Recent responses to climate change reveal the drivers of species extinction and survival

Abstract

Climate change may be a major threat to biodiversity in the next 100 years. Although there has been important work on mechanisms of decline in some species, it generally remains unclear which changes in climate actually cause extinctions, and how many species will likely be lost. Here, we identify the specific changes in climate that are associated with the widespread local extinctions that have already occurred. We then use this information to predict the extent of future biodiversity loss and to identify which processes may forestall extinction. We used data from surveys of 538 plant and animal species over time, 44% of which have already had local extinctions at one or more sites. We found that locations with local extinctions had larger and faster changes in hottest yearly temperatures than those without. Surprisingly, sites with local extinctions had significantly smaller changes in mean annual temperatures, despite the widespread use of mean annual temperatures as proxies for overall climate change. Based on their past rates of dispersal, we estimate that 57–70% of these 538 species will not disperse quickly enough to avoid extinction. However, we show that niche shifts appear to be far more important for avoiding extinction than dispersal, although most studies focus only on dispersal. Specifically, considering both dispersal and niche shifts, we project that only 16–30% of these 538 species may go extinct by 2070. Overall, our results help identify the specific climatic changes that cause extinction and the processes that may help species to survive.

The importance of species interactions in spatially explicit eco-evolutionary community dynamics under climate change

“…One might think that combining good dispersal ability with large genetic variance should temper this problem by allowing the northernmost species to adapt locally, and thus alleviate the negative impacts of increased temperatures better than each of these processes on their own. This expectation is also consistent with recent projections based on empirical data 37 . However, the projected extinctions, considering both dispersal and species' ability to adapt, have been obtained without explicitly considering species interactions 37 .…”

“…This expectation is also consistent with recent projections based on empirical data 37 . However, the projected extinctions, considering both dispersal and species' ability to adapt, have been obtained without explicitly considering species interactions 37 . We show that large genetic variance combined with good dispersal ability result in a global biodiversity loss as high as when both dispersal ability and evolutionary rate are low.…”

Insects and recent climate change

“…That transition and the rise of climate change as a more severe threat could happen through a number of related processes. A very partial list would include the inability to disperse quickly enough to track changing conditions (18), or the phenomenon of dispersal out of previously suitable habitat into regions where habitat is suboptimal or cannot be found at all (19). There is also the possibility that abiotic stress associated with changing climatic conditions could simply be the last straw, reducing vital rates below replacement levels as a result of physiological stress in populations already pushed to the edge by other stressors (5).…”

“…In Greenland, changes in the structure of arthropod communities over 18 years have been influenced by warming summers and falls and fewer freeze-thaw events, with the most negative associations observed for surface detritivores (29). On the other side of the temperature spectrum is maximum temperature, which has been shown to be the variable most associated with local extinctions in a global survey of insects and other taxa (18).…”

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) .…”