Ecosystem degradation and carbon sequestration are two of the most pressing land management issues we face today. To address these challenges, we need creative solutions that promote resilient landscapes. Prescribed herbivory or managed grazing is a cost-effective and scalable land management strategy that can help us achieve conservation and carbon sequestration goals. According to the US Department of Agriculture, well-managed grazing systems can improve the health and vigor of native plants, enhance the quality and quantity of water, reduce soil erosion, and support carbon sequestration. However, overgrazing can have negative impacts, such as reducing native plant cover, disturbing soils, and promoting invasive plant overgrowth. Channel Islands Restoration is a nonprofit organization that works to restore habitat on California’s Channel Islands and central coast, and has been navigating this land management strategy in recent years. The San Marcos Foothills Preserve, managed by Channel Islands Restoration, primarily comprises native grassland habitat (204.6 acres) and supports one of the largest and best-remaining grasslands in California’s central coast region. In 2018 and 2022, the organization conducted baseline vegetation monitoring of the site to assess grazing efficacy and impacts on the preserve before and after a 3-year grazing period from 2019 to 2021. In 2022, a new West Mesa portion of the site was acquired but has not yet been grazed. This provides a natural experiment to compare the effects of long-term grazing on native vegetation cover and variability by assessing fluxes in native species cover, bare ground, and thatch levels. While our results are still in the preliminary stages of analysis, our vegetation monitoring data collected from 8 sampling zones suggests that prescribed herbivory has led to an overall increase in native grass cover by an average of 12%, with special attention drawn to an increase in Purple Needlegrass (Stipa pulchra) communities. By completing this study, we hope to gain a more informed perspective on improved land management practices for prescribed grazing of native grass species at the San Marcos Foothills and determine the efficacy of grazing in achieving long-term grassland resiliency.
