Aim Forest understorey microclimates are often buffered against extreme heat or cold, with important implications for the organisms living in these environments. We quantified seasonal effects of understorey microclimate predictors describing canopy structure, canopy composition and topography (i.e., local factors) and the forest patch size and distance to the coast (i.e., landscape factors). Location Temperate forests in Europe. Time period 2017-2018. Major taxa studied Woody plants. Methods We combined data from a microclimate sensor network with weather-station records to calculate the difference, or offset, between temperatures measured inside and outside forests. We used regression analysis to study the effects of local and landscape factors on the seasonal offset of minimum, mean and maximum temperatures. Results The maximum temperature during the summer was on average cooler by 2.1 degrees C inside than outside forests, and the minimum temperatures during the winter and spring were 0.4 and 0.9 degrees C warmer. The local canopy cover was a strong nonlinear driver of the maximum temperature offset during summer, and we found increased cooling beneath tree species that cast the deepest shade. Seasonal offsets of minimum temperature were mainly regulated by landscape and topographic features, such as the distance to the coast and topographic position. Main conclusions Forest organisms experience less severe temperature extremes than suggested by currently available macroclimate data; therefore, climate-species relationships and the responses of species to anthropogenic global warming cannot be modelled accurately in forests using macroclimate data alone. Changes in canopy cover and composition will strongly modulate the warming of maximum temperatures in forest understories, with important implications for understanding the responses of forest biodiversity and functioning to the combined threats of land-use change and climate change. Our predictive models are generally applicable across lowland temperate deciduous forests, providing ecologically important microclimate data for forest understories.
1.Univ Cambridge, Dept Plant Sci, Forest Ecol & Conservat Grp, Cambridge, England 2.Swiss Fed Inst Forest Snow & Landscape Res WSL, Birmensdorf, Switzerland 3.UPJV, EDYSAN, CNRS, UMR UR Ecol & Dynam Syst Anthropises 7058, Amiens, France 4.Univ Ghent, Dept Environm, Forest & Nat Lab, Melle Gontrode, Belgium 5.Leibniz ZALF eV Muncheberg, Muncheberg, Germany 6.Univ Oxford, Dept Plant Sci, Oxford, England 7.Swedish Univ Agr Sci, Southern Swedish Forest Res Ctr, Alnarp, Sweden 8.Czech Acad Sci, Inst Bot, Pruhonice, Czech Republic 9.Czech Univ Life Sci, Fac Forestry & Wood Sci, Prague, Czech Republic 10.Tech Univ Zvolen, Fac Forestry, Zvolen, Slovakia 11.Univ Gottingen, Dept Silviculture & Forest Ecol Temperate Zones, Gottingen, Germany 12.Wageningen Univ, Forest Ecol & Forest Management Grp, Wageningen, Netherlands 13.Univ Warsaw, Fac Biol, Bialowieza Geobot Stn, Bialowieza, Poland
Recommended Citation:
Zellweger, Florian,Coomes, David,Lenoir, Jonathan,et al. Seasonal drivers of understorey temperature buffering in temperate deciduous forests across Europe[J]. GLOBAL ECOLOGY AND BIOGEOGRAPHY,2019-01-01