Geology topics

Rebecca L. Flitcroft

Publications and source records attributed to Rebecca L. Flitcroft.

9 recordsLinked to original sources

USGS2025

Opportunities to better integrate inland fish and fisheries in multilateral environmental agreements

Inland fish and fisheries are globally important to environmental function and human services, yet their persistent lack of recognition in global agreements, especially multilateral environmental agreements (MEAs), may hinder progress towards biodiversity conservation and human well-being. The connection between inland fish, fisheries, and their ecosystems means that addressing the needs of fish directly offers opportunities to meet multiple global commitments and provide indicators of progress towards many global goals. In this perspective, we highlight opportunities to better integrate inland fish and fisheries into MEAs, specifically the Convention on Biological Diversity (CBD), Convention on Wetlands (commonly known as the Ramsar Convention), Convention on Conservation of Migratory Species (CMS), Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), and World Heritage Convention (WHC). Greater attention on inland fish and fisheries through MEAs could help ensure more holistic planning, investment, and conservation of these important fish and fisheries, their biodiversity, the essential resources they provision, and the environments they inhabit.

Environmental Science & Policy↗

USGS2025

Linking fire, food webs, and fish in stream ecosystems

As wildfire regimes shift, resource managers are concerned about potential threats to aquatic ecosystems and the species they support, especially fishes. However, predicting fish responses can be challenging because wildfires affect aquatic ecosystems via multiple pathways. Application of whole-ecosystem approaches, such as food web modeling, can act as heuristic tools that offer valuable insights that account for these different mechanisms. We applied a dynamic food web simulation model that mechanistically linked stream trophic dynamics to the myriad effects that wildfires can have on aquatic and riparian ecosystems at a local stream reach-scale. We simulated how wildfires of different severity may influence short- (months to years) and long-term (years to decades) periphyton, aquatic invertebrate, and fish biomass dynamics in forested headwater streams of the western Pacific Northwest (USA). In many cases, wildfire increased modeled periphyton, invertebrate, and fish biomass over both short- and long-time periods. However, modeled responses varied extensively in their direction (that is, positive or negative), magnitude, and duration depending on fire severity, time since fire, and trophic level. The shapes of these response trajectories were especially sensitive to predicted wildfire effects on water temperature, canopy cover, riparian shading, and instream turbidity. Model simulations suggest a single fire could result in a wide range of aquatic ecosystem responses, especially in watersheds with mixed burn severity. Our analysis highlights the utility of whole-ecosystem approaches, like food web modeling, as heuristic tools for improving our understanding of the mechanisms linking fire, food webs, and fish and for identifying contexts where fires could have deleterious impacts on fishes.

Oregon, Washington↗

USGS2023

Science to support conservation action in a large river system: The Willamette River, Oregon, USA

Management and conservation efforts that support the recovery and protection of large rivers are daunting, reflecting the complexity of the challenge and extent of effort (in terms of policy, economic investment, and spatial extent) needed to afford measurable change. These large systems have generally experienced intensive development and regulation, compromising their capacity to respond to disturbances such as climate change or wildfire. Functionally, large river and basin management require insights gained from social, ecological, geophysical, and hydrological sciences. This multi-disciplinary perspective can unveil the integrated relationship between a river network's biotic community and seasonally variable environmental conditions that are often influenced by human activities. Large rivers and their basins are constantly changing due to anthropogenic influences and as climate modifies patterns of temperature and precipitation. Because of these factors, the state of knowledge must advance to address changing conditions. The Willamette River, in western Oregon, USA, is a prime example of a basin that has experienced significant degradation and investment in rehabilitation in recent decades. Innovative science has facilitated development of fine-scale, spatially extensive datasets and models that can generate targeted conservation and rehabilitation actions that are prioritized across the entire river network. This prioritization allows investment decisions to be driven by site-specific conditions while simultaneously considering potentials for ecological improvement. Here, we review hydrologic, geomorphic, ecologic, and social conditions in the Willamette River basin through time—including pre-settlement, river development, and contemporary periods—and offer a future vision for consideration. Currently, detailed information about fish populations and habitat, hydrologic conditions, geomorphology, water quality, and land use can be leveraged to make informed decisions about protection, rehabilitation, and development. The time is ripe for strategic management and goal development for the entire Willamette River, and these efforts can be informed by comprehensive science realized through established institutions (e.g., public agencies, non-profit watershed groups, Tribes, and universities) focused on conservation and management. The approaches to science and social-network creation that were pioneered in the Willamette River basin offer insights into the development of comprehensive conservation-based planning that could be implemented in other large river systems globally.

