The commonness of rarity: Global and future distribution of rarity across land plants

Abstract

A key feature of life’s diversity is that some species are common but many more are rare. Nonetheless, at global scales, we do not know what fraction of biodiversity consists of rare species. Here, we present the largest compilation of global plant diversity to quantify the fraction of Earth’s plant biodiversity that are rare. A large fraction, ~36.5% of Earth’s ~435,000 plant species, are exceedingly rare. Sampling biases and prominent models, such as neutral theory and the k-niche model, cannot account for the observed prevalence of rarity. Our results indicate that (i) climatically more stable regions have harbored rare species and hence a large fraction of Earth’s plant species via reduced extinction risk but that (ii) climate change and human land use are now disproportionately impacting rare species. Estimates of global species abundance distributions have important implications for risk assessments and conservation planning in this era of rapid global change.

Extinction risk and threats to plants and fungi

“…V VI VII I II III IV V VII VIII IX X humid climates and lowland and riparian habitats. In contrast, climate change affects the remotest plant and fungal communities, including those on mountains, hilltops, and steep slopes (Pimm, 2008;Pimm & Jenkins, 2019), hosting a disproportionately large fraction of the world's rare plant species (Enquist et al, 2019). Patterns vary between regions, with the Amazon Forest appearing more vulnerable to plant extinctions due to climate change than Brazil's Atlantic Forest (Silva, Rapini, Barbosa, & Torres, 2019).…”

“…Patterns vary between regions, with the Amazon Forest appearing more vulnerable to plant extinctions due to climate change than Brazil's Atlantic Forest (Silva, Rapini, Barbosa, & Torres, 2019). In general, narrowranged plant species face the greatest risks from multiple threats (Enquist et al, 2019;Newbold et al, 2018;Silva et al, 2019;Staude, Navarro, & Pereira, 2020).…”

Progress Towards Plant Community Transcriptomics: Pilot RNA-Seq Data from 24 Species of Vascular Plants at Harvard Forest

“…Many questions in ecology and evolutionary biology increasingly require combining data from these fields at large scales. In particular, integrated, large-scale analyses of multispecies ecological and phylogenetic data sets have become critical to understanding plant distributions and responses to climate change (Zanne et al, 2014;Swenson and Jones, 2017;Maitner et al, 2018;Enquist et al, 2019;Gallagher et al, 2019;McFadden et al, 2019;Rice et al, 2019;Baniaga et al, 2020;Román-Palacios and Wiens, 2020) . Recognizing this need, NSF recently launched the National Ecological Observatory Network (NEON) to generate large-scale data on species occurrence, phenology, climate, and more, for ecological communities across the United States (Collinge, 2018;Knapp and Collins, 2019) .…”

Management implications based on diversity patterns under climate change scenarios in a continental island biodiversity hotspot

“…Climate change is projected to alter biodiversity and biogeographical patterns all over the globe (e.g., Enquist et al, 2019). The Mediterranean Basin is expected to face the largest changes in climate worldwide (e.g., Giorgi and Lionello, 2008), with these impacts being more prominent on islands and mountain summits (Médail, 2017).…”