Erika S. Zavaleta

Erika S. Zavaleta
University of California, Santa Cruz | UCSC · Department of Ecology & Evolutionary Biology

About

123
Publications
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Publications

Publications (123)
Article
Full-text available
Racial and ethnic discrimination persist in science, technology, engineering and mathematics fields, including ecology, evolution and conservation biology (EECB) and related disciplines. Marginalization and oppression as a result of institutional and structural racism continue to create barriers to inclusion for Black people, Indigenous people and...
Article
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This paper introduces the collection of manuscripts from the symposium, “Biology Beyond the Classroom: Experiential Learning through Authentic Research, Design, and Community Engagement,” presented at the 2021 annual meeting of the Society for Integrative and Comparative Biology. The following papers showcase innovative approaches for engaging unde...
Article
Significance We present multiyear results from a realistic biodiversity loss experiment, examining how two key ecosystem functions (productivity and invasion resistance) responded to randomized and realistic (drought-driven) species losses across years with high yearly climatic variation. We show that realistic low-diversity communities do not alwa...
Article
Synopsis Field courses have been identified as powerful tools for student success in science, but the potential for field courses to address demographic disparities and the mechanisms behind these benefits are not well understood. To address these knowledge gaps, we studied students in a nonmajors Ecology and Evolutionary Biology course, Introducti...
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The COVID-19 pandemic has disrupted many standard approaches to STEM education. Particularly impacted were field courses, which rely on specific natural spaces often accessed through shared vehicles. As in-person field courses have been found to be particularly impactful for undergraduate student success in the sciences, we aimed to compare and und...
Article
Field courses have been identified as powerful tools for inclusion and student success in science. However, not all students are equally likely to take field courses. How do we remove barriers to equity in field courses, to make them engines for inclusion, diversity, and collective excellence in ecology and evolution?
Article
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Helping the world’s coastal communities adapt to climate change impacts requires evaluating the vulnerability of coastal communities and assessing adaptation options. This includes understanding the potential for ‘natural’ infrastructure (ecosystems and the biodiversity that underpins them) to reduce communities’ vulnerability, alongside more tradi...
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Disparities remain in the representation of marginalized students in STEM. Classroom‐based experiential learning opportunities can increase student confidence and academic success; however, the effectiveness of extending learning to outdoor settings is unknown. Our objectives were to examine (a) demographic gaps in ecology and evolutionary biology...
Article
Conservation and restoration of riparian vegetation in agricultural landscapes has had mixed success at protecting in‐stream habitat, potentially due to the mismatch between watershed‐scale impacts and reach‐scale restoration. Prioritizing contiguous placement of small‐scale restoration interventions may effectively create larger‐scale restoration...
Article
Unpredictable or variable ecosystem recovery from disturbance presents a challenge to conservation, particularly as the scale of human disturbance continues to increase. Theory suggests that land cover and disturbance characteristics should influence recovery, but individual studies of disturbance and recovery frequently struggle to uncover general...
Article
We provide updated spatial distribution and inventory data for on-road NH3 emissions for the continental United States (U.S.) On-road NH3 emissions were determined from on-road CO2 emissions data and empirical NH3:CO2 vehicle emissions ratios. Emissions of NH3 from on-road sources in urbanized regions are typically 0.1-1.3tkm-2yr-1 while NH3 emissi...
Article
The distribution of conservation effort on the landscape is affected by both ecological and social priorities and constraints. Together these influences can result in bias towards certain types of ecological or human communities. We evaluate the distribution of restoration projects on the California Central Coast, USA, to evaluate sociopolitical an...
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Since its inception, conservation biology has inspired thousands of students, spurred the creation of new initiatives, organizations and agencies, and informed conservation efforts worldwide. Nevertheless, global biodiversity loss is accelerating (Butchart et al. 2010), and our field needs to change to keep pace with mounting challenges. Conservati...
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Observational studies and experimental evidence agree that rising global temperatures have altered plant phenology—the timing of life events, such as flowering, germination, and leaf-out. Other large-scale global environmental changes, such as nitrogen deposition and altered precipitation regimes, have also been linked to changes in flowering times...
Article
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Nitrogen (N) pollution is increasingly recognized as a threat to biodiversity. However, our understanding of how N is affecting vulnerable species across taxa and broad spatial scales is limited. We surveyed approximately 1400 species in the continental United States listed as candidate, threatened, or endangered under the US Endangered Species Act...
