Green Plants in the Red: A Baseline Global Assessment for the IUCN Sampled Red List Index for Plants

PLoS One. 2015 Aug 7;10(8):e0135152. doi: 10.1371/journal.pone.0135152. eCollection 2015.


Plants provide fundamental support systems for life on Earth and are the basis for all terrestrial ecosystems; a decline in plant diversity will be detrimental to all other groups of organisms including humans. Decline in plant diversity has been hard to quantify, due to the huge numbers of known and yet to be discovered species and the lack of an adequate baseline assessment of extinction risk against which to track changes. The biodiversity of many remote parts of the world remains poorly known, and the rate of new assessments of extinction risk for individual plant species approximates the rate at which new plant species are described. Thus the question 'How threatened are plants?' is still very difficult to answer accurately. While completing assessments for each species of plant remains a distant prospect, by assessing a randomly selected sample of species the Sampled Red List Index for Plants gives, for the first time, an accurate view of how threatened plants are across the world. It represents the first key phase of ongoing efforts to monitor the status of the world's plants. More than 20% of plant species assessed are threatened with extinction, and the habitat with the most threatened species is overwhelmingly tropical rain forest, where the greatest threat to plants is anthropogenic habitat conversion, for arable and livestock agriculture, and harvesting of natural resources. Gymnosperms (e.g. conifers and cycads) are the most threatened group, while a third of plant species included in this study have yet to receive an assessment or are so poorly known that we cannot yet ascertain whether they are threatened or not. This study provides a baseline assessment from which trends in the status of plant biodiversity can be measured and periodically reassessed.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biodiversity*
  • Conservation of Natural Resources*
  • Databases, Factual
  • Ecosystem
  • Endangered Species*
  • Extinction, Biological
  • Geography
  • Rainforest
  • Tropical Climate
  • Viridiplantae / classification*

Grant support

Funding and support for the first phase of the IUCN Sampled Red List Index for Plants has been provided by the Charles Wolfson Charitable Trust, the Esmée Fairbairn Foundation, Rio Tinto plc., the World Summit on Sustainable Development Implementation Fund of the Department of Environment, Food and Rural Affairs (Defra) of the United Kingdom government and the World Collections Programme, as well as The Natural History Museum and the Royal Botanic Gardens, Kew. The IUCN Red List Unit is generously supported by the Rufford Foundation, the MAVA Foundation and the Environment Agency of Abu Dhabi. Artisan Plant Nurseries did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. Rio Tinto plc. contributed to the funding of digitisation of specimen data and Red List assessment generation during the course of the project, but in no way did this hold any influence over the scientific outputs of this project. The funders had no role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript.