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Decline in small mammal species richness in coastal-central California, 1997–2013

The richness and composition of a small mammal community inhabiting semiarid California oak woodland may be changing in response to climate change, but we know little about the causes or consequence of these changes. We applied a capture-mark-recapture model to 17 years (1997–2013) of live trapping data to estimate species-specific abundances. The big-eared woodrat was the most frequently captured species in the area, contributing 58% of total captures. All small mammal populations exhibited seasonal fluctuations, whereas those of the California mouse, brush mouse, and pinyon mouse declined during the study period. We also applied a multispecies dynamic occupancy model to our small mammal detection history data to estimate species richness, occupancy ( ), detection (p), local extinction ( ), and colonization ( ) probabilities, and to discern factors affecting these parameters. We found that decreased from 0.369 ± 0.088 in 1997 to 0.248 ± 0.054 in 2013; was lower during the dry season (May–September) than the wet season (October–April) and was positively influenced by total seasonal rainfall (slope parameter, = 0.859 ± 0.371; 95% CI = 0.132–1.587). Mean mammalian species richness decreased from 11.943 ± 0.461 in 1997 to 7.185 ± 0.425 in 2013. With highly variable climatic patterns expected in the future, especially increased frequency and intensity of droughts, it is important to monitor small mammal communities inhabiting threatened California oak woodlands.

California↗

Vegetation changes associated with a population irruption by Roosevelt elk

Interactions between large herbivores and their food supply are central to the study of population dynamics. We assessed temporal and spatial patterns in meadow plant biomass over a 23-year period for meadow complexes that were spatially linked to three distinct populations of Roosevelt elk (Cervus elaphus roosevelti) in northwestern California. Our objectives were to determine whether the plant community exhibited a tolerant or resistant response when elk population growth became irruptive. Plant biomass for the three meadow complexes inhabited by the elk populations was measured using Normalized Difference Vegetation Index (NDVI), which was derived from Landsat 5 Thematic Mapper imagery. Elk populations exhibited different patterns of growth through the time series, whereby one population underwent a complete four-stage irruptive growth pattern while the other two did not. Temporal changes in NDVI for the meadow complex used by the irruptive population suggested a decline in forage biomass during the end of the dry season and a temporal decline in spatial variation of NDVI at the peak of plant biomass in May. Conversely, no such patterns were detected in the meadow complexes inhabited by the nonirruptive populations. Our findings suggest that the meadow complex used by the irruptive elk population may have undergone changes in plant community composition favoring plants that were resistant to elk grazing.

Ecology and Evolution↗

Intraspecific functional diversity of common species enhances community stability

Common species are fundamental to the structure and function of their communities and may enhance community stability through intraspecific functional diversity (iFD). We measured among-habitat and within-habitat iFD (i.e., among- and within-plant community types) of two common small mammal species using stable isotopes and functional trait dendrograms, determined whether iFD was related to short-term population stability and small mammal community stability, and tested whether spatially explicit trait filters helped explain observed patterns of iFD. Southern red-backed voles ( Myodes gapperi ) had greater iFD than deer mice ( Peromyscus maniculatus ), both among habitats, and within the plant community in which they were most abundant (their “primary habitat”). Peromyscus maniculatus populations across habitats differed significantly between years and declined 78% in deciduous forests, their primary habitat, as did the overall deciduous forest small mammal community. Myodes gapperi populations were stable across habitats and within coniferous forest, their primary habitat, as was the coniferous forest small mammal community. Generalized linear models representing internal trait filters (e.g., competition), which increase within-habitat type iFD, best explained variation in M. gapperi diet, while models representing internal filters and external filters (e.g., climate), which suppress within-habitat iFD, best explained P. maniculatus diet. This supports the finding that M. gapperi had higher iFD than P. maniculatus and is consistent with the theory that internal trait filters are associated with higher iFD than external filters. Common species with high iFD can impart a stabilizing influence on their communities, information that can be important for conserving biodiversity under environmental change.

Ecology and Evolution↗

Hydrologic modeling as a predictive basis for ecological restoration of salt marshes

Roads, bridges, causeways, impoundments, and dikes in the coastal zone often restrict tidal flow to salt marsh ecosystems. A dike with tide control structures, located at the mouth of the Herring River salt marsh estuarine system (Wellfleet, Massachusetts) since 1908, has effectively restricted tidal exchange, causing changes in marsh vegetation composition, degraded water quality, and reduced abundance of fish and macroinvertebrate communities. Restoration of this estuary by reintroduction of tidal exchange is a feasible management alternative. However, restoration efforts must proceed with caution as residential dwellings and a golf course are located immediately adjacent to and in places within the tidal wetland. A numerical model was developed to predict tide height levels for numerous alternative openings through the Herring River dike. Given these model predictions and knowledge of elevations of flood-prone areas, it becomes possible to make responsible decisions regarding restoration. Moreover, tidal flooding elevations relative to the wetland surface must be known to predict optimum conditions for ecological recovery. The tide height model has a universal role, as demonstrated by successful application at a nearby salt marsh restoration site in Provincetown, Massachusetts. Salt marsh restoration is a valuable management tool toward maintaining and enhancing coastal zone habitat diversity. The tide height model presented in this paper will enable both scientists and resource professionals to assign a degree of predictability when designing salt marsh restoration programs.

