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At least 19 recordsLinked to original sources
USGS2022

Terrestrial ecosystem modeling with IBIS: Progress and future vision

Dynamic Global Vegetation Models (DGVM) are powerful tools for studying complicated ecosystem processes and global changes. This review article synthesizes the developments and applications of the Integrated Biosphere Simulator (IBIS), a DGVM, over the past two decades. IBIS has been used to evaluate carbon, nitrogen, and water cycling in terrestrial ecosystems, vegetation changes, land-atmosphere interactions, land-aquatic system integration, and climate change impacts. Here we summarize model development work since IBIS v2.5, covering hydrology (evapotranspiration, groundwater, lateral routing), vegetation dynamics (plant functional type, land cover change), plant physiology (phenology, photosynthesis, carbon allocation, growth), biogeochemistry (soil carbon and nitrogen processes, greenhouse gas emissions), impacts of natural disturbances (drought, insect damage, fire) and human induced land use changes, and computational improvements. We also summarize IBIS model applications around the world in evaluating ecosystem productivity, carbon and water budgets, water use efficiency, natural disturbance effects, and impacts of climate change and land use change on the carbon cycle. Based on this review, visions of future cross-scale, cross-landscape and cross-system model development and applications are discussed.

Journal of Resources and Ecology↗
USGS2009

Fungal endophytes: diversity and functional roles

All plants in natural ecosystems appear to be symbiotic with fungal endophytes. This highly diverse group of fungi can have profound impacts on plant communities through increasing fitness by conferring abiotic and biotic stress tolerance, increasing biomass and decreasing water consumption, or decreasing fitness by altering resource allocation. Despite more than 100 yr of research resulting in thousands of journal articles, the ecological significance of these fungi remains poorly characterized. Historically, two endophytic groups (clavicipitaceous (C) and nonclavicipitaceous (NC)) have been discriminated based on phylogeny and life history traits. Here, we show that NC-endophytes represent three distinct functional groups based on host colonization and transmission, in planta biodiversity and fitness benefits conferred to hosts. Using this framework, we contrast the life histories, interactions with hosts and potential roles in plant ecophysiology of C- and NC-endophytes, and highlight several key questions for future work in endophyte biology.

New Phytologist↗
USGS2003

Demographic and growth responses of a guerrilla and a phalanx perennial grass in competitive mixtures

The advantages of guerrilla and phalanx growth for the guerrilla Elymus lanceolatus ssp. lanceolatus and phalanx E. l. ssp. wawawaiensis were evaluated over 2 years in two taxon mixtures with a range of densities of each subspecies and under two levels of watering. Ramet numbers and biomass of the guerrilla subspecies were higher than those of the phalanx grass in the first year but in the second year declined greatly, while the phalanx grass showed no change in biomass and an increase in ramet numbers. High neighbour densities affected the phalanx subspecies more strongly than the guerrilla subspecies in the first year, but in the second year there were few differences between subspecies. Biomass of the guerrilla grass remained greater than that of the phalanx grass but ramet numbers were similar in the second year. For both subspecies in both years, probability of flowering decreased at higher neighbour densities, indicating adaptation for competitive ability. In the first year, biomass was more strongly reduced by densities than flowering was, but in the second year, when crowding was apparently greater, flowering was more severely affected. Genet survival was high and similar for both subspecies. The presumed advantage of guerrilla subspecies in exploiting open space was supported. The guerrilla grass exploited resources more quickly in the first year by faster growth and greater ramet production, but its biomass, ramet numbers and rhizome growth, and thus its advantage, were reduced in the second year. The phalanx subspecies had slower growth, produced more ramets in later years, and delayed flowering until later years. Although less able to exploit open resources, it appeared adapted to more stressful conditions, and may be able to exploit temporal resource pulses more effectively.

Journal of Ecology↗
USGS2025

Between a rock and a hard place: Experiences of the chronic wasting disease management community

Chronic wasting disease (CWD) is a widespread and incurable cervid disease. Despite continuing investments, the logistical challenges of CWD have required wildlife managers and researchers to navigate changing priorities with conflicting public perceptions. When overcoming difficult management problems, leveraging exploratory methods may identify previously unrecognized hypotheses. In this study, we interviewed wildlife managers and researchers to describe the diverse experiences of experts in the CWD management community. Our study asked about common management strategies used, challenges experienced, and attempted to understand how decision-making in CWD management is shaped and constrained. Our study participants experienced a wide range of constraining factors, primarily related to external influences. We also identified connections between these constraints and a common concern for staff and public burnout. The results of this study provide insight on constraints limiting CWD management success and possible explanations for some commonly recognized challenges resulting from social and ecological interactions.

