@article{maurer_gross_stapleton_2022, title={Beached Sargassum alters sand thermal environments: Implications for incubating sea turtle eggs}, volume={546}, ISSN={["1879-1697"]}, DOI={10.1016/j.jembe.2021.151650}, abstractNote={Global environmental change has featured a rise in macroalgae blooms. These events generate immense amounts of biomass that can subsequently arrive on shorelines. Such a scenario has been playing out since 2011 in the tropical and subtropical Atlantic, where Sargassum spp. have been causing periodic ‘golden tides’ in coastal habitats. Here we describe impacts on sea turtle nesting ecology, with a focus on the below-ground thermal environment for incubating eggs. Sargassum may blanket the surface of beaches due to natural wave or wind energy and can be redistributed via anthropogenic beach cleaning. When it covers egg clutches, it may alter incubation temperatures and therefore affect both embryonic survival and primary sex ratios. To evaluate the thermal impacts of Sargassum, we measured sand temperatures with data loggers buried under Sargassum cover treatments on a beach in Antigua, West Indies. Our split-plot experiment also tested for effects from shade, season (summer versus autumn), and high rainfall events. We modeled temperatures with a mixed-effects model and, surprisingly, our most compelling finding suggested that Sargassum's effects on below-ground temperatures were contingent on season. Greater Sargassum cover was associated with a cooling effect in the summer but warming in the autumn. We assume that the model term for season integrates several climate-related factors that vary seasonally in the Eastern Caribbean and modulate Sargassum's impact, including windspeeds. Comparing estimated marginal means for the high-cover treatments versus the controls, Sargassum cover led to a 0.21 °C increase in the autumn and a 0.17 °C decrease in the summer; these thermal changes can significantly impact developmental outcomes for sea turtle embryos. Atlantic nesting beach managers should monitor this macroalgal phenomenon and can use these data to begin to infer impacts on sea turtle populations and develop potential management strategies.}, journal={JOURNAL OF EXPERIMENTAL MARINE BIOLOGY AND ECOLOGY}, author={Maurer, Andrew S. and Gross, Kevin and Stapleton, Seth P.}, year={2022}, month={Jan} }
 @article{gross_roos_2021, title={Resonance in Physiologically Structured Population Models}, volume={83}, ISSN={["1522-9602"]}, DOI={10.1007/s11538-021-00915-2}, abstractNote={Ecologists have long sought to understand how the dynamics of natural populations are affected by the environmental variation those populations experience. A transfer function is a useful tool for this purpose, as it uses linearization theory to show how the frequency spectrum of the fluctuations in a population's abundance relates to the frequency spectrum of environmental variation. Here, we show how to derive and to compute the transfer function for a continuous-time model of a population that is structured by a continuous individual-level state variable such as size. To illustrate, we derive, compute, and analyze the transfer function for a size-structured population model of stony corals with open recruitment, parameterized for a common Indo-Pacific coral species complex. This analysis identifies a sharp multi-decade resonance driven by space competition between existing coral colonies and incoming recruits. The resonant frequency is most strongly determined by the rate at which colonies grow, and the potential for resonant oscillations is greatest when colony growth is only weakly density-dependent. While these resonant oscillations are unlikely to be a predominant dynamical feature of degraded reefs, they suggest dynamical possibilities for marine invertebrates in more pristine waters. The size-structured model that we analyze is a leading example of a broader class of physiologically structured population models, and the methods we present should apply to a wide variety of models in this class.}, number={8}, journal={BULLETIN OF MATHEMATICAL BIOLOGY}, author={Gross, Kevin and Roos, Andre M.}, year={2021}, month={Aug} }
 @article{gross_roos_2021, title={Resonance in Physiologically Structured Population Models (vol 83, 86, 2021)}, volume={83}, ISSN={["1522-9602"]}, DOI={10.1007/s11538-021-00931-2}, number={10}, journal={BULLETIN OF MATHEMATICAL BIOLOGY}, author={Gross, Kevin and Roos, Andre M.}, year={2021}, month={Oct} }
 @misc{gross_bergstrom_2021, title={Why ex post peer review encourages high-risk research while ex ante review discourages it}, volume={118}, ISSN={["1091-6490"]}, DOI={10.1073/pnas.2111615118}, abstractNote={Significance Science operates within social structures that govern and shape scientific activity. One such institution is peer review, which focuses attention on promising and interesting science while encouraging scientists to pursue some questions instead of others. Here, we show that ex ante review of proposals for future work and ex post review of completed science create different incentives for researchers. This tension creates a dilemma, because most researchers need to find projects that will survive both ex ante and ex post peer review. By unpacking this dynamic, we can understand how peer review shapes scientific activity and how changes to peer review might take science in unforeseen directions. Peer review is an integral component of contemporary science. While peer review focuses attention on promising and interesting science, it also encourages scientists to pursue some questions at the expense of others. Here, we use ideas from forecasting assessment to examine how two modes of peer review—ex ante review of proposals for future work and ex post review of completed science—motivate scientists to favor some questions instead of others. Our main result is that ex ante and ex post peer review push investigators toward distinct sets of scientific questions. This tension arises because ex post review allows investigators to leverage their own scientific beliefs to generate results that others will find surprising, whereas ex ante review does not. Moreover, ex ante review will favor different research questions depending on whether reviewers rank proposals in anticipation of changes to their own personal beliefs or to the beliefs of their peers. The tension between ex ante and ex post review puts investigators in a bind because most researchers need to find projects that will survive both. By unpacking the tension between these two modes of review, we can understand how they shape the landscape of science and how changes to peer review might shift scientific activity in unforeseen directions.}, number={52}, journal={PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA}, author={Gross, Kevin and Bergstrom, Carl T.}, year={2021}, month={Dec} }
 @article{courtney_barnes_chollett_elahi_gross_guest_kuffner_lenz_nelson_rogers_et al._2020, title={Disturbances drive changes in coral community assemblages and coral calcification capacity}, volume={11}, ISSN={["2150-8925"]}, DOI={10.1002/ecs2.3066}, abstractNote={. Anthropogenic environmental change has increased coral reef disturbance regimes in recent decades, altering the structure and function of many coral reefs globally. In this study, we used coral community survey data collected from 1996 to 2015 to evaluate reef-scale coral calci fi cation capacity (CCC) dynamics with respect to recorded pulse disturbances for 121 reef sites in the Main Hawaiian Islands and Mo'orea (French Polynesia) in the Paci fi c and the Florida Keys Reef Tract and St. John (U.S. Virgin Islands) in the western Atlantic. CCC remained relatively high in the Main Hawaiian Islands in the absence of recorded widespread disturbances; declined and subsequently recovered in Mo'orea following a crown-of-thorns sea star outbreak, coral bleaching, and major cyclone; decreased and remained low following coral bleaching in the Florida Keys Reef Tract; and decreased following coral bleaching and disease in St. John. Individual coral taxa have variable calci fi cation rates and susceptibility to disturbances because of their differing life-history strategies. As a result, temporal changes in CCC in this study were driven by shifts in both overall coral cover and coral community composition. Analysis of our results considering coral life-history strategies showed that weedy corals generally increased their contributions to CCC over time while the contribution of competitive corals decreased. Shifts in contributions by stress-tolerant and generalist corals to CCC were more variable across regions. The increasing frequency and intensity of disturbances under 21st century global change therefore has the potential to drive lower and more variable CCC because of the increasing dominance of weedy and some stress-tolerant corals.}, number={4}, journal={ECOSPHERE}, author={Courtney, Travis A. and Barnes, Brian B. and Chollett, Iliana and Elahi, Robin and Gross, Kevin and Guest, James R. and Kuffner, Ilsa B. and Lenz, Elizabeth A. and Nelson, Hannah R. and Rogers, Caroline S. and et al.}, year={2020}, month={Apr} }
 @article{grantham_guan_reich_borer_gross_2020, title={MIMIX: A Bayesian Mixed-Effects Model for Microbiome Data From Designed Experiments}, volume={115}, ISSN={["1537-274X"]}, DOI={10.1080/01621459.2019.1626242}, abstractNote={Abstract Recent advances in bioinformatics have made high-throughput microbiome data widely available, and new statistical tools are required to maximize the information gained from these data. For example, analysis of high-dimensional microbiome data from designed experiments remains an open area in microbiome research. Contemporary analyses work on metrics that summarize collective properties of the microbiome, but such reductions preclude inference on the fine-scale effects of environmental stimuli on individual microbial taxa. Other approaches model the proportions or counts of individual taxa as response variables in mixed models, but these methods fail to account for complex correlation patterns among microbial communities. In this article, we propose a novel Bayesian mixed-effects model that exploits cross-taxa correlations within the microbiome, a model we call microbiome mixed model (MIMIX). MIMIX offers global tests for treatment effects, local tests and estimation of treatment effects on individual taxa, quantification of the relative contribution from heterogeneous sources to microbiome variability, and identification of latent ecological subcommunities in the microbiome. MIMIX is tailored to large microbiome experiments using a combination of Bayesian factor analysis to efficiently represent dependence between taxa and Bayesian variable selection methods to achieve sparsity. We demonstrate the model using a simulation experiment and on a 2 × 2 factorial experiment of the effects of nutrient supplement and herbivore exclusion on the foliar fungal microbiome of Andropogon gerardii, a perennial bunchgrass, as part of the global Nutrient Network research initiative. Supplementary materials for this article, including a standardized description of the materials available for reproducing the work, are available as an online supplement.}, number={530}, journal={JOURNAL OF THE AMERICAN STATISTICAL ASSOCIATION}, author={Grantham, Neal S. and Guan, Yawen and Reich, Brian J. and Borer, Elizabeth T. and Gross, Kevin}, year={2020}, month={Apr}, pages={599–609} }
 @article{gross_bergstrom_2019, title={Contest models highlight inherent inefficiencies of scientific funding competitions}, volume={17}, ISSN={["1545-7885"]}, DOI={10.1371/journal.pbio.3000065}, abstractNote={Scientific research funding is allocated largely through a system of soliciting and ranking competitive grant proposals. In these competitions, the proposals themselves are not the deliverables that the funder seeks, but instead are used by the funder to screen for the most promising research ideas. Consequently, some of the funding program's impact on science is squandered because applying researchers must spend time writing proposals instead of doing science. To what extent does the community's aggregate investment in proposal preparation negate the scientific impact of the funding program? Are there alternative mechanisms for awarding funds that advance science more efficiently? We use the economic theory of contests to analyze how efficiently grant proposal competitions advance science, and compare them with recently proposed, partially randomized alternatives such as lotteries. We find that the effort researchers waste in writing proposals may be comparable to the total scientific value of the research that the funding supports, especially when only a few proposals can be funded. Moreover, when professional pressures motivate investigators to seek funding for reasons that extend beyond the value of the proposed science (e.g., promotion, prestige), the entire program can actually hamper scientific progress when the number of awards is small. We suggest that lost efficiency may be restored either by partial lotteries for funding or by funding researchers based on past scientific success instead of proposals for future work.}, number={1}, journal={PLOS BIOLOGY}, author={Gross, Kevin and Bergstrom, Carl T.}, year={2019}, month={Jan} }
