Harnessing the potential of integrated systematics for conservation of taxonomically complex, megadiverse plant groups

Abstract

The value of natural history collections for conservation science research is increasingly recognized, despite their well‐documented limitations in terms of taxonomic, geographic, and temporal coverage. Specimen‐based analyses are particularly important for tropical plant groups for which field observations are scarce and potentially unreliable due to high levels of diversity‐amplifying identification challenges. Specimen databases curated by specialists are rich sources of authoritatively identified, georeferenced occurrence data, and such data are urgently needed for large genera. We compared entries in a monographic database for the large Neotropical genus Myrcia in 2007 and 2017. We classified and quantified differences in specimen records over this decade and determined the potential impact of these changes on conservation assessments. We distinguished misidentifications from changes due to taxonomic remodeling and considered the effects of adding specimens and georeferences. We calculated the potential impact of each change on estimates of extent of occurrence (EOO), the most frequently used metric in extinction‐risk assessments of tropical plants. We examined whether particular specimen changes were associated with species for which changes in EOO over the decade were large enough to change their conservation category. Corrections to specimens previously misidentified or lacking georeferences were overrepresented in such species, whereas changes associated with taxonomic remodeling (lumping and splitting) were underrepresented. Among species present in both years, transitions to less threatened status outnumbered those to more threatened (8% vs 3%, respectively). Species previously deemed data deficient transitioned to threatened status more often than to not threatened (10% vs 7%, respectively). Conservation scientists risk reaching unreliable conclusions if they use specimen databases that are not actively curated to reflect changing knowledge.

The use and misuse of herbarium specimens in evaluating plant extinction risks

“…As a result, up-to-date identifications for a taxon of interest often reside not in online databases but on herbarium sheets annotated by specialist monographers as part of their research. While monographic work is often perceived as proceeding at a glacial pace, recent research has shown that cumulated identification changes to specimens over a few years can result in significant changes to extinction risk assessments based on this material [ 40 ]. It is therefore vital to ensure that specimen-based assessments include the latest available taxonomic updates.…”

Botanical Monography in the Anthropocene

“…Amid alarmingly high rates of species invasions [5], range shifts (see Glossary) [6] and extinctions [7], there has never been greater urgency to document the estimated 20% of the Earth's flora that remains to be scientifically described [8]. Comprehensive syntheses of information about individual plant groups underlie all kinds of research, the conservation of plant diversity [9], sustainable and fair use [10], and science outreach activities to improve awareness of plants [11]. Monographs are a key resource for taxonomists, and are widely used in fields such as ecology, genetics, evolutionary biology, palaeontology, and applied contexts, including horticulture, conservation, natural resource management, and plant breeding.…”

“…Over the centuries, monographs have provided the backbone to much of the world's research on plants. The data compiled in monographs (Box 1) reflect scientific advances in documenting plant diversity [9,[23][24][25] and illustrate trends in the knowledge deemed useful since the first plant monograph was published during the 17th century [26]. To meet the needs of today's users (Box 1), monographs must continue to integrate new data sources and be widely accessible, while also being produced and updated more rapidly: monographs are still needed for most of the world's plant genera.…”

Introduction

“…Nic Lughadha et al. () demonstrate how digital specimen databases can speed access to the latest data about species undergoing major taxonomic evaluations before monographs are published, which supports more timely conservation research and increases communication between conservation and taxonomic communities. Prior to the advent of online biodiversity databases, researchers often relied on published monographs for the most up‐to‐date information on a species (e.g., current identification and nomenclature, species range, conservation status).…”

“…To quantify the timing of the flow of specimen information, and changes to it, Nic Lughadha et al. () examined biodiversity records over time and evaluated the extent to which changes and updates to records influenced how those data are reflected in research results. This work not only sheds light on the advantages and utility of online databases for conservation research, but also serves as a call to action for researchers to more fully make use of the features of databases that allow for taxonomic updates, georeferencing, and communication between taxonomists and conservation biologists.…”