title: Leaf temperatures in glasshouses and open-top chambers.
abstract: Climate manipulation experiments are of key importance in identifying possible responses of plant communities and ecosystems to climate change. Experiments for warming the air under sunlit conditions are carried out in (partial) enclosures. These inevitably alter the energy balance inside, potentially altering tissue temperatures which affect metabolism and growth. Using an empirically validated energy balance model, we investigate effects of two widely used warming methods, climate-controlled glasshouses and passively warmed open-top chambers (OTCs), on leaf temperatures. The model applies standard energy balance formulas, supplemented with data on optical properties of glasshouse materials and wind conditions inside OTCs. Results show that the different radiation environment inside glasshouses did not produce large leaf temperature deviations compared with outside. Poor glasshouse design with significant radiation blockage by the structure or with insufficient ventilation did affect tissue temperatures more significantly. The drastic wind speed reduction inside OTCs approximately doubled the actual (canopy) warming compared with earlier reported increases in air temperature provided by this technique - an effect that was inflated if the plants' stomates closed. These results demonstrate that leaf temperatures were higher than previously considered in OTCs but not in climate-controlled glasshouses.
authors.affiliation: Research Group of Plant and Vegetation Ecology, Department of Biology, Universiteit Antwerpen (Campus Drie Eiken), Universiteitsplein 1, B-2610 Wilrijk, Belgium.
authors.forename: Hans J
authors.initials: HJ
authors.lastname: De Boeck
authors.affiliation: Research Group of Plant and Vegetation Ecology, Department of Biology, Universiteit Antwerpen (Campus Drie Eiken), Universiteitsplein 1, B-2610 Wilrijk, Belgium.
authors.forename: Toon
authors.initials: T
authors.lastname: De Groote
authors.affiliation: Research Group of Plant and Vegetation Ecology, Department of Biology, Universiteit Antwerpen (Campus Drie Eiken), Universiteitsplein 1, B-2610 Wilrijk, Belgium.
authors.forename: Ivan
authors.initials: I
authors.lastname: Nijs
mesh_terms: D057231:Climate Change; D004780:Environment, Controlled; D008962:Models, Theoretical; D018515:Plant Leaves; D013696:Temperature