Open forests of savanna and woodlands span the spectrum between closed canopy forests and treeless grasslands, and therefore contain structure, composition, and function distinctive from either endpoint. In this special issue, researchers provide examples from different open forest ecosystems to examine the underlying ecological principles and specific management challenges affecting successful restoration of these systems.
Fire has been a source of global biodiversity for millions of years. However, interactions with anthropogenic drivers such as climate change, land use, and invasive species are changing the nature of fire activity and its impacts. We review how such changes are threatening species with extinction and transforming terrestrial ecosystems.
Multiple research and management partners collaboratively developed a multiscale approach for assessing the geomorphic sensitivity of streams and ecological resilience of riparian and meadow ecosystems in upland watersheds of the Great Basin to disturbances and management actions. The approach builds on long-term work by the partners on the responses of these systems to disturbances and management actions.
Wildland fires are globally widespread, constituting the primary forest disturbance in many ecosystems. Burn severity (fire-induced change to vegetation and soils) has short-term impacts on erosion and post-fire environments, and persistent effects on forest regeneration, making burn severity data important for managers and scientists.
Increases in burned area across the western United States (US) since the mid‐1980s have been widely documented and linked partially to climate factors, yet evaluations of trends in fire severity are lacking. Here we evaluate fire severity trends and their interannual relationships to climate for western US forests from 1985 to 2017.
Increased wildfire activity combined with warm and dry post-fire conditions may undermine the mechanisms maintaining forest resilience to wildfires, potentially causing ecosystem transitions, or fire-catalyzed vegetation shifts. Stand-replacing fire is especially likely to catalyze vegetation shifts expected from climate change, by killing mature trees that are less sensitive to climate than juveniles.
A conceptual framework for evaluation of climate effects on tree diseases is presented. Climate can exacerbate tree diseases by favouring pathogen biology, including reproduction and infection processes. Climatic conditions can also cause abiotic disease—direct stress or mortality when trees’ physiological limits are exceeded. When stress is sublethal, weakened trees may subsequently be killed by secondary organisms.
The Forest and Rangeland Renewable Resources Planning Act of 1974 (RPA) mandates a periodic assessment of the conditions and trends of the Nation’s renewable resources on forests and rangelands. The 2020 RPA Assessment will evaluate the future of the Nation’s renewable natural resources through 2070.
The 2020 RPA Assessment includes climate change as a driver affecting natural resources on forests and rangelands in the United States. This publication describes the process used to select the scenarios, climate models, and climate projections that will be used to project renewable resource conditions 50 years into the future.
The Resources Planning Act (RPA) Assessment uses a combination of land use and land cover data to evaluate trends in the United States land base and project future changes. This publication describes how the RPA Assessment uses the National Resources Inventory, National Land Cover Database, and Forest Inventory and Analysis to support analyses of forest trends.