About

Brian Enquist is a Professor of Ecology and Evolutionary Biology at the University of Arizona, a position he has held since 2009. His research investigates how functional constraints at the level of the individual, including anatomical and physiological factors, influence larger-scale ecological and evolutionary patterns. He is broadly trained as a plant ecologist and employs a combination of theoretical, computational, biophysical, and physiological approaches to address integrative questions related to the evolution of form and functional diversity, the origin of allometric relationships, the scaling of biological processes from cells to ecosystems, the evolution of life-history and allocation strategies, and community ecology and macroecology. His work also includes monitoring long-term dynamics of growth and change within a tropical forest in Costa Rica.

Research topics

• Biology
• Ecology
• Geography
• Environmental science
• Agroforestry
• Sociology
• Computer Science
• Evolutionary biology
• Demography
• World Wide Web
• Data science
• Environmental resource management
• Atmospheric sciences
• Climatology
• Genetics

Selected publications

• The number of tree species on Earth

  Proceedings of the National Academy of Sciences · 2022 · 216 citations

  • Ecology
  • Geography
  • Biology

  One of the most fundamental questions in ecology is how many species inhabit the Earth. However, due to massive logistical and financial challenges and taxonomic difficulties connected to the species concept definition, the global numbers of species, including those of important and well-studied life forms such as trees, still remain largely unknown. Here, based on global ground-sourced data, we estimate the total tree species richness at global, continental, and biome levels. Our results indicate that there are ∼73,000 tree species globally, among which ∼9,000 tree species are yet to be discovered. Roughly 40% of undiscovered tree species are in South America. Moreover, almost one-third of all tree species to be discovered may be rare, with very low populations and limited spatial distribution (likely in remote tropical lowlands and mountains). These findings highlight the vulnerability of global forest biodiversity to anthropogenic changes in land use and climate, which disproportionately threaten rare species and thus, global tree richness.

  DOI

• Tropical tree growth driven by dry-season climate variability

  Nature Geoscience · 2022 · 133 citations

  • Environmental science
  • Climatology
  • Atmospheric sciences
  PublisherOA PDFDOI

• How deregulation, drought and increasing fire impact Amazonian biodiversity

  Nature · 2021 · 179 citations

  Senior authorCorresponding
  • Geography
  • Agroforestry
  • Ecology
  DOI

• Areas of global importance for conserving terrestrial biodiversity, carbon and water

  Nature Ecology & Evolution · 2021 · 363 citations

  • Environmental resource management
  • Environmental science
  • Geography

  To meet the ambitious objectives of biodiversity and climate conventions, the international community requires clarity on how these objectives can be operationalized spatially and how multiple targets can be pursued concurrently. To support goal setting and the implementation of international strategies and action plans, spatial guidance is needed to identify which land areas have the potential to generate the greatest synergies between conserving biodiversity and nature's contributions to people. Here we present results from a joint optimization that minimizes the number of threatened species, maximizes carbon retention and water quality regulation, and ranks terrestrial conservation priorities globally. We found that selecting the top-ranked 30% and 50% of terrestrial land area would conserve respectively 60.7% and 85.3% of the estimated total carbon stock and 66% and 89.8% of all clean water, in addition to meeting conservation targets for 57.9% and 79% of all species considered. Our data and prioritization further suggest that adequately conserving all species considered (vertebrates and plants) would require giving conservation attention to ~70% of the terrestrial land surface. If priority was given to biodiversity only, managing 30% of optimally located land area for conservation may be sufficient to meet conservation targets for 81.3% of the terrestrial plant and vertebrate species considered. Our results provide a global assessment of where land could be optimally managed for conservation. We discuss how such a spatial prioritization framework can support the implementation of the biodiversity and climate conventions.

  DOI

• Where we've been and where we're going: the importance of source communities in predicting establishment success from phylogenetic relationships

  Ecography · 2021 · 17 citations

  • Sociology
  • Biology
  • Ecology

  The last two decades have seen growing use of phylogenetic patterns to test hypotheses predicting the success of introduced species. Nearly all of these tests have focused on hypotheses pertaining to phylogenetic relatedness between introduced species and those of the recipient community, largely neglecting hypotheses regarding phylogenetic relationships in the source region. We synthesize hypotheses regarding how phylogenetic relationships of both recipient and source regions together influence establishment success. We also detail how best to account for differences in source communities within phylogenetic frameworks of invasion. Existing studies have predominantly focused on the environmental filtering and competition‐relatedness hypotheses, which deal with relatedness to the recipient community. We discuss how these recipient–region hypotheses can be integrated with three hypotheses focused on the relatedness between an introduced species and the source community in which it originated: the evolutionary imbalance, universal tradeoff and competitive constraint hypotheses. We detail important issues that arise when testing alternative hypotheses and interpreting results. We highlight a lack of tests of synthetic phylogenetic hypotheses including both the source and recipient community phylogenetic structure, as well as important covariates such as propagule pressure. Such synthetic tests may be valuable for identifying general phylogenetic patterns in establishment success, predicting future invasions, and for stimulating further exploration of the underlying mechanisms of invasibility. We conclude with recommendations for future studies that use phylogenetic relationships to predict invasions: including source and recipient communities, using complete phylogenies and accounting for phylogenetic uncertainty, considering multiple stages of invasion and conducting analyses across spatial and phylogenetic scales where possible.

