With the increase of risk of large, high severity fire across forests in the US, thinning of small trees and shrubs (i.e. fuels reduction treatments) has been widely implemented to reduce fire hazards. Although fuel reduction treatments can reduce the intensities of fire, less is known about the impacts of reducing understory complexity on the small mammal community which is not only an important prey base for larger forest carnivores, but also key in dispersing seeds and fungi. Using capture-recapture techniques, we estimate treatment impacts on the density of different species in the small mammal community within the Sagehen Experimental Forest in the central Sierra Nevada using a Before-After Control-Impact design. Our analysis shows that treatment impacts species differently, consistent with their natural history, but that this response was small relative to interannual variation. This study shows how larger-scale heterogeneity can support the small mammal community while increasing resiliency to forest fire across the landscape.

Sierra Nevada forests provide critical habitat for wildlife and associated biotic communities. Climate change impacts combined with a century of fire suppression are leading to disturbances (fire, drought, pest) that can have differential impacts on forested ecosystems based on their species composition and structure (i.e., their habitat type).  Examining the extent to which the biotic communities within these habitat types are distinct aids in understanding patterns and drivers of community formation, and how they might be sensitive to changes into the future. We developed functional metrics based of trophic interactions (i.e., food webs) to quantify the complexity of biotic communities, and quantify the degree to which habitat types within the Lake Tahoe basin (e.g., Jeffrey pine forest) are distinct in their composition, structure, and function. Results showed habitat types had similar and variable patterns in metrics describing structure and function, indicating that future changes may have variable impacts on habitat types, while the composition of biotic communities was driven by life zone. This highlights the importance of abiotic factors for structuring communities, and potential impacts associated with changing climate, while providing a more comprehensive view of biotic communities, which can help managers steward healthy and resilient habitats.

California’s Mediterranean climate is expected to continue experiencing climate whiplash, going from periods of extreme wet to extreme dry with increasing frequency. The extreme dry periods vary across time and space, making the management of diverse habitats and species assemblages during and after drought periods challenging. Identifying quantitative and reproducible approaches to prioritizing which species may be most vulnerable, and which habitats or localities may be most at risk to both short and long-term drought remains a significant management hurdle. We piloted an effort to quantify the risk to sensitive species and habitats at scale by combining newly developed drought products, such as the Evaporative Demand Drought Index (EDDI), with occupancy records for species of conservation concern, generation time estimates, and range sizes. EDDI provides a measure of how anomalous the atmospheric evaporative demand (E0; also known as "the thirst of the atmosphere") is for a given location and time interval. When combined with species generation time and range size, it enables us to identify where drought exposure is greatest for the species, both in the near- and long-term, and in turn, facilitates science-based prioritization of management and monitoring efforts.

San Clemente Island’s native ecosystems were significantly affected by domestic animal grazing and introduced herbivores. While feral goats (Capra hircus) and pigs (Sus scrofa) were extirpated by the late 1990s, their historic impacts on habitats had lasting negative consequences for imperiled native species such as the endangered San Clemente loggerhead shrike (Lanius ludovicianus mearnsi). Invasive mesopredators – black rats (Rattus rattus) and feral cats (Felis catus) – are present on the island alongside naturalized island foxes (Urocyon littoralis), all of which have been observed preying upon shrike nests. In addition to past and present threats to shrike populations, we must now consider how climate change may challenge shrike conservation on the island. To better understand potential trajectories of the San Clemente loggerhead shrike population under different climate change scenarios, we first quantified the effects of weather on shrike breeding and survival. We then conducted population viability analyses incorporating predictions from our initial modelling effort for current climate conditions, and both moderate and severe climate change projections. We also examined the effects of increased predator management and captive juvenile shrike releases throughout climate change scenarios. The results of this work provide a foundation for adaptive management practices as climate change progresses.

California is at the forefront of the climate crisis. Poor land-use planning and extreme weather events have led to an onslaught of disasters harming communities and threatening the state’s ecosystems. Strategies that maximize the carbon storage and sequestration of trees and forests are important to fight climate change. But offset programs are massively failing to accomplish the proclaimed carbon storage gains or forest protections. And large-scale tree-planting initiatives around the world in the past 50 years have not led to the promised carbon storage or sequestration gains. Policymakers are ignoring other nature-based sequestration strategies right in front of us. Diversifying and maximizing carbon storage opportunities is necessary to ward off the worst harms of the climate crisis. In our report “Hidden in Plain Sight: California’s Native Habitats are Valuable Carbon Sinks” we highlight the carbon-storage potential of California’s iconic habitats including shrublands, grasslands, deserts, and riparian corridors. We recommend strategic land-use planning and mitigation standards to increase local, nature-based carbon sequestration, and we highlight the co-benefits of protecting and enhancing California’s diverse habitats. We also urge additional research into arid and semi-arid habitats for their abilities to store and sequester carbon while remaining resilient under a changing climate.