Journal of Society and Natural Resources↗
USGS2024

Indications of preferential groundwater seepage feeding northern peatland pools

Groundwater seepage from underlying permeable glacial sedimentary structures, such as eskers, has been hypothesized to directly feed pools in northern peat bogs. These hypotheses directly contradict classical peat bog models for ombrogenous systems, wherein meteoric water is the sole water input to these systems. Variations in the underlying mineral sediment in contact with the peat imply that unrecognized hydrogeologic connectivity may exist with pools in northern peat bogs, particularly where high permeability materials are in contact with the peat. Seepage dynamics originating from these structural variations were investigated using a suite of thermal and hydrogeophysical methods deployed around pools in a peat bog of northeastern Maine, USA. Thermal characterization methods mapped anomalies that were confirmed as matrix seepage or preferential flow pathways (PFPs). Geochemical methods were employed at identified thermal anomalies to confirm upwelling of solute-rich groundwater. Conduits around pools were associated with surficial terminations of suspected peat pipes, based on the inference of pathways extending down into the peat, that focus flow through PFPs in the peat matrix. Discharge also occurred through the peat matrix adjacent to suspected pipe structures and matrix seepage rates were quantified using analysis of diurnal temperature signals recorded at multiple depths. Seepage rates, with a maximum of nearly 0.4 m/d, were measured at localized points around pools. Periods of synchronized temperatures paired with highly muted diurnal temperature signals, recorded in diurnal temperature with depth data, were interpreted qualitatively as activation of strong upward discharge rates through suspected peat pipes. These time periods correlated strongly with local precipitation events around the peatland. Ground-penetrating radar surveys revealed discontinuities in the low permeability glacio-marine clay at the mineral sediment-peat interface, interpreted to be regional glacial esker deposits, which were located beneath and around pools. Heat tracing, specific conductance contrasts, seepage rates, and trace metal concentrations all imply groundwater seepage originating from underlying permeable glacial esker deposits and directly sourcing pools. Preferential groundwater inputs into northern peat bogs may play a key role in developing and maintaining pool systems, with enhanced solute transport impacting peatland ecology, water resources, and carbon cycling.

Maine↗
USGS2007

Catch-and-release science and its application to conservation and management of recreational fisheries

Catch-and-release angling is a well-established practice in recreational angler behaviour and fisheries management. Accompanying this is a growing body of catch-and-release research that can be applied to reduce injury, mortality and sublethal alterations in behaviour and physiology. Here, the status of catch-and-release research from a symposium on the topic is summarised. Several general themes emerged including the need to: (1) better connect sublethal assessments to population-level processes; (2) enhance understanding of the variation in fish, fishing practices and gear and their role in catch and release; (3) better understand animal welfare issues related to catch and release; (4) increase the exchange of information on fishing-induced stress, injury and mortality between the recreational and commercial fishing sectors; and (5) improve procedures for measuring and understanding the effect of catch-and-release angling. Through design of better catch-and-release studies, strategies could be developed to further minimise stress, injury and mortality arising from catch-and-release angling. These strategies, when integrated with other fish population and fishery characteristics, can be used by anglers and managers to sustain or enhance recreational fishing resources. ?? 2007 The Authors. Journal compilation 2007 Blackwell Publishing Ltd.

