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United States Department of Agriculture

Agricultural Research Service

Research Project: DISTURBANCE ASSESSMENT AND MITIGATION OF GREAT BASIN RANGELAND

Location: Northwest Watershed Management Research

2008 Annual Report


1a.Objectives (from AD-416)
The overall objective of this research project is to improve scientific understanding to transfer technology related to assessing and mitigating the impacts of ecological disturbances by invasion-weeds,fire and predation on rangeland water, vegetation and animal resources within sagebrush ecosystems of the Intermountain West. The aim is to provide sound science-base information and management tools in support of private and public land management activities. Specific research objectives inclued:.
1)Develop strategic management tools and guidelines for use in fire impact assessment and rehabilitation planning of sagebrush ecosystems of the Intermountain West to aid land managers in determining the location, severity and persistence of fire impacts on post-fire runoff/erosion..
2)Improve guidelines and methods for monitoring and assessing impacts of juniper encroachment and management on plant, soil and water resources in sagebrush-steppe ecosystems to enhance efficiency and success in action agency planning and implementation of juniper-control treatments throughout the Intermountain West:.
3)Develop methodology for classifying seedbed microclimate and identify microclimatic thresholds for successful germination and early establishment of seeded grass species in sagebrush-steppe ecosystems to improve success of rangeland restoration efforts across the Intermountain West: 4)Evaluate the effects of landscape-scale disturbance such as fire, invasive plants, and predation on livestock productivity and livestock use of stream systems and other critical resouces of sagebrush-steppe ecosystems throughout the Intermountain West so producers and land managers can employ adaptive management and better plan for changes in animal resources use and productivity.


1b.Approach (from AD-416)
A suite of hydrology, vegetation, remote sensing and animal behavior experiments will be conducted from point to landscape scales to improve scientific understanding and produce technology for managing impacts of ecological disturbances by fire,invasive-weed and predation within sagebrush ecosystems of the Intermountain West. This research project will deliver products to aid land managers in conducting fire impact risk assessments, inventory and assessing the impacts of juniper encroachment, planning and implementing juniper-control treatments, determining seedbed-microclimatic requirements for establishment of native and introduced rangeland-grass species appropriate plant species and optimal planting time for post-fire rangeland rehabilitation and restoration treatments, evaluating livestock behavioral response and resource use following disturbance and establish appropriate post-fire livestock grazing strategies. Outcomes of this project help to assesss and quantify environmental benefits of conservation practices and improve action agency land use planning and management activities. Resultant benefits include potential savings of millions of dollars in wildfire mitigation,improve water quality by reducing sediment delivery to streams, reduced loss of forage for livestock and wildlife from juniper and cheatgrass invaion, improved species diversity and wildlife habitat, and greater livestock productivity from rangeland systems.


3.Progress Report
DISTURBANCE ASSESSMENT AND MITIGATION OF GREAT BASIN RANGELANDS: This report serves to document research progress for CRIS Project 5362-13610-009-00D, which was initiated in February 2008. The goal of this research project is to deliver products to land managers for conducting fire impact risk assessments, inventorying and assessing the impacts of juniper encroachment, planning and implementing juniper-control treatments, determining seedbed-microclimatic requirements for establishment of native and introduced rangeland-grass species, selecting appropriate plant species and optimal planting time for post-fire rangeland rehabilitation and restoration treatments, evaluating livestock behavioral response and resource use following disturbance, and establishing appropriate post-fire livestock grazing strategies. Field studies on the impacts of wild and prescribed fire on hillslope hydrology and erosion in steep sagebrush systems showed that fire had the greatest long-lasting impacts concentrated overland flow dynamics and resultant erosion rates. Data from numerous field studies using rainfall and overland flow simulation techniques are being combined to provide the basis for parameterizing the rill components of the RHEM model. Field sites have been selected and initial field data on juniper impacts on hillslope hydrology have been collected from three locations across the Great Basin. The Light Detection and Ranging (LiDAR) flight scheduled for FY 2007 was implemented in October, 2007. The Northwest Watershed Research Center (NWRC) is monitoring field plots to characterize juniper canopy characteristics and provide ground-truth validation of LiDAR remote sensing products. These data will be used to evaluate the utility of LiDAR for monitoring juniper distribution and invasion trajectories. During the past CRIS cycle, NWRC instrumented 4 juniper-dominated watersheds in southwestern Idaho for long-term monitoring prior to juniper control. The watersheds are now fully instrumented, data collection protocols have been established, and data error checking routines are being developed. The NWRC used thermal-response models to predict relative variability in field performance of 41 accessions of bottlebrush and big squirreltail, and multiple collections of cheatgrass as a function of measured and simulated variability in field temperature and moisture. This research demonstrated significant regional differences in response of native plant materials and relatively uniform response of diverse collections of annual weed seeds. Data on the long-term change in livestock utilization patterns following prescribed fire on the RCEW are continuing to be collected. Long-term data collection efforts on livestock utilization patterns in the presence of large predators are also continuing. Improved GPS-based animal tracking systems with greater data-storage capacity, global communication satellite coverage, 2-way collar-user communication, and transmitted data throughput necessary for true, real-time tracking of free-ranging animals are being field-tested on free-ranging reindeer (Alaska) and beef cattle (Idaho/Oregon). NP215, Component 1.


