Ecophysiological variation of transpiration of pine forests: synthesis of new and published results
OTTOSSON-LÖFVENIUS, Mikaell
Swedish University of Agricultural Sciences = Sveriges lantbruksuniversitet [SLU]
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Swedish University of Agricultural Sciences = Sveriges lantbruksuniversitet [SLU]
Langue
en
Article de revue
Ce document a été publié dans
Ecological Applications. 2017, vol. 27, n° 1, p. 118-133
Ecological Society of America
Résumé en anglais
Canopy transpiration (EC) is a large fraction of evapotranspiration, integrating physical and biological processes within the energy, water and carbon cycles of forests. Quantifying EC is of both scientific and practical ...Lire la suite >
Canopy transpiration (EC) is a large fraction of evapotranspiration, integrating physical and biological processes within the energy, water and carbon cycles of forests. Quantifying EC is of both scientific and practical importance, providing information relevant to questions ranging from energy partitioning to ecosystem services, such as primary productivity and water yield. We estimated EC of four pine stands differing in age, and growing on sandy soils. The stands consisted of two wide-ranging conifer species: Pinus taeda and Pinus sylvestris, in temperate and boreal zones, respectively. Combining results from these and published studies on all soil types, we derived an approach to estimate daily EC of pine forests, representing a wide range of conditions from 35 º S to 64 º N latitude. During the growing season and under moist soils, maximum daily EC (ECm) at day-length normalized vapor pressure deficit of 1 kPa (ECm-ref) increased by 0.55 ± 0.02 (mean ± standard error) mm d−1 for each unit increase of leaf area index (L) up to L = ~5, showing no sign of saturation within this range of quickly rising mutual shading. The initial rise of ECm with atmospheric demand was linearly related to ECm-ref. Both relations were unaffected by soil type. Consistent with theoretical prediction, daily EC was sensitive to decreasing soil moisture at an earlier point of relative extractable water in loamy than sandy soils. Our finding facilitates the estimation of daily EC of wide-ranging pine forests using remotely-sensed L and meteorological data. We advocate an assembly of worldwide sap flux database for further evaluation of this approach. This article is protected by copyright.< Réduire
Mots clés
conifère
pinus taeda
pin sylvestre
zone tempérée
forêt boréale
canopée
évapotranspiration
Mots clés en anglais
Pinus sylvestris
Relative Extractable Water
soil texture
vapor pressure deficit
coniferous tree
loblolly pine
temperate zone
boreal forest
canopy
canopy transpiration
leaf area index
Origine
Importé de halUnités de recherche