VIDEO: Click here or play button in image above.
TITLE: Prescribed Goat Grazing for Wildland Management
SPEAKERS: Robert Freese, PhD, Senior Project Manager, Irvine Ranch Conservancy and Alissa Cope, Principal Planner and Restoration Ecologist, Sage Environmental Group.
(Introductory biographies are embedded in the video’s audio track).
NOTE: This presentation is an update of a panel discussion about Prescribed Grazing at the 2019 California Invasive Plant Council Symposium. Updates include 2020 status of the two case studies…..two success stories.
ABSTRACT: Prescribed grazing involves targeting undesired plants for removal while preventing overgrazing through close monitoring and adaptive management. IRC has collaborated with Sage to explore applications of goat grazing in habitat restoration at two sites.
SAGE: Sage Environmental Group (Sage) owns an in-house herd of goats used to suppress invasive plants and remove fire fuel load. Herd ownership is unique for an environmental planning firm and an advantage to land managers who can rely on grazing activities that are planned and implemented from a scientific and reguIatory compliance perspective in accordance with local conservation plans.
IRC. Irvine Ranch Conservancy (IRC) manages 30,000 acres of wildlands in Orange County, CA and practices landscape-scale restoration with the goal of creating resilient and diverse habitats. Priority is given to restoring ecosystem processes whenever possible.
CASE STUDY #1. The first study involves prescribed grazing to reduce thatch cover, selectively remove annual grasses, and increase vigor of purple needlegrass (Stipa pulchra) in a native grassland restoration project. Response of native grasslands to grazing relative to mowing and control plots is examined with respect to cover, density, and vigor (e.g. numbers of inflorescences) of purple needlegrass. Cover of annual grasses and thickness of the thatch layer are also examined.
2020 UPDATE: Grazing removed thatch and increased absolute cover of purple needlegrass from 83 percent (2017) to 91 percent (2019). Non-native vegetation (mostly annual grasses) decreased from 39 percent to 20 percent absolute cover. Grazing created openings for introduction of native forbs. Forb cover was poor in 2017 but common in 2019, especially Deinandra fasciculata, Amsinkia menziesii, and Escholtzia californica. All success criteria were met and sign-off was obtained in July 2020.
CASE STUDY #2. The second study involves intensive, multi-year grazing to deplete the weed seed bank and prepare sites for direct seeding with native species. This project is a recent experiment being tried in locales where use of synthetic herbicides is not an option. Preliminary data include percent removal of annual grasses and broad leaf weeds, thatch reduction, and presence of viable seeds within fecal pellets. Results will be compared with data from adjacent mowed plots. In both projects, the timing, duration, and frequency of grazing with respect to grass and weed phenology need to be carefully considered.
2020 UPDATE: One season of grazing reduced the extent of annual grasses that germinated the following spring. The extent of non-native forbs that germinated the following spring remained high. Additional seasons of grazing are needed for control. Thatch removal by grazing allowed a proliferation of native annual forbs.