Jonathan B Shurin

• Ph.D.
• Professor (Full) at University of California, San Diego

Many microbes disperse through the air, yet the phenotypic traits that enhance or constrain aerial dispersal or allow successful colonization of new habitats are poorly understood. We used a metabarcoding bacterial and eukaryotic data set to explore the trait structures of the aquatic, terrestrial, and airborne microbial communities near the Salton...

Fire can lead to transitions between forest and grassland ecosystems and trigger positive feedbacks to climate warming by releasing CO2 into the atmosphere. Climate change is projected to increase the prevalence and severity of wildfires. However, fire effects on the fate and impact of terrestrial organic matter (i.e., terrestrial subsidies) in aqu...

Drier and hotter conditions linked with anthropogenic climate change can increase wildfire frequency and severity, influencing terrestrial and aquatic carbon cycles at broad spatial and temporal scales. The impacts of wildfire are complex and dependent on several factors that may increase terrestrial deposition and the influx of dissolved organic m...

The salinization of freshwaters is a global threat to aquatic biodiversity. We quantified variation in chloride (Cl−) tolerance of 19 freshwater zooplankton species in four countries to answer three questions: (1) How much variation in Cl− tolerance is present among populations? (2) What factors predict intraspecific variation in Cl− tolerance? (3)...

The Magdalena River in Colombia is one of the world's largest (discharge = 7100 m3 s−1) tropical rivers, hosting > 170 aquatic vertebrate species. However, concise synthesis of the current ecological and environmental status is lacking. By documenting the anthropogenic stressors impacting the river on time scales ranging from centuries to decades,...

Daphnia, an ecologically important zooplankton species in lakes, shows both genetic adaptation and phenotypic plasticity in response to temperature and fish predation, but little is known about the molecular basis of these responses and their potential interactions. We performed a factorial experiment exposing laboratory-propagated Daphnia pulicari...

Predators drive trophic cascades by reducing prey biomass and altering prey traits, selecting for prey that exhibit constitutive and induced anti‐predator defenses that decrease susceptibility to consumption. These defense traits are often costly, generating a tradeoff between consumptive (CEs) and non‐consumptive predator effects (NCEs). The ecolo...

Functional trade‐offs among ecologically important traits govern the diversity of communities and changes in species composition along environmental gradients. A trade‐off between predator defense and resource competitive ability has been invoked as a mechanism that may maintain diversity in lake phytoplankton. Trade‐offs may promote diversity in c...

Significance The salinity of freshwater ecosystems is increasing worldwide. Given that most freshwater organisms have no recent evolutionary history with high salinity, we expect them to have a low tolerance to elevated salinity caused by road deicing salts, agricultural practices, mining operations, and climate change. Leveraging the results from...

Daphnia , an ecologically important zooplankton species in lakes, shows both genetic adaptation and phenotypic plasticity in response to temperature and fish predation, but little is known about the molecular basis of these responses and their potential interactions. We performed a factorial experiment exposing laboratory-propagated Daphnia pulicar...

Human-induced salinization increasingly threatens inland waters; yet we know little about the multifaceted response of lake communities to salt contamination. By conducting a coordinated mesocosm experiment of lake salinization across 16 sites in North America and Europe, we quantified the response of zooplankton abundance and (taxonomic and functi...

Introgressive hybridization may erode phenotypic divergence along environmental gradients, collapsing locally adapted populations into a hybrid swarm. Alternatively, introgression may promote phenotypic divergence by providing variation on which natural selection can act. In freshwater fishes, water flow often selects for divergent morphological tr...

How communities reorganize during climate change depends on the distribution of diversity within ecosystems and across landscapes. Understanding how environmental and evolutionary history constrain community resilience is critical to predicting shifts in future ecosystem function. The goal of our study was to understand how communities with differe...

Runoff containing road salt (sodium chloride, NaCl) causes the salinization of inland freshwaters, with potentially severe impacts on aquatic species. We performed a mesocosm experiment to test the effects of salinization on plankton community structure in an oligotrophic mountain lake with a limited history of elevated salt concentrations. We expo...

Warming, eutrophication (nutrient fertilization) and brownification (increased loading of allochthonous organic matter) are three global trends impacting lake ecosystems. However, the independent and synergistic effects of resource addition and warming on autotrophic and heterotrophic microorganisms are largely unknown. In this study, we investigat...