4.Accomplishments
1. SOIL WATER REPELLENCY AND INFILTRATION IN BURNED AND UNBURNED SAGEBRUSH ECOSYSTEMS Land managers often assume that soil water repellency induced by burning greatly reduces infiltration of water into surface soils after fire resulting in increased runoff and erosion rates. Multiple studies, by ARS scientists in the Watershed Management Research Unit in Boise, ID, on burned and unburned sagebrush sites showed that soil water repellency and infiltration capacity were highly variable over time and that unburned sites had greater water repellency and lower infiltration than burned sites. These results are contrary to common belief that fire increases soil water repellency and will improve application of fire runoff and erosion mitigation practices on sagebrush dominated landscapes. This research supports ARS Rangeland, Pasture and Forages National Program 215, Component 1, Problem Area A.

2. A DIRECT APPROACH TO QUANTIFYING STREAM SHADING Existing field and analysis techniques for assessing stream shading require costly equipment and instrumentation and only make indirect assessments. The ARS scientists in the Watershed Management Research Unit in Boise, ID developed and evaluated new, effective, and low-cost field and image analysis techniques for assessing stream surface shading from digital images. These research products will allow researchers, natural resource managers, and environmental quality regulators to more efficiently and effectively monitor stream shading and investigate its relationship with stream temperature variability. This research supports ARS Rangeland, Pasture and Forages National Program 215, Component 1, Problem Area A.

3. PREDICTION OF RANGELAND GRASS ESTABLISHMENT UNDER FIELD TEMPERATURE AND MOISTURE CONDITIONS It is difficult to predict the successful establishment of rangeland grass due to the high variablity in seedbed temperature and moisture during the establishment period. The ARS scientists in the Watershed Management Research Unit in Boise, ID used thermal-response models to predict relative variability in field performance of 41 accessions of bottlebrush and big squirreltail, and multiple collections of cheatgrass as a function of measured and simulated variability in field temperature and moisture. This research demonstrated significant regional differences in response of native plant materials and relatively uniform response of diverse collections of annual weed seeds. Regional differences in species used for rangeland restoration may be an important factor in plant-materials selection for rangeland rehabilitation projects. This research supports ARS Rangeland, Pasture and Forages National Program 215, Component 1, Problem Area C.


5.Significant Activities that Support Special Target Populations
None


6.Technology Transfer

Number of Non-Peer Reviewed Presentations and Proceedings1

Review Publications
Hardegree, S.P., Jones, T.A., Pierson Jr, F.B., Clark, P., Flerchinger, G.N. 2008. Dynamic Variability in Thermal-Germination Response of Squirreltail (Elymus elymoides and Elymus multisetus). Environmental and Experimental Botany 62:120-128.

Clark, P., Johnson, D.E., Hardegree, S.P. 2008. A direct approach for quantifying stream shading. Rangeland Ecology and Management.61:339-345.

Pierson, F.B., Robichaud, P.R., Moffet, C.A., Spaeth, K.E., Williams, C.J., Hardegree, S.P., and Clark, P.E. 2008. Soil water repellency and infiltration in coarse-textured soils of burned and unburned sagebrush ecosystems. Catena 74:98-108.

Last Modified: 10/1/2014
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