Author: Wes

  • U.S. Tree Assessment

    U.S. Tree Assessment

    Assessment · Data · Conservation Priorities

    U.S. Tree Assessment

    Conservation action begins with a deceptively simple set of questions: What species are here? Where do they occur? And which are most at risk? This collaboration created a standardized checklist of native U.S. trees and a common conservation framework for answering them.

    U.S. Tree Assessment research graphic

    Why it matters

    The contiguous United States supports nearly 900 native tree species. Yet conservation efforts had been limited by inconsistencies in the underlying information: which plants qualify as trees, which species are native, where they occur, and how threatened they are. Without a shared baseline, it is difficult to coordinate priorities across agencies, gardens, conservation organizations, and researchers.

    Building a common foundation

    Our collaboration assembled a standardized checklist, mapped distributions, and brought conservation-status information together in a form that could be shared and acted upon. The work was led by a broad partnership that included The Morton Arboretum, the United States Botanic Garden, NatureServe, Botanic Gardens Conservation International, the U.S. Forest Service, and others.

    From data to priorities

    The value of a national assessment is not simply the list itself. Standardized information makes it possible to identify gaps, compare risk, coordinate collections and recovery work, and direct limited conservation capacity toward the trees that need it most. That connection between authoritative biodiversity data and practical action has remained a central theme of my work.

    The publication

    Carrero, C., E. Beckman Bruns, A.L. Frances, D. Jerome, W. Knapp, A. Meyer, R. Mims, D. Pivorunas, D. Speed, A. Treher Eberly & M. Westwood. 2022. Data sharing for conservation: A standardized checklist of US native tree species and threat assessments to prioritize and coordinate action. Plants, People, Planet.

  • Rediscovering Quercus tardifolia

    Rediscovery · Extinction · Conservation

    Rediscovering Quercus tardifolia

    In May 2022, a collaborative expedition in Big Bend National Park found a living lateleaf oak after the species had been feared extinct. Finding the tree was only the beginning. The discovery created an immediate obligation to understand what it is, why it is disappearing, and how to keep it from vanishing.

    Field team gathered around a rediscovered Quercus tardifolia in Big Bend National Park

    Why it matters

    Quercus tardifolia is an exceptionally rare oak associated with the Chisos Mountains of West Texas. The last known living specimen was believed to have died in 2011. When our team encountered a roughly 30-foot tree in 2022, it was alive but in poor condition, scarred by fire and showing signs of fungal infection. A single drought, fire, or other disturbance could have erased what might have been the species’ last known foothold.

    Nature rarely hands us a second chance, and I doubt we’ll get a third. We won’t waste it.

    The search

    The expedition brought together researchers from more than ten institutions and was led by The Morton Arboretum and the United States Botanic Garden. I participated while serving as Chief Botanist at NatureServe. The team searched the rugged Chisos Mountains for rare oaks and, on May 25, 2022, located the tree that renewed the possibility that Q. tardifolia persisted.

    What we needed to learn

    Rediscovery did not settle the science. Oaks hybridize readily, and the taxonomic identity of lateleaf oak has long raised questions. Molecular work was therefore essential to compare the rediscovered material with historical Q. tardifolia and related red oaks. The conservation problem and the taxonomic problem were inseparable: before deciding how best to safeguard a lineage, we needed to understand its genetic distinctiveness and relationships.

    From rediscovery to recovery

    The immediate work shifted from searching to conservation: reducing threats, looking for reproductive material, attempting propagation, and building the genetic evidence needed to guide future action. For me, the lesson is larger than a single oak. Rediscovery is meaningful only when it creates a pathway to recovery. Finding a species gives conservation another opportunity to act before documentation becomes an obituary.

  • Conservation Status of Trillium in North America

    Conservation Status of Trillium in North America

    Assessment · Native Plants · Conservation

    Conservation Status of Trillium in North America

    Trilliums are among North America’s most recognizable native wildflowers. Their familiarity can obscure an important conservation reality: species with restricted ranges, slow life histories, and specialized habitats can be vulnerable to pressures that operate across entire landscapes.

    A continent-wide assessment

    Working with colleagues across the continent, I helped assess the conservation status of 53 Trillium taxa using both NatureServe and IUCN methodologies. The goal was not simply to assign ranks. It was to create a consistent picture of which trilliums are secure, which are declining, what is driving those declines, and where conservation attention is most urgently needed.

    What threatens trilliums?

    The assessment identified a suite of interacting pressures, including habitat loss and fragmentation, browsing by white-tailed deer, damage from feral pigs, invasive plants, harvest pressure, and other changes to forest ecosystems. These threats do not affect every species equally. Wide-ranging species may remain common overall while declining locally, while narrow endemics can be placed at risk by changes affecting only a small number of sites.

    Why assessment matters

    Good conservation begins with knowing what exists, where it occurs, and how it is doing. A rigorous assessment turns scattered botanical knowledge into priorities that agencies, land managers, botanical gardens, scientists, and conservation organizations can use. That progression from taxonomy and field knowledge to assessment and action has become a recurring theme throughout my career.