Article
While most studies of the relationship between biodiversity and ecosystem functioning have examined randomized diversity losses, several recent experiments have employed nested, realistic designs and found that realistic species losses had larger consequences than random losses for ecosystem functioning. Progressive, realistic, biodiversity losses...
Article
Full-text available
Maintaining native biodiversity in grasslands requires management and mitigation of anthropogenic changes that have altered resource availability, grazing regimes, and community composition. In California (USA), high levels of atmospheric nitrogen (N) deposition have facilitated the invasion of exotic grasses, posing a threat to the diverse plant a...
Article
Maintaining native biodiversity in grasslands requires management and mitigation of anthropogenic changes that have altered resource availability, grazing regimes, and community composition. In California (USA), high levels of atmospheric nitrogen (N) deposition have facilitated the invasion of exotic grasses, posing a threat to the diverse plant a...
Article
This chapter focuses on evapotranspiration (ET) by tamarisk in the Colorado River basin. In particular, it considers whether restoration of tamarisk-invaded rivers and riverbanks could result in increased water savings. The chapter begins with a background on tamarisk and its reputated use of large quantities of water as an aggressive invasive spec...
Article
The interaction of resource availability and disturbance can strongly affect plant species richness and the spread of exotic plants. Several ecological theories posit that disturbance mediates the richness-reducing effects of increased competition as resource levels rise. In the low-nutrient serpentine grasslands of the San Francisco Bay Area, the...
Article
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An age-old conflict around a seemingly simple question has resurfaced: why do we conserve nature? Contention around this issue has come and gone many times, but in the past several years we believe that it has reappeared as an increasingly acrimonious debate between, in essence, those who argue that nature should be protected for its own sake (intr...
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Ecosystem-based management requires the promotion and integration of locally relevant ecosystem services. This needs an understanding of which ecosystem services local people value and how local valuation varies with socio-cultural and market factors. We convened ten focus group discussions and performed 105 household surveys from major indigenous...
Conference Paper
Background/Question/Methods Most studies of the relationship between biodiversity and ecosystem function have examined randomized diversity losses, although in natural systems biodiversity loss tends to occur progressively rather than randomly. Many studies now support the finding that realistic biodiversity loss generally leads to greater effect...
Article
Full-text available
Understanding how insular ecosystems recover or are restructured after the eradication of an invasive species is crucial in evaluating conservation success and prioritizing island conservation efforts. Globally, herbivores have been removed from 762 islands, most with limited active restoration actions following eradication. Few studies have docume...
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When a species becomes extinct, its ecological functions are lost as well. Taxon substitution is a controversial approach to restoring such functions via introduction of non-native species known to serve similar functions elsewhere. Due to the possibility of nontarget effects from such introductions, taxon substitution has been proposed and impleme...
Article
Numerous experiments have demonstrated that diverse plant communities use nitrogen (N) more completely and efficiently, with implications for how species conservation efforts might influence N cycling and retention in terrestrial ecosystems. However, most such experiments have randomly manipulated species richness and minimized environmental hetero...
Article
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Native plant species that have lost their mutualist partners may require non-native pollinators or seed dispersers to maintain reproduction. When natives are highly specialized, however, it appears doubtful that introduced generalists will partner effectively with them. We used visitation observations and pollination treatments (experimental manipu...
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Soils are globally significant sources and sinks of atmospheric CO2. Increasing the resolution of soil carbon turnover estimates is important for predicting the response of soil carbon cycling to environmental change. We show that soil carbon turnover times can be more finely resolved using a dual isotope label like the one provided by elevated CO2...
Article
AimThe perceived absence of young cohorts in many long-lived trees, particularly Quercus species, has raised concerns about their long-term viability. While there is a robust body of literature on valley oak (Quercus lobata) planting experiments, conducted mainly on research reserves, an assessment of natural recruitment across a range of climate a...
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Mokany et al. (1) reiterate an important consideration about the interpretation of results in our PNAS report (2). The authors suggest that the use of a different metric of β diversity might reveal a larger effect of β diversity on ecosystem multifunctionality. We agree, and reiterate that our reported effects of β diversity on ecosystem multifunct...
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A great part of the Earth's biodiversity occurs on islands, to which humans have brought a legion of invasive species that have caused population declines and even extinctions. The domestic cat is one of the most damaging species introduced to islands, being a primary extinction driver for at least 33 insular endemic vertebrates. Here, we examine t...