Environmental Management↗

Projecting mangrove forest resilience to sea-level rise on a Pacific Island: Species dynamics and ecological thresholds

Mangroves can increase their elevation relative to tidal flooding through biogeomorphic feedbacks but can submerge if rates of sea-level rise are too great. There is an urgent need to understand the vulnerability of mangroves to sea-level rise so local communities and resource managers can implement and prioritize actions. The need is especially pressing for small islands, which have been identified as an area of concern by the IPCC. We developed a generalizable modeling framework for tidal wetlands (WARMER-3) that accounts for species interactions and the belowground processes that dictate soil elevation building relative to sea levels. The model was calibrated with extensive field datasets, including accretion rates derived from 29 soil cores, over 300 forest inventory plots, water level, and elevation. The model included five mangrove tree species and was applied across seven regions around the Pacific Island of Pohnpei, Federated States of Micronesia, where mangrove forest is a critical ecosystem that supports subsistence living for local communities. We explored mangrove resilience and carbon accumulation under six sea-level rise scenarios. We also conducted an analysis to determine the sea-level rise rate threshold above which mangroves would be lost. The results suggest that Pohnpei mangroves can build their elevations relative to low and moderate rates of sea-level rise to prevent submergence, with limited loss of mangrove area through 2150. Under higher sea-level rise rates, however, forest elevation decreased substantially relative to mean sea level and there was extensive loss of mangrove area by that year. Regarding mangrove community composition, for all sea-level rise scenarios, the model predicted a change to increasing relative abundance of flood tolerant species and decreasing relative abundance of high-elevation species, which started to being realized by 2100. Variation in sediment supply, water levels, and elevation capital led to differential vulnerability around the island. We identified a threshold for Pohnpei mangroves where if local sea-level rise rates exceed 7.8 ± 2.2 mm/year they are projected to eventually submerge and be lost. Our modeling framework is novel by addressing both species interactions and critical belowground processes to better understand potential tidal ecosystem responses to sea-level rise.

Pohnpei↗

Interactions of an insecticide, herbicide, and natural stressors in amphibian community mesocosms

Amphibians developing in wetlands embedded within or near agricultural lands may frequently encounter chemical mixtures. The objectives of our study were to determine the effects that post-application concentrations of an insecticide (carbaryl) and an herbicide (atrazine) have on body mass, development, and survival of two anuran species (southern leopard frog, Rana sphenocephala ; American toad, Bufo americanus ) and two caudate species (spotted salamander, Ambystoma maculatum ; small-mouthed salamander, A. texanum ) reared in outdoor cattle tank mesocosms. In one experiment, we manipulated tadpole density (low or high), carbaryl exposure (0, 3.5, 7.0 mg/L), and atrazine exposure (0 or 200 μg/L) to test for effects on development, mass, and survival of larvae. In a second experiment, we manipulated pond hydroperiod (constant or drying), carbaryl exposure (0 or 5 mg/L), and atrazine exposure (0 or 200 μg/L) to test for effects on mass, time, and survival to metamorphosis. Salamanders were virtually eliminated in carbaryl treatments, indicating that at realistic levels, this insecticide could cause population declines for salamanders in contaminated habitats. Carbaryl also had negative effects on toad survival. Exposure to atrazine had negative effects on body size, development, and time to metamorphosis in anuran species, which were associated with reduced chlorophyll levels. Both chemicals interacted significantly with density or hydroperiod, indicating that the environmental conditions could influence the impact of a contaminant. A significant atrazine-by-carbaryl interaction resulted in smaller and less developed spotted salamander larvae than in control ponds. Atrazine exposure, however, appeared to moderate negative effects of carbaryl for spotted salamanders. Our research suggests that important changes in the community's food web result from chemical exposure, which influence the susceptibility of amphibian species to contaminants.

