Land-surface evapotranspiration derived from a first-principles primary production model
نویسندگان
چکیده
Evapotranspiration (ET) links the water and carbon cycles in atmosphere, hydrosphere, biosphere. In this study, we develop an ET modelling framework based on idea that transpiration uptake are closely coupled, as predicted by 'least-cost hypothesis' canopy conductance acclimates to environmental variations. According eco-evolutionary optimality theory, which has been previously applied monitoring land-surface processes, total costs (per unit fixed) for maintaining carboxylation capacities should be minimized. We calculate gross primary production (GPP) assuming light- Rubisco-limited rates of photosynthesis, described classical biