Research

***AS OF SUMMER 2017, THIS IS AN OLD SITE. PLEASE VISIT THE NEW GORNISH LAB SITE AT THE UNIVERSITY OF ARIZONA: gornish.arizona.edu ****

 

Ecology and restoration of rangelands after catastrophic wildfire

As a result of global change, the intensity and frequency of wildfires occurring in California rangelands are increasing. Subsequently, there is a pressing need for effective restoration approaches that address the ecological and agricultural nuances of these working landscapes after a fire event. On the 6,800 acre Bobcat Ranch in Winters, CA, we are conducting several experiments to understand the interplay among fire, plant community stability, grazing and restoration. ‘We are following trajectories of plant community response to fire on historically grazed and historically ungrazed plots to understand how the presence of grazing might modify community processes after disturbance. With exclosure experiments we are also documenting how previously grazed plant communities respond to different grazing management techniques after a fire in order to develop effective post-disturbance grazing approaches. Finally, we are testing different seed mixes and deployment strategies to investigate practical solutions to applied disturbance recovery.

researchCollaborators
Ken Tate (University of California, Davis)
Leslie Roche (University of California, Davis)
Carissa Koopman-Rivers (Audubon California)

Restoration handout
Natives in annual dominated systems in central CA

 

 

Ecology of Taeniatherum caput-medusae (Medusahead rye)  
The winter annual grass medusahead is one of the dominant invasive range species in the West. A variety of methods have been tested to control the noxious weed, including grazing, herbicide, and fire. However, despite a broad understanding of medusahead impacts, we have a limited understanding of how environmental conditions and management strategies influence medusahead population dynamics. This insight is key if we are to ultimately forecast changes in medusahead abundance and spread under various conditions. Using periodic matrix models, we are investigating how seed density, habitat type (grassland vs. oak woodland), and management strategy (clipping) influence population dynamics of the weed at the Sierra Foothills Research and Extension Center in Browns Valley, CA. We are also investigating how the soil microbiome might play a role in mediating the dominance of medusahead. In case you want a more thorough description provided in an extremely awkward manner, check out our youtube video.

 

researchCollaborators
Hal Caswell (Woods Hole)
Noah Fierer (University of Colorado, Boulder)
Albert Barberán (University of Colorado, Boulder)
Jeremy James (Sierra Foothill Research and Extension Center)

 

 

 

A systems approach to seedling establishment on degraded rangeland: Managing ecological processes driving recruitment bottlenecks
Despite the widely accepted importance of dryland restoration and the enormous financial investments made annually for these activities, restoration success in drylands is low.  We are attempting to understand how the demography of four bunchgrass rangeland restoration species are affected by biotic and abiotic factors across three states in the Great Basin.  Broadly, the goal of this work is to develop, validate and deploy a systems approach for improving establishment of restoration species in arid ecosystems, which cover 40% of the Earth’s land surface. We are using transient analysis, life table response experiments, and integral projection models to understand how invasion, diversity, and microclimate affect vital rates and population growth rates of perennial grasses.

 

researchCollaborators
Jeremy James (Sierra Foothill Research and Extension Center)
Peter Adler (Utah State University)
Stuart Hardegree (USDA ARS)
Roger Sheley (USDA ARS)
Mark Brunson (Utah State University)

 

 

 

Investigating pretreatment approaches for restoration of invaded rangeland habitat
Weed management and soil re-nourishment are two important rangeland restoration pre-treatment techniques. The type, order and magnitude of the pre-treatment approaches can play a dominant role in driving subsequent seeding success. We are conducting a series of experiments on the degraded Yanci ranch, an 800 acre site located on the western edge of the Lower Sacremento Valley. In separate fields across the ranch, we initiated different types (burning, herbicide, grazing by sheep, and mixtures) of pre-treatments on weed dominated grasslands. First, we are investigating the effectiveness of different type and timing of application of these management strategies to reduce the cover of invasive plant species. We are also testing how these pre-treatments affect the germination and survival of native seeded restoration grass species.

 

researchCollaborators
Cory Shake (Point Blue)
John Anderson (Hedgerow farms)
Jaymee Marty (Marty Ecological Consulting)

 

 

 

 

Use of Census Data to Inform Oil Spill Effects on Gulf Coast Dune Vegetation
The oil spill from the Deepwater Horizon accident will have significant effects on the ecology of the Gulf of Mexico and recent history shows these effects on marine and coastal communities will continue over the next several decades. We are collecting critical data on the effects of the Deepwater Horizon oil spill on the vegetation of the coastal beaches and dunes all along the expected impact zone of the NE Gulf of Mexico. Sampling occurs at six long-term coastal sites for vegetation studies, using methods consistent with current studies on St. George Island, Florida, conducted since 1998.

 

researchCollaborators
Thomas Miller (FSU)