 @article{rana_gross_price_2019, title={Drivers of Elevational Richness Peaks, Evaluated for Trees in the East Himalaya}, volume={100}, ISSN={0012-9623}, url={http://dx.doi.org/10.1002/BES2.1499}, DOI={10.1002/BES2.1499}, abstractNote={A mid-elevation peak in species richness is common in many clades. Here, we studied trees of the east Himalaya and found a richness peak at 500–1,000 m. We argue that this results from a correlation of climate with both the numbers and kinds of species, coupled with a geometric constraint in which range expansions from the plains introduce few new species at the base, whereas just above the base, novel species have ranges extending from both above and below. We develop a mathematical model to derive conditions for this to happen. A prediction is that species’ elevational ranges should be smaller at lower elevations, as we find. These photographs illustrate the article “Drivers of elevational richness peaks, evaluated for trees in the east Himalaya” by Suresh K. Rana, Kevin Gross, and Trevor D. Price published in Ecology. https://doi.org/10.1002/ecy.2548}, number={1}, journal={The Bulletin of the Ecological Society of America}, publisher={Wiley}, author={Rana, Suresh K. and Gross, Kevin and Price, Trevor D.}, year={2019}, month={Jan}, pages={e01499} }
 @article{rana_gross_price_2019, title={Drivers of elevational richness peaks, evaluated for trees in the east Himalaya}, volume={100}, ISSN={["1939-9170"]}, DOI={10.1002/ecy.2548}, abstractNote={Along elevational gradients, species richness often peaks at intermediate elevations and not the base. Here we refine and test eight hypotheses to evaluate causes of a richness peak in trees of the eastern Himalaya. In the field, we enumerated trees in 50 plots of size 0.1 ha each at eight zones along an elevational gradient and compared richness patterns with interpolation of elevational ranges of species from a thorough review of literature, including floras from the plains of India. The maximum number of species peaks at similar elevations in the two data sets (at 500 m in the field sampling and between 500 m and 1,000 m in range interpolation); concordance between the methods implies that statistical artefacts are unlikely to explain the peak in the data. We reject most hypotheses (e.g., area, speciation rate, mixing of distinct floras). We find support for a model in which climate (actual evapotranspiration [AET] or its correlates) sets both the number of species and each species optimum, coupled with a geometric constraint. We consider that AET declines with elevation, but an abrupt change in the association of AET with geographical distance into the plains means that the location of highest AET, at the base of the mountain, receives range overlaps from fewer species than the location just above the base. We formalize this explanation with a mathematical model to show how this can generate the observed low-elevation richness peak.}, number={1}, journal={ECOLOGY}, author={Rana, Suresh K. and Gross, Kevin and Price, Trevor D.}, year={2019}, month={Jan} }
 @article{guest_edmunds_gates_kuffner_andersson_barnes_chollett_courtney_elahi_gross_et al._2018, title={A framework for identifying and characterising coral reef "oases" against a backdrop of degradation}, volume={55}, ISSN={["1365-2664"]}, DOI={10.1111/1365-2664.13179}, abstractNote={1. Human activities have led to widespread ecological decline; however, the severity of degradation is spatially heterogeneous due to some locations resisting, escaping, or rebounding from disturbances.2. We developed a framework for identifying oases within coral reef regions using long-term monitoring data. We calculated standardised estimates of coral cover (z-scores) to distinguish sites that deviated positively from regional means. We also used the coefficient of variation (CV) of coral cover to quantify how oases varied temporally, and to distinguish among types of oases. We estimated "coral calcification capacity" (CCC), a measure of the coral community's ability to produce calcium carbonate structures and tested for an association between this metric and z-scores of coral cover.3. We illustrated our z-score approach within a modelling framework by extracting z-scores and CVs from simulated data based on four generalized trajectories of coral cover. We then applied the approach to time-series data from long-term reef monitoring programmes in four focal regions in the Pacific (the main Hawaiian Islands and Mo'orea, French Polynesia) and western Atlantic (the Florida Keys and St. John, US Virgin Islands). Among the 123 sites analysed, 38 had positive z-scores for median coral cover and were categorised as oases.4. Synthesis and applications. Our framework provides ecosystem managers with a valuable tool for conservation by identifying "oases" within degraded areas. By evaluating trajectories of change in state (e.g., coral cover) among oases, our approach may help in identifying the mechanisms responsible for spatial variability in ecosystem condition. Increased mechanistic understanding can guide whether management of a particular location should emphasise protection, mitigation or restoration. Analysis of the empirical data suggest that the majority of our coral reef oases originated by either escaping or resisting disturbances, although some sites showed a high capacity for recovery, while others were candidates for restoration. Finally, our measure of reef condition (i.e., median z-scores of coral cover) correlated positively with coral calcification capacity suggesting that our approach identified oases that are also exceptional for one critical component of ecological function.}, number={6}, journal={JOURNAL OF APPLIED ECOLOGY}, author={Guest, James R. and Edmunds, Peter J. and Gates, Ruth D. and Kuffner, Ilsa B. and Andersson, Andreas J. and Barnes, Brian B. and Chollett, Iliana and Courtney, Travis A. and Elahi, Robin and Gross, Kevin and et al.}, year={2018}, month={Nov}, pages={2865–2875} }
 @article{stone_gross_2018, title={Evolution of host preference in anthropophilic mosquitoes}, volume={17}, journal={Malaria Journal}, author={Stone, C. and Gross, K.}, year={2018} }
 @article{gross_snyder-beattie_2016, title={A General, Synthetic Model for Predicting Biodiversity Gradients from Environmental Geometry}, volume={188}, ISSN={["1537-5323"]}, DOI={10.1086/688171}, abstractNote={Latitudinal and elevational biodiversity gradients fascinate ecologists, and have inspired dozens of explanations. The geometry of the abiotic environment is sometimes thought to contribute to these gradients, yet evaluations of geometric explanations are limited by a fragmented understanding of the diversity patterns they predict. This article presents a mathematical model that synthesizes multiple pathways by which environmental geometry can drive diversity gradients. The model characterizes species ranges by their environmental niches and limits on range sizes and places those ranges onto the simplified geometries of a sphere or cone. The model predicts nuanced and realistic species-richness gradients, including latitudinal diversity gradients with tropical plateaus and mid-latitude inflection points and elevational diversity gradients with low-elevation diversity maxima. The model also illustrates the importance of a mid-environment effect that augments species richness at locations with intermediate environments. Model predictions match multiple empirical biodiversity gradients, depend on ecological traits in a testable fashion, and formally synthesize elements of several geometric models. Together, these results suggest that previous assessments of geometric hypotheses should be reconsidered and that environmental geometry may play a deeper role in driving biodiversity gradients than is currently appreciated.}, number={4}, journal={AMERICAN NATURALIST}, author={Gross, Kevin and Snyder-Beattie, Andrew}, year={2016}, month={Oct}, pages={E85–E97} }
 @article{gross_2016, title={Biodiversity and productivity entwined}, volume={529}, ISSN={["1476-4687"]}, DOI={10.1038/nature16867}, abstractNote={A systems-level analysis of grasslands across the planet provides stimulating insight into the interlaced pathways that connect species diversity and biological productivity in ecological communities. See Letter p.390 The relationship between species richness and ecosystem productivity is a central topic in ecological research, and also the focus of competing and overlapping hypotheses. These authors use data from grassland experiments across five continents to compare the different mechanistic explanations in an integrative framework. They show how important components of different mechanisms are operating together, and increase considerably our power to explain the results.}, number={7586}, journal={NATURE}, author={Gross, Kevin}, year={2016}, month={Jan}, pages={293–294} }
 @article{stone_chitnis_gross_2016, title={Environmental influences on mosquito foraging and integrated vector management can delay the evolution ofbehavioral resistance}, volume={9}, ISSN={["1752-4571"]}, DOI={10.1111/eva.12354}, abstractNote={Along with the scaled‐up distribution of long‐lasting insecticidal nets for malaria control has become concern about insecticide resistance. A related concern regards the evolution of host‐seeking periodicity from the nocturnal to the crepuscular periods of the day. Why we observe such shifts in some areas but not others and which methods could prove useful in managing such behavioral resistance remain open questions. We developed a foraging model to explore whether environmental conditions affect the evolution of behavioral resistance. We looked at the role of the abundance of blood hosts and nectar sources and investigated the potential of attractive toxic sugar baits for integrated control. Higher encounter rates with hosts and nectar sources allowed behaviorally resistant populations to persist at higher levels of bed net coverage. Whereas higher encounter rates with nectar increased the threshold where resistance emerged, higher encounter rates of hosts lowered this threshold. Adding sugar baits lowered the coverage level of bed nets required to eliminate the vector population. In certain environments, using lower bed net coverage levels together with toxic sugar baits may delay or prevent the evolution of behavioral resistance. Designing sustainable control strategies will depend on an understanding of vector behavior expressed in local environmental conditions.}, number={3}, journal={EVOLUTIONARY APPLICATIONS}, author={Stone, Chris and Chitnis, Nakul and Gross, Kevin}, year={2016}, month={Mar}, pages={502–517} }
 @article{backus_gross_2016, title={Genetic engineering to eradicate invasive mice on islands: modeling the efficiency and ecological impacts}, volume={7}, ISSN={2150-8925 2150-8925}, url={http://dx.doi.org/10.1002/ECS2.1589}, DOI={10.1002/ECS2.1589}, abstractNote={Invasive rodents are usually eradicated from islands through the application of chemical toxicants that can harm surrounding ecosystems. A recently proposed alternative involves engineering a house mouse (Mus musculus) to carry a genetic construct that would cause a majority of its offspring to be male, many of which would be sterile. Releasing these genetically engineered mice to interbreed with an invasive population would reduce the number of fertile female mice until no more remain. We constructed a mathematical model to analyze the population dynamics of eradication with this genetically engineered mouse and determined its eradication efficiency through model analysis and simulations. Because genetically engineered mice would likely have a fitness disadvantage compared to wild mice, we found that they would need to be repeatedly released into the population to ensure complete eradication. However, if genetically engineered mice have a substantial survival advantage, we determined that the genetic construct could theoretically spread and eradicate a population after a single pulsed release onto the target island or after an engineered mouse escapes to a non-target location. Also, while the species specificity of genetic engineering avoids some of the non-target impacts of traditional eradication methods, ecological impacts could manifest indirectly. We compared several metrics to estimate potential transient impacts on the ecosystem and found that there is a trade-off between the speed of an eradication and the intensity of increased disruptive ecological interactions. Together, our results can inform safe and efficient ecological practices for eradication with developing genetic engineering technology.}, number={12}, journal={Ecosphere}, publisher={Wiley}, author={Backus, Gregory A. and Gross, Kevin}, year={2016}, month={Dec} }
