Despite fundamental differences in their biology, plants and animals are strikingly similar in how they have evolved in response to climate, according to a new study. national science foundation-funded study published this week in Nature ecology and evolution.
“When it’s sunny and warm where the animals are at any given time, most can just move around to find shade and cool off,” said study lead author John Wiens. ecologist and evolutionary biologist University of Arizona. “Plants, on the other hand, have to stay where they are and tolerate these higher temperatures.”
Wiens and his team analyzed climate data for 952 plant species and 1,135 animal species. They included many major groups of flowering plants, from oaks to orchids to grasses, and all major groups of terrestrial vertebrates, including frogs, salamanders, lizards, snakes, turtles, crocodilians, birds and mammals.
The researchers used climate data and detailed evolutionary trees to test hypotheses about the temperature and precipitation conditions where each species occurs, and how these change over time between species. This set of conditions is also known as the species’ “climate niche”.
This niche reflects where a species may live, Wiens explained — for example, in the tropics versus the temperate zone, or at sea level versus a mountaintop — and how it will respond to climate change. For all the hypotheses tested by the authors, they found that plants and animals exhibited similar patterns of niche evolution.
However, the species are adapted to a narrower temperature range in the tropics, the researchers found, which helps explain why a higher frequency of extinctions is projected there than in the temperate zone.
The co-authors also found that in plants and animals, species seem to have more difficulty adapting quickly to warmer temperatures and drier conditions than to cooler, wetter conditions.
“This study adds to a growing body of evidence that all kinds of organisms in the tropics operate near the upper temperature limit of their physiological functions,” said Christopher Schneider, program director in the Division of Environmental Biology at the NSF. “A small increase in temperature in the tropics can have large effects on a species’ ability to persist in the face of climate change.”