Ecological Applications↗

Cape Romain partnership for coastal protection

This final report summarizes activities, outcomes, and lessons learned from a 3-year project titled “Climate Change Adaptation for Coastal National Wildlife Refuges” with the Cape Romain National Wildlife Refuge (NWR) and local partners in the surrounding South Carolina Lowcountry. The Lowcountry is classified as the 10-county area encompassing the coastal plain of South Carolina (this report specifically focuses on Berkeley, Charleston, and Georgetown Counties). The goals of this work, sponsored by the U.S. Geological Survey’s Southeast Climate Adaptation Science Center (SECASC), were to foster active engagement with stakeholders; to develop a comprehensive definition of adaptation problems faced by agencies, organizations, and individuals near the Cape Romain NWR that accounts for global change, local values, knowledge and perceptions; and to encourage social learning and building of effective networks and trust across South Carolina Lowcountry organizations and individuals. Although project scoping began at the scale of the Atlantic seaboard, by engaging with NWRs from Massachusetts to Florida, participating refuge personnel eventually selected the Cape Romain NWR to serve as a case study for testing our goals. The Cape Romain Partnership for Coastal Conservation was established to address global change impacts at a regional level and includes representation from Federal and State resource agencies, local conservation nongovernmental organizations, and organizations representing underserved community interests. Research topics, originating from discussions with Cape Romain Partnership for Coastal Conservation members, focused on quantifying key drivers of change including localized sea-level rise (SLR) predictions, estimates of coastal hurricane inundation as amplified by SLR, and urban growth trends and forecasts. These key drivers provided a foundation to engage stakeholders in planning exercises to begin a process of collective understanding and collaborative decision making. The goal of this process was to develop collective strategies of adaptation to enhance community and ecosystem resilience in the South Carolina Lowcountry. South Carolina’s Lowcountry is experiencing rapid environmental and social transformation because of SLR rates approaching twice the global average, chronic tidal flooding and catastrophic storm surges, erosion and loss of habitats that provide essential services to wildlife and humans, and increasing social polarization fueled by aggressive low-density urban growth and other forms of land conversion. To support characterizations of plausible future scenarios, we used available or, in some cases, developed new models to project future conditions of key environmental and social-economic drivers. Because of the imprecision of mean global SLR projections, the SECASC commissioned a climatological study to account for local conditions and multiple representative concentration pathways to project a tailored distribution of future sea levels. These projections were matched to SLR scenarios provided by existing models to anticipate the range of future coastal habitat changes in the South Carolina Lowcountry. SLR scenarios were also incorporated into existing storm-surge models, which do not account for alternate baseline sea levels, to project the local effects of future hurricanes. To evaluate the extent and effects of population growth and urban expansion, we relied on an existing urban-growth model to map the spatial distribution of land-conversion probabilities, the total area of which is predicted to increase twofold to threefold over the next 60 years. In addition to this simplified model, an econometric model is in development to account for nonlinear feedback dynamics in land value, land use, and ecosystem service production. Although not yet completed, the goals of this model are to produce more-detailed projections of growth dynamics and to allow predictions of development patterns resulting from alternate land-use planning policies and incentives. Collaborative planning for an uncertain future requires more than providing decision makers with information on future physical and ecological conditions; developing effective and consensual strategies must also integrate sociological values, multiple cultural perspectives, and an understanding of human behavior. To support broad stakeholder engagement in integrative approaches to adaptation planning, emphasis was placed on the importance of considering differences in how individuals perceive their environment and create meaning. Because cultural frameworks form the basis for perceptions and, ultimately, the behaviors of individuals and institutions, we describe a model of human behavior and how it can be used to understand the effect of cultural complexity and variation in perception on choices, behavioral change, and long-term maintenance of behaviors. We consider a model commonly used in the field of behavioral health that accommodates variation in human perception when describing stages of behavior and the dynamics of behavioral change. Tailoring communication and engagement activities to targeted stakeholders is likely to benefit from increased understanding of behavioral change processes. The complex nature of this problem limited the usefulness of a traditional decision-analytic approach, we explored alternative methods for engagement, collaborative learning and decision making. Recognizing that project partners and Lowcountry stakeholders may be at different stages of preparedness and interest level for modifying behavior as a function of global change, we facilitated a scenario-planning exercise to familiarize partners with this well-established approach for communicating the opportunities and threats arising under alternative, plausible futures. We developed narratives for four alternative South Carolina Lowcountry scenarios to be used in later strategic planning that focus on quantitative trends for three primary drivers with high impact and high uncertainty: manifestations of climate change, social-political shifts at a global level, and forces of local value and power structures. This scenario-planning exercise underscored the complex relation between the temporospatial scale of the production of ecological goods and services and the institutional scale at which they are managed. We then guided the partners through an assessment of the relevant strengths and weaknesses of the Cape Romain Partnership for Coastal Protection, using the threats and opportunities characterized by each scenario to understand how the partnership might respond when attempting to meet conservation and societal objectives. The partnership identified key strengths including partnership experience, outreach and technical capacities, a substantial conservation land base, and high social cohesion in the South Carolina Lowcountry. Limited communication expertise, institutional inertia, and insufficient staffing and funding were recognized as important weaknesses across the partnership. By examining and scoring combinations of internal strengths and weaknesses and external threats and opportunities, the partnership developed sets of prioritized strategies to consider in the context of a given scenario. Although we had insufficient time to examine all scenarios in detail, the intent was to identify a portfolio of strategic actions to address threats and opportunities represented in multiple plausible futures. Top-ranking strategies encompassed a range of actions that focused on strengthening the conservation community and communicating the benefits of nature (that is, ecosystem services) to leveraging partnerships to expand land protection. This report also details the methods and preliminary results of several models developed or applied in support of this project. Two parcel-selection algorithms were used to evaluate anticipated habitat changes and patterns of urban growth to guide decisions on optimal conservation reserve design to protect habitat communities. One approach used a widely available planning software (MARXAN) to maximize conservation benefits near the Cape Romain NWR, whereas the other approach was a novel application of economic theory to account for uncertainty in future conditions and for the risks of unanticipated habitat loss. This latter model applies modern portfolio theory to estimate the risk of investing in any portfolio of land parcels (that is, candidate “reserves”) under climate-change uncertainty by quantifying the variation and spatial correlation of conservation benefits derived from each portfolio. We expanded the range of actions beyond simply whether or not to invest in a set of land parcels, an approach commonly used in spatial conservation planning, to also include consideration of divestment from currently protected lands. Such refinements allow for better accounting of system dynamics and can evaluate the benefits of flexible conservation tools such as rolling easements. Model results were conditional on a decision maker’s risk tolerance but highlighted general strategies of land conservation to increase future habitat representation beyond what is expected under the current protected land base. We built models that may help inform coastal planning by estimating salinity dynamics and the performance of oyster reef restoration efforts to predict the combined effects of global change and management of freshwater flows on coastal habitats and the processes that contribute to their resilience. These models can support restoration decisions by evaluating the expected benefits of site locations for shoreline protection and fisheries production. Lastly, we developed a spatially explicit economic model that predicts feedback dynamics among land value, land-use change, and effects on ecosystem service provision to explore zoning policies and incentives on urban growth and ecosystem services. We summarize these efforts with insights and considerations for the Cape Romain Partnership for Coastal Protection to continue to engage stakeholders in effective adaptation planning. First, notions of place attachment (referred to as sense of place), and the role of culture in social discourse are increasingly being used to understand the complex interactions between society and the environment and how societies respond and adapt to climate change. Sense of place was a unifying theme whenever the future of the South Carolina Lowcountry was discussed. The contribution of the South Carolina Lowcountry’s environmental wealth, rich cultural heritage, and quality of life to sense of place has important implications for how adaptation planning might best be pursued. More community-based governance of the commons (in other words, natural and cultural resources held in common), in which broad stakeholder participation and power sharing are key elements, is considered important. This devolution of governance is characterized by polycentric institutions and self-organizing social networks that promote a local culture of knowledge sharing, problem solving, and learning. These so-called bridging organizations (or individuals) often provide the leadership necessary to bring together potentially disparate Government agencies and institutions, private organizations, and individuals in a collective process of problem solving. Our observations also suggest that the conservation community in the South Carolina Lowcountry views its activities as integral to the broader governance of social-ecological systems, in which responses to the forces of global change are mediated through culture, economics, and politics. Rather than directly competing with other interests, the South Carolina Lowcountry conservation community seems to embrace an interpretation of conservation in which the fundamental objective is the quality of human life rather than environmental protection. Fundamental to the types of governance reforms described above is the notion of coproduction, in which experts and users collaborate to develop a shared body of knowledge. In this approach, scientists work with stakeholders to help frame questions, design research, and collect and analyze data. Such sustained collaborations are increasingly believed to be an effective way to produce useable (or actionable) science. The emphasis on social learning, leveraging strong social networks, coordinating and deliberating among diverse stakeholders, and applying principles of adaptive management is an essential contribution to adaptive capacity. The diverse and robust set of scientific approaches, methods to help stakeholders collaborate in effective and goal-driven planning processes, and decision tools resulting from this project hopefully will assist Cape Romain NWR and its partners prepare for climatic, ecological, and social changes over the coming decades.