The benefits of ecosystem restoration Human activities have fundamentally altered many ecosystems. Recent successful restoration efforts have led to healthier ecosystems, but this has led to a disruption in economies dependent on the altered state of the system. One of the best-known trophic cascades is the sea otter–kelp forest system, wherein rec...

The keystone roles of mega‐fauna in many terrestrial ecosystems have been lost to defaunation. Large predators and herbivores often play keystone roles in their native ranges, and some have established invasive populations in new biogeographic regions. However, few empirical examples are available to guide expectations about how mega‐fauna affect e...

Biomass distribution among size classes follows a power law where the Log-abundance of taxa scales to Log-size with a slope that responds to environmental abiotic and biotic conditions. The interactions between ecological mechanisms controlling the slope of locally realized size-abundance relationships (SAR) are however not well understood. Here we...

Global change involves shifts in multiple environmental factors that act in concert to shape ecological systems in ways that depend on local biotic and abiotic conditions. Little is known about the effects of combined global change stressors on phytoplankton communities, and particularly how these are mediated by distinct community properties such...

Resources and temperature play major roles in determining biological production in lake ecosystems. Lakes have been warming and ‘browning’ over recent decades due to climate change and increased loading of terrestrial organic matter. Conflicting hypotheses and evidence have been presented about whether these changes will increase or decrease fish g...

Recruitment and connectivity are important criteria for designing effective marine protected areas, as coastal fish populations must be sustained by settling juveniles. However, patterns of recruitment are difficult to observe, and adults and juveniles may occupy distinct habitats. We examined patterns of adult black rockfish Sebastes melanops abun...

Trade‐offs among traits that shape different components of fitness determine the potential for species to coexist in communities and the regulation of ecosystem productivity by consumers vs. resources. We compared functional and structural traits of 14 species of freshwater phytoplankton to test the influence of life history (exponential growth rat...

Compliance with spatial fishing regulations (e.g., marine protected areas, fishing closures) is one of the most important, yet rarely measured, determinants of ecological recovery. We used aerial observations of recreational fishing events from creel surveys before, during, and after 77 Rockfish Conservation Areas (RCAs) were established in British...

Consensus has emerged in the literature that increased biodiversity enhances the capacity of ecosystems to perform multiple functions. However, most biodiversity/ecosystem function studies focus on a single ecosystem, or on landscapes of homogenous ecosystems. Here, we investigate how increased landscape‐level environmental dissimilarity may affect...

Between 2004 and 2007, Fisheries and Oceans Canada undertook a management action to conserve overfished populations of Inshore Rockfishes by designating 164 Rockfish Conservation Areas (RCAs) closed to most recreational and commercial fishing. However, no research has yet assessed the effectiveness of the RCA network at promoting groundfish populat...

Lago de Tota, the largest lake in Colombia, is the primary source of water for 250,000 people and a focus of regional economic activity in agriculture, aquaculture, and tourism. Recently, agencies and stakeholders report a shift from the naturally oligotrophic state toward eutrophy. However, the relative contributions of different inputs, including...

Variation in resource use among species determines their potential for competition and co-existence, as well as their impact on ecosystem processes. Planktonic crustaceans consume a range of micro-organisms that vary among habitats and species, but these differences in resource consumption are difficult to characterize due to the small size of the...

The relationship between biodiversity and productivity has emerged as a central theme in ecology. Mechanistic explanations for this relationship suggest that the role organisms play in the ecosystem (i.e., niches or functional traits) is a better predictor of ecosystem stability and productivity than taxonomic richness. Here, we tested the capacity...

The strength of species interactions often varies geographically and locally with environmental conditions. Competitive interactions are predicted to be stronger in benign environments while facilitation is expected to be stronger in harsh ones. We tested these ideas with an aboveground neighbor removal experiment at six salt marshes along the Cali...

Genetically engineered (GE) algae offer the promise of producing food, fuel, and other valuable products with reduced requirements for land and fresh water. While the gains in productivity measured in GE terrestrial crops are predicted to be mirrored in GE algae, the stability of phenotypes and ecological risks posed by GE algae in large-scale outd...

Interactions among microbes determine the prevalence of harmful algal blooms that threaten water quality. These interactions can be indirectly mediated by shared resources or consumers, or through interference by the production of allelochemicals. Allelopathic interactions and resource competition have been shown to occur among algae and associated...

Environmental variability and the frequency of extreme events are predicted to increase in future climate scenarios; however, the role of fluctuations in shaping community composition, diversity and stability is not well understood. Identifying current patterns of association between measures of community stability and climatic means and variabilit...