  DOI

• Global gradients in intraspecific variation in vegetative and floral traits are partially associated with climate and species richness

  Global Ecology and Biogeography · 2020 · 95 citations

  • Biology
  • Ecology

  Abstract Aim Intraspecific trait variation (ITV) within natural plant communities can be large, influencing local ecological processes and dynamics. Here, we shed light on how ITV in vegetative and floral traits responds to large‐scale abiotic and biotic gradients (i.e., climate and species richness). Specifically, we tested whether associations of ITV with temperature, precipitation and species richness were consistent with any of four hypotheses relating to stress tolerance and competition. Furthermore, we estimated the degree of correlation between ITV in vegetative and floral traits and how they vary along the gradients. Location Global. Time period 1975–2016. Major taxa studied Herbaceous and woody plants. Methods We compiled a dataset of 18,401 measurements of the absolute extent of ITV (measured as the coefficient of variation) in nine vegetative and seven floral traits from 2,822 herbaceous and woody species at 2,372 locations. Results Large‐scale associations between ITV and climate were trait specific and more prominent for vegetative traits, especially leaf morphology, than for floral traits. The ITV showed pronounced associations with climate, with lower ITV values in colder areas and higher values in drier areas. The associations of ITV with species richness were inconsistent across traits. Species‐specific associations across gradients were often idiosyncratic, and covariation in ITV was weaker between vegetative and floral traits than within the two trait groups. Main conclusions Our results show that, depending on the traits considered, ITV either increased or decreased with climate stress and species richness, suggesting that both factors can constrain or enhance ITV, which might foster plant‐population persistence in stressful conditions. Given the species‐specific responses and covariation in ITV, associations can be hard to predict for traits and species not yet studied. We conclude that consideration of ITV can improve our understanding of how plants cope with stressful conditions and environmental change across spatial and biological scales.

  DOI

• Open Science principles for accelerating trait-based science across the Tree of Life

  Nature Ecology & Evolution · 2020 · 227 citations

  Senior authorCorresponding
  • Computer Science
  • Data science
  • Computer Science

  Synthesizing trait observations and knowledge across the Tree of Life remains a grand challenge for biodiversity science. Species traits are widely used in ecological and evolutionary science, and new data and methods have proliferated rapidly. Yet accessing and integrating disparate data sources remains a considerable challenge, slowing progress toward a global synthesis to integrate trait data across organisms. Trait science needs a vision for achieving global integration across all organisms. Here, we outline how the adoption of key Open Science principles-open data, open source and open methods-is transforming trait science, increasing transparency, democratizing access and accelerating global synthesis. To enhance widespread adoption of these principles, we introduce the Open Traits Network (OTN), a global, decentralized community welcoming all researchers and institutions pursuing the collaborative goal of standardizing and integrating trait data across organisms. We demonstrate how adherence to Open Science principles is key to the OTN community and outline five activities that can accelerate the synthesis of trait data across the Tree of Life, thereby facilitating rapid advances to address scientific inquiries and environmental issues. Lessons learned along the path to a global synthesis of trait data will provide a framework for addressing similarly complex data science and informatics challenges.

  DOI

Recent grants

• Collaborative Research: Developing integrated trait-based scaling theory to predict community change and forest function in light of global change

  NSF · $355k · 2015–2019

• Combining Theories For Plant Architecture, Allometry, and Traits to Develop the Next Generation of Scaling Theory

  NSF · $738k · 2007–2011

• Collaborative Research: BoCP-Implementation: BioFI- Biodiversity Forecasting Initiative to Understand Population, Community and Ecosystem Function Under Global Change

  NSF · $900k · 2022–2025

• Collaborative Research: ABI Development: Creating a generic workflow for scaling up the production of species ranges

  NSF · $525k · 2016–2020

• CAREER: Scaling Plant Life History, Ontogeny, Diversity, and Ecology: Elaboration of a General Model

  NSF · $520k · 2002–2007

Frequent coauthors

• Cyrille Violle

  Centre d'Écologie Fonctionnelle et Évolutive

  418 shared

• James H. Brown

  171 shared

• Geoffrey B. West

  159 shared

• Pablo A. Marquet

  Santa Fe Institute

  122 shared

• Benjamin Blonder

  121 shared

• Josep M. Serra‐Diaz

  Aarhus University

  114 shared

• Brian Maitner

  University of Arizona

  107 shared

• Sean T. Michaletz

  University of British Columbia

  98 shared

Education

• PhD, Biology

  University of New Mexico

  1998

Awards & honors

• NSF Young Investigators CAREER Award
• Ecological Society of America, Young Investigator Mercer Awa…
• Fulbright Fellow, Costa Rica, 1995-1996

Similar researchers at University of Arizona

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• Jeremy Garciah-129
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