Tree species richness strengthens forest microclimate cooling under high evaporative demand and soil water availability - Data and Code
Year: 2026
Type: dataset
Abstract: of the article the code and data belong to:Forest ecosystems are increasingly exposed to extreme heat and drought conditions that threaten their vitality and functioning. Forest canopies can mitigate these extremes by buffering understorey temperatures, yet the seasonal dynamics of this buffering and the influence of tree species richness remain poorly understood. Here, we quantified forest microclimate buffering across seasons and species richness levels using five years (2021-2025) of high-resolution understorey temperature measurements at the BIOTREE tree diversity experiment in central Germany. Intra-annual microclimate buffering was highly variable, with cooling of daily maximum temperatures peaking in summer and reaching up to 3.6 °C relative to open-field conditions. The cooling effect increased with air temperature and vapour pressure deficit (VPD). Cooling was strongest when high atmospheric evaporative demand coincided with sufficient soil water availability. Tree species richness enhanced cooling, with the strongest effects in spring and early summer. Further, the cooling advantage of species mixtures varied with atmospheric and soil water conditions. Mixtures showed the largest cooling benefit when high evaporative demand and ample soil water coincided. Additionally, higher tree water stress expressed as tree water deficit increased species richness effects on cooling. Our findings provide experimental evidence that species richness amplifies forest microclimate buffering, and that the effects of species richness on forest microclimate cooling depended on soil and atmospheric drought intensity, as well as on tree water status. Promoting tree diversity may therefore improve forest cooling under future climate extremes, even though it is uncertain if these benefits can be maintained as drought severity increases.
Source: Figshare
Language: English
Subfield: Global and Planetary Change
Field: Environmental Science
Domain: Physical Sciences
SDGs: Life on land, Climate action
Open Access status: green
OpenAlex ID: W7225244554