Larios Ecology Lab

Western Riverside County is currently experiencing a widespread invasion by an annual forb from South Africa, Oncosiphon piluliferum, which we affectionately call Stinknet. Within the last decade, many of the open grasslands in the semi-arid system have been converted to monocultures of this species. Land managers are particularly concerned as much of this habitat is also critical habitat for the endangered Stephen’s Kangaroo Rat. Our lab is leading a multi-pronged effort to understand the ecological impacts of this invasion and management strategies to most effectively control it. Collaborators: Brian Shomo (RCHCA), Joseph Messin (Motte Rimrock Reserve), and Ken Kitzer (CA Parks) Travis Bean (UCR), Chris McDonald (UCCE), Melanie Burlaza, Clarissa Rodriguez, and Stuart Schwab Press: USFWS article

Restoration efforts are regularly nested within a larger mandate to conduct actions that enhance the resilience of a system to future environmental threats. Even though resilience has become an essential goal in environmental policy and management, its application remains largely heuristic as we continue to struggle with how best to assess and measure it. We used an integrative approach where we leveraged experimental and observational studies to parameterize population models to forecast community dynamics that identified multiple stable communities and hysteresis. We were able to project dynamics that can be used to prioritize management efforts of conservation of native grasslands and restoration of exotic grasslands in the face of increasing N deposition. Collaborators: Lauren Hallett & Katie Suding

Increasingly, we are observing that simply removing an invasive species is not sufficient to restore native biodiversity. Further intervention – with a focus on restoration – may be necessary to take into account the impacts an invader has on a system. We use ecological theory to guide these key management questions: when will passive recovery following these invader removal efforts be sufficient to recover desired native communities, and when will active intervention be needed? Collaborators: Katie Suding

After one of the largest wildfires in Orange County, we investigated how landscape dispersal processes may facilitate the invasion of existing native patches by neighboring exotic patches. We monitored plant community composition in paired grassland patches that were initially dominated by native or exotic grasses, starting in a record drought year prior to an intense fire and then for three years with more typical rainfall patterns after the fire. Following the extreme drought/fire disturbance, the exotic annual grasses quickly recovered in abundance in patches that they dominated prior to the disturbance. However, the native grass, Stipa pulchra, was not able to recover in the patches it once dominated. This work suggests that future management strategies that enhance vegetative regeneration of natives and decrease propagule pressure of exotics such as low intensity prescribed fires or introductions of native species via seed addition will be key in maintaining these remnant grasslands. Collaborators: Rebecca Aicher & Katie Suding