Climate change could wipe out habitat for thousands of plant species

Climate change could erase suitable habitat for thousands of plant species by the end of the century, and the damage would reach far beyond botany. A new Science study modeled more than 67,000 vascular plant species, about 18% of the world’s known vascular plants, and found that roughly 7% to 16% could lose more than 90% of their range by 2100.

The species at risk include Catalina ironwood, a rare California endemic tree; bluish spike-moss, part of a lineage more than 400 million years old; and about one third of Eucalyptus species, a group that shapes entire landscapes in Australia. Those plants are not just biological curiosities. Vascular plants underpin food systems, provide raw material for medicines and help sustain the forests, soils and water cycles that communities depend on.

The study was led by Xiaoli Dong of the University of California, Davis, and Junna Wang of Yale University. Researchers analyzed millions of plant-location records along with greenhouse-gas scenarios for 2081 to 2100, then mapped where future conditions would still match the needs of each species. The warning that emerged was blunt: a plant does not survive just because it can move. It has to find the right mix of temperature, rainfall, soil, land use and even shade, and those conditions are becoming more fragmented as the climate warms.

That fragmentation has clear policy stakes. High extinction risk was concentrated in southern Europe, the western United States and southern Australia, regions where habitat loss, development and climate stress can leave species stranded in shrinking pockets of suitable land. Some plants with broader ranges may be able to shift, but species tied to narrow habitats or broken landscapes have far fewer options. For those species, migration is not enough if the destination no longer exists in a usable form.

The researchers also found that even a scenario in which plants could disperse anywhere they wanted did not sharply reduce extinction risk. That finding weakens the idea that seed movement alone can solve the crisis. UC Davis said assisted migration may not prevent many global plant extinctions, while restoration and protection of climate refugia could be more effective. A 2020 UC Davis study found about 15% of California’s natural lands may serve as climate refugia for plants, underscoring the value of protecting the places most likely to remain livable as warming accelerates.