Climate change shuffles species ranges and creates novel interactions that may either buffer communities against climate change or exacerbate its effect. For instance, facilitation can become more prevalent in salt marshes under stressful conditions while competition is stronger in benign environments. Sea-level rise (SLR) is a consequence of clima...

Distance-based redundancy analysis of plant community composition. Shown at TJ (left) and KF (right). Only species with scores >0.1 were included in this plot. (DOCX)

Subordinate species cover in relation to realized S. pacifica cover. Cover is shown at high (black), medium (green) and low (red) elevations at KF (top) and TJ (bottom). Solid lines indicate significant relationships while dotted lines indicate non-significance. Dashed lines indicate 95% confidence intervals. (DOCX)

To date, the algal biofuel industry has focused on the cultivation of monocultures of highly productive algal strains, but scaling up production remains challenging. Algal monocultures are difficult to maintain because they are easily contaminated by wild algal strains, grazers, and pathogens. In contrast, theory suggests that polycultures (multisp...

Modern society is fueled by fossil energy produced millions of years ago by photosynthetic organisms. Cultivating contemporary photosynthetic producers to generate energy and capture carbon from the atmosphere is one potential approach to sustaining society without disrupting the climate. Algae, photosynthetic aquatic microorganisms, are the fastes...

Between 2004 and 2007, Fisheries and Oceans Canada undertook a management action to conserve overfished populations of Inshore Rockfishes by designating 164 Rockfish Conservation Areas (RCAs) closed to most recreational and commercial fishing. However, no research has yet assessed the effectiveness of the RCA network at promoting groundfish populat...

Human activities have resulted in rising temperatures and the introduction or extirpation of top predators worldwide. Both processes generate cascading impacts throughout food webs and can jeopardize important ecosystem services. We examined the impact of fish stocking on communities and ecosystems in California mountain lakes across an elevation (...

Compliance with spatial fishing regulations (e.g., marine protected areas, fishing closures) is one of the most important, yet rarely measured, determinants of ecological recovery. We used aerial observations of recreational fishing events from creel surveys before, during, and after 77 Rockfish Conservation Areas (RCAs) were established in British...

Managing ecosystems to maintain biodiversity may be one approach to insuring their dynamic stability, productivity, and delivery of vital services. The applicability of this approach to industrial ecosystems that harness the metabolic activities of microbes has been proposed but never been tested at relevant scales. We used a tag-sequencing approac...

Species that occur along broad environmental gradients often vary in phenotypic traits that make them better adapted to local conditions. Variation in species interactions across gradients could therefore be due to either phenotypic differences among populations or environmental conditions that shift the balance between competition and facilitation...

Evidence shows the important role biota play in the carbon cycle, and strategic management of plant and animal populations could enhance CO2 uptake in aquatic ecosystems. However, it is currently unknown how managementdriven changes to community structure may interact with climate warming and other anthropogenic perturbations to alter CO2 fluxes. H...

Global demand for transportation fuels will increase rapidly during the upcoming decades, and concerns about fossil-fuel consumption have stimulated research on renewable biofuels that can be sustainably produced from biological feedstocks. However, if unchecked, pathogens and parasites are likely to infect these cultivated biofuel feedstocks, grea...

Reservoirs around the world contribute to cycling of carbon dioxide (CO2) with the atmosphere, but there is little information on how ecosystem processes determine the absorption or emission of CO2. Reservoirs are the most prevalent freshwater systems in the arid southwest of North America, yet it is unclear whether they sequester or release CO2 an...

Sea otters are a classic example of a predator controlling ecosystem productivity through cascading effects on basal, habitat-forming kelp species. However, their indirect effects on other kelp-associated taxa like fishes are poorly understood. We examined the effects of sea otter (Enhydra lutris) reintroduction along the west coast of Vancouver Is...

Understanding the evolutionary potential of organisms to adapt to a changing climate, and the fitness consequences of temperature fluctuations, are critical to forecasting the future of biodiversity. Geographic variation among populations in life history response to temperature mean and variability offers one view of the potential for local adaptat...

Abstract Trophic cascades are indirect positive effects of predators on resources via control of intermediate consumers. Larger-bodied predators appear to induce stronger trophic cascades (a greater rebound of resource density toward carrying capacity), but how this happens is unknown because we lack a clear depiction of how the strength of trophic...

