Global shortfalls in threat assessments for endemic flora by country

Abstract

Societal Impact StatementPlants are fundamental to terrestrial and aquatic ecosystems and are key to human livelihoods. To protect plant diversity, systematic approaches to conservation assessment are needed. Many nations have legislation or other policy instruments that seek to protect biodiversity (including plants), and species‐level assessments are essential for identifying the most threatened species that require special and immediate protection measures. Some plants occur in only one place (for instance, a single country) and here we have estimated how many of these ‘endemic’ species have had their threats assessed in each country or close country‐equivalent worldwide. We show that the level of assessment completion is only weakly related to the income of countries or the likely level of threat that species face.Summary The Global Strategy for Plant Conservation ambitiously called for an assessment of the conservation status of all recognised plant taxa by 2020. This target was not met in the short term. Nevertheless, the need for conservation assessments remains urgent as plants go extinct and face increasing threats from human impacts on the biosphere. Here, the completeness of threat assessments for endemic flora in 179 countries or their close equivalents was assessed. To do so, distribution information from the World Checklist of Vascular Plants was combined with assessments collated in the ThreatSearch database. The completeness of assessments was expected to be associated with the objective affluence of countries (measured using inequality‐adjusted Human Development Index (IHDI)) and/or the exposure of their plant species to threats associated with human impacts (measured using Global Human Modification index (GHM)). The number of endemic species per country was also hypothesised to influence the completion of assessments. Overall, 58% of all country‐based endemic species examined have no conservation assessment (127,643 species). Countries' progress toward the completion of threat assessments for endemic plants could not be confidently predicted by IHDI, GHM or the richness of endemic plant flora. The shortfall in threat assessments identified here restricts national regulation of actions which imperil plant species, with particular consequences for endemic plant species subject to local laws. Some nations with high IHDI scores (i.e. wealthier nations) are not systematically assessing extinction risk in their endemic species. Scarce funding should be directed to global hotspots of endemism with few available resources for assessment.

Why plant diversity and distribution matter

“…The scientific literature on global biodiversity extinction remains dominated by research on vertebrates. Several studies contribute to redressing this (Bachman et al, 2023;Gallagher et al, 2023;Soto Gomez et al, 2023;Brown et al, 2023a,b), by combining WCVP geographical data with extinction risk data from the International Union for Conservation of Nature (IUCN, 2022) Red List of Threatened Species (hereafter Red List). While WCVP is comprehensive at the species level, Red List coverage of vascular plants is incomplete; fewer than one-in-five plants have expert assessments despite concerted efforts to increase coverage (Bachman et al, 2023).…”

“…Socio-economic and environmental factorsmay also contribute: the probability of speciesendemic to one country being assessed could be associated with national income or levels of threat, as several species-rich countries have programmes dedicated to assessing endemic species, typically prioritising species considered likely threatened (e.g. Raimondo et al, 2013;Martins et al, 2018;Ren et al, 2019) Contrary to their expectations, Gallagher et al (2023) show that levels of assessment completion for endemic species are weakly related to national income or threat levels and that the number of endemic species in a country is a poor predictor of the proportion having completed assessments.…”

Small and in‐country herbaria are vital for accurate plant threat assessments: A case study from Peru

“…Aggregation of data in repositories such as the Global Biodiversity Information Facility (GBIF) facilitate this use, but aggregated data are biased towards institutions with the funding and facilities required for large‐scale digitisation and data sharing. In fact, greater wealth of a country as measured by GDP can even explain a higher density of occurrence records (Amano & Sutherland, 2013); wealthier nations, however, are not making faster progress towards completing IUCN threat assessments for plants (Gallagher et al, 2023), despite having more resource available. Data resources are far from exclusive to the Global North, and GBIF includes significant data from Brazilian, Colombian, and Mexican institutions (GBIF Secretariat, 2023), but most specimens shared through GBIF today are from institutions in Europe and the United States (Betts et al, 2020; Heberling et al, 2021; Park et al, 2023).…”

Three in four undescribed plant species are threatened with extinction

“…To be formally protected, species must be noticed, described and assessed (either for the Red List or another schema, noting that Red List assessments are not universally considered sufficient or used as the basis for legislative protection; Gallagher et al, 2023). In the light of our results, we recommend that all species new to science should be assumed to be threatened until formally assessed.…”