South Carolina↗

Predicting wetland plant community responses to proposed water-level-regulation plans for Lake Ontario: GIS-based modeling

Integrated, GIS-based, wetland predictive models were constructed to assist in predicting the responses of wetland plant communities to proposed new water-level regulation plans for Lake Ontario. The modeling exercise consisted of four major components: 1) building individual site wetland geometric models; 2) constructing generalized wetland geometric models representing specific types of wetlands (rectangle model for drowned river mouth wetlands, half ring model for open embayment wetlands, half ellipse model for protected embayment wetlands, and ellipse model for barrier beach wetlands); 3) assigning wetland plant profiles to the generalized wetland geometric models that identify associations between past flooding / dewatering events and the regulated water-level changes of a proposed water-level-regulation plan; and 4) predicting relevant proportions of wetland plant communities and the time durations during which they would be affected under proposed regulation plans. Based on this conceptual foundation, the predictive models were constructed using bathymetric and topographic wetland models and technical procedures operating on the platform of ArcGIS. An example of the model processes and outputs for the drowned river mouth wetland model using a test regulation plan illustrates the four components and, when compared against other test regulation plans, provided results that met ecological expectations. The model results were also compared to independent data collected by photointerpretation. Although data collections were not directly comparable, the predicted extent of meadow marsh in years in which photographs were taken was significantly correlated with extent of mapped meadow marsh in all but barrier beach wetlands. The predictive model for wetland plant communities provided valuable input into International Joint Commission deliberations on new regulation plans and was also incorporated into faunal predictive models used for that purpose.