 @article{edmunds_comeau_lantz_andersson_briggs_cohen_gattuso_grady_gross_johnson_et al._2016, title={Integrating the Effects of Ocean Acidification across Functional Scales on Tropical Coral Reefs}, volume={66}, ISSN={["1525-3244"]}, DOI={10.1093/biosci/biw023}, abstractNote={There are concerns about the future of coral reefs in the face of ocean acidification and warming, and although studies of these phenomena have advanced quickly, efforts have focused on pieces of the puzzle rather than integrating them to evaluate ecosystem-level effects. The field is now poised to begin this task, but there are information gaps that first must be overcome before progress can be made. Many of these gaps focus on calcification at the levels of cells, organisms, populations, communities, and ecosystem, and their closure will be made difficult by the complexity of the interdependent processes by which coral reefs respond to ocean acidification, with effects scaling from cells to ecosystems and from microns to kilometers. Existing ecological theories provide an important and largely untapped resource for overcoming these difficulties, and they offer great potential for integrating the effects of ocean acidification across scales on coral reefs.}, number={5}, journal={BIOSCIENCE}, author={Edmunds, Peter J. and Comeau, Steeve and Lantz, Coulson and Andersson, Andreas and Briggs, Cherie and Cohen, Anne and Gattuso, Jean-Pierre and Grady, John M. and Gross, Kevin and Johnson, Maggie and et al.}, year={2016}, month={May}, pages={350–362} }
 @article{nissen_magidson_gross_bergstrom_2016, title={Publication bias and the canonization of false facts}, volume={5}, journal={Elife}, author={Nissen, S. B. and Magidson, T. and Gross, K. and Bergstrom, C. T.}, year={2016} }
 @article{mordecai_gross_mitchell_2016, title={Within-Host Niche Differences and Fitness Trade-offs Promote Coexistence of Plant Viruses}, volume={187}, ISSN={["1537-5323"]}, DOI={10.1086/684114}, abstractNote={Pathogens live in diverse, competitive communities, yet the processes that maintain pathogen diversity remain elusive. Here, we use a species-rich, well-studied plant virus system, the barley yellow dwarf viruses, to examine the mechanisms that regulate pathogen diversity. We empirically parameterized models of three viruses, their two aphid vectors, and one perennial grass host. We found that high densities of both aphids maximized virus diversity and that competition limited the coexistence of two closely related viruses. Even limited ability to simultaneously infect (coinfect) host individuals strongly promoted virus coexistence; preventing coinfection led to priority effects. Coinfection generated stabilizing niche differences by allowing viruses to share hosts. However, coexistence also required trade-offs between vector generalist and specialist life-history strategies. Our predicted outcomes broadly concur with previous field observations. These results show how competition within individual hosts and vectors may lead to unexpected population-level outcomes between pathogens, including coexistence, competitive exclusion, and priority effects, and how contemporary coexistence theory can help to predict these outcomes.}, number={1}, journal={AMERICAN NATURALIST}, author={Mordecai, Erin A. and Gross, Kevin and Mitchell, Charles E.}, year={2016}, month={Jan}, pages={E13–E26} }
 @article{mordecai_molinari_stahlheber_gross_d'antonio_2015, title={Controls over native perennial grass exclusion and persistence in California grasslands invaded by annuals}, volume={96}, DOI={10.1890/14-2023.1}, abstractNote={Despite obvious impacts of nonnative species in many ecosystems, the long-term outcome of competition between native and exotic species often remains unclear. Demographic models can resolve the outcome of competition between native and exotic species and provide insight into conditions favoring exclusion vs. coexistence. California grasslands are one of the most heavily invaded ecosystems in North America. Although California native perennial bunchgrasses are thought to be restricted to a fraction of their original abundance, the eventual outcome of competition with invasive European annual grasses at a local scale (competitive exclusion, stable persistence, or priority effects) remains unresolved. Here, we used a two-species discrete time population growth model to predict the outcome of competition between exotic annual and native perennial grasses in California, and to determine the demographic traits responsible for the outcome. The model is parameterized with empirical data from several field experiments. We found that, once introduced, annual grasses persist stably with little uncertainty. Although perennial grasses are competitively excluded on average, the most likely range of model predictions also includes stable coexistence with annual grasses. As for many other perennial plants, native bunchgrass population growth is highly sensitive to the survival of adults. Management interventions that improve perennial adult survival are likely to be more effective than those that reduce exotic annual seed production or establishment, reduce competition, or increase perennial seedling establishment. Further empirical data on summer survival of bunchgrass adults and competitive effects of annuals on perennials would most improve model predictions because they contribute most to the uncertainty in the predicted outcome for the perennial grass. This work demonstrates how demographic approaches can clarify the outcome of competition between native and exotic species, identify key targets for future empirical work, and predict the effectiveness of management interventions. Such studies are critical both for understanding the impacts of invasion and for targeting management responses that maximize the benefit to native species.}, number={10}, journal={Ecology}, author={Mordecai, E. A. and Molinari, N. A. and Stahlheber, K. A. and Gross, K. and D'Antonio, C.}, year={2015}, pages={2643–2652} }
 @article{cayton_haddad_gross_diamond_ries_2015, title={Do growing degree days predict phenology across butterfly species?}, volume={96}, ISSN={["1939-9170"]}, DOI={10.1890/15-0131.1}, abstractNote={Global climate change is causing shifts in phenology across multiple species. We use a geographically and temporally extensive data set of butterfly abundance across the state of Ohio to ask whether phenological change can be predicted from climatological data. Our focus is on growing degree days (GDD), a commonly used measure of thermal accumulation, as the mechanistic link between climate change and species phenology. We used simple calculations of median absolute error associated with GDD and an alternative predictor of phenology, ordinal date, for both first emergence and peak abundance of 13 butterfly species. We show that GDD acts as a better predictor than date for first emergence in nearly all species, and for peak abundance in more than half of all species, especially univoltine species. Species with less ecological flexibility, in particular those with greater dietary specialization, had greater predictability with GDD. The new method we develop for predicting phenology using GDD offers a simple...}, number={6}, journal={ECOLOGY}, author={Cayton, Heather L. and Haddad, Nick M. and Gross, Kevin and Diamond, Sarah E. and Ries, Leslie}, year={2015}, month={Jun}, pages={1473–1479} }
 @article{cook_peterson_colter chitwood_palmer_deperno_gross_2015, title={Evaluating Deer Hunters’ Support for Hunting Deer with Dogs}, volume={20}, ISSN={1087-1209 1533-158X}, url={http://dx.doi.org/10.1080/10871209.2014.997328}, DOI={10.1080/10871209.2014.997328}, abstractNote={Hunting deer with dogs (dog hunting) has a long tradition in the United States but has created conflict among deer hunters. Our objectives were to determine factors predicting support for dog hunting in North Carolina. Using a 2006 survey of North Carolina deer hunters, we evaluated factors that potentially influenced support for dog hunting (e.g., geographic region, hunting method, perceptions about deer populations and hunter participation, leasing practices). Nearly half (46%) of the deer hunters (n = 5,005) believed dog hunting should be illegal. Most deer hunters who opposed dog hunting neither dog hunted nor hunted in regions where dog hunting had a strong history. Concerns among non–dog hunters mostly focused on competition for deer hunting opportunities. Our results indicate a need to promote greater awareness among the diverse hunting groups and suggest dog hunters may be important allies in efforts to acquire large contiguous tracts of hunting land.}, number={2}, journal={Human Dimensions of Wildlife}, publisher={Informa UK Limited}, author={Cook, Merril A. and Peterson, M. Nils and Colter Chitwood, M. and Palmer, Dain and DePerno, Christopher S. and Gross, Kevin}, year={2015}, month={Mar}, pages={174–181} }
 @article{cardinale_venail_gross_oakley_narwani_allan_flombaum_joshi_reich_tilman_et al._2015, title={Further re-analyses looking for effects of phylogenetic diversity on community biomass and stability}, volume={29}, ISSN={["1365-2435"]}, DOI={10.1111/1365-2435.12540}, abstractNote={Species richness (SR) and phylogenetic diversity (PD) are highly correlated measures of plant diversity. Each, by itself, is significantly associated with plant community biomass in biodiversity experiments. As presented by Cadotte (2015) and as we present below, reasonable but alternative analyses that attempt to control for this correlation in different ways provide contradictory or inconclusive support for the hypothesis that PD is superior to SR as a predictor of community biomass. In Venail et al. (2015), we re-analysed data from 16 experimental manipulations of grassland SR to look at how SR and PD influence variation in plant community biomass through time. Using four types of analyses, we showed that, after statistically controlling for variation in SR, PD was not related to community biomass or to the temporal stability of biomass. We did, however, find that SR tends to increase the biomass production of plant communities after controlling for PD. In his comment, Cadotte expressed two concerns about our analyses. One is that we used non-random subsets of experiments, rather than the full data set, for some of our analyses (types 2, 3). We were clear in stating these analyses were based on non-random subsets that were specifically chosen to minimize the SR–PD correlation and avoid problems associated with multicollinearity. We acknowledge that our tests are conservative, a cost of which is that they sacrifice statistical power while, at the same time, minimizing the chance of drawing an incorrect conclusion. But we disagree with Cadotte’s suggestion that our use of non-random data subsets led to ‘biased’ conclusions, and demonstrate later in this response that his claim of bias is unsubstantiated. Cadotte’s second concern was that our analyses did not account for differences in biomass across studies. This is an important criticism to consider; we made a mistake by not controlling for variation in biomass. To address this issue, Cadotte used mixed models where study was included as a random effect, and ran analyses that standardized biomass among sites. Collectively, these led Cadotte to conclude ‘All analyses strongly support previous literature claims about the value of PD and I further show that: (i) PD provides a more powerful explanation of variation in biomass production than species richness; (ii) PD explains variation in biomass production after controlling for richness; and (iii) the use of data subsets inadvertently biased the conclusions’. We have two concerns with Cadotte’s re-analysis. First, Cadotte’s approach largely ignores the concerns we raised about multicollinearity. When two or more predictors}, number={12}, journal={FUNCTIONAL ECOLOGY}, author={Cardinale, Bradley J. and Venail, Patrick and Gross, Kevin and Oakley, Todd H. and Narwani, Anita and Allan, Eric and Flombaum, Pedro and Joshi, Jasmin and Reich, Peter B. and Tilman, David and et al.}, year={2015}, month={Dec}, pages={1607–1610} }