Oregon↗

USGS2023

Northwest Forest Plan — The first 25 years (1994–2018): Watershed condition status and trends

This report describes status and trends in watershed condition across the Northwest Forest Plan (NWFP) area over the first 25 years since its inception in 1994. The program charged with this task is the Aquatic and Riparian Effectiveness Monitoring Program (AREMP), which has assembled information from field data collection, spatial datasets, and a host of landscape models to evaluate the status and trends in aquatic resources in streams and watersheds. Field data included hydrologic measurements (stream wetted widths and temperatures), geomorphic responses (instream wood and sediment), and biological responses (macroinvertebrates and aquatic organism passage). Novel statistical models were used to estimate trends in these measured responses. A suite of complementary modeled results was also employed to describe hydrometeorological drivers (e.g., drought indices and stream discharge), forest cover (upslope and riparian vegetation), and geomorphic conditions (e.g., road-related estimates of chronic and shallow landslide sediment delivery risk). Collectively, information on these responses allowed us to rigorously evaluate instream responses and hypothesize watershed drivers of those responses across the NWFP area and over time. The majority of responses we observed indicated widespread and incremental improvements from active management of forests, forest roads, and road-stream crossings as envisioned by the aquatic conservation strategy of the NWFP. Additionally, many of the responses we observed were consistent with those expected under the influences of changing climates in the Pacific Northwest. Ultimately, the long-term, broad-scale information provided by AREMP is a critical foundation for evaluating the effectiveness of federal land management and the effects of changing climates on water resources that sustain the Pacific Northwest’s human and natural landscapes.

California, Oregon, Washington↗

USGS2022

Monitoring framework to evaluate effectiveness of aquatic and floodplain habitat restoration activities for native fish along the Willamette River, northwestern Oregon