Journal of Great Lakes Research↗

Ten best practices for effective phenological research

The number and diversity of phenological studies has increased rapidly in recent years. Innovative experiments, field studies, citizen science projects, and analyses of newly available historical data are contributing insights that advance our understanding of ecological and evolutionary responses to the environment, particularly climate change. However, many phenological data sets have peculiarities that are not immediately obvious and can lead to mistakes in analyses and interpretation of results. This paper aims to help researchers, especially those new to the field of phenology, understand challenges and practices that are crucial for effective studies. For example, researchers may fail to account for sampling biases in phenological data, struggle to choose or design a volunteer data collection strategy that adequately fits their project’s needs, or combine data sets in inappropriate ways. We describe ten best practices for designing studies of plant and animal phenology, evaluating data quality, and analyzing data. Practices include accounting for common biases in data, using effective citizen or community science methods, and employing appropriate data when investigating phenological mismatches. We present these best practices to help researchers entering the field take full advantage of the wealth of available data and approaches to advance our understanding of phenology and its implications for ecology.

International Journal of Biometeorology↗

Laboratory toxicity and benthic invertebrate field colonization of Upper Columbia River sediments: Finding adverse effects using multiple lines of evidence

From 1930 to 1995, the Upper Columbia River (UCR) of northeast Washington State received approximately 12 million metric tons of smelter slag and associated effluents from a large smelter facility located in Trail, British Columbia, approximately 10 km north of the United States–Canadian border. Studies conducted during the past two decades have demonstrated the presence of toxic concentrations of heavy metals in slag-based sandy sediments, including cadmium, copper, zinc, and lead in the UCR area as well as the downstream reservoir portion of Lake Roosevelt. We conducted standardized whole-sediment toxicity tests with the amphipod Hyalella azteca (28-day) and the midge Chironomus dilutus (10-day) on 11 samples, including both UCR and study-specific reference sediments. Metal concentrations in sediments were modeled for potential toxicity using three approaches: (1) probable effects quotients (PEQs) based on total recoverable metals (TRMs) and simultaneously extracted metals (SEMs); (2) SEMs corrected for acid-volatile sulfides (AVS; i.e., ∑SEM − AVS); and (3) ∑SEM − AVS normalized to the fractional organic carbon (f oc ) (i.e., ∑SEM − AVS/f oc ). The most highly metal-contaminated sample (∑PEQ TRM = 132; ∑PEQ SEM = 54; ∑SEM − AVS = 323; and ∑SEM − AVS/ foc = 64,600 umol/g) from the UCR was dominated by weathered slag sediment particles and resulted in 80% mortality and 94% decrease in biomass of amphipods; in addition, this sample significantly decreased growth of midge by 10%. The traditional ∑AVS – SEM, uncorrected for organic carbon, was the most accurate approach for estimating the effects of metals in the UCR. Treatment of the toxic slag sediment with 20% Resinex SIR-300 metal-chelating resin significantly decreased the toxicity of the sample. Samples ∑SEM − AVS > 244 was not toxic to amphipods or midge in laboratory testing, indicating that this value may be an approximate threshold for effects in the UCR. In situ benthic invertebrate colonization studies in an experimental pond (8-week duration) indicated that two of the most metal-contaminated UCR sediments (dominated by high levels of sand-sized slag particles) exhibited decreased invertebrate colonization compared with sand-based reference sediments. Field-exposed SIR-300 resin samples also exhibited decreased invertebrate colonization numbers compared with reference materials, which may indicate behavioral avoidance of this material under field conditions. Multiple lines of evidence (analytical chemistry, laboratory toxicity, and field colonization results), along with findings from previous studies, indicate that high metal concentrations associated with slag-enriched sediments in the UCR are likely to adversely impact the growth and survival of native benthic invertebrate communities. Additional laboratory toxicity testing, refinement of the applications of sediment benchmarks for metal toxicity, and in situ benthic invertebrate studies will assist in better defining the spatial extent, temporal variations, and ecological impacts of metal-contaminated sediments in the UCR system.

Trail↗

Fitness in animals correlates with proximity to discontinuities in body mass distributions.

Discontinuous structure in landscapes may cause discontinuous, aggregated species body-mass patterns, reflecting the scales of structure available to animal communities within a landscape. Empirical analyses have shown that the location of species within body mass aggregations, which reflect this scale-specific organization, is non-random with regard to several ecological phenomena, including species extinctions. The propensity of declining species to have body masses proximate to discontinuities suggests that transition zones between scaling regimes ultimately decreases the ecological fitness for some species. We test this proposition using vulnerable and unthreatened fish species in Mediterranean streams with differing levels of human impact. We show that the proximity to discontinuities in body mass aggregations (“distance-to-edge”) of more vs. less fit individuals within vulnerable and unthreatened populations differs. Specifically, regression analysis between the scaled mass index, a proxy of animal fitness, and distance-to-edge reveals negative and positive relationships for vulnerable and unthreatened species, respectively. That is, fitness is higher close to discontinuities in vulnerable populations and toward the center of body mass aggregation groups in unthreatened populations. Our results demonstrate the suitability of the discontinuity framework for scrutinizing non-random patterns of environmental impact in populations. Further exploration of the usefulness of this method across other ecosystems and organism groups is warranted.