 @article{venail_gross_oakley_narwani_allan_flombaum_isbell_joshi_reich_tilman_et al._2015, title={Species richness, but not phylogenetic diversity, influences community biomass production and temporal stability in a re-examination of 16 grassland biodiversity studies}, volume={29}, ISSN={["1365-2435"]}, DOI={10.1111/1365-2435.12432}, abstractNote={Summary 1. Hundreds of experiments have now manipulated species richness (SR) of various groups of organisms and examined how this aspect of biological diversity influences ecosystem functioning. Ecologists have recently expanded this field to look at whether phylogenetic diversity (PD) among species, often quantified as the sum of branch lengths on a molecular phylogeny leading to all species in a community, also predicts ecological function. Some have hypothesized that phylogenetic divergence should be a superior predictor of ecological function than SR because evolutionary relatedness represents the degree of ecological and functional differentiation among species. But studies to date have provided mixed support for this hypothesis. 2. Here, we reanalyse data from 16 experiments that have manipulated plant SR in grassland ecosystems and examined the impact on above-ground biomass production over multiple time points. Using a new molecular phylogeny of the plant species used in these experiments, we quantified how the PD of plants impacts average community biomass production as well as the stability of community biomass production through time. 3. Using four complementary analyses, we show that, after statistically controlling for variation in SR, PD (the sum of branches in a molecular phylogenetic tree connecting all species in a community) is neither related to mean community biomass nor to the temporal stability of biomass. These results run counter to past claims. However, after controlling for SR, PD was}, number={5}, journal={FUNCTIONAL ECOLOGY}, author={Venail, Patrick and Gross, Kevin and Oakley, Todd H. and Narwani, Anita and Allan, Eric and Flombaum, Pedro and Isbell, Forest and Joshi, Jasmin and Reich, Peter B. and Tilman, David and et al.}, year={2015}, month={May}, pages={615–626} }
 @article{gross_edmunds_2015, title={Stability of Caribbean coral communities quantified by long-term monitoring and autoregression models}, volume={96}, ISSN={["1939-9170"]}, DOI={10.1890/14-0941.1}, abstractNote={Tropical coral reefs exemplify ecosystems imperiled by environmental change. Anticipating the future of reef ecosystems requires understanding how scleractinian corals respond to the multiple environmental disturbances that threaten their survival. We analyzed the stability of coral reefs at three habitats at different depths along the south shore of St. John, U.S. Virgin Islands, using multivariate autoregression (MAR) models and two decades of monitoring data. We quantified several measures of ecosystem stability, including the magnitude of typical stochastic fluctuations, the rate of recovery following disturbance, and the sensitivity of coral cover to hurricanes and elevated sea temperature. Our results show that, even within a -4 km shore, coral communities in different habitats display different stability properties, and that the stability of each habitat corresponds with the habitat's known synecology. Two Orbicella-dominated habitats are less prone to annual stochastic fluctuations than coral communities in shallower water, but they recover slowly from disturbance, and one habitat has suffered recent losses in scleractinian cover that will not be quickly reversed. In contrast, a shallower, low-coral-cover habitat is subject to greater stochastic fluctuations, but rebounds more quickly from disturbance and is more robust to hurricanes and seawater warming. In some sense, the shallower community is more stable, although the stability arguably arises from having little coral cover left. Our results sharpen understanding of recent changes in coral communities at these habitats, provide a more detailed understanding of how these habitats may change in future environments, and illustrate how MAR models can be used to assess stability of communities founded upon long-lived species.}, number={7}, journal={ECOLOGY}, author={Gross, Kevin and Edmunds, Peter J.}, year={2015}, month={Jul}, pages={1812–1822} }
 @misc{seabloom_borer_gross_kendig_lacroix_mitchell_mordecai_power_2015, title={The community ecology of pathogens: coinfection, coexistence and community composition}, volume={18}, ISSN={["1461-0248"]}, DOI={10.1111/ele.12418}, abstractNote={Disease and community ecology share conceptual and theoretical lineages, and there has been a resurgence of interest in strengthening links between these fields. Building on recent syntheses focused on the effects of host community composition on single pathogen systems, we examine pathogen (microparasite) communities using a stochastic metacommunity model as a starting point to bridge community and disease ecology perspectives. Such models incorporate the effects of core community processes, such as ecological drift, selection and dispersal, but have not been extended to incorporate host-pathogen interactions, such as immunosuppression or synergistic mortality, that are central to disease ecology. We use a two-pathogen susceptible-infected (SI) model to fill these gaps in the metacommunity approach; however, SI models can be intractable for examining species-diverse, spatially structured systems. By placing disease into a framework developed for community ecology, our synthesis highlights areas ripe for progress, including a theoretical framework that incorporates host dynamics, spatial structuring and evolutionary processes, as well as the data needed to test the predictions of such a model. Our synthesis points the way for this framework and demonstrates that a deeper understanding of pathogen community dynamics will emerge from approaches working at the interface of disease and community ecology.}, number={4}, journal={ECOLOGY LETTERS}, author={Seabloom, Eric W. and Borer, Elizabeth T. and Gross, Kevin and Kendig, Amy E. and Lacroix, Christelle and Mitchell, Charles E. and Mordecai, Erin A. and Power, Alison G.}, year={2015}, month={Apr}, pages={401–415} }
 @article{fabina_baskett_gross_2015, title={The differential effects of increasing frequency and magnitude of extreme events on coral populations}, volume={25}, ISSN={["1939-5582"]}, DOI={10.1890/14-0273.1}, abstractNote={Extreme events, which have profound ecological consequences, are changing in both frequency and magnitude with climate change. Because extreme temperatures induce coral bleaching, we can explore the relative impacts of changes in frequency and magnitude of high temperature events on coral reefs. Here, we combined climate projections and a dynamic population model to determine how changing bleaching regimes influence coral persistence. We additionally explored how coral traits and competition with macroalgae mediate changes in bleaching regimes. Our results predict that severe bleaching events reduce coral persistence more than frequent bleaching. Corals with low adult mortality and high growth rates are successful when bleaching is mild, but bleaching resistance is necessary to persist when bleaching is severe, regardless of frequency. The existence of macroalgae-dominated stable states reduces coral persistence and changes the relative importance of coral traits. Building on previous studies, our results predict that management efforts may need to prioritize protection of "weaker" corals with high adult mortality when bleaching is mild, and protection of "stronger" corals with high bleaching resistance when bleaching is severe. In summary, future reef projections and conservation targets depend on both local bleaching regimes and biodiversity.}, number={6}, journal={ECOLOGICAL APPLICATIONS}, author={Fabina, Nicholas S. and Baskett, Marissa L. and Gross, Kevin}, year={2015}, month={Sep}, pages={1534–1545} }
 @article{fiske_royle_gross_2014, title={Inference for finite-sample trajectories in dynamic multi-state site-occupancy models using hidden Markov model smoothing}, volume={21}, ISSN={["1573-3009"]}, DOI={10.1007/s10651-013-0256-1}, number={2}, journal={ENVIRONMENTAL AND ECOLOGICAL STATISTICS}, author={Fiske, Ian J. and Royle, J. Andrew and Gross, Kevin}, year={2014}, month={Jun}, pages={313–328} }
 @article{picha_biga_galt_mcginty_gross_hedgpeth_siopes_borski_2014, title={Overcompensation of circulating and local insulin-like growth factor-1 during catch-up growth in hybrid striped bass (Morone chrysops Chi Morone saxatilis) following temperature and feeding manipulations}, volume={428}, ISSN={["1873-5622"]}, DOI={10.1016/j.aquaculture.2014.02.028}, abstractNote={Teleosts and other aquatic ectotherms have the ability to withstand prolonged periods of low water temperatures (cold-acclimation) and fasting, and can often respond with phases of accelerated (compensatory) growth when favorable conditions are restored. We assessed whether complete feed restriction prior to (24 °C, days 0–23) and/or during (14 °C, days 24–114) a simulated period of cold-acclimation could elicit episodes of compensatory growth (CG) and catch-up growth upon warm-up to 24 °C and satiation feeding (days 115–148). Control hybrid striped bass (HSB: Morone chrysops × Morone saxatilis) were fed to satiation throughout the entire experiment under these temperature fluctuations. Compensatory growth and ultimately catch-up growth were achieved in groups of HSB that were deprived of feed during either the initial period at 24 °C (days 0–23), during the cold-acclimation period (14 °C, days 24–114), or during both of these periods (days 0–114). Further, it appears that HSB are better able to compensate for weight loss when skeletal length is not significantly compromised during the treatment period, which occurred in HSB feed restricted during cold-acclimation only. The most dramatic CG responses were defined by specific growth rates (SGRs) up to 4.2 times that of controls and were accompanied by hyperphagia and improvements in temporal and overall feed conversion. Levels of plasma insulin-like growth factor (IGF)-1 and muscle IGF-1 mRNA were significantly correlated to growth rate for all groups throughout the experiment (R2 = 0.40, 0.23, respectively), with an overcompensation of both observed in HSB with the most elevated SGRs during the CG response. Interestingly, opposing trends were observed between muscle mRNA expression of growth hormone receptor (GHR)-1 and -2, with fasting at 24 °C and 14 °C resulting in depressed levels of GHR-1 and elevated levels of GHR-2 relative to controls. Levels of muscle myostatin (MSTN)-1 mRNA were significantly depressed in HSB fasted at 24 °C and/or 14 °C while MSTN-2 mRNA was lower following initial feed restriction at 24 °C. Likewise, levels of unprocessed pro-MSTN (precursor) and mature MSTN protein were both depressed in fasted fish at 24 °C. This study demonstrates that a previous period of feed restriction and cold-acclimation followed by realimentation at more favorable water temperatures produces a strong CG response and catch-up growth in fish. These studies also suggest that an overcompensation of circulating and local IGF-1 along with changes in MSTN mRNA and protein expression may contribute to accelerated growth rates characteristic of CG. Furthermore, our studies indicate that overall feed conversion can improve by as much as 30% with CG induced through temperature and feeding manipulations with no adverse effects on growth of HSB. This raises the possibility that CG protocols can improve production efficiency of HSB and other temperate teleosts in pond or tank culture.}, journal={AQUACULTURE}, author={Picha, Matthew E. and Biga, Peggy R. and Galt, Nicholas and McGinty, Andy S. and Gross, Kevin and Hedgpeth, Vickie S. and Siopes, Thomas D. and Borski, Russell J.}, year={2014}, month={May}, pages={174–183} }
 @article{edmunds_adjeroud_baskett_baums_budd_carpenter_fabina_fan_franklin_gross_et al._2014, title={Persistence and change in community composition of reef corals through present, past, and future climates}, volume={9}, number={10}, journal={PLoS One}, author={Edmunds, P. J. and Adjeroud, M. and Baskett, M. L. and Baums, I. B. and Budd, A. F. and Carpenter, R. C. and Fabina, N. S. and Fan, T. Y. and Franklin, E. C. and Gross, K. and et al.}, year={2014} }
