When it comes to reforestation, planting a diversity of tree species could have a plethora of positive effects on forest health and resilience, climate mitigation and biodiversity. That’s based on research from the world’s largest tree-planting experiment, in China, and the world’s longest-running tropical forest planting experiment, in Panama.
Florian Schnabel, lecturer and chair of silviculture at Freiburg University in Germany, and his team recently published two papers illustrating how planting diverse forests can buffer them against climate extremes and enhance carbon storage.
“The results of our research in Panama and in China really call for preserving and also planting diverse forests as a strategy under climate change,” he says.
Researchers with the BEF-China project planted multiple forests, ranging from just one tree species up to 24, then measured microclimate temperatures over six years.
They found that the more diverse the forest, the greater the “temperature buffering” effect during hot and cold peaks. The most diverse plantings, those with 24 species, reduced temperatures during peak midday summer heat by 4.4° Celsius (7.92° Fahrenheit) when compared to the project’s monoculture. That finding could have important consequences for biodiversity and forest functions, such as soil respiration, says Schnabel. “What was quite striking to me was how strong this [temperature buffering] effect actually was.”