Since 2008, large-scale restoration programs have been implemented along the Willamette River, Oregon, to address historical losses of floodplain habitats caused by dam construction, bank protection, large wood removal, land conversion, and other anthropogenic influences. The Willamette Focused Investment Partnership (WFIP) restoration initiative brings together more than 16 organizations to improve floodplain habitats on more than 35,000 hectares upstream from Willamette Falls with the overarching goal to expand and enhance native fish habitats through the following restoration activities implemented along the floodplains and off-channel areas of the Willamette River: (A) modify floodplain topography and human-made barriers to inundation; (B) enhance gravel pits; (C) remove revetments; (D) construct off-channel features; (E) increase and enhance floodplain forest vegetation; and (F) treat aquatic invasive plant species (AIS). The WFIP Effectiveness Monitoring Program was initiated to inform future refinement of Willamette River restoration program goals and activities and has three goals: (1) evaluate the effectiveness of different restoration activities at increasing and enhancing native fish habitat, (2) improve overall understanding of the physical and ecological responses associated with different restoration activities undertaken by the WFIP, and (3) relate site-scale responses to restoration with broader patterns of fish communities, hydrogeomorphology, stream temperature, and vegetation across the Willamette River floodplain, so that the relative importance of restoration activities on habitat availability for native fish can be assessed. A monitoring framework was developed to evaluate effectiveness of floodplain restoration activities at increasing and enhancing habitat for native fish in the Willamette River corridor, northwestern Oregon. This framework describes monitoring indicators, metrics, and approaches for evaluating responses in native fish communities and physical habitat conditions to restoration activities and determining effectiveness of restoration activities at improving habitats for native fish. The monitoring indicators and approaches are grouped into five restoration monitoring categories that are useful for characterizing ecological and physical habitat responses to restoration activities: fish, hydrogeomorphology, floodplain forest vegetation, birds, and AIS. This monitoring framework provides a common science foundation to support collaborative decisions on future interdisciplinary effectiveness monitoring activities for Willamette River restoration programs. To evaluate restoration effectiveness, data must be evaluated according to metrics and thresholds that permit direct comparison between habitat conditions at the restoration site and restoration program goals; this framework provides examples of metrics and thresholds for evaluating data, recognizing that the precise evaluation criteria for a particular site or program will need to be tailored to meet program questions and available resources. Refining restoration goals and activities as part of an adaptively managed process requires addressing critical uncertainties between restoration goals, restoration activities, and outcomes for habitats used by native fish. Although the monitoring activities of this framework will generate important datasets useful for evaluating restoration effectiveness, additional research, syntheses, and reporting is ultimately necessary to provide a common science foundation to support adaptively managed restoration programs. This report is intended as a resource for restoration program managers, practitioners, scientists, and contractors as they develop detailed annual monitoring plans for data collection and identify the monitoring indicators, metrics, and approaches that are appropriate for evaluating effectiveness of different restoration activities.

Oregon↗

USGS2021

Resilience of terrestrial and aquatic fauna to historical and future wildfire regimes in western North America

Wildfires in many western North American forests are becoming more frequent, larger, and severe, with changed seasonal patterns. In response, coniferous forest ecosystems will transition toward dominance by fire-adapted hardwoods, shrubs, meadows, and grasslands, which may benefit some faunal communities, but not others. We describe factors that limit and promote faunal resilience to shifting wildfire regimes for terrestrial and aquatic ecosystems. We highlight the potential value of interspersed nonforest patches to terrestrial wildlife. Similarly, we review watershed thresholds and factors that control the resilience of aquatic ecosystems to wildfire, mediated by thermal changes and chemical, debris, and sediment loadings. We present a 2-dimensional life history framework to describe temporal and spatial life history traits that species use to resist wildfire effects or to recover after wildfire disturbance at a metapopulation scale. The role of fire refuge is explored for metapopulations of species. In aquatic systems, recovery of assemblages postfire may be faster for smaller fires where unburned tributary basins or instream structures provide refuge from debris and sediment flows. We envision that more-frequent, lower-severity fires will favor opportunistic species and that less-frequent high-severity fires will favor better competitors. Along the spatial dimension, we hypothesize that fire regimes that are predictable and generate burned patches in close proximity to refuge will favor species that move to refuges and later recolonize, whereas fire regimes that tend to generate less-severely burned patches may favor species that shelter in place. Looking beyond the trees to forest fauna, we consider mitigation options to enhance resilience and buy time for species facing a no-analog future.

Ecology and Evolution↗

USGS2016

Aquatic biodiversity in forests: A weak link in ecosystem services resilience

The diversity of aquatic ecosystems is being quickly reduced on many continents, warranting a closer examination of the consequences for ecological integrity and ecosystem services. Here we describe intermediate and final ecosystem services derived from aquatic biodiversity in forests. We include a summary of the factors framing the assembly of aquatic biodiversity in forests in natural systems and how they change with a variety of natural disturbances and human-derived stressors. We consider forested aquatic ecosystems as a multi-state portfolio, with diverse assemblages and life-history strategies occurring at local scales as a consequence of a mosaic of habitat conditions and past disturbances and stressors. Maintaining this multi-state portfolio of assemblages requires a broad perspective of ecosystem structure, various functions, services, and management implications relative to contemporary stressors. Because aquatic biodiversity provides multiple ecosystem services to forests, activities that compromise aquatic ecosystems and biodiversity could be an issue for maintaining forest ecosystem integrity. We illustrate these concepts with examples of aquatic biodiversity and ecosystem services in forests of northwestern North America, also known as Northeast Pacific Rim. Encouraging management planning at broad as well as local spatial scales to recognize multi-state ecosystem management goals has promise for maintaining valuable ecosystem services. Ultimately, integration of information from socio-ecological ecosystems will be needed to maintain ecosystem services derived directly and indirectly from forest aquatic biota.