 @article{williams_reading_amano_hiramatsu_schilling_salger_williams_gross_sullivan_2014, title={Proportional Accumulation of Yolk Proteins Derived From Multiple Vitellogenins is Precisely Regulated During Vitellogenesis in Striped Bass (Morone saxatilis)}, volume={321}, ISSN={["2471-5646"]}, url={http://europepmc.org/abstract/med/24648375}, DOI={10.1002/jez.1859}, abstractNote={We quantified three vitellogenins (VtgAa, VtgAb, VtgC) or their derived yolk proteins (YPs) in the liver, plasma, and ovary during pre-vitellogenic (PreVG), mid-vitellogenic (MVG), and late-vitellogenic (LVG) oocyte growth and during post-vitellogenesis (PostVG) in the striped bass (Morone saxatilis) using label-free quantitative mass spectrometry (MS). Western blotting of the samples using antisera raised against gray mullet (Mugil cephalus) lipovitellins derived from VtgAa, VtgAb, and VtgC confirmed the MS results. Semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) revealed liver as the primary site of expression for all three Vtgs, with extra-hepatic transcription weakly detected in ovary, foregut, adipose tissue, and brain. Quantitative real-time RT-PCR confirmed vtgAb to be primarily expressed in liver and VtgAb proteins were predominant in liver and plasma from MVG to PostVG. However, the primary period of deposition into oocytes of VtgAb occurred up until MVG, whereas VtgAa was primarily deposited from MVG to LVG. The VtgC was gradually taken up by oocytes throughout vitellogenesis and was detected at trace levels in plasma. The ratio of yolk proteins derived from VtgAa, VtgAb, VtgC (YPAa/YPAb/YPC) in PostVG ovary is 1.4:1.4:1, which differs from ratios previously reported for other fish species in that YPC comprises a greater proportion of the egg yolk. Our results indicate that proportional accumulation of multiple Vtgs in the yolk may depend both on the precise rates of their hepatic secretion and specific uptake by oocytes. Furthermore, composition of the Vtg-derived yolk may vary among Acanthomorph fishes, perhaps reflecting their different early life histories and reproductive strategies.}, number={6}, journal={JOURNAL OF EXPERIMENTAL ZOOLOGY PART A-ECOLOGICAL AND INTEGRATIVE PHYSIOLOGY}, author={Williams, Valerie N. and Reading, Benjamin J. and Amano, Haruna and Hiramatsu, Naoshi and Schilling, Justin and Salger, Scott A. and Williams, Taufika Islam and Gross, Kevin and Sullivan, Craig V.}, year={2014}, month={Jul}, pages={301–315} }
 @article{baskett_fabina_gross_2014, title={Response Diversity Can Increase Ecological Resilience to Disturbance in Coral Reefs}, volume={184}, ISSN={["1537-5323"]}, DOI={10.1086/676643}, abstractNote={Community-level resilience depends on the interaction between multiple populations that vary in individual responses to disturbance. For example, in tropical reefs, some corals can survive higher stress (resistance) while others exhibit faster recovery (engineering resilience) following disturbances such as thermal stress. While each type will negatively affect the other through competition, each might also benefit the other by reducing the potential for an additional competitor such as macroalgae to invade after a disturbance. To determine how community composition affects ecological resilience, we modeled coral-macroalgae interactions given either a resistant coral, a resilient coral, or both together. Having both coral types (i.e., response diversity) can lead to observable enhanced ecological resilience if (1) the resilient coral is not a superior competitor and (2) disturbance levels are high enough such that the resilient coral would collapse when considered alone. This enhanced resilience occurs through competitor-enabled rescue where each coral increases the potential for the other to recover from disturbance through external recruitment, such that both corals benefit from the presence of each other in terms of total cover and resilience. Therefore, conservation management aimed at protecting resilience under global change requires consideration of both diversity and connectivity between sites experiencing differential disturbance.}, number={2}, journal={AMERICAN NATURALIST}, author={Baskett, Marissa L. and Fabina, Nicholas S. and Gross, Kevin}, year={2014}, month={Aug}, pages={E16–E31} }
 @article{gross_cardinale_fox_gonzalez_loreau_polley_reich_ruijven_2014, title={Species Richness and the Temporal Stability of Biomass Production: A New Analysis of Recent Biodiversity Experiments}, volume={183}, ISSN={["1537-5323"]}, DOI={10.1086/673915}, abstractNote={The relationship between biological diversity and ecological stability has fascinated ecologists for decades. Determining the generality of this relationship, and discovering the mechanisms that underlie it, are vitally important for ecosystem management. Here, we investigate how species richness affects the temporal stability of biomass production by reanalyzing 27 recent biodiversity experiments conducted with primary producers. We find that, in grasslands, increasing species richness stabilizes whole-community biomass but destabilizes the dynamics of constituent populations. Community biomass is stabilized because species richness impacts mean biomass more strongly than its variance. In algal communities, species richness has a minimal effect on community stability because richness affects the mean and variance of biomass nearly equally. Using a new measure of synchrony among species, we find that for both grasslands and algae, temporal correlations in species biomass are lower when species are grown together in polyculture than when grown alone in monoculture. These results suggest that interspecific interactions tend to stabilize community biomass in diverse communities. Contrary to prevailing theory, we found no evidence that species’ responses to environmental variation in monoculture predicted the strength of diversity’s stabilizing effect. Together, these results deepen our understanding of when and why increasing species richness stabilizes community biomass.}, number={1}, journal={AMERICAN NATURALIST}, author={Gross, Kevin and Cardinale, Bradley J. and Fox, Jeremy W. and Gonzalez, Andrew and Loreau, Michel and Polley, H. Wayne and Reich, Peter B. and Ruijven, Jasper}, year={2014}, month={Jan}, pages={1–12} }
 @article{cardinale_gross_fritschie_flombaum_fox_rixen_ruijven_reich_scherer-lorenzen_wilsey_2013, title={Biodiversity simultaneously enhances the production and stability of community biomass, but the effects are independent}, volume={94}, ISSN={["1939-9170"]}, DOI={10.1890/12-1334.1}, abstractNote={To predict the ecological consequences of biodiversity loss, researchers have spent much time and effort quantifying how biological variation affects the magnitude and stability of ecological processes that underlie the functioning of ecosystems. Here we add to this work by looking at how biodiversity jointly impacts two aspects of ecosystem functioning at once: (1) the production of biomass at any single point in time (biomass/area or biomass/volume), and (2) the stability of biomass production through time (the CV of changes in total community biomass through time). While it is often assumed that biodiversity simultaneously enhances both of these aspects of ecosystem functioning, the joint distribution of data describing how species richness regulates productivity and stability has yet to be quantified. Furthermore, analyses have yet to examine how diversity effects on production covary with diversity effects on stability. To overcome these two gaps, we reanalyzed the data from 34 experiments that have manipulated the richness of terrestrial plants or aquatic algae and measured how this aspect of biodiversity affects community biomass at multiple time points. Our reanalysis confirms that biodiversity does indeed simultaneously enhance both the production and stability of biomass in experimental systems, and this is broadly true for terrestrial and aquatic primary producers. However, the strength of diversity effects on biomass production is independent of diversity effects on temporal stability. The independence of effect sizes leads to two important conclusions. First, while it may be generally true that biodiversity enhances both productivity and stability, it is also true that the highest levels of productivity in a diverse community are not associated with the highest levels of stability. Thus, on average, diversity does not maximize the various aspects of ecosystem functioning we might wish to achieve in conservation and management. Second, knowing how biodiversity affects productivity gives no information about how diversity affects stability (or vice versa). Therefore, to predict the ecological changes that occur in ecosystems after extinction, we will need to develop separate mechanistic models for each independent aspect of ecosystem functioning.}, number={8}, journal={ECOLOGY}, author={Cardinale, Bradley J. and Gross, Kevin and Fritschie, Keith and Flombaum, Pedro and Fox, Jeremy W. and Rixen, Christian and Ruijven, Jasper and Reich, Peter B. and Scherer-Lorenzen, Michael and Wilsey, Brian J.}, year={2013}, month={Aug}, pages={1697–1707} }
 @article{canner_dunn_giladi_gross_2012, title={Redispersal of seeds by a keystone ant augments the spread of common wildflowers}, volume={40}, ISSN={["1873-6238"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84858731679&partnerID=MN8TOARS}, DOI={10.1016/j.actao.2012.02.004}, abstractNote={Myrmecochory (dispersal of seeds by ants) is an evolutionarily and ecologically common mutualism. Most of the research on the costs and benefits of myrmecochory in North America assumes that ant-dispersed seeds are taken to, and left in, the ant nest. Here, we use a novel seed-tracking technique to quantify secondary dispersal of seeds from the nest into the surrounding leaf litter by the keystone seed-dispersing ant, Aphaenogaster rudis. We found that A. rudis redispersed >90% of the seeds it took into its nest an average distance of 51.5 cm. A mathematical model shows redispersal increases the rate of population spread of the myrmecochores Hexastylis arifolia and Asarum canadense by 22.5%, and increases the expected cumulative dispersal distance away from the parent plant by 24%. Our results suggest myrmecochory benefits plants in eastern North American forests by increasing the distance between the seed and parent plant and reducing competition among siblings.}, journal={ACTA OECOLOGICA-INTERNATIONAL JOURNAL OF ECOLOGY}, author={Canner, Judith E. and Dunn, Robert R. and Giladi, Itamar and Gross, Kevin}, year={2012}, month={Apr}, pages={31–39} }
 @article{raybuck_moorman_greenberg_deperno_gross_simon_warburton_2012, title={Short-term response of small mammals following oak regeneration silviculture treatments}, volume={274}, ISSN={["1872-7042"]}, DOI={10.1016/j.foreco.2012.02.012}, abstractNote={Upland, mixed-oak forests in the eastern United States have experienced widespread oak regeneration failure, largely due to cessation of anthropogenic disturbance. Silvicultural practices used to promote advance oak regeneration may affect ground-dwelling mammals. From May to August 2008 (pre-treatment), 2010 (first year post-treatment), and 2011 (second year post-treatment), we trapped small mammals to assess changes in species richness and abundance following experimental tests of three silvicultural treatments (prescribed burns, midstory herbicide applications, and shelterwood harvests) used to promote oak regeneration. We trapped small mammals in five replicates of each treatment and controls using Sherman live traps (2008 and 2010) and drift fences (2008, 2010, and 2011). From pre- to post-treatment, we evaluated the change in estimated peromyscid abundance and relative abundance of masked shrews (Sorex cinereus), smoky shrews (Sorex fumeus), and northern short-tailed shrews (Blarina brevicauda). Additionally, we evaluated the change in species richness across treatments for both sampling techniques. For all measures analyzed (i.e., species richness, peromyscid abundance, and relative abundance of shrews), the change from pre- to post-treatment did not differ among treatments. However, more masked shrews, smoky shrews, and northern short-tailed shrews were captured in 2011 (i.e., second year post-treatment) than in 2010 (i.e., first year post-treatment). Our research indicates that, in the short-term, small mammals (e.g., mice and shrews) can tolerate a wide range of forest disturbance following oak regeneration treatments. However, delayed treatment effects (e.g., additional post-herbicide midstory dieback) or additive changes following future treatments (e.g., prescribed burns following shelterwood harvests or multiple prescribed burns) may compound effects on small mammal populations, and should be assessed with long-term research (>2 years post-treatment).}, journal={FOREST ECOLOGY AND MANAGEMENT}, author={Raybuck, Amy L. and Moorman, Christopher E. and Greenberg, Cathryn H. and DePerno, Christopher S. and Gross, Kevin and Simon, Dean M. and Warburton, Gordon S.}, year={2012}, month={Jun}, pages={10–16} }