Conference Paper
Background/Question/Methods Species losses from communities do not occur at random. A growing body of literature has emerged in the last decade to explore the effects of realistic species losses on ecosystem processes and to compare it to the effects of the randomized biodiversity treatments most commonly used in biodiversity-ecosystem functionin...
Article
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As global environmental change accelerates, biodiversity losses can disrupt interspecific interactions. Extinctions of mutualist partners can create "widow" species, which may face reduced ecological fitness. Hypothetically, such mutualism disruptions could have cascading effects on biodiversity by causing additional species coextinctions. However,...
Data
Sources used in quantitative estimates. (DOC)
Data
PRISMA Checklist for systematic review. (DOC)
Data
Vertebrate seed dispersers and pollinators. (XLS)
Article
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Society values landscapes that reliably provide many ecosystem functions. As the study of ecosystem functioning expands to include more locations, time spans, and functions, the functional importance of individual species is becoming more apparent. However, the functional importance of individual species does not necessarily translate to the functi...
Article
AimQuestions about the relative importance of top-down and bottom-up regulation of populations have long occupied ecologists. Recent work has explored how the strength of consumer- versus resourced-based limitation can shift in strength across both time and space, and indicates the need for larger scales of study across spatial resource gradients....
Article
Full-text available
Soils are globally significant sources and sinks of atmospheric CO2. Increasing the resolution of soil carbon turnover estimates is important for predicting the response of soil carbon cycling to environmental change. We show that soil carbon turnover times can be more finely resolved using a dual isotope label like the one provided by elevated CO2...
Conference Paper
Background/Question/Methods We investigate global change at the land-sea margin, specifically salt marshes’ function as a “coastal filter” in central California, intercepting watershed-derived nitrogen (N) pollution. The uptake of N is understood to buffer the major coastal problem of eutrophication, and at the same time, sea-level rise may chang...
Conference Paper
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Background/Question/Methods Current global extinction rates, arising from rapid environmental change, generate broadscale disruption in interspecific interactions. Losses of mutualists can erode ecosystem functions, provoke novel numerical and behavioral responses among remnant native species, and further threaten biodiversity. In some settings,...
Conference Paper
Background/Question/Methods Ecosystem-based adaptation (EbA) – targeted ecosystem management, conservation, and restoration that will help people adapt to climate change – has the potential to both protect biodiversity and reduce the impacts of climate change. For example, restoring and/or conserving mangroves protects coastal communities from tr...
Article
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Coastal salt marshes are among Earth's most productive ecosystems and provide a number of ecosystem services, including interception of watershed-derived nitrogen (N) before it reaches nearshore oceans. Nitrogen pollution and climate change are two dominant drivers of global-change impacts on ecosystems, yet their interacting effects at the land-se...
Conference Paper
Background/Question/Methods While most studies of the relationship between biodiversity and ecosystem function have examined randomized diversity losses, real biodiversity loss generally occurs progressively rather than randomly. Progressive, realistic biodiversity losses through time are necessarily strongly nested – that is, each decreasing leve...
Data
Marsh plants are vulnerable to sea-level rise simulation. Simulation of +30 cm sea-level rise resulted in the death of all salt marsh plants before the summer of Year Two of the experiment (bar graph), where plant tissue N concentrations increased with N treatment (XY graph). Error bars depict standard error. (TIF)
Data
Nitrogen concentration in aboveground plant tissue increased strongly in plots with nitrogen addition. N concentration ([N]) (mgN g−1 plant tissue) in a) July 2008; b) Nov 2008; c) July 2009; and d) Nov 2009 harvests. Four out of five harvests are shown. Control treatment (no N) is shown in grey, and N-addition treatment (+N) in green. Error bars d...
Article
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Earlier spring phenology observed in many plant species in recent decades provides compelling evidence that species are already responding to the rising global temperatures associated with anthropogenic climate change. There is great variability among species, however, in their phenological sensitivity to temperature. Species that do not phenologic...
Article
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Extinctions can leave species without mutualist partners and thus potentially reduce their fitness. In cases where non-native species function as mutualists, mutualism disruption associated with species' extinction may be mitigated. To assess the effectiveness of mutualist species with different origins, we conducted a meta-analysis in which we com...
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As natural resource management agencies and conservation organizations seek guidance on responding to climate change, myriad potential actions and strategies have been proposed for increasing the long-term viability of some attributes of natural systems. Managers need practical tools for selecting among these actions and strategies to develop a tai...