Ecological Complexity↗

Piscivory in recovering Lake Michigan Cisco (Coregonus artedi): The role of invasive species

Contemporary conditions in Lake Michigan where cisco ( Coregonus artedi ) populations are expanding are vastly different from those encountered by the historic fish community. Invasive species introductions have substantially altered the Lake Michigan ecosystem in the last half century. Successful management efforts for cisco in Lake Michigan hinge on our ability to understand their contemporary ecology, especially diet. We collected 725 cisco stomachs opportunistically from commercial fisheries (2%) and in agency surveys (98%) over six years (2014–2019). The majority (70%) of stomachs were from East Grand Traverse Bay and 96% of these were collected at Elk Rapids. Additional samples were collected from Charlevoix (8%), Little Traverse Bay (11%), other sites in northern Lake Michigan (4%), Central Lake Michigan (6%), and Green Bay (1%). Our results indicated a high degree of piscivory, in contrast to historical and contemporary accounts of planktivory for cisco in the other Laurentian Great Lakes. The top three prey items by mass were not native to the Great Lakes and these accounted for 87% of all observed prey mass consumed: round goby ( Neogobius melanostomus) (58%), Bythotrephes longimanus (15%), and alewife ( Alosa pseudoharengus) (14%). Round goby dominated the prey in the spring and summer, while B. longimanus and alewife occurred more in summer and fall diets. The contemporary population of cisco in Lake Michigan has been able to uniquely capitalize on abundant invasive prey resources, which may be less limiting and more energy-rich than a more typical planktivorous cisco diet.

Lake Michigan↗

A proposed coast-wide reference monitoring system for evaluating Wetland restoration trajectories in Louisiana

Wetland restoration efforts conducted in Louisiana under the Coastal Wetlands Planning, Protection and Restoration Act require monitoring the effectiveness of individual projects as well as monitoring the cumulative effects of all projects in restoring, creating, enhancing, and protecting the coastal landscape. The effectiveness of the traditional paired-reference monitoring approach in Louisiana has been limited because of difficulty in finding comparable reference sites. A multiple reference approach is proposed that uses aspects of hydrogeomorphic functional assessments and probabilistic sampling. This approach includes a suite of sites that encompass the range of ecological condition for each stratum, with projects placed on a continuum of conditions found for that stratum. Trajectories in reference sites through time are then compared with project trajectories through time. Plant community zonation complicated selection of indicators, strata, and sample size. The approach proposed could serve as a model for evaluating wetland ecosystems.

Environmental Monitoring and Assessment↗

Quantifying restoration success and recovery in a metal-polluted stream: A 17-year assessment of physicochemical and biological responses

Evaluating the effectiveness of stream restoration is often challenging because of the lack of pre-treatment data, narrow focus on physicochemical measures and insufficient post-restoration monitoring. Even when these fundamental elements are present, quantifying restoration success is difficult because of the challenges associated with distinguishing treatment effects from seasonal variation, episodic events and long-term climatic changes.2. We report results of one of the most comprehensive and continuous records of physical, chemical and biological data available to assess restoration success for a stream ecosystem in North America. Over a 17 year period we measured seasonal and annual changes in metal concentrations, physicochemical characteristics, macroinvertebrate communities, and brown trout Salmo trutta populations in the Arkansas River, a metal-contaminated stream in Colorado, USA.3. Although we observed significant improvements in water quality after treatment, the effectiveness of restoration varied temporally, spatially and among biological response variables. The fastest recovery was observed at stations where restoration eliminated point sources of metal contamination. Recovery of macroinvertebrates was significantly delayed at some stations because of residual sediment contamination and because extreme seasonal and episodic variation in metal concentrations prevented recolonization by sensitive species. Synthesis and applications. Because recovery trajectories after the removal of a stressor are often complex or nonlinear, long-term studies are necessary to assess restoration success within the context of episodic events and changes in regional climate. The observed variation in recovery among chemical and biological endpoints highlights the importance of developing objective criteria to assess restoration success. Although the rapid response of macroinvertebrates to reduced metal concentrations is encouraging, we have previously demonstrated that benthic communities from the Arkansas River remained susceptible to other novel anthropogenic stressors. We suggest that the resistance or resilience of benthic macroinvertebrate communities to novel stressors may be effective indicators of restoration success that can account for the non-additive (e.g. synergistic) nature of compound perturbations. ?? 2010 The Authors. Journal compilation ?? 2010 British Ecological Society.