 @article{rosenheim_parsa_forbes_krimmel_law_segoli_segoli_sivakoff_zaviezo_gross_2011, title={Ecoinformatics for Integrated Pest Management: Expanding the Applied Insect Ecologist's Tool-Kit}, volume={104}, ISSN={["0022-0493"]}, DOI={10.1603/ec10380}, abstractNote={ABSTRACT Experimentation has been the cornerstone of much of integrated pest management (IPM) research. Here, we aim to open a discussion on the possible merits of expanding the use of observational studies, and in particular the use of data from farmers or private pest management consultants in “ecoinformatics” studies, as tools that might complement traditional, experimental research. The manifold advantages of experimentation are widely appreciated: experiments provide definitive inferences regarding causal relationships between key variables, can produce uniform and high-quality data sets, and are highly flexible in the treatments that can be evaluated. Perhaps less widely considered, however, are the possible disadvantages of experimental research. Using the yield-impact study to focus the discussion, we address some reasons why observational or ecoinformatics approaches might be attractive as complements to experimentation. A survey of the literature suggests that many contemporary yield-impact studies lack sufficient statistical power to resolve the small, but economically important, effects on crop yield that shape pest management decision-making by farmers. Ecoinformatics-based data sets can be substantially larger than experimental data sets and therefore hold out the promise of enhanced power. Ecoinformatics approaches also address problems at the spatial and temporal scales at which farming is conducted, can achieve higher levels of “external validity,” and can allow researchers to efficiently screen many variables during the initial, exploratory phases of research projects. Experimental, observational, and ecoinformatics-based approaches may, if used together, provide more efficient solutions to problems in pest management than can any single approach, used in isolation.}, number={2}, journal={JOURNAL OF ECONOMIC ENTOMOLOGY}, author={Rosenheim, Jay A. and Parsa, Soroush and Forbes, Andrew A. and Krimmel, William A. and Law, Yao Hua and Segoli, Michal and Segoli, Moran and Sivakoff, Frances S. and Zaviezo, Tania and Gross, Kevin}, year={2011}, month={Apr}, pages={331–342} }
 @article{haddad_crutsinger_gross_haarstad_tilman_2011, title={Plant diversity and the stability of foodwebs}, volume={14}, ISSN={["1461-0248"]}, DOI={10.1111/j.1461-0248.2010.01548.x}, abstractNote={Insect outbreaks in forest and agriculture monocultures led Charles Elton to propose, a half-century ago, that higher plant diversity stabilized animal foodweb dynamics in natural ecosystems. We tested this hypothesis by studying arthropod community dynamics in a long-term experimental manipulation of grassland plant species diversity. Over the course of a decade, we found that higher plant diversity increased the stability (i.e. lowered year-to-year variability) of a diverse (>700 species) arthropod community across trophic levels. As the number of plant species increased, the stability of both herbivore and predator species richness and of total herbivore abundance increased. The underlying mechanisms driving these diversity-stability relationships were plant diversity, via effects on primary productivity and plant community stability, and portfolio effects. Taken together, our results show that higher plant diversity provides more temporally consistent food and habitat resources to arthropod foodwebs. Consequently, actively managing for high plant diversity may have stronger than expected benefits for increasing animal diversity and controlling pest outbreaks.}, number={1}, journal={ECOLOGY LETTERS}, author={Haddad, Nick M. and Crutsinger, Gregory M. and Gross, Kevin and Haarstad, John and Tilman, David}, year={2011}, month={Jan}, pages={42–46} }
 @article{gross_rosenheim_2011, title={Quantifying secondary pest outbreaks in cotton and their monetary cost with causal-inference statistics}, volume={21}, ISSN={["1051-0761"]}, DOI={10.1890/11-0118.1}, abstractNote={Secondary pest outbreaks occur when the use of a pesticide to reduce densities of an unwanted target pest species triggers subsequent outbreaks of other pest species. Although secondary pest outbreaks are thought to be familiar in agriculture, their rigorous documentation is made difficult by the challenges of performing randomized experiments at suitable scales. Here, we quantify the frequency and monetary cost of secondary pest outbreaks elicited by early-season applications of broad-spectrum insecticides to control the plant bug Lygus spp. (primarily L. hesperus) in cotton grown in the San Joaquin Valley, California, USA. We do so by analyzing pest-control management practices for 969 cotton fields spanning nine years and 11 private ranches. Our analysis uses statistical methods to draw formal causal inferences from nonexperimental data that have become popular in public health and economics, but that are not yet widely known in ecology or agriculture. We find that, in fields that received an early-season broad-spectrum insecticide treatment for Lygus, 20.2% +/- 4.4% (mean +/- SE) of late-season pesticide costs were attributable to secondary pest outbreaks elicited by the early-season insecticide application for Lygus. In 2010 U.S. dollars, this equates to an additional $6.00 +/- $1.30 (mean +/- SE) per acre in management costs. To the extent that secondary pest outbreaks may be driven by eliminating pests' natural enemies, these figures place a lower bound on the monetary value of ecosystem services provided by native communities of arthropod predators and parasitoids in this agricultural system.}, number={7}, journal={ECOLOGICAL APPLICATIONS}, author={Gross, Kevin and Rosenheim, Jay A.}, year={2011}, month={Oct}, pages={2770–2780} }
 @article{allen_fathi_gross_mace_2010, title={An optimal and near-optimal strategy to selecting individuals for transfer in captive breeding programs}, volume={143}, ISSN={["1873-2917"]}, DOI={10.1016/j.biocon.2010.08.003}, abstractNote={As species extinction rates continue to rise, zoos have adopted a more active role in the conservation of endangered species. A central concern is to preserve genetic diversity of zoological populations. Accordingly, when selecting individuals to transfer to new or existing populations, zoo managers must consider the genetic effects on all populations involved. We propose a quadratic integer programming (IP) model to identify a group of individuals to transfer that maximizes genetic diversity within two subpopulations. We then reduce this model to a linear IP formulation and apply it to the California condor (Gymnogyps californianus) studbook. After simplifying the linear IP model, optimality is achieved within a reasonable time limit when a limited number of individuals are relocated. We also develop a local improvement algorithm (LIA) to efficiently provide near-optimal solutions when we increase the number of transferred individuals. The LIA quickly obtains optimal solutions when few individuals are transferred and in most cases, the LIA outperforms MetaMK, an existing program used to select animals for transfer.}, number={11}, journal={BIOLOGICAL CONSERVATION}, author={Allen, S. D. and Fathi, Y. and Gross, K. and Mace, M.}, year={2010}, month={Nov}, pages={2858–2863} }
 @article{weiser_sanders_agosti_andersen_ellison_fisher_gibb_gotelli_gove_gross_et al._2010, title={Canopy and litter ant assemblages share similar climate-species density relationships}, volume={6}, ISSN={["1744-9561"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-78649884769&partnerID=MN8TOARS}, DOI={10.1098/rsbl.2010.0151}, abstractNote={Tropical forest canopies house most of the globe's diversity, yet little is known about global patterns and drivers of canopy diversity. Here, we present models of ant species density, using climate, abundance and habitat (i.e. canopy versus litter) as predictors. Ant species density is positively associated with temperature and precipitation, and negatively (or non-significantly) associated with two metrics of seasonality, precipitation seasonality and temperature range. Ant species density was significantly higher in canopy samples, but this difference disappeared once abundance was considered. Thus, apparent differences in species density between canopy and litter samples are probably owing to differences in abundance–diversity relationships, and not differences in climate–diversity relationships. Thus, it appears that canopy and litter ant assemblages share a common abundance–diversity relationship influenced by similar but not identical climatic drivers.}, number={6}, journal={BIOLOGY LETTERS}, author={Weiser, Michael D. and Sanders, Nathan J. and Agosti, Donat and Andersen, Alan N. and Ellison, Aaron M. and Fisher, Brian L. and Gibb, Heloise and Gotelli, Nicholas J. and Gove, Aaron D. and Gross, Kevin and et al.}, year={2010}, month={Dec}, pages={769–772} }
 @article{midway_aday_kwak_gross_2010, title={Cover Preference of the Carolina Madtom (Noturus furiosus), an Imperiled, Endemic Southeastern Stream Fish}, volume={25}, ISSN={0270-5060 2156-6941}, url={http://dx.doi.org/10.1080/02705060.2010.9664368}, DOI={10.1080/02705060.2010.9664368}, abstractNote={ABSTRACT In a laboratory setting, we investigated cover preference of the Carolina madtom (Noturus furiosus), an imperiled, endemic southeastern USA stream fish. Fish were tested individually and given 24 hours to make a selection from four cover options, including rock, leaf pack, mussel shell, and an artificial cover unit. Among 30 trials, Carolina madtom preferred the artificial cover unit, selecting it 63% of the time. Rock was selected 23% of the time, and leaf pack 13%. Mussel shells were not selected during any trial.}, number={1}, journal={Journal of Freshwater Ecology}, publisher={Informa UK Limited}, author={Midway, S. R. and Aday, D. D. and Kwak, T. J. and Gross, K.}, year={2010}, month={Mar}, pages={151–154} }
 @article{pratt_lamson_collier_crawford_harris_gross_ballard_sarvey_saporito_2009, title={Camp Golden Treasures: A multidisciplinary weight-loss and a healthy lifestyle camp for adolescent girls.}, volume={27}, ISSN={1939-0602 1091-7527}, url={http://dx.doi.org/10.1037/a0014912}, DOI={10.1037/a0014912}, abstractNote={Camp Golden Treasures, (CGT) the first non-profit weight loss camp for overweight adolescent girls in the nation, was held for six weeks from June 24 to August 3, 2007 at the East Carolina University campus in Greenville, NC. The primary goal was to support campers to lose weight, raise self esteem, and to learn the tools necessary to lead a healthy lifestyle while reducing risks for developing chronic disease or mitigating the effects of existing obesity-related conditions (sleep apnea, insulin resistance, hypertension, lower extremity dysfunction, etc.). While at CGT, campers learned about the importance of physical activity and proper nutrition through workshops, discussion groups and hands-on activities. Additionally campers were taught the necessary tools and strategies needed to make concrete, positive lifestyle changes so they can achieve a healthy weight. Due to the nature of a chronic disease such as obesity, multidisciplinary collaborators including physical therapy, nutrition, health education, management, family therapy, risk management, fundraising, public relations, medical, nursing, and physician coverage were involved in designing, planning, and implementing CGT.}, number={1}, journal={Families, Systems, & Health}, publisher={American Psychological Association (APA)}, author={Pratt, Keeley J. and Lamson, Angela L. and Collier, David N. and Crawford, Yancey S. and Harris, Nancy and Gross, Kevin and Ballard, Sharon and Sarvey, Sharon and Saporito, Maria}, year={2009}, pages={116–124} }