Bacteria are ubiquitous and important components of marine ecosystems, yet the interaction between bacteria and higher trophic levels remain poorly understood. The trophic cascade involving sea otters, urchins, and kelp in the North Pacific is a classic case of altered ecosystem states; however, its impacts on microbial communities are unknown. We...

Background/Question/Methods Species that occur along large environmental gradients can display corresponding variation in traits that make them better adapted to local conditions. In stressful environments, the Stress-Gradient Hypothesis predicts that interactions will be more facilitative, but it is unclear whether interactions differ along envi...

Background/Question/Methods Increasing global temperatures can interact with local processes, causing indirect responses that are difficult to anticipate. Theory and experiments show that the strength of top-down forces structuring food webs increases with temperature; however little is known about these patterns vary in natural systems where com...

Background/Question/Methods While many lakes export CO2 to the atmosphere, the ecological and environmental factors that determine whether manmade reservoirs emit or sequester CO2 emissions are poorly known. As atmospheric CO2 concentrations continue to increase and more reservoirs are created for hydroelectric power, it is important to determine...

Although competing species are expected to exhibit compensatory dynamics (negative temporal covariation), empirical work has demonstrated that competitive communities often exhibit synchronous dynamics (positive temporal covariation). This has led to the suggestion that environmental forcing dominates species dynamics; however, synchronous and comp...

Although competing species are expected to exhibit compensatory dynamics (negative temporal covariation), empirical work has demonstrated that competitive communities often exhibit synchronous dynamics (positive temporal covariation). This has led to the suggestion that environmental forcing dominates species dynamics; however, synchronous and comp...

Changing temperature can substantially shift ecological communities by altering the strength and stability of trophic interactions. Because many ecological rates are constrained by temperature, new approaches are required to understand how simultaneous changes in multiple rates alter the relative performance of species and their trophic interaction...

Understanding the factors that influence larval dispersal and connectivity among marine populations is critical to the conservation and sustainable management of marine resources. We assessed genetic subdivision among ten populations of copper rockfish (Sebastes caurinus) representing paired samples of outer coast and the heads of inlets in five re...

Phytoplankton offer great potential as a bioenergy crop; however, technological advances are needed to intensify their yield and reduce their footprints for water, nutrients and land. One approach to enhance productivity is to grow polycultures of mixed species, which convert abiotic resources into biomass more efficiently than any single taxon. We...

Predicting the ecological causes and consequences of global climate change requires a variety of approaches, including the use of experiments, models, and surveys. Among experiments, mesocosms have become increasingly popular because they provide an important bridge between smaller, more tightly-controlled, microcosm experiments (which can suffer f...

Microalgae represent one of the most promising groups of candidate organisms for replacing fossil fuels with contemporary primary production as a renewable source of energy. Algae can produce many times more biomass per unit area than terrestrial crop plants, easing the competing demands for land with food crops and native ecosystems. However, seve...

Background/Question/Methods Explicitly relating theory to empirical results is a familiar challenge in consumer-resource research. However, concern for climate change impacts and an interest in metabolic ecology have renewed efforts to integrate experimental results and theory for how warming affects trophic interactions. Experiments have shown t...

Inter and intra-population variation in morphological traits, such as body size and shape, provides important insights into the ecological importance of individual natural populations. The radiation of Diaptomid species (~400 species) has apparently produced little morphological differentiation other than those in secondary sexual characteristics,...

Clustering of female Diaptomids along the four principle component axes of body shape by species and populations. Species are identified by color and bounded by a convex hull: Red - A. denticornis, Green - H. franciscanus, Black - L. ashlandi; Purple - L. tyrrelli; Blue - S. oregonensis. Populations within each species are denoted by different symb...

Species' ecology and evolution can have strong effects on communities. Both may change concurrently when species colonize a new ecosystem. We know little, however, about the combined effects of ecological and evolutionary change on community structure. We simultaneously examined the effects of top-predator ecology and evolution on freshwater commun...

Loadings plotted on NMDS axes 1 and 2 demonstrating the zooplankton genera responsible for the most variation in community composition across treatments. (EPS)

Percent replacement (of deceased/sick fish with new fish throughout experiment) and recovery (total number of fish collected at end of experiment) of each fish ecotype in each treatment. (DOCX)

Predators can influence the exchange of carbon dioxide between ecosystems and the atmosphere by altering ecosystem processes such as decomposition and primary production, according to food web theory1, 2. Empirical knowledge of such an effect in freshwater systems is limited, but it has been suggested that predators in odd-numbered food chains supp...