California, Oregon, Washington↗

USGS2016

Wildfire may increase habitat quality for spring Chinook salmon in the Wenatchee River subbasin, WA, USA

Pacific Northwest salmonids are adapted to natural disturbance regimes that create dynamic habitat patterns over space and through time. However, human land use, particularly long-term fire suppression, has altered the intensity and frequency of wildfire in forested upland and riparian areas. To examine the potential impacts of wildfire on aquatic systems, we developed stream-reach-scale models of freshwater habitat for three life stages (adult, egg/fry, and juvenile) of spring Chinook salmon ( Oncorhynchus tshawytscha ) in the Wenatchee River subbasin, Washington. We used variables representing pre- and post-fire habitat conditions and employed novel techniques to capture changes in in-stream fine sediment, wood, and water temperature. Watershed-scale comparisons of high-quality habitat for each life stage of spring Chinook salmon habitat suggested that there are smaller quantities of high-quality juvenile overwinter habitat as compared to habitat for other life stages. We found that wildfire has the potential to increase quality of adult and overwintering juvenile habitat through increased delivery of wood, while decreasing the quality of egg and fry habitat due to the introduction of fine sediments. Model results showed the largest effect of fire on habitat quality associated with the juvenile life stage, resulting in increases in high-quality habitat in all watersheds. Due to the limited availability of pre-fire high-quality juvenile habitat, and increased habitat quality for this life stage post-fire, occurrence of characteristic wildfires would likely create a positive effect on spring Chinook salmon habitat in the Wenatchee River subbasin. We also compared pre- and post-fire model results of freshwater habitat for each life stage, and for the geometric mean of habitat quality across all life stages, using current compared to the historic distribution of spring Chinook salmon. We found that spring Chinook salmon are currently distributed in stream channels in which in-stream habitat for most life stages has a consistently positive response to fire. This compares to the historic distribution of spring Chinook, in which in-stream habitat exhibited a variable response to fire, including decreases in habitat quality overall or for specific life stages. This suggests that as the distribution of spring Chinook has decreased, they now occupy those areas with the most positive potential response to fire. Our work shows the potentially positive link between wildfire and aquatic habitat that supports forest managers in setting broader goals for fire management, perhaps leading to less fire suppression in some situations.

Washington↗

USGS2015

Climate change and vulnerability of bull trout (Salvelinus confluentus) in a fire-prone landscape.

Linked atmospheric and wildfire changes will complicate future management of native coldwater fishes in fire-prone landscapes, and new approaches to management that incorporate uncertainty are needed to address this challenge. We used a Bayesian network (BN) approach to evaluate population vulnerability of bull trout ( Salvelinus confluentus ) in the Wenatchee River basin, Washington, USA, under current and future climate and fire scenarios. The BN was based on modeled estimates of wildfire, water temperature, and physical habitat prior to, and following, simulated fires throughout the basin. We found that bull trout population vulnerability depended on the extent to which climate effects can be at least partially offset by managing factors such as habitat connectivity and fire size. Moreover, our analysis showed that local management can significantly reduce the vulnerability of bull trout to climate change given appropriate management actions. Tools such as our BN that explicitly integrate the linked nature of climate and wildfire, and incorporate uncertainty in both input data and vulnerability estimates, will be vital in effective future management to conserve native coldwater fishes.

Canadian Journal of Fisheries and Aquatic Sciences↗