Journal of Applied Ecology↗

Hydraulic, geomorphic, and trout habitat conditions of the Lake Fork of the Gunnison River in Hinsdale County, Lake City, Colorado, Water Years 2010-2011

Channel rehabilitation, or reconfiguration, to mitigate a variety of riverine problems has become a common practice in the western United States. However, additional work to monitor and assess the channel response to, and the effectiveness of, these modifications over longer periods of time (decadal or longer) is still needed. The Lake Fork of the Gunnison River has been an area of active channel modification to accommodate the needs of the Lake City community since the 1950s. The Lake Fork Valley Conservancy District began a planning process to assess restoration options for a reach of the Lake Fork in Lake City to enhance hydraulic and ecologic characteristics of the reach. Geomorphic channel form is affected by land-use changes within the basin and geologic controls within the reach. The historic channel was defined as a dynamic, braided channel with an active flood plain. This can result in a natural tendency for the channel to braid. A braided channel can affect channel stability of reconfigured reaches when a single-thread meandering channel is imposed on the stream. The U.S. Geological Survey, in cooperation with the Colorado Water Conservation Board and Colorado River Water Conservation District, began a study in 2010 to quantify existing hydraulic and habitat conditions for a reach of the Lake Fork of the Gunnison River in Lake City, Colorado. The purpose of this report is to quantify existing Lake Fork hydraulic and habitat conditions and establish a baseline against which post-reconfiguration conditions can be compared. This report (1) quantifies the existing hydraulic and geomorphic conditions in a 1.1-kilometer section of the Lake Fork at Lake City that has been proposed as a location for future channel-rehabilitation efforts, (2) characterizes the habitat suitability of the reach for two trout species based on physical conditions within the stream, and (3) characterizes the current riparian canopy density. The FaSTMECH computational flow-model within MD_SWMS was selected to characterize the effects of streamflow on hydraulic and habitat-suitability conditions for a study reach of the Lake Fork. Habitat suitability was evaluated for cutthroat ( Oncorhynchus clarkii ) and brown trout ( Salmo trutta morpha fario ) fry, juveniles, and adults. Microscale (point locations) and mesoscale (reach features) habitats were assessed using the combination of field observations, measurements, and hydraulic simulations within the study reach of the Lake Fork. Microscale trout habitat, presented as weighted usable area, generally increased as streamflow increased for both trout species and all life stages. Areas of suitable microscale habitat occur along the banks for flows of 900 cubic feet per second (ft 3 /s) and less. Out-of-bank areas became more substantial contributors to overall habitat availability for flows of 1,300 ft 3 /s or more when compared to other features. Adult habitat, for both trout species, was the most abundant habitat type for nearly all streamflows. In general, the upper reach provided 2–3 times more available habitat than the lower reach for both trout species. Mesoscale trout habitat of the Lake Fork was assessed based on the conditions present in the 150 ft 3 /s flow simulation as well as field observation. Both the upper and lower reach is primarily characterized as riffle/run habitat. The presence of pool habitat was limited throughout both reaches and occurred along the channel margins. For both reaches, the pool habitat was less than 5 percent of the total wetted area, a percentage that is substantially lower than the recommendations for sustainable populations of 40–70 percent. Areas of cover were adjacent to potential drift feeding areas in the lower reach, and often occurred within the same pool habitat. This may favor energy expenditure ratios of both fish species, wherein little energy is needed to acquire adequate food sources. Sediment mobility is an important process for flushing fine sediments from within the gravel frameworks. Evaluations of channel and flow characteristics at cross-section locations 2–8 show a range of streambed mobility. In general, boundary shear stress and streambed mobility increase with increases in streamflow. Within the cross sections, the greatest boundary shear stress occurs towards the center of the channel. Reach-scale assessment of sediment mobility in the lower reach shows increased streambed mobility. This is due in part to smaller grain sizes in the lower reach, but may also reflect the greater extent of channel alterations, specifically the temporary berms constructed by CDOT in the late 1980s and 1990s, present in this reach.

Colorado↗

National seed strategy for rehabilitation and restoration progress report 2022 & 2023: Handout

Restoring healthy, resilient, biodiverse ecosystems is crucial for our Nation’s future. Native plant communities provide essential environmental benefits, such as buffering against extreme weather, improving air, soil, and water quality, and habitat for wildlife. However, the limited availability of locally adapted native plants hampers effective ecological restoration. To address this need, the Plant Conservation Alliance released the National Seed Strategy in 2015 to foster coordination to increase the supply of native seeds for restoration on public, Tribal, state, and private lands. Developing and using native seeds nurtures a growing restoration economy that creates jobs, stimulates rural economies, and reduces risks from environmental hazards.

Report↗

Southeastern freshwater fishes

North America has the richest fauna of temperate freshwater fishes in the world, with about 800 native species in the waters of Canada and the United States. The center of this diversity is in the southeastern United States, where as many as 500 species may exist (62% of the continental fauna north of Mexico). Many coastal marine species also enter fresh waters of the Southeast, and at least 34 foreign fish species are established in the region. Although freshwater fishes of the United States are better studied than any fish fauna of comparable scope in the world (Lee et al. 1980; Hocutt and Wiley 1986; Matthews and Heins 1987; Page and Burr 1991; Mayden 1992), large gaps exist in scientific knowledge about the biology and ecology of most species. New species are still being discovered, and the taxonomy of other species is being refined. Seriously declining populations of freshwater fishes in the United States concern the scientific community (Deacon et al. 1979; Williams et al. 1989; Moyle and Leidy 1992; Warren and Burr 1994). This article briefly summarizes the current conservation status of southeastern freshwater fishes; the Southeast is emphasized because of its important fish biodiversity and to focus attention on the growing problem of adverse human impacts on the region's aquatic habitats (Mount 1986; Burkhead and Jenkins 1991; Etnier and Starnes 1991; Warren and Burr 1994).

