Associate Editor, Sharif Mukul, introduces this month’s Editor’s Choice article by Zhang and colleagues, which shows that microclimate offsetting depends on tree species identity and diversity, and that buffered forest microclimates can be achieved rapidly in young plantations, depending on the species being planted. 

Tree canopies can significantly buffer temperature fluctuations and enhance water availability, which has the potential to mitigate the effects of macroclimate warming on forest biodiversity and functioning. While the role of forest ecosystems in regulating local climate is well studied, the forest ecosystem’s role in microclimate regulation is still less clear. 

In this month’s Editor’s Choice article, Zhang and colleagues examined the role of tree species richness and composition on microclimate regulation through below-canopy offsets. The authors also tested for any non-additive diversity effects on microclimate buffering in mixed stands, as well as the underlying mechanisms (e.g. selection vs. complementarity).

Their results show that microclimate offsets depends on tree species identity and mixing. Monocultures of larch (Larix x eurolepis) and Douglas fir (Pseudotsuga menziesii) had a high performance for thermal buffering, but so did mixtures with species such as birch (Betula pendula) and pine (Pinus sylvestris). Non-additive effects brought about by tree species mixing were found to amplify microclimate offsets. However, the type of diversity effect (selection vs. complementarity) underpinning these non-additive effects differed among sites and microclimate variables (temperature vs. vapor pressure deficit). Finally, they observed that increased canopy cover in mixed stands emerged as the primary driver of these effects.

The authors conclude that increasing species richness can be a good approach to minimizing climate change effects on the forest floor. More broadly, their work could be useful to optimize tree plantation designs in the face of predicted climate change so as to minimize climate-change impacts on below-canopy biodiversity and functioning both in Europe and elsewhere.

Read the full paper Tree species mixing can amplify microclimate offsets in young forest plantations in Journal of Applied Ecology.