2018/02/09 by Arceo, Martin, Content-Castro, Riley, Jougla, Jacques +1
#cattle #ecology #grazing #native plant persistence #range management
paper · doi:10.21973/n3ww8c
There is ongoing debate over the effectiveness of cattle grazing as a prospect for plant community conservation. Since the National Park Service acquired the land at Point Reyes Seashore, controversies over whether ranching should continue in the protected area have defined part of the park's public image. Resolving uncertainties over impacts of cattle on the Point Reyes landscape could inform these debates and lead to viable long-term management strategies. In this study, we examine grassland species richness and composition under four different grazing land-use histories throughout the park (active grazing and 17, 39, and 87 years-since-grazing). Results point toward positive effects of active grazing on native forb richness through suppression of the invasive grasses Holcus lanatus and Festuca perennis. We find steep declines in native plant richness and abundances in the early decades following cessation of grazing and subsequent partial recovery of native species over longer timescales. Our research suggests that cattle foraging impacts plants according to functional group more than provenance. Cattle grazing and associated disturbances may have promoted the initial introduction and establishment of exotic plants into the Point Reyes landscape, but with exotic plants now well established throughout California and most native grazers absent or severely declined, new research suggests that cattle fill an important ecological role in promoting coexistence by native species on exotic-dominated landscapes.