Article
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Adapting to climate change is among the biggest challenges humanity faces in the next century. An overwhelming focus of adaptation strategies to reduce climate change-related hazards has been on hard-engineering structures such as sea walls, irrigation infrastructure and dams. Closer attention to a broader spectrum of adaptation options is urgently...
Article
Anticipating species movement under climate change is a major focus in conservation. Bioclimate models are one of the few predictive tools for adaptation planning, but are limited in accounting for (i) climatic tolerances in preadult life stages that are potentially more vulnerable to warming; and (ii) local‐scale movement and use of climatic refug...
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Ecosystems worldwide are rapidly losing taxonomic, phylogenetic, genetic, and functional diversity as a result of human appropriation of natural resources, modification of habitats and climate, and the spread of pathogenic, exotic, and domestic plants and animals. Twenty years of intense theoretical and empirical research have shown that such bioti...
Article
Previous research suggests that atmospheric nitrogen (N) deposition may facilitate the invasion and persistence of exotic plant species in serpentine grasslands, but the relative impact of increased N availability on native and exotic competitive dynamics has yet to be clearly elucidated. In this study, we evaluated how increased N deposition affec...
Article
1. The majority of experiments examining effects of species diversity on ecosystem functioning have randomly manipulated species richness. More recent studies demonstrate that realistic species losses have dramatically different effects on ecosystem functioning than those of randomized losses, but these results are based primarily on microcosm expe...
Article
The effects of declining plant biodiversity on ecosystem processes are well studied, with most investigations examining the role of species richness declines rather than declines of species abundance. Using grassland mesocosms, we examined how the abundance of a native, resident species, Hemizonia congesta (hayfield tarweed), affected exotic Centau...
Article
Full-text available
Cats are generalist predators that have been widely introduced to the world's ~179 000 islands. Once introduced to islands, cats prey on a variety of native species many of which lack evolved defenses against mammalian predators and can suffer severe population declines and even extinction. As islands house a disproportionate share of terrestrial b...
Conference Paper
Background/Question/Methods In recent decades, human activities have increased the amount of biologically available nitrogen (N) in the biosphere. The resulting increase in N availability has broadly affected ecosystems, through increased productivity, changes in species composition, altered nutrient cycles, and increases in invasion by exotic pl...
Article
Full-text available
Biodiversity is rapidly declining worldwide, and there is consensus that this can decrease ecosystem functioning and services. It remains unclear, though, whether few or many of the species in an ecosystem are needed to sustain the provisioning of ecosystem services. It has been hypothesized that most species would promote ecosystem services if man...
Conference Paper
Background/Question/Methods Accelerating human-caused declines in biodiversity have spurred a large body of research investigating linkages between species richness and ecosystem function. With few exceptions, these experiments have randomly manipulated species richness, while observed patterns of species losses in real ecosystems are non-random...
Conference Paper
Background/Question/Methods In grasslands, resident species with functional traits similar to invaders’ can reduce invasion by competing for resources. Less is known about how resident species’ abundance affects competitive interactions. Additionally, because many studies occur in highly controlled plots or microcosms, it is sometimes unclear how...
Conference Paper
Background/Question/Methods Biodiversity is rapidly declining worldwide, and there is consensus that biodiversity declines can lead to subsequent declines in ecosystem functioning and services. It remains unclear, though, whether few or many of the species in an ecosystem are needed to sustain the provisioning of ecosystem services. It has been h...
Conference Paper
Background/Question/Methods As worldwide biodiversity losses accelerate, a growing body of experiments has documented the consequences of species losses to ecosystem functions and services. Syntheses of these studies show that local species richness (alpha diversity, α) positively affects many ecosystem functions and that these effects become str...
Article
Full-text available
Cats are among the most successful and damaging invaders on islands and a significant driver of extinction and endangerment. Better understanding of their ecology can improve effective management actions such as eradication. We reviewed 72 studies of insular feral cat diet from 40 islands worldwide. Cats fed on a wide range of species from large bi...
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The Bay Checkerspot Butterfly reached its threatened status largely as a result of habitat loss through development. The species now benefits from the habitat pro-tection powers of the Endangered Species Act, yet the biggest new hazard to the survival of remaining Bay Checkerspot Butterfly populations may come from atmos-pheric nitrogen deposition....
Article
Until the 1980s, California's biodiverse serpentine grasslands were threatened primarily by development and protected by reserve creation. However, nitrogen (N) fertilization due to increasing fossil fuel emissions in the expanding Bay Area is thought to be contributing to rapid, recent invasion of these ecosystems by exotic annual grasses that are...