Project : USDA ARS

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Research Project: Restoration and Conservation of Great Basin Ecosystems

Location: Range and Meadow Forage Management Research

2023 Annual Report

Objectives
The long-term objective of this project is to develop practices and strategies to restore and conserve Great Basin rangelands. Specifically, during the next five years we will focus on the following objectives: Objective 1 (Restoration): Develop practices and strategies for restoring perennial livestock forages and ecosystem function on degraded and fire-prone Great Basin rangelands using combinations of grazing management, vegetation treatments, seed enhancements, and traditional restoration techniques. Subobjective 1A: Develop seed enhancement technologies for overcoming barriers to rangeland seeding success. (Davies, Boyd, Copeland) Subobjective 1B: Determine appropriate seed mixes for use after wildfires to limit exotic annual grass invasion and restore productivity. (Davies, Boyd, Copeland) Subobjective 1C: Develop and evaluate management practices for controlling juniper encroachment of sagebrush steppe plant communities. (Bates, Davies) Subobjective 1D: Determine post-treatment change in vegetation composition and structure over a 30 year time horizon in cut compared with burned juniper-encroached sagebrush steppe. (Boyd, Bates, Davies) Objective 2 (Conservation): Develop practices and strategies (including decision-support tools) to maintain and enhance livestock forage production and other ecosystem services in rangelands across different site characteristics, climate conditions, and management systems. Subobjective 2A: Evaluate grazing management as a tool to decrease wildfire risk, behavior, and severity. (Davies, Bates, Boyd, Copeland) Subobjective 2B: Evaluate post-fire grazing management effects on herbaceous productivity and sage-grouse habitat. (Bates, Davies) Subobjective 2C: Determine the influence of site attributes and climate variation on long-term productivity and diversity of sagebrush steppe. (Bates, Davies, Copeland) Subobjective 2D: Develop a science-based framework for management planning. (Boyd, Bates, Davies) Subobjective 2E: Use precision management technologies (global positioning of livestock, virtual fencing, remote sensing of landscape and others) to enhance livestock producer capability for optimum management of pastures and rangelands, balancing production and ecosystem services.

Approach
Objective 1: Hypotheses: 1) Incorporating seeds into activated carbon pellets will protect seeded vegetation from pre-emergent herbicides, 2) Seeds treated with abscisic acid will have delayed germination and increased seedling density relative to non-coated seeds, 3) Coating and imbibing treatments will produce similar seedling densities, 4) The effects of abscisic acid treatment will be dependent on level of coating; based on previous lab work we hypothesize that intermediate levels of treatment will produce highest seedling densities, 5) Drill seeding a mixture of native and introduced bunchgrasses after wildfire in sagebrush steppe will reduce exotic annual grass invasion compared to seeding native bunchgrasses, seeding introduced bunchgrasses, and not seeding, 6) Burning juniper-encroached sagebrush steppe will increase desirable herbaceous production, 7) Herbaceous vegetation productivity and abundance will be greater when juniper is controlled with either fall broadcast burning treatment or clear-cut/slash burning treatment compared to untreated woodlands, 8) Clear-cut/slash burning of encroaching junipers will produce more favorable habitat characteristics for sage-grouse compared to fall broadcast burning, 9) Juniper cover and density will increase at a faster rate in cut vs. burned western juniper plant communities, 10) Cover and density of mountain big sagebrush will decrease in association with burning but will recover to levels in cut treatments within 30 years, 11) Rate of increase in density and cover of large perennial bunchgrasses will be faster in burned vs. cut treatments, and 12) exotic annual grasses will initially increase more in the burned compared to the cut treatment. Objective 2:Hypotheses: 1) moderate livestock grazing compared to grazing exclusion will reduce fine fuel continuity, height, total biomass, and accumulation of residual biomass on perennial grass crowns and 2) decrease fire-induced mortality of perennial grasses and thereby reduce post-fire exotic annual grass invasion, 3) increasing grazing pressure will reduce fuels and thereby decrease fire ignition potential and propagation, 4) Long-term heavy rotational grazing after fire will decrease herbaceous productivity, sage-grouse dietary forbs, and horizontal screening cover compared to light, moderate, and no grazing treatments, and 5) No grazing and light grazing will have greater herbaceous productivity, sage-grouse dietary forbs, and horizontal screening cover than moderate grazing. Experimental approaches and research procedures: We will use a combination of grow room studies and small and large replicated field studies to answer these research questions. Many of these field studies will be long-term studies. If initial research plan is unsuccessful, we will revise our grow room and field studies to address the reasons why our initial research plan was unsuccessful or replicate the original experiment if it was unsuccessful because of an act of nature.

Progress Report
In support of Objective 1, ARS scientists in Burns, Oregon, collected data on grow room and field experiments designed to test the effectiveness of activated seed coatings and carbon pellets at protecting seeds from pre-emergent herbicide damage. Researchers prepared a peer-reviewed manuscript on the effects of activated carbon pellets and seed coatings on species. Researchers also collected data on grow room and field plots designed to evaluate coating and imbibing seeds with abscisic acid to delay germination. They prepared a peer-reviewed manuscript on new strategies for restoration in the face of variable climatic conditions. Researchers and support staff collected data on experiments evaluating drill seeding native compared to non-native grasses after wildfire and experiments investigating the effects of burning juniper on herbaceous production. They prepared a peer-reviewed manuscript on the effects lagomorph herbivory on restoration efforts in sagebrush steppe communities. In support of Objective 2, ARS researchers continued to collect data on experiments designed to evaluate grazing management as a tool to decrease wildfire probability, behavior, and severity. The researchers prepared peer-reviewed manuscripts on the effects of the interaction between grazing and fire on fire probability and post-fire recovery. They continue to evaluate the effects of different grazing intensities after fire in sagebrush steppe communities. The researchers prepared peer-reviewed manuscripts on the effects of grazing after fire in annual grass invaded and non-invaded sagebrush steppe communities. Lastly, the researchers continue to develop management-oriented materials to guide rangeland and riparian area management based on ecological threats and the influence of management and non-management factors on plant community change.

Accomplishments
1. Using precision agriculture to manage livestock grazing distribution and fuels on fire-prone rangelands. Ameliorating the occurrence of wildfire is a generational-level challenge for rangeland managers across the western United States. Management of livestock grazing distribution is critical before a fire for fuels management. Managing livestock on fire-prone landscapes is complicated by reliance on existing fences which may not be distributed to facilitate targeted reduction of spatially and temporally dynamic fuels. ARS researchers from Burns, Oregon, have pioneered the use of virtual fencing technology for proactively creating fuel breaks with livestock grazing before fires occur. Their current research focuses on linking satellite-derived estimates of fuel loading/fire likelihood with virtual fencing technology to create a precision fuels management system that is both strategic and defensible within a public lands context. ARS researchers from Burns, Oregon, are receiving a large volume of calls and presentation requests as land managers are integrating this technology in their management and other researchers are conducting similar experiments.

2. Grazing effects on fuels and fire probability vary by community type and grazing intensity. Increased wildfire frequency, size, and severity is threatening western U.S. rangelands. Grazing by livestock shows promise for being a tool to manage fuels and subsequently wildfire probability and severity. ARS researchers from Burns, Oregon, found that grazing can substantially reduce fuels and fire probability; however, grazing effects vary by community type and grazing intensity. Grazing was most effective at reducing fuels and fire probability when applied at moderate and heavy levels. This research provides natural resource managers with new information to apply grazing to reducing wildfire probability and severity.

U.S. DEPARTMENT OF AGRICULTURE

Range and Meadow Forage Management Research: Burns, OR