Treesearch

Groundwater systems in snow-dominated drainage areas supply cool baseflows that support instream and downstream users late into the dry season. Yet, these catchments are becoming rarer with climate change and anthropogenic pressures that threaten groundwater systems. Restoration of low-gradient meadows and streams can recover a catchment’s natural storage potential, especially in Mediterranean biomes such as the Sierra Nevada of California where summer groundwater recharge is scarce. The degradation of meadows due to intense human modification has decreased groundwater elevations and...

In the past, the dry mixed conifer forests of California’s Sierra Nevada mountains experienced frequent low to mixed severity fires. However, due to fire suppression and past management, forest structure has changed, and the new fire regimes are characterized by large, high severity fires which kill a majority of the overstory trees. These new disturbance patterns require novel approaches to regenerate the forest as they are not adapted to large, high severity fires. We forecasted growth and fire behavior of young plantations for 100 years into the future using the Forest Vegetation...

Rivers and their adjacent riparian zones are model ecosystems for observing cross-ecosystem energy transfers. Aquatic insects emerging from streams, for example, are resource subsidies that support riparian consumers such as birds, spiders, lizards, and bats. We collaborated with recreational river runners in Grand Canyon, Arizona, USA, to record acoustic bat activity and sample riparian insects using light traps at dusk from April through October 2017–2020. River runners collected these data on 1,428 events over 611 sampling nights at 410 sites throughout a 470-km segment of the Colorado...

Forest restoration of landscapes benefits both biodiversity and multiple stakeholder groups. We examined how the concept of hybrid ecosystem restoration could be employed in invaded lowland wet forest in Hawai′i to examine biological, economic, and sociocultural benefits of restoration. We quantified the market prevalence of all species found within the Liko Nā Pilina experimental plots in comparison to an invaded lowland wet forest reference site with remnant native species. Using a combination of formal market and informal interviews with cultural practitioners, we examined the use of...

Nevada lies in one of the driest parts of North America. The region has long grappled with droughts and also with extended periods in which the already dry climate aridified for decades or centuries. Here we place Nevada’s most recent statewide drought (2020 – present) in the context of historical, archaeological and paleoclimate records dating back through the Mid-Holocene. The current drought is distinct from historical droughts that impacted the state in the 1930s, 1950s, and 1970’s and 1980s. It is notably warmer than droughts of the 20th century and more spatially extensive than any...

InSTREAM is a simulation model designed to support river management decisions. InSTREAM 7 is a major revision of the individual-based stream trout model we developed and have used for over 20 years. This user manual provides background information on inSTREAM and its purposes, a complete description of the model formulation, a software guide, and guidance on applying the model. InSTREAM is designed to predict how stream trout populations respond to habitat alteration including altered flow, temperature, and turbidity regimes and changes in channel morphology. The model represents individual...

In many watersheds, runoff occurring with snowmelt brings the largest pulse of dissolved organic matter (DOM) from soils to streams. Yet, exactly how soil and stream DOM fractions are altered as snowmelt timing changes is not well understood. We studied the optical character of DOM as it moved through a first-order northern hardwood watershed through the snowmelt period. While stream dissolved organic carbon (DOC; mean = 4.6 mg C L−1) concentrations were not correlated with snowmelt flushing, stream DOM appeared humic-like throughout the study period (humification index, HIX; mean = 10.9)....

Multiple aspects of forest land management present research partnership opportunities for the USDA Forest Service and tribal nations. These aspects include forests, fuels, and ecocultural resources that often are appropriate to manage at the landscape scale. The impacts of global climate change heighten the timeliness and need for partnerships. Practices that are appropriate for Forest Service-tribal partnerships generally have not been documented in a designated publication. This report responds to this technical knowledge need by presenting field-based insights about effective practices...

In recent years, environmental stewardship has been emphasized as one solution to social-ecological sustainability concerns, especially at the local scale. The Stewardship Mapping and Assessment Project (STEW-MAP) is a national research program developed by the USDA Forest Service that has been implemented at numerous locations in the United States and internationally. This study compared the mission statements of environmental stewardship groups in the Los Angeles River Watershed to previously proposed definitions and frameworks of organizational environmental stewardship to see how well...

Historical logging practices and fire exclusion have reduced the proportion of pine in mixed-conifer forests of the western United States. To better understand pine’s decline, we investigate the impact of historical logging on the tree regeneration layer and subsequent stand development over almost a century of fire exclusion. We use a unique dataset derived from contemporary (∼2016) remeasurement of 440 historical quadrats (∼4m2) in the central Sierra Nevada, California, in which overstory trees, tree regeneration, and microsite conditions were measured and mapped both before and after...