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Biophysical homoeostasis of leaf temperature: A neglected process for vegetation and land-surface modelling
Title: | Biophysical homoeostasis of leaf temperature: A neglected process for vegetation and land-surface modelling |
Authors: | Dong, N Prentice, IC Harrison, SP Song, QH Zhang, YP |
Item Type: | Journal Article |
Abstract: | Aim Leaf and air temperatures are seldom equal, but many vegetation models assume that they are. Land-surface models calculate canopy temperatures, but how well they do so is unknown. We encourage consideration of the leaf- and canopy-to-air temperature difference (ΔΤ) as a benchmark for land-surface modelling and an important feature of plant and ecosystem function. Location Tropical SW China. Time period 2013. Major Taxa studies Tropical trees. Methods We illustrate diurnal cycles of leaf- and canopy-to-air temperature difference (ΔΤ) with field measurements in a tropical dry woodland and with continuous monitoring data in a tropical seasonal forest. The Priestley–Taylor (PT) and Penman–Monteith (PM) approaches to evapotranspiration are used to provide insights into the interpretation and prediction of ΔT. Field measurements are also compared with land-surface model results obtained with the Joint U.K. Land Environment Simulator (JULES) set up for the conditions of the site. Results The ΔT followed a consistent diurnal cycle, with negative values at night (attributable to negative net radiation) becoming positive in the morning, reaching a plateau and becoming negative again when air temperature exceeded a ‘crossover’ in the 24–29 °C range. Daily time courses of ΔT could be approximated by either the PT or the PM model, but JULES tended to underestimate the magnitude of negative ΔT. Main conclusions Leaves with adequate water supply are partly buffered against air-temperature variations, through a passive biophysical mechanism. This is likely to be important for optimal leaf function, and land-surface and vegetation models should aim to reproduce it. |
Issue Date: | 16-Aug-2017 |
Date of Acceptance: | 4-Jun-2017 |
URI: | http://hdl.handle.net/10044/1/54730 |
DOI: | https://dx.doi.org/10.1111/geb.12614 |
ISSN: | 1466-822X |
Publisher: | Wiley |
Start Page: | 998 |
End Page: | 1007 |
Journal / Book Title: | Global Ecology and Biogeography |
Volume: | 26 |
Issue: | 9 |
Copyright Statement: | This is the peer reviewed version of the following article: Dong N, Prentice IC, Harrison SP, Song QH, Zhang YP. Biophysical homoeostasis of leaf temperature: A neglected process for vegetation and land-surface modelling. Global Ecol Biogeogr. 2017;26:998–1007, which has been published in final form at https://dx.doi.org/10.1111/geb.12614. This article may be used for non-commercial purposes in accordance With Wiley Terms and Conditions for self-archiving. |
Sponsor/Funder: | AXA Research Fund |
Funder's Grant Number: | AXA Chair Programme in Biosphere and Climate Impacts |
Keywords: | Science & Technology Life Sciences & Biomedicine Physical Sciences Ecology Geography, Physical Environmental Sciences & Ecology Physical Geography boundary-layer conductance crossover temperature energy balance land-surface model leaf temperature stomatal conductance transpiration CONVECTIVE BOUNDARY-LAYER ENVIRONMENT SIMULATOR JULES STOMATAL CONDUCTANCE ENERGY TRANSPIRATION EVAPORATION PLANTS SIZE THERMOREGULATION CONVERGENCE 0602 Ecology 0501 Ecological Applications |
Publication Status: | Published |
Appears in Collections: | Department of Life Sciences Faculty of Natural Sciences |