Fisheries Management and Ecology↗
USGS2009

Lake St. Clair zooplankton: Evidence for post-Dreissena changes

We surveyed the zooplankton of Lake St. Clair at 12 sites over ten dates from May to October 2000. Mean zooplankton density by site and date was 168.6 individuals/L, with Dreissena spp. veligers the most abundant taxon at 122.7 individuals/L. Rotifers, copepods, and cladocerans were far lower in mean abundance than in the early 1970s (rotifers, 20.9/L; copepods, 18.1/L; and cladocerans, 6.8/L). Species richness of zooplankton taxa in 2000 was 147, which was virtually unchanged from that of the first reported survey in 1894. Overall, the decline in abundance was greatest for rotifers (-90%) and about equal for cladocerans (-69%) and copepods (-66%). The decrease in abundance of Daphnia spp. was especially dramatic in Canadian waters. The decline in the southeastern region was significant for all three major groups of zooplankton, whereas in the northwestern region the decline was significant only for rotifers. From June to August 2000, Lake St. Clair open waters were numerically dominated by Dreissena spp. veligers, with a reduced abundance of rotifers and crustaceans compared to pre-Dreissena spp. surveys. Mean nutrient concentrations were not different from the 1970s, but Secchi depth (greater) and chlorophyll a concentration (lower) were. Disproportionate reduction in rotifer abundance is consistent with hypotheses implicating direct consumption by settled Dreissena spp. Reduction of crustaceans is likely due to more complex interactions including removal of nauplii as well as resource competition for phytoplankton.

Michigan, Ontario↗
USGS2015

On formally integrating science and policy: walking the walk

The contribution of science to the development and implementation of policy is typically neither direct nor transparent. In 1995, the U.S. Fish and Wildlife Service (FWS) made a decision that was unprecedented in natural resource management, turning to an unused and unproven decision process to carry out trust responsibilities mandated by an international treaty. The decision process was adopted for the establishment of annual sport hunting regulations for the most economically important duck population in North America, the 6 to 11 million mallards Anas platyrhynchos breeding in the mid-continent region of north-central United States and central Canada. The key idea underlying the adopted decision process was to formally embed within it a scientific process designed to reduce uncertainty (learn) and thus make better decisions in the future. The scientific process entails use of models to develop predictions of competing hypotheses about system response to the selected action at each decision point. These prediction not only are used to select the optimal management action, but also are compared with the subsequent estimates of system state variables, providing evidence for modifying degrees of confidence in, and hence relative influence of, these models at the next decision point. Science and learning in one step are formally and directly incorporated into the next decision, contrasting with the usual ad hoc and indirect use of scientific results in policy development and decision-making. Application of this approach over the last 20 years has led to a substantial reduction in uncertainty, as well as to an increase in transparency and defensibility of annual decisions and a decrease in the contentiousness of the decision process. As resource managers are faced with increased uncertainty associated with various components of global change, this approach provides a roadmap for the future scientific management of natural resources.

Journal of Applied Ecology↗
USGS2012

Olympic Fisher Reintroduction Project: Progress report 2008-2011

This progress report summarizes the final year of activities of Phase I of the Olympic fisher restoration project. The intent of the Olympic fisher reintroduction project is to reestablish a self-sustaining population of fishers on the Olympic Peninsula. To achieve this goal, the Olympic fisher reintroduction project released 90 fishers within Olympic National Park from 2008 to 2010. The reintroduction of fishers to the Olympic Peninsula was designed as an adaptive management project, including the monitoring of released fishers as a means to (1) evaluate reintroduction success, (2) investigate key biological and ecological traits of fishers, and (3) inform future reintroduction, monitoring, and research efforts. This report summarizes reintroduction activities and preliminary research and monitoring results completed through December 2011. The report is non-interpretational in nature. Although we report the status of movement, survival, and home range components of the research, we have not completed final analyses and interpretation of research results. Much of the data collected during the monitoring and research project will be analyzed and interpreted in the doctoral dissertation being developed by Jeff Lewis; the completion of this dissertation is anticipated prior to April 2013. We anticipate that this work, and analyses of other data collected during the project, will result in several peer-reviewed scientific publications in ecological and conservation journals, which collectively will comprise the final reporting of work summarized here. These publications will include papers addressing post-release movements, survival, resource selection, food habits, and age determination of fishers.

Report↗
USGS2004

Toward a scientifically rigorous basis for developing mapped ecological regions.

Despite the wide use of ecological regions in conservation and resource-management evaluations and assessments, a commonly accepted theoretical basis for ecological regionalization does not exist. This fact, along with the paucity of focus on ecological regionalization by professional associations, journals, and faculties, has inhibited the advancement of a broadly acceptable scientific basis for the development, use, and verification of ecological regions. The central contention of this article is that ecological regions should improve our understanding of geographic and ecological phenomena associated with biotic and abiotic processes occurring in individual regions and also of processes characteristic of interactions and dependencies among multiple regions. Research associated with any ecoregional framework should facilitate development of hypotheses about ecological phenomena and dominant landscape elements associated with these phenomena, how these phenomena are structured in space, and how they function in a hierarchy. Success in addressing the research recommendations outlined in this article cannot occur within an ad hoc, largely uncoordinated research environment. Successful implementation of this plan will require activities--coordination, funding, and education--that are both scientific and administrative in nature. Perhaps the most important element of an infrastructure to support the scientific work of ecoregionalization would be a national or international authority similar to the Water and Science Technology Board of the National Academy of Sciences.

