reducing brome abundance, there is important site-to-site variation. At one pinyon-juniper site (Crater Hill), herbicide decreased brome abundance even two years after application. At the other pinyon-juniper site (Kolob Terrace), however, the effect of herbicide was dependent on what measure of abundance was used. For example, density of individuals decreased more with herbicide the second year, but biomass at the square meter level stayed the same even as biomass in control plots decreased the second year. In Zion Canyon, small-scale experiments showed that burning followed by fall application of herbicide resulted in similar cover of brome as we report here (O'Neil 2008; Matchett et al. 2009). Those studies suggest that burning is more effective than other methods of biomass removal (i.e., mowing), particularly when followed up with fall herbicide application. This has interesting implications for the timing of herbicide spray following wildfire. PARTICIPANTS: Not relevant to this project. TARGET AUDIENCES: Not relevant to this project. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
The fifth and sixth seasons of data collection on vegetation communities were completed. Data from these two season may be somewhat at odds with previously seasons due to extremes in the weather. The spring (fifth) season was characterized by wet, cold conditions and plants were less developed at the time of sampling. The fall (sixth) season followed an extremely dry summer with virtually no late-summer/early fall monsoonal moisture. As a result, all plants were in a desiccated condition during the time of data collection.
Publications
- No publications reported this period
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Progress 01/01/07 to 12/31/07
Outputs
In FY 2007 we were able to sample over 150 plots in both the fall and this spring. This includes 12 blocks with 4 plots each at the Kolb Terrace site. This study area is designed to assess the effectiveness of the seeding treatment, the herbicide spraying and the combination of the two against a control plot. The Dalton wash site is the one grassland/shrubland area and includes 30 smaller paired plots (60 plots total) at this site. This area is only assessing the effect of the herbicide. The last site is Crater Hill, which also consists of 26 paired plots, but these plots are 5 meters by 30 meters. During the fall of 2007 we sampled all the above plots and cleared all the necessary park permits for doing this work. This included cover and density data for all species within 5 subsample frames in all the plots. In addition, biomass data was collected at all three sites. Soil samples for texture and chemistry analysis along with seedbank samples were taken at the Kolob
Terrace and Dalton wash sites. The seedbank samples allow the current seedbank study to continue. Soil samples collected fall 2007 have been growing in the greenhouse since since May 2007 and is still on-going. Soil samples for the seedbank study from Fall 2006 are in their last cycle and will be done in the next month or so. In May and June of 2008, all the sites will again be sampled. This includs cover, density and biomass data. Soil samples from the spring of 2007 are processed except for one test (total nitrogen), all biomass from spring 2007 is processed and the fall 2007 is 50% processed. Biomass processing will be completed by July 2007. In addition to the above accomplishments, a database was created, plant identification was verified, and herbarium samples were collected for plant species. Coordination with park staff was done and written updates and presentations on the project were given. Creation of a Fire Effect/ Revegetation working herbarium has been coordinated with
park staff. GIS data on plot locations were finalized and have been shared with the park. All permits for data collection in 2007 were also taken care of.
Impacts
Cheatgrass is a major threat to many vegetation types in the West (Brooks and Pyke 2001, Evans and Young 1975), particularly in vegetation types that historically have longer fire return intervals. Since cheatgrass creates a continuous layer of fuel that is susceptible to burning every year, many vegetation types are at risk of a complete type change. This is the case with Pinyon/Juniper (Evangelista et al. 2004). Evidence of fire return intervals in Pinyon/Juniper range from 150-400+ years between fires (Floyd et al 2004, Baker and Shinneman 2004). One approach to control cheatgrass post-fire has been seeding with natives (Beyers, J.L. 2004, Young and Allen 1997). These efforts have shown reductions in cheatgrass in the short-term but the advantages are not expected to last since cheatgrass is still present at high levels. Recently, the use of the herbicide PlateauTM has shown promise in battling cheatgrass, and has been applied by itself and in combination with native
seeding (JFSP#05-2-1-13, unpublished data). The existing studies on PlateauTM and cheatgrass are small scale experiments. The landscape application of PlateauTM across an entire burned area is a first, and such methods for battling cheatgrass need to be well monitored for effectiveness. In addition, if PlateauTM is more effective than other methods used for battling cheatgrass, an understanding of when to use just PlateauTM and when to use PlateauTM with follow-up seeding is needed. There are many issues surrounding seeding that make it difficult and expensive, and there are ecological risks of gene pool contamination and additional invasive species contamination (Beyers 2004, Keeley et al 2006).
Publications
- No publications reported this period
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Progress 01/01/06 to 12/31/06
Outputs
This project monitors the effectiveness of two treatments, seeding and herbicide spraying, in reducing or eliminating cheatgrass (Bromus tectorum). There are three research cites as part of this study: the Kolob Terrace site, the Dalton Wash site and the Crater Hill site. This is the first landscape scale application of herbicide (about 8,000 acres) to control cheatgrass and thus monitoring the effects of this treatment is critical.
Impacts
In FY 2006 we were able to put in 168 plots for this work. This includes 12 blocks with 4 plots each at the Kolb Terrace site. This study area is designed to assess the effectiveness of the seeding treatment, the herbicide spraying and the combination of the two against a control plot. The Dalton wash site is the one grassland/shrubland area and thus has smaller plots. There are 30 paired plots (60 plots total) at this site. Creating controls at this site included covering 30 plots with plastic and then removing the plastic within 24 hours of the herbicide spraying. This area is only assessing the effect of the herbicide. The last site is Crater Hill, which also consists of 30 paired plots, but these plots at 5 meters by 30 meters. During the fall of 2006 we put in all the above plots, worked with the park and helicopter crews to ensure the integrity of our control plots and cleared all the necessary park permits for doing this work. In addition, soil samples were
taken at the Kolob terrace and Dalton Wash sites for a seedbank study. This study has been in the greenhouse since Feburary 2006 and is still on-going. In the spring of 2006, all the sites were sampled. This included cover and density data for all species within 5 subsample frames in all the plots. In addition, biomass data was collected at the Kolob Terrace and Dalton Wash sites. Soil samples for texture and chemistry analysis were also taken at these two sites. Soil samples are about 50% processed and the biomass is about 50% processed from the spring sampling season. The goal is to have this all done before the fall sampling season in October 2007. In addition to the above accomplishments, a database was created, data loggers were set-up and herbarium samples were collected for plant species. Coordination with park staff was done and updates on the project were given. GIS data on plot locatations were finalized and have been shared with the park. All permits for data collection in
2007 were also taken care of.
Publications
- No publications reported this period
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