Forest cover creates a specific microclimate by buffering most environmental variables. If the influence of the overstory on microclimatic variables has been well studied, the role of the understory has received less attention. In this study we investigated how the shrub layer modifies solar radiation, air temperature (T), relative air humidity (RH), vapor pressure deficit (VPD) and soil moisture under different thinning treatments in an Aleppo pine forest (Pinus halepensis Mill.). Microclimatic variables were measured along a vegetation cover gradient made up of three pine densities (dense, medium, low) and open conditions, with or without the presence of shrubs. The results were analyzed with a focus on the summer period which represents a major bottleneck for plant development in the Mediterranean area. Average T and VPD values increased with decreasing vegetation cover (+1.38°C and +0.21 kPa for the whole year) while RH decreased (-2.34%). Along the same gradient, daily amplitude of T, RH, VPD increased while the buffering capacity decreased. These patterns were more Highlights A buffering effect on T, VPD, RH was noted for the overstory and the understory This effect was more pronounced in summer due to a stronger shading effect Shrub influence on T, RH, VPD was higher in low pine cover and in open conditions Soil moisture was reduced in the presence of a developed shrub layer
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.