 @article{cardinale_bennett_nelson_gross_2009, title={Does productivity drive diversity or vice versa? A test of the multivariate productivity-diversity hypothesis in streams}, volume={90}, ISSN={["1939-9170"]}, DOI={10.1890/08-1038.1}, abstractNote={The idea that productivity regulates species diversity is deeply ingrained in the field of ecology. Yet, over the past few decades, an increasing number of experiments have shown that species diversity controls, rather than simply responds to, biomass production. These contrasting perspectives have led to a seeming paradox: Is diversity the cause or the consequence of biological production? Here we present empirical evidence for the multivariate productivity-diversity (MPD) hypothesis, which argues that differing perspectives on productivity-diversity relationships can be resolved by recognizing that historical research has focused on how resource supply regulates both the productivity and richness of local competitors, whereas more recent studies have focused on how the richness of a colonist pool regulates the efficiency by which resources are captured and converted into new tissue. The MPD hypothesis predicts that three pathways operate concurrently to generate productivity diversity relationships in nature: (1) resource supply directly limits the standing biomass and/or rate of new production by primary producers, (2) producer biomass is directly influenced by the richness of species that locally compete for resources, and (3) resource supply rate indirectly affects producer biomass by influencing the fraction of species from a colonist pool that locally coexist. To examine whether this set of pathways explains covariation between productivity and diversity in natural streams, we used nutrient-diffusing agar "patches" to manipulate resource supply rates in 20 streams throughout the Sierra Nevada mountain range, California, USA. We then measured the fraction of periphyton species from the stream colonist pool co-occurring on each nutrient patch, as well as the standing biomass and rates of primary production. Natural patterns of covariation agreed with predictions of the MPD hypothesis. Algal biomass was an increasing function of nutrient supply, and an increasing function of local richness. The fraction of species from the colonist pool found co-occurring on a patch was a concave-down function of nutrient supply, causing nutrients to indirectly affect biomass via control over local richness. These results suggest that the MPD hypothesis is a viable explanation of patterns of diversity and productivity in natural stream ecosystems, and that it has potential to merge the historical view that productivity drives diversity with a parallel view that diversity drives productivity.}, number={5}, journal={ECOLOGY}, author={Cardinale, Bradley J. and Bennett, Danuta M. and Nelson, Craig E. and Gross, Kevin}, year={2009}, month={May}, pages={1227–1241} }
 @article{haddad_crutsinger_gross_haarstad_knops_tilman_2009, title={Plant species loss decreases arthropod diversity and shifts trophic structure}, volume={12}, ISSN={["1461-0248"]}, DOI={10.1111/j.1461-0248.2009.01356.x}, abstractNote={Plant diversity is predicted to be positively linked to the diversity of herbivores and predators in a foodweb. Yet, the relationship between plant and animal diversity is explained by a variety of competing hypotheses, with mixed empirical results for each hypothesis. We sampled arthropods for over a decade in an experiment that manipulated the number of grassland plant species. We found that herbivore and predator species richness were strongly, positively related to plant species richness, and that these relationships were caused by different mechanisms at herbivore and predator trophic levels. Even more dramatic was the threefold increase, from low- to high-plant species richness, in abundances of predatory and parasitoid arthropods relative to their herbivorous prey. Our results demonstrate that, over the long term, the loss of plant species propagates through food webs, greatly decreasing arthropod species richness, shifting a predator-dominated trophic structure to being herbivore dominated, and likely impacting ecosystem functioning and services.}, number={10}, journal={ECOLOGY LETTERS}, author={Haddad, Nick M. and Crutsinger, Gregory M. and Gross, Kevin and Haarstad, John and Knops, Johannes M. H. and Tilman, David}, year={2009}, month={Oct}, pages={1029–1039} }
 @article{cardinale_hillebrand_harpole_gross_ptacnik_2009, title={Separating the influence of resource 'availability' from resource 'imbalance' on productivity-diversity relationships}, volume={12}, ISSN={["1461-0248"]}, DOI={10.1111/j.1461-0248.2009.01317.x}, abstractNote={One of the oldest and richest questions in biology is that of how species diversity is related to the availability of resources that limit the productivity of ecosystems. Researchers from a variety of disciplines have pursued this question from at least three different theoretical perspectives. Species energy theory has argued that the summed quantities of all resources influence species richness by controlling population sizes and the probability of stochastic extinction. Resource ratio theory has argued that the imbalance in the supply of two or more resources, relative to the stoichiometric needs of the competitors, can dictate the strength of competition and, in turn, the diversity of coexisting species. In contrast to these, the field of Biodiversity and Ecosystem Functioning has argued that species diversity acts as an independent variable that controls how efficiently limited resources are utilized and converted into new tissue. Here we propose that all three of these fields give necessary, but not sufficient, conditions to explain productivity-diversity relationships (PDR) in nature. However, when taken collectively, these three paradigms suggest that PDR can be explained by interactions among four distinct, non-interchangeable variables: (i) the overall quantity of limiting resources, (ii) the stoichiometric ratios of different limiting resources, (iii) the summed biomass produced by a group of potential competitors and (iv) the richness of co-occurring species in a local competitive community. We detail a new multivariate hypothesis that outlines one way in which these four variables are directly and indirectly related to one another. We show how the predictions of this model can be fit to patterns of covariation relating the richness and biomass of lake phytoplankton to three biologically essential resources (N, P and light) in a large number of Norwegian lakes.}, number={6}, journal={ECOLOGY LETTERS}, author={Cardinale, Bradley J. and Hillebrand, Helmut and Harpole, W. S. and Gross, Kevin and Ptacnik, Robert}, year={2009}, month={Jun}, pages={475–487} }
 @article{haddad_hudgens_damiani_gross_kuefler_pollock_2008, title={Determining optimal population monitoring for rare butterflies}, volume={22}, ISSN={["1523-1739"]}, DOI={10.1111/j.1523-1739.2008.00932.x}, abstractNote={Abstract:  Determining population viability of rare insects depends on precise, unbiased estimates of population size and other demographic parameters. We used data on the endangered St. Francis' satyr butterfly (Neonympha mitchellii francisci) to evaluate 2 approaches (mark–recapture and transect counts) for population analysis of rare butterflies. Mark–recapture analysis provided by far the greatest amount of demographic information, including estimates (and standard errors) of population size, detection, survival, and recruitment probabilities. Mark–recapture analysis can also be used to estimate dispersal and temporal variation in rates, although we did not do this here. Models of seasonal flight phenologies derived from transect counts (Insect Count Analyzer) provided an index of population size and estimates of survival and statistical uncertainty. Pollard–Yates population indices derived from transect counts did not provide estimates of demographic parameters. This index may be highly biased if detection and survival probabilities vary spatially and temporally. In terms of statistical performance, mark–recapture and Pollard–Yates indices were least variable. Mark–recapture estimates were less likely to fail than Insect Count Analyzer, but mark–recapture estimates became less precise as sampling intensity decreased. In general, count‐based approaches are less costly and less likely to cause harm to rare insects than mark–recapture. The optimal monitoring approach must reconcile these trade‐offs. Thus, mark–recapture should be favored when demographic estimates are needed, when financial resources enable frequent sampling, and when marking does not harm the insect populations. The optimal sampling strategy may use 2 sampling methods together in 1 overall sampling plan: limited mark–recapture sampling to estimate survival and detection probabilities and frequent but less expensive transect counts.}, number={4}, journal={CONSERVATION BIOLOGY}, author={Haddad, Nick M. and Hudgens, Brian and Damiani, Chris and Gross, Kevin and Kuefler, Daniel and Pollock, Ken}, year={2008}, month={Aug}, pages={929–940} }
 @article{gross_2008, title={Fusing spatial resource heterogeneity with a competition-colonization trade-off in model communities}, volume={1}, ISSN={["1874-1746"]}, DOI={10.1007/s12080-007-0005-x}, number={2}, journal={THEORETICAL ECOLOGY}, author={Gross, Kevin}, year={2008}, month={Jun}, pages={65–75} }
 @article{gross_2008, title={Positive interactions among competitors can produce species-rich communities}, volume={11}, ISSN={["1461-0248"]}, DOI={10.1111/j.1461-0248.2008.01204.x}, abstractNote={Although positive interactions between species are well documented, most ecological theory for investigating multispecies coexistence remains rooted in antagonistic interactions such as competition and predation. Standard resource-competition models from this theory predict that the number of coexisting species should not exceed the number of factors that limit population growth. Here I show that positive interactions among resource competitors can produce species-rich model communities supported by a single limiting resource. Simulations show that when resource competitors reduce each others' per capita mortality rate (e.g. by ameliorating an abiotic stress), stable multispecies coexistence with a single resource may be common, even while the net interspecific interaction remains negative. These results demonstrate that positive interactions may provide an important mechanism for generating species-rich communities in nature. They also show that focusing on the net interaction between species may conceal important coexistence mechanisms when species simultaneously engage in both antagonistic and positive interactions.}, number={9}, journal={ECOLOGY LETTERS}, author={Gross, Kevin}, year={2008}, month={Sep}, pages={929–936} }
 @article{abbott_morris_gross_2008, title={Simultaneous effects of food limitation and inducible resistance on herbivore population dynamics}, volume={73}, ISSN={0040-5809}, url={http://dx.doi.org/10.1016/j.tpb.2007.09.006}, DOI={10.1016/j.tpb.2007.09.006}, abstractNote={Many herbivore populations fluctuate temporally, but the causes of those fluctuations remain unclear. Plant inducible resistance can theoretically cause herbivore population fluctuations, because herbivory may induce plant changes that reduce the survival or reproduction of later-feeding herbivores. Herbivory can also simply reduce the quantity of food available for later feeders and this, too, can cause population fluctuations. Inducible resistance and food limitation often occur simultaneously, yet whether they jointly facilitate or suppress herbivore fluctuations remains largely unexplored. We present models that suggest that food limitation and inducible resistance may have synergistic effects on herbivore population dynamics. The population-level response of the food plant to herbivory and the details of how inducible resistance affects herbivore performance both influence the resulting herbivore dynamics. Our results identify some biological properties of plant–herbivore systems that might determine whether or not cycles occur, and suggest that future empirical and theoretical population dynamics studies should account for the effects of both food limitation and inducible resistance.}, number={1}, journal={Theoretical Population Biology}, publisher={Elsevier BV}, author={Abbott, Karen C. and Morris, William F. and Gross, Kevin}, year={2008}, month={Feb}, pages={63–78} }
 @article{harvey_gross_simon_hastie_2008, title={Trophic and fishery interactions between Pacific hake and rockfish: effect on rockfish population rebuilding times}, volume={365}, ISSN={["1616-1599"]}, DOI={10.3354/meps07510}, abstractNote={Several species of overfished Pacific rockfish (genus Sebastes) are incidentally caught in the fishery targeting Pacific hake Merluccius productus. Juvenile rockfish also comprise a small amount of Pacific hake diets. We used 2-species, age-structured models to estimate how prey selectivity by Pacific hake, life history and population structure of rockfish, spatiotemporal overlap, and fishery closures might affect the time required to rebuild overfished rockfish populations to 40% of unfished spawning stock biomass. As prey selectivity increased, rebuilding time increased moderately for widow rockfish S. entomelas and darkblotched rockfish S. crameri, and more sharply for canary rockfish S. pinniger. Darkblotched rockfish were the least sensitive to Pacific hake predatory selectivity, which was likely related to their rarity in Pacific hake diets, not their stochastic reproductive success. Spatiotemporal overlap between rockfish and Pacific hake also increased rebuilding times, primarily because of higher rockfish bycatch, not predation. Early fishery closures and Pacific hake predation had an interactive effect that prolonged widow and canary rockfish rebuilding times, partly as a function of model assumptions and partly because fishery closures led to increased predation on juvenile rockfish. Because an ecosystem-based approach to fisheries management involves considering the influence of ecological factors on fish populations, models that examine interactions between depleted species and predatory species are essential. In this case, it appears that overfished rockfish rebuilding times can be significantly affected by the dynamics of a key predator, but also that the predatory effect can be mitigated by effective bycatch control.}, journal={MARINE ECOLOGY PROGRESS SERIES}, author={Harvey, Chris J. and Gross, Kevin and Simon, Victor H. and Hastie, James}, year={2008}, pages={165–176} }