Environmental Management↗
USGS2010

Constructing an interdisciplinary flow regime recommendation

It is generally agreed that river rehabilitation most often relies on restoring a more natural flow regime, but credibly defining the desired regime can be problematic. I combined four distinct methods to develop and refine month-by-month and event-based flow recommendations to protect and partially restore the ecological integrity of the Cache la Poudre River through Fort Collins, Colorado. A statistical hydrologic approach was used to summarize the river's natural flow regime and set provisional monthly flow targets at levels that were historically exceeded 75% of the time. These preliminary monthly targets were supplemented using results from three Poudre-specific disciplinary studies. A substrate maintenance flow model was used to better define the high flows needed to flush accumulated sediment from the river's channel and help sustain the riparian zone in this snowmelt-dominated river. A hydraulic/habitat model and a water temperature model were both used to better define the minimum flows necessary to maintain a thriving cool water fishery. The result is a range of recommended monthly flows and daily flow guidance illustrating the advantage of combining a wide range of available disciplinary information, supplemented by judgment based on ecological principles and a general understanding of river ecosystems, in a highly altered, working river. ?? 2010 American Water Resources Association.

Journal of the American Water Resources Associatio↗
USGS2018

A database of natural monthly streamflow estimates from 1950 to 2015 for the conterminous United States

Quantifying and understanding the natural streamflow regime, defined as expected streamflow that would occur in the absence of anthropogenic modification to the hydrologic system, is critically important for the development of management strategies aimed at protecting aquatic ecosystems. Water balance models have been applied frequently to estimate natural flows, but are limited in the number of predictor variables that can be included. Here, a statistical machine learning technique — random forest modeling — was applied to estimate natural flows at a monthly time‐step from 1950 to 2015 for >2.5 million stream reaches in the conterminous United States (U.S.) using 200 potential predictor variables. We describe the development and documentation of this dataset and assess model performance. Model fit statistics (mean Nash–Sutcliffe efficiency = 0.85; observed/expected ratio = 0.94) indicate good correspondence between predicted and observed flows at nearly 2,000 streamgages. As an example application of the dataset, the observed streamflow record at a site prior to and after the construction of an upstream reservoir was compared with estimated natural flows to demonstrate the magnitude of seasonal depletions in streamflow due to the reservoir. This dataset can be applied to quantify natural and anthropogenic processes contributing to streamflow depletion or augmentation, and assess associated ecological effects.

Journal of the American Water Resources Associatio↗
USGS2025

Seasonal body mass dynamics mediate life-history trade-offs in a hibernating mammal

1. Energetic acquisition and growth are key traits that affect demography and life-history strategies. Many animals that live in seasonal environments in which food availability fluctuates store energy endogenously as fat in anticipation of food shortage. Fat-storing mammalian hibernators are an extreme example of this strategy where the optimal resolution of resource allocation trade-offs is essential to survival. Hence, these species provide an opportunity to test potential causes and consequences of seasonal body mass dynamics. 2. We used a 12-year dataset with 8753 body mass records from 3351 individually marked northern Idaho ground squirrels ( Urocitellus brunneus ) – a federally threatened hibernator – to meet three objectives: (1) document seasonal body mass changes by sex, age, and reproductive status, (2) test ecological hypotheses to explain spatiotemporal variation in body mass, and (3) document fitness consequences of pre-hibernation body condition via condition-dependent overwinter survival. 3. Squirrels varied substantially in seasonal body mass dynamics. The magnitude (36-155%) and onset (late May to early July) of rapid active-season mass gain varied among demographic groups. Reproductive females acquired the necessary fat stores to survive hibernation later in the active season than did males and non-reproductive females. Moreover, squirrels with better pre-hibernation body condition were more likely to survive to the subsequent year, potentially because they allocated excess energetic reserves to prolonging hibernation via early immergence and thereby reduced predation risk. These results suggest a direct trade-off between current and future reproduction mediated by resource acquisition and allocation, as predicted by life-history theory. 4. Colder active-season temperatures and lower conspecific densities negatively influenced squirrel body condition, possibly via reductions in foraging activity associated with those conditions. These ecological effects on body condition constrain resource allocation and demographic outcomes. As such, our results can help guide research and conservation strategies to benefit hibernating animals.