Dispersal limitation is generally considered to have little influence on the spatial structure of biodiversity in microbial metacommunities. This notion derives mainly from the analysis of spatial patterns in the field, but experimental tests of dispersal limitation using natural communities are rare for prokaryotes and, to our knowledge, non-exist...

The effects of global and local environmental changes are transmitted through networks of interact-ing organisms to shape the structure of communities and the dynamics of ecosystems. We tested the impact of elevated temperature on the top-down and bottom-up forces structuring experimental freshwater pond food webs in western Canada over 16 months....

Conceptual models of adaptive radiation predict that competitive interactions among species will result in an early burst of speciation and trait evolution followed by a slowdown in diversification rates. Empirical studies often show early accumulation of lineages in phylogenetic trees, but usually fail to detect early bursts of phenotypic evolutio...

Climate warming is occurring in concert with other anthropogenic changes to ecosystems. However, it is unknown whether and how warming alters the importance of top-down vs. bottom-up control over community productivity and variability. We performed a 16-month factorial experimental manipulation of warming, nutrient enrichment, and predator presence...

The exchange of organisms and energy among ecosystems has major impacts on food web structure and dynamics, yet little is known about how climate warming combines with other pervasive anthropogenic perturbations to affect such exchanges. We used an outdoor freshwater mesocosm experiment to investigate the interactive effects of warm-ing, eutrophica...

Organisms alter the biotic and abiotic conditions of ecosystems. They can modulate the availability of resources to other species (ecosystem engineering) and shape selection pressures on other organisms (niche construction). Very little is known about how the engineering effects of organisms vary among and within species, and, as a result, the ecos...

1. Climate change and other human-driven environmental perturbations are causing reductions in biodiversity and impacting the functioning of ecosystems on a global scale. Metacommunity theory suggests that ecosystem connectivity may reduce the magnitude of these impacts if the regional species pool contains functionally redundant species that diffe...

Ecology Letters (2011) 14 : 852–862 Abstract Synergistic interactions between multiple limiting resources are common, highlighting the importance of co‐limitation as a constraint on primary production. Our concept of resource limitation has shifted over the past two decades from an earlier paradigm of single‐resource limitation towards concepts of...

Background/Question/Methods The ecological principles surrounding the relationships among diversity, productivity and grazing control of autotrophs have major implications for biofuel production. Unicellular phytoplankton are much more productive than terrestrial plants due to their small size, short generation times and rapid turnover, and are th...

Background/Question/Methods Kelp forests are one of the most productive ecosystems on our planet providing a diversity of ecosystem goods and services that coastal communities have relied on economically and culturally for millennia. These ecosystems are also highly susceptible to top-down forcing by strongly interacting predators such as sea ott...

The introduction and expansion of exotic species have caused dramatic changes in marine macroalgal assemblages globally. Mechanisms underlying the impacts of macroalgal invaders have been identified for only a few species over small portions of their introduced distribution, and over short time scales. Invasive macroalgae can impact native species...

Until recently, large apex consumers were ubiquitous across the globe and had been for millions of years. The loss of these animals may be humankind’s most pervasive influence on nature. Although such losses are widely viewed as an ethical and aesthetic problem, recent research reveals extensive cascading effects of their disappearance in marine, t...

Rising temperatures, altered predator guilds and eutrophication are three pervasive global changes that alter freshwater communities. However, freshwater systems are linked to adjacent terrestrial environments by the reciprocal exchange of resources, and the effect of global change drivers on these cross-ecosystem subsidies are poorly understood. W...

Ecology Letters (2010) 13: 1160–1171 Species interactions come in a variety of forms, from weak to strong, and negative or positive, each with unique consequences for local community structure. However, interactions depend on several biotic, abiotic and scale-dependent variables that make their magnitude and direction difficult to predict. Here, we...

Background/Question/Methods Rising temperatures, declining predator populations and eutrophication are three pervasive global changes that alter communities in aquatic ecosystems. Aquatic systems are linked to adjacent terrestrial environments by the reciprocal exchange of resources, but the effects of global change drivers on these cross-ecosyst...

Background/Question/Methods Rising temperatures, declining predator populations and eutrophication are three pervasive global changes taking place in aquatic ecosystems. These processes may interact in a number of ways that are likely to vary seasonally as temperature affects consumer-resource interactions and metabolic processes. We used a year-lo...