 @article{gross_cardinale_2007, title={Does species richness drive community production or vice versa? Reconciling historical and contemporary paradigms in competitive communities}, volume={170}, ISSN={["1537-5323"]}, DOI={10.1086/518950}, abstractNote={Studies examining the relationship between species richness and the productivity of ecological communities have taken one of two opposite viewpoints, viewing either productivity as a primary driver of richness or richness as a driver of productivity. Recently, verbal and graphical hypotheses have been proposed that attempt to merge these perspectives by clarifying the causal pathways that link resource supply, species richness, resource use, and biomass production. Here we present mathematical models that formalize how these pathways can operate simultaneously in a single ecological system. Using a metacommunity framework in which classic consumer‐resource competition theory governs species interactions within patches, we show that the mechanisms by which resource supply influences species richness are inherently linked to the mechanisms by which species richness controls resource use and biomass production. Unlike prior hypotheses, our models show that resource supply can affect species richness and that richness can affect productivity simultaneously at a single spatial scale. Our models also reproduce scale‐dependent associations between species richness and community biomass that have been reported elsewhere. By detailing the pathways by which resource supply, species richness, biomass production, and resource use are connected, our models move closer to resolving the nature of causality in diversity‐productivity relationships.}, number={2}, journal={AMERICAN NATURALIST}, author={Gross, Kevin and Cardinale, Bradley J.}, year={2007}, month={Aug}, pages={207–220} }
 @article{gross_kalendra_hudgens_haddad_2007, title={Robustness and uncertainty in estimates of butterfly abundance from transect counts}, volume={49}, ISSN={["1438-390X"]}, DOI={10.1007/s10144-007-0034-8}, abstractNote={Abstract Many butterfly populations are monitored by counting the number of butterflies observed while walking transects during the butterfly's flight season. Methods for estimating population abundance from these transect counts are appealing because they allow rare populations to be monitored without capture–recapture studies that could harm fragile individuals. An increasingly popular method for estimating abundance from transect counts relies on strong assumptions about the counting process and the processes that govern butterfly population dynamics. Here, we study the statistical performance of this method when underlying model assumptions are violated. We find that estimates of population size are robust to departures from underlying model assumptions, but that the uncertainty in these estimates (i.e., confidence intervals) is substantially underestimated. Alternative bootstrap and Bayesian methods provide better measures of the uncertainty in estimated population size, but are conditional upon knowledge of butterfly detectability. Because of these requirements, a mixed approach that combines data from small capture–recapture studies with transect counts strikes the best balance between accurate monitoring and minimal injury to individuals. Our study is motivated by monitoring studies for St. Francis satyr ( Neonympha mitchelli francisci ), a rare and relatively immobile butterfly occurring only in the sandhills region of south‐central North Carolina, USA.}, number={3}, journal={POPULATION ECOLOGY}, author={Gross, Kevin and Kalendra, Eric J. and Hudgens, Brian R. and Haddad, Nick M.}, year={2007}, month={Jul}, pages={191–200} }
 @article{kilpatrick_lapointe_atkinson_woodworth_lease_reiter_gross_2006, title={Effects of chronic avian malaria (Plasmodium relictum) infection on reproductive success of Hawaii Amakihi (Hemignathus virens)}, volume={123}, ISSN={["1938-4254"]}, DOI={10.1642/0004-8038(2006)123[764:EOCAMP]2.0.CO;2}, abstractNote={Abstract We studied the effects of chronic avian malaria (Plasmodium relictum) infections on the reproductive success of a native Hawaiian honeycreeper, Hawaii Amakihi (Hemignathus virens). Chronic malaria infections in male and female parents did not significantly reduce reproductive success as measured by clutch size, hatching success, fledging mass, number of nestlings fledged, nesting success (daily survival rate), and minimum fledgling survival. In fact, nesting success of pairs with chronically infected males was significantly higher than those with uninfected males (76% vs. 38%), and offspring that had at least one parent that had survived the acute phase of malaria infection had a significantly greater chance of being resighted the following year (25% vs. 10%). The reproduction and survival of infected birds were sufficient for a per-capita population growth rate >1, which suggests that chronically infected Hawaii Amakihi could support a growing population. Efectos de las Infecciones Crónicas de Malaria Aviaria (Plasmodium relictum) en el Éxito Reproductivo de Hemignathus virens}, number={3}, journal={AUK}, author={Kilpatrick, A. Marm and LaPointe, Dennis A. and Atkinson, Carter T. and Woodworth, Bethany L. and Lease, Julie K. and Reiter, Matthew E. and Gross, Kevin}, year={2006}, month={Jul}, pages={764–774} }
 @article{gross_morris_wolosin_doak_2006, title={Modeling vital rates improves estimation of population projection matrices}, volume={48}, ISSN={["1438-390X"]}, DOI={10.1007/s10144-005-0238-8}, abstractNote={Abstract Population projection matrices are commonly used by ecologists and managers to analyze the dynamics of stage‐structured populations. Building projection matrices from data requires estimating transition rates among stages, a task that often entails estimating many parameters with few data. Consequently, large sampling variability in the estimated transition rates increases the uncertainty in the estimated matrix and quantities derived from it, such as the population multiplication rate and sensitivities of matrix elements. Here, we propose a strategy to avoid overparameterized matrix models. This strategy involves fitting models to the vital rates that determine matrix elements, evaluating both these models and ones that estimate matrix elements individually with model selection via information criteria, and averaging competing models with multimodel averaging. We illustrate this idea with data from a population of Silene acaulis (Caryophyllaceae), and conduct a simulation to investigate the statistical properties of the matrices estimated in this way. The simulation shows that compared with estimating matrix elements individually, building population projection matrices by fitting and averaging models of vital‐rate estimates can reduce the statistical error in the population projection matrix and quantities derived from it.}, number={1}, journal={POPULATION ECOLOGY}, author={Gross, K and Morris, WF and Wolosin, MS and Doak, DF}, year={2006}, month={Jan}, pages={79–89} }
 @article{gross_ives_nordheim_2005, title={Estimating fluctuating vital rates from time-series data: a case study of aphid biocontrol}, volume={86}, ISSN={["1939-9170"]}, DOI={10.1890/03-4085}, abstractNote={Many ecological time series describe population dynamics. Indirectly, these data also provide information about the vital rates (e.g., birth rates, mortality rates) un- derlying these dynamics, but extracting this information from the data can be difficult. Here, we present a method for estimating fluctuating vital rates from ecological time series by using a model to re-code information in observed dynamics into information about unobserved vital rates. This model construction differs from most current models by re- placing strong assumptions about the functional relationships dictating population dynamics with more conservative assumptions about how vital rates change with time. Thus, this method is a tool for analyzing time-series data that avoids strong assumptions about the mechanisms driving population dynamics. Our work is motivated by studying the biological control of pea aphids in alfalfa in south-central Wisconsin. Pea aphid populations are consistently held below economic threshold, although the source of this regulation is unclear. Here, we analyze monitoring data to understand the role that a specialist parasitoid plays in aphid biocontrol. Our mod- eling methodology allows us to estimate the vital rates that determine aphid dynamics (in particular, parasitism) without making arbitrary assumptions about the relationship between parasitism and aphid or parasitoid density. We find that, while parasitism depresses aphid population growth rate substantially, declines in aphid population growth rates do not coincide with increases in parasitism. Therefore, parasitism cannot be responsible for the density-dependent regulation of aphid populations observed in the field.}, number={3}, journal={ECOLOGY}, author={Gross, K and Ives, AR and Nordheim, EV}, year={2005}, month={Mar}, pages={740–752} }
 @article{gross_cardinale_2005, title={The functional consequences of random vs. ordered species extinctions}, volume={8}, ISSN={["1461-0248"]}, DOI={10.1111/j.1461-0248.2005.00733.x}, abstractNote={Recent work suggests that the effect of extinction on ecosystem function depends on whether or not species have identical extinction risks. Here, we use a simple model of community dynamics to predict how the functional consequences of random and non-random extinction may differ. The model suggests that when resource partitioning or facilitation structures communities, the functional consequences of non-random extinction depend on the covariance between species traits and cumulative extinction risks, and the compensatory responses among survivors. Strong competition increases the difference between random and ordered extinctions, but mutualisms reduce the difference. When diversity affects function via a sampling effect, the difference between random and ordered extinction depends on the covariance between species traits and the change in the probability of being the competitive dominant caused by ordered extinction. These findings show how random assembly experiments can be combined with information about species traits to make qualitative predictions about the functional consequences of various extinction scenarios.}, number={4}, journal={ECOLOGY LETTERS}, author={Gross, K and Cardinale, BJ}, year={2005}, month={Apr}, pages={409–418} }
 @article{doak_gross_morris_2005, title={Understanding and predicting the effects of sparse data on demographic analyses}, volume={86}, ISSN={["1939-9170"]}, DOI={10.1890/04-0611}, abstractNote={Demographic models are an increasingly important tool in population biology. However, these models, especially stochastic matrix models, are based upon a multitude of parameters that must usually be estimated with only a few years of data and limited sample sizes within each year, calling into question the accuracy of the results of these models. We first discuss how these data limitations create sampling uncertainty and bias in the estimated parameters for a stochastic demography model. Next, we ask whether limited data can favor the construction of deterministic models that ignore variation and correlation of rates. With less than five years of data, the mean squared error of deterministic models will sometimes be smaller than that of stochastic models, favoring the use of simple models, even when their predictions are known to be biased. Finally, we introduce a procedure to estimate the sampling variation around population growth rate estimates made from demographic models that are based on specified sampling durations and intensities.}, number={5}, journal={ECOLOGY}, author={Doak, DF and Gross, K and Morris, WF}, year={2005}, month={May}, pages={1154–1163} }