Plant species might not need to move far for favourable climates

Plant species may only need to move short distances to track their preferred habitats as the climate changes, according to a study published in Nature Climate Change.

This finding contrasts with previous models that have predicted the need for major shifts in plant ranges.

It is widely predicted that many species will have to either adapt or move to survive as climate change alters the environment, a prediction that shapes current conservation policy.

Dr Ilya Maclean and Dr Regan Early, from the Centre for Ecology and Conservation at the University of Exeter’s Penryn Campus in Cornwall, used historical data from 1977-1995 to model the distribution of 244 European heathland and grassland plant taxa, which they then used to project plant distributions between 2003-2021 to assess the impacts of climate variables.

“For a long-time, a need to better connect habitats has been seen as the best conservation response to climate change,” Dr Maclean said.

“However, we know that this comes at the expense of making habitat patches bigger and better for wildlife.

“Our study emphasises that, even under climate change, enhancing connectivity is less critical.

“This finding is particularly timely given the recent launch of Local Nature Recovery Strategies, which will set out an approach for creating and restoring wildlife habitat across England.”

Previous research has suggested that species seeking favourable climates may need to move long distances, but these studies have used climate data at broad scales, which do not accurately represent the highly heterogeneous microclimate conditions that organisms experience.

Using macro- and microclimate data, the researchers compared three different grid resolutions: approximately 50 km, 5 km and 100 m length grids.

According to the largest scales, species would have had to shift between 3.7 and 62.4 km (14 km median) within 26 years to keep pace with changing climates.

However, when microclimate data at 100 m resolution were used, the same species would have to move just a median of 114 m over 26 years, or 4.4 m per year, to shift into favourable microclimates.

The authors show that these smaller shifts more closely match the actual observed patterns of species shifts.

The authors propose that conservation efforts should prioritise protection of areas with suitable microclimates within species’ historic geographic range.

The paper is entitled: “Macroclimate data overestimate range shifts of plants in response to climate change.”