    From science to a broader audience

    The assessment also became an opportunity to bring plant conservation to people far beyond the scientific community. In 2022, Margaret Roach explored the conservation story of trilliums in The New York Times and subsequently invited me onto her A Way to Garden podcast to discuss rare plants, extinction, NatureServe, and why taking stock of native plant diversity matters.

    Listen to the A Way to Garden conversation →

    The work in context

    Trilliums are charismatic enough to attract attention, but the conservation problem they illustrate is much larger. Thousands of plant species receive far less public notice. Assessments like this provide the evidence needed to move from appreciation of biodiversity to deliberate action on its behalf.

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  • Vascular Plant Extinction in the United States and Canada

    Vascular Plant Extinction in the United States and Canada

    Extinction · Research · Conservation

    Vascular Plant Extinction in the United States and Canada

    Extinction is permanent, but even in one of the most botanically studied parts of the world we did not have a reliable accounting of how many plants had already been lost. I led a national team to find out.

    Counting what had disappeared

    We queried conservation databases, searched the botanical literature, and then vetted candidate extinctions with experts across the United States and Canada. Because taxonomy itself can complicate extinction counts, we also developed an Index of Taxonomic Uncertainty to evaluate the strength of each taxon’s scientific standing.

    65

    taxa assessed as extinct in the study

    51

    species, plus 14 infraspecific taxa

    64%

    of extinct plants were single-site endemics

    What surprised us

    The study identified 65 extinct taxa, representing 51 species and 14 infraspecific taxa. That was a 109% increase over the number previously reported for the United States and Canada. Seven persisted in cultivation despite being extinct in the wild. Perhaps most strikingly, 64% of the extinct plants had been known from only a single site, and many losses occurred outside places typically recognized as biodiversity hotspots.

    The conservation lesson

    The work changed how I think about extinction prevention. Species known from one or a few places can disappear before broad-scale conservation strategies ever reach them. Preventing extinction therefore requires both landscape conservation and an ability to identify and act on the most imperiled species individually, using complementary in situ and ex situ approaches.

    New York Botanical Garden Symposium

    Here Today, Gone Forever

    In November 2020, I presented this research at NYBG’s international symposium on plant extinction alongside Thomas Lovejoy, Stuart Pimm, Maria Vorontsova and other conservation leaders. The symposium connected the North American evidence with the larger global extinction crisis and the strategies needed to prevent future losses.

    Watch the NYBG symposium recording →

    A continuing question

    Our count was not the end of the story. Extinction records change as taxonomy improves, historical evidence is reexamined, and occasionally a species is rediscovered. The larger conclusion remains: documented losses are a minimum, not a ceiling. Better biodiversity data must ultimately lead to earlier conservation action.

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  • From Field Botanist to Conservation Leadership

    From Field Botanist to Conservation Leadership

    Career · Perspective · Conservation

    From Field Botanist to Conservation Leadership

    For twenty years, my professional life was rooted in the field. I searched for rare plants, mapped natural communities, documented biodiversity, and learned landscapes one population at a time. Eventually, that work led me to a larger question: how can the knowledge generated by field biologists be translated into conservation at a much greater scale?

    Learning conservation from the ground up

    I spent fifteen years with the Maryland Natural Heritage Program as Eastern Region Ecologist, followed by five years with the North Carolina Natural Heritage Program as Mountains Ecologist and Botanist. Those two decades within the Natural Heritage Network shaped how I understand biodiversity conservation. Fieldwork teaches you that conservation is ultimately specific: a species, a population, a place, a threat, and a decision about what to do next.

    It also teaches humility. Even in well-studied landscapes there are plants still waiting to be documented, populations that have not been seen in decades, and losses that can occur before science has fully understood what was there.

    A change in scale

    In 2021, I accepted the position of Chief Botanist at NatureServe. It was a significant departure from the work that had defined my career. I would spend less time conducting field inventories myself and more time thinking about how a continental network of scientists, shared biodiversity data, conservation assessments, and technology could help thousands of individual observations inform larger decisions.

    The question was no longer only how to understand a rare plant. It was how to build systems capable of acting on what we know.

    Science, data, and networks

    NatureServe offered a different vantage point on conservation. The organization and its network bring together biodiversity expertise across North America and use science, data, and technology to inform conservation and stewardship. For a botanist accustomed to working population by population, the opportunity was to connect detailed biological knowledge with systems that could influence decisions across states, regions, and institutions.

    What I carried forward

    Moving into conservation leadership did not replace the lessons of field botany. It made them more important. Good systems still depend on good observations. National priorities still have to result in action somewhere on the ground. Data matter because they represent living populations in real places.

    That transition changed the scale at which I thought about my work. I became increasingly interested not only in discovering and documenting rare plants, but in the institutions, partnerships, information, and capacity required to keep them from disappearing.

    The larger arc

    The progression from field discovery to conservation assessment and ultimately to conservation leadership continues to shape how I approach plant extinction today.

    Read more about my path →

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