A paper published today in Conservation Biology reports that conservation assessments are now available for a quarter of all known plant species. This marks significant progress towards Target 2 of the Global Strategy for Plant Conservation (GSPC), a programme of the Convention on Biological Diversity, which calls for conservation assessments for all known plants to be completed by 2020.

Scientists from the Royal Botanic Gardens, Kew (RBG Kew) and BGCI analysed digitally available plant conservation assessments from a range of sources, and then, by reconciling the plants’ scientific names and assessment statuses to predefined standards, have been able to provide, for the first time, a quantitative measure of progress towards GSPC Target 2. The results of the study show that 21–26% of known plant species have been assessed on a global scale and 20-44% of assessed species are threatened with extinction.

In the face of ever-growing threats to plant diversity, conservation assessments provide an essential tool in priority setting and the planning of conservation interventions. While the results of this study show that considerable progress has been made in assessing the conservation status of plant species, many gaps remain. For example, the analysis revealed wide gaps in taxonomic coverage, with some families such as Zamiaceae and Magnoliaceae being almost completely assessed, whereas other families such as Orchidaceae, Asteraceae, and Rubiaceae are under-assessed relative to the average.

The greatest challenges in carrying out this study were matching the 241,919 plant conservation assessments to accepted plant species names (vascular plants and bryophytes) and reconciling the different assessments that might have been made for the same species. In total, the assessments relate to 111,824 accepted species names (matched to The Plant List ), with at least 27,148 and up to 32,542 species being threatened.

Although around one-quarter of a million plant assessments have been compiled, the majority of plants are still unassessed. However, the data set used for this study is accessible online (ThreatSearch ) and it provides a baseline that can be used to directly support plant conservation action. The challenge now is to build on this progress and redouble efforts to document the conservation status of unassessed plants to better inform conservation decisions and conserve the most threatened species.

The full paper is accessible to read and download here.