Differences in leaf thermoregulation and water use strategies between three co‐occurring Atlantic forest tree species |
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| Authors: | Sophie Fauset Helber C Freitas David R Galbraith Martin JP Sullivan Marcos PM Aidar Carlos A Joly Oliver L Phillips Simone A Vieira Manuel U Gloor |
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| Affiliation: | 1. School of Geography, University of Leeds, Leeds, UK;2. Departamento de Física, Faculdade de Ciências, Universidade Estadual Paulista, S?o Paulo, Brazil;3. Instituto de Botanica de S?o Paulo, S?o Paulo, Brazil;4. Departamento de Biologia Vegetal, Instituto de Biologia, Universidade Estadual de Campinas, S?o Paulo, Brazil;5. Núcleo de Estudos e Pesquisas Ambientais, Universidade Estadual de Campinas, S?o Paulo, Brazil |
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| Abstract: | Given anticipated climate changes, it is crucial to understand controls on leaf temperatures including variation between species in diverse ecosystems. In the first study of leaf energy balance in tropical montane forests, we observed current leaf temperature patterns on 3 tree species in the Atlantic forest, Brazil, over a 10‐day period and assessed whether and why patterns may vary among species. We found large leaf‐to‐air temperature differences (maximum 18.3 °C) and high leaf temperatures (over 35 °C) despite much lower air temperatures (maximum 22 °C). Leaf‐to‐air temperature differences were influenced strongly by radiation, whereas leaf temperatures were also influenced by air temperature. Leaf energy balance modelling informed by our measurements showed that observed differences in leaf temperature between 2 species were due to variation in leaf width and stomatal conductance. The results suggest a trade‐off between water use and leaf thermoregulation; Miconia cabussu has more conservative water use compared with Alchornea triplinervia due to lower transpiration under high vapour pressure deficit, with the consequence of higher leaf temperatures under thermal stress conditions. We highlight the importance of leaf functional traits for leaf thermoregulation and also note that the high radiation levels that occur in montane forests may exacerbate the threat from increasing air temperatures. |
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| Keywords: | boundary layer energy balance functional traits leaf temperature leaf width montane radiation stomatal conductance transpiration tropical forest |
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