Idaho↗
USGS1990

Growth and equilibrium in sea otter populations

(1) Counts through time were compiled for five sea otter ( Enhydra lutris ) populations in the north-east Pacific Ocean that were below equilibrium density: Attu Island, south-east Alaska, British Columbia, Washington State, and central California. Similar data were obtained from the equilibrium density population at Amchitka Island in 1971 and 1986. (2) Shorelines of Attu and Amchitka islands each were divided into forty-five segments, within which lineal (length of shore at mean higher high water) and areal (mean higher high water to the 10-fathom (18.3-m) depth contour) measures were made of the amount of habitat. (3) Rate of increase for the four northern populations was 17-20% year-1. Density- or size-dependent changes in rate of increase could not be demonstrated for any of these populations. The California population, in contrast, has undergone three apparent growth phases: the early 1900s to the mid-1970s when it increased about 5% year-1; the mid-1970s to the mid-1980s when it declined about 5% year-1; and the mid-1980s to 1988 when it increased about 7% year-1. An exponential growth model accounted for 92-98% of the variation in counts through time in all cases. (4) Population increase at Attu Island was achieved largely by range expansion as opposed to increased density. Range expansion in lineal and areal habitat occurred at 11% and 13% year-1, respectively; neither rate was lower (P > 0.25) than the observed rate of increase in numbers of animals counted. (5) Despite similarities in island size and physical environment, the most conservative estimates of population density at Amchitka Island were > 3 X greater than maximum density estimates for Attu Island. (6) Surveys of Amchitka Island from the mid-1930s through the mid-1980s indicate that the population increased to a peak in the 1940s; declined abruptly thereafter; and subsequently increased to a new and higher equilibrium in the 1960s, where it has since remained. (7) These population data, together with information on sea otter foraging and benthic community structure at Attu and Amchitka islands, suggest that multiple population equilibria exist in this system, emanating from complex trophic interactions low in the food web. I hypothesize that the lower population equilibrium is achieved largely or exclusively on an invertebrate diet consisting principally of herbivorous sea urchins. When unregulated by sea otter predation, the rocky benthos is deforested by sea urchin grazing. As growing otter populations compete increasingly for food, grazing intensity declines and the system shifts to one dominated by kelp beds, in turn leading to increased production, a shift in habitat structure, and population increases of kelp bed fishes. Apparently this new food resource elevates the sea otter population to a higher and more stable equilibrium.

Journal of Animal Ecology↗
USGS1986

Mid-winter food use and body weights of mallards and wood ducks in Mississippi

We obtained esophageal food samples from 311 mallards (Anas platyrhynchos) and 94 wood ducks (Aix sponsa) and body weights from 2,118 mallards and 315 wood ducks in western Mississippi during December and January 1979-83. On average, mallards ingested 3.0% animal food, principally aquatic invertebrates, and 97.0% plant food. Rice, soybeans, and seeds of 'moist soil' plants provided 41.3, 41.6, and 10-11% of the total food intake. Wood ducks ingested nearly 100% plant food, of which 23.4% was soybeans and 74.3% was acorns from Nuttall (Quercus nuttallii), water (Q. nigra), and willow oaks (Q. phellos). Mallard food use varied with water conditions; the use of rice decreased and soybeans increased during 1980-81 when cumulative November-January precipitation was < 50% of normal. Wood duck food use varied with habitat; the diet included more acorns at sites having larger acreages of intact bottomland hardwood forest. Mallard and wood duck body weights varied within and among winters. Mallard weights decreased by about 2% from December to January each year. We considered this a regulated loss, whereas we attributed increases and decreases of 4-5% in average weights during wet and dry winters to changes in feeding opportunities associated with winter precipitation. Wood duck weights followed similar trends. We concluded that continued drainage in the Mississippi Delta will adversely affect waterfowl foraging opportunities, and that research on winter feeding ecology will progress more rapidly if we develop an understanding of the foraging efficiencies associated with alternate food resources.