Book chapter↗

Evaluating drivers of hydrology, water quality, and benthic macroinvertebrates in streams of Fairfax County, Virginia, 2007–18

In 2007, the U.S. Geological Survey partnered with Fairfax County, Virginia, to establish a long-term water-resources monitoring program to evaluate the hydrology, water quality, and ecology of Fairfax County streams and the watershed-scale effects of management practices. Fairfax County uses a variety of management practices, policies, and programs to protect and restore its water resources, but the effects of such strategies are not well understood. This report used streamflow, water-quality, and ecological monitoring data collected from 20 Fairfax County watersheds from 2007 through 2018 to assess the effects of management practices, landscape factors, and climatic conditions on observed nutrient, sediment, salinity, and benthic-macroinvertebrate community responses. Urbanization, climatic variability, and an increase in management practices occurred within Fairfax County during the study period. Impervious cover, housing units, wastewater infrastructure, and (or) stormwater infrastructure increased in most study watersheds. Climatic conditions varied among study years; countywide estimates of average-annual air temperature differed by about 3 degrees Celsius, and total precipitation ranged from about 34 to 63 inches per year. The effects of the management practices, implemented to reduce nitrogen, phosphorus, and (or) sediment loads, are considered in this study. These management practices primarily consist of stormwater retrofits and stream restorations; however, stream restorations account for most of the financial investment and expected load reductions. Management practices were implemented in half of the study watersheds, and most practices were installed and reductions credited late in the study period. Changes in hydrologic response during storm events were evaluated over the study period because many management practices that were implemented were designed to achieve nutrient and sediment reductions by slowing or intercepting runoff. The average number and length of storm events was mostly unchanged throughout the monitoring network. Four watersheds with 10 years of streamflow data showed a mixture of trends in stormflow peak, volume, and rate-of-change. Event-mean nutrient and sediment concentrations from these watersheds were evaluated during storm events and generally showed increases in total phosphorus (TP) and suspended sediment and reductions or no changes in total nitrogen (TN). Landscape inputs of nitrogen and phosphorus and the percentage of inputs delivered to streams were estimated for the study watersheds. Estimated phosphorus from fertilizer and nitrogen from atmospheric deposition represented large nutrient inputs in most watersheds; amounts of other nonpoint sources varied based on land use. Estimated nitrogen inputs declined throughout Fairfax County and in most study watersheds from 2008 through 2018; in comparison, phosphorus input changes were relatively small. Most nonpoint-nutrient inputs were retained on the landscape and did not reach streams, with slightly more nitrogen retention than phosphorus, on average. Retention rates were lower for years with more precipitation and streamflow. After adjusting for streamflow, TN and TP loads were generally higher for years with more nutrient inputs. Calculated as a function of flow-adjusted loads, TP retention declined at most stations from 2009 through 2018, in comparison, TN retention was relatively unchanged. Landscape and climatic conditions affected spatial differences and changes in Fairfax County stream conditions from 2009 through 2018. TN concentrations were higher and increases over time were larger in watersheds with elevated septic-system density. TP concentrations were higher in watersheds with more turfgrass; concentrations were lower, but had larger increases over time, in watersheds with deeper soils. Suspended-sediment concentrations were higher in watersheds with greater stream densities. Specific conductance was higher in watersheds with more developed land use and shallower soils. Benthic-macroinvertebrate index of biotic integrity (IBI) scores were lower in watersheds with high road density and had larger increases over time in bigger, more developed watersheds. Annual variability in TN and TP concentrations and benthic-macroinvertebrate IBI scores was affected by precipitation; annual variability in suspended sediment concentrations and specific conductance was affected by air temperature. After accounting for influences from landscape and climatic conditions, expected management-practice effects were not consistently observed in monitored stream responses. These effects were assessed by comparing expected management-practice load reductions with the timing, direction, and magnitude of changes in storm-event hydrology, nutrient and sediment loads, median-annual water-quality conditions, and benthic-macroinvertebrate IBI scores. An important consideration for future investigations of management-practice effects is how to control for water-quality and ecological variability caused by geologic properties, the urban environment, precipitation, and (or) air temperature. The interpretation of management-practice effects in this report was likely influenced by a combination of factors, including (1) the amount, timing, and location of management-practice implementation; (2) unmeasured landscape and climatic factors; (3) uncertain management-practice expectations; (4) hydrologic variability; and (5) analytical assumptions. Through continued data-collection efforts, particularly after management practices have been completed, many of these factors may become less influential in the future.

Virginia↗