Forests with greater numbers of different species are better able to mitigate heat waves in summer and cold snaps in winter, according to a new study.
Published in the journal Ecology Letters, a study led by the German Centre for Integrative Biodiversity Research (iDiv) shows that forests with lower tree diversity are the ones most affected by temperature extremes, with all the consequences that follow for the life that inhabits them.
Although previous studies had already highlighted the role of trees in buffering thermal extremes in forests, the authors emphasize that it had not yet been understood whether species diversity could be a factor of influence, as demonstrated by this study.
Based on measurements taken in the subtropical region of China, where lies what is considered the largest experiment in planted tree diversity, with several hundred thousand individuals, the team found that forests with greater species richness (that is, with greater variety of species) were able to reduce the temperature much more below the forest canopy during heat peaks than forests with fewer species.
Conversely, during cold peaks, the temperature beneath the forest canopy was higher than in forests with fewer species.
The researchers believe that greater variety of tree species helps prevent the air mass below the canopy from contacting the air mass above it.
Rémy Beugnon, one of the article’s authors, says in a press release that this “thermal buffer” effect allows the creation and maintenance of microclimates that foster “more favorable conditions for ecosystems and protect the services they provide.”
In this way, “it is likely that forests will grow and regenerate more effectively, while soils function better, supporting greater biodiversity, improving nutrient cycles and increasing carbon storage,” the scientist explains.
The authors conclude the article stating that “our results highlight the benefits of diverse planted forests for large-scale forest restoration initiatives,” adding that applying the same diversity to urban forests helps to mitigate “heat stress in a warming world.”