Mississippi↗
USGS1984

Elk and deer diets in old-growth forests in western Washington

Dietary quality and overlap of sympatric Roosevelt elk ( Cervus elaphus roosevelti ) and Columbian black-tailed deer ( Odocoileus hemionus columbianus ) were investigated in old-growth forests of the Hoh Valley, Olympic National Park, Washington. Diets of both cervids were comprised mainly of common old-growth flora, particularly in winter. High dietary overlap suggested competitive interactions for food, especially in winter when forage resources were least available. Predominant forages in fall and winter diets seemed to afford little opportunity for cervids to select different plant parts. Crude protein (CP), in vitro dry matter digestibility (IVDMD), and phosphorus (P) in important forages varied with phenology, but seasonal trends were more pronounced for shrubs and grasses than forbs and trees. CP, IVDMD, and P in cervid diets also varied seasonally and usually in the following ascending order: winter, fall, summer, spring. CP and P appeared to be adequate in diets, but low IVDMD suggested that digestible energy was limited. Few significant differences in seasonal dietary qualities were demonstrated between elk and deer. The collective cervid population (and its habitat) in the Hoh Valley is unmanaged and probably at equilibrium with its food resource, or at ecological carrying capacity. Results are discussed in light of herbivore--habitat interactions at equilibrium densities.

Washington↗
USGS2009

A cautionary note on substituting spatial subunits for repeated temporal sampling in studies of site occupancy

1. Assessing the probability that a given site is occupied by a species of interest is important to resource managers, as well as metapopulation or landscape ecologists. Managers require accurate estimates of the state of the system, in order to make informed decisions. Models that yield estimates of occupancy, while accounting for imperfect detection, have proven useful by removing a potentially important source of bias. To account for detection probability, multiple independent searches per site for the species are required, under the assumption that the species is available for detection during each search of an occupied site. 2. We demonstrate that when multiple samples per site are defined by searching different locations within a site, absence of the species from a subset of these spatial subunits induces estimation bias when locations are exhaustively assessed or sampled without replacement. 3. We further demonstrate that this bias can be removed by choosing sampling locations with replacement, or if the species is highly mobile over a short period of time. 4. Resampling an existing data set does not mitigate bias due to exhaustive assessment of locations or sampling without replacement. 5. Synthesis and applications. Selecting sampling locations for presence/absence surveys with replacement is practical in most cases. Such an adjustment to field methods will prevent one source of bias, and therefore produce more robust statistical inferences about species occupancy. This will in turn permit managers to make resource decisions based on better knowledge of the state of the system.

Journal of Applied Ecology↗
USGS2004

Energy density and variability in abundance of pigeon guillemot prey: Support for the quality-variability trade-off hypothesis

1. The quality-variability trade-off hypothesis predicts that (i) energy density (kJ g-1) and spatial-temporal variability in abundance are positively correlated in nearshore marine fishes; and (ii) prey selection by a nearshore piscivore, the pigeon guillemot (Cepphus columba Pallas), is negatively affected by variability in abundance. 2. We tested these predictions with data from a 4-year study that measured fish abundance with beach seines and pigeon guillemot prey utilization with visual identification of chick meals. 3. The first prediction was supported. Pearson's correlation showed that fishes with higher energy density were more variable on seasonal (r = 0.71) and annual (r = 0.66) time scales. Higher energy density fishes were also more abundant overall (r = 0.85) and more patchy at a scale of 10s of km (r = 0.77). 4. Prey utilization by pigeon guillemots was strongly non-random. Relative preference, defined as the difference between log-ratio transformed proportions of individual prey taxa in chick diets and beach seine catches, was significantly different from zero for seven of the eight main prey categories. 5. The second prediction was also supported. We used principal component analysis (PCA) to summarize variability in correlated prey characteristics (energy density, availability and variability in abundance). Two PCA scores explained 32% of observed variability in pigeon guillemot prey utilization. Seasonal variability in abundance was negatively weighted by these PCA scores, providing evidence of risk-averse selection. Prey availability, energy density and km-scale variability in abundance were positively weighted. 6. Trophic interactions are known to create variability in resource distribution in other systems. We propose that links between resource quality and the strength of trophic interactions may produce resource quality-variability trade-offs.

Journal of Animal Ecology↗