Royal Botanic Gardens, Kew (RBG Kew), has released its fifth edition of the “State of the World’s Plants and Fungi” report, providing a comprehensive overview of the current status of the planet’s flora and fungi. The report, a result of the collaborative efforts of 200 international researchers, assesses the latest scientific findings across 11 critical themes, shedding light on global biodiversity patterns, drivers, and the pressing knowledge gaps that demand attention.
The theme of this year’s report, “Tackling the Nature Emergency: Evidence, gaps and priorities,” delves deep into the existing knowledge and unknowns concerning the diversity and threats faced by these essential components of our ecosystems—plants and fungi. The extensive research compiled in this report spans more than 25 groundbreaking scientific papers.
The scientific evidence underpinning this report can be found in a special collection published in the journals New Phytologist and Plants, People, Planet, titled “Global Plant Diversity and Distribution.” It also includes a review of global fungal diversity and conservation published in the journal Annual Review of Environment and Resources. The launch of this report coincides with a hybrid symposium held at Kew Gardens in West London.
Plants and fungi are the cornerstone of life on Earth, contributing vital ecosystem services that support human survival by providing food, medicine, clothing, and raw materials. However, the world currently grapples with an ecological imbalance, marked by the dual crises of climate change and biodiversity loss.
The researchers have analyzed data from the World Checklist of Vascular Plants (WCVP) in collaboration with the International Union for Conservation of Nature (IUCN) Red List of Threatened Species. Their findings are alarming—up to 75% of the undescribed vascular plants may already be threatened with extinction. Moreover, this threat disproportionately affects recently described species, with over 77% of species described in 2020 meeting the criteria for being assessed as threatened. As a matter of fact, 59% of species described in 2020 are likely to be categorized as Endangered, and 24.2% may meet the criteria for being Critically Endangered.
To address this crisis, RBG Kew scientists advocate for the precautionary principle, suggesting that all newly described species should be treated as if they were assessed as threatened unless proven otherwise. As newly described species often exhibit narrow ranges and face declining populations and habitat loss, prioritizing them for formal assessments on the IUCN Red List can bolster conservation efforts.
The report also presents a dire estimation that 45% of all known flowering plant species are at risk of extinction. Notably, families such as Orchidaceae (orchids), Piperaceae (including black pepper), Bromeliaceae (containing pineapples), and Araceae (including several important crops) are among the most threatened. By leveraging probability-based models, researchers are developing a more robust understanding of the threat levels for flowering plants that have already been described and use this information to prioritize species for the IUCN Red List assessments.
Regarding fungi, the vast majority of these organisms remain largely undocumented, with only about 155,000 species having received formal names to date. Nonetheless, scientists estimate that there are approximately 2.5 million species of fungi globally. The rate of discovery is inadequate to address the diversity of fungi. Since 2020, over 10,200 new fungal species have been formally described, yet it would take 750 to 1,000 years at the current pace to document them all. Scientists are hopeful that focusing on DNA sequencing and molecular data could potentially result in the cataloging of 50,000 new species from environmental samples each year.
Furthermore, the report identifies 32 biodiversity “darkspots,” areas with limited geographic and taxonomic data that hinder our understanding of biodiversity in those regions. Of these, 44% are located in tropical Asia, emphasizing the importance of targeted fieldwork in these areas to improve our knowledge.
The report emphasizes the importance of sharing scientific knowledge and promoting open access publications, as only 23% of peer-reviewed studies between 2012 and 2021 were published in open access formats. In light of the fact that many species-rich areas are in low- and middle-income countries, the report calls for journals to waive publication fees for authors from these regions.
Overall, the “State of the World’s Plants and Fungi” report underscores the critical need for immediate action to address biodiversity imbalances and emphasizes the importance of an integrated approach to plant and fungal conservation in light of the pressing challenges posed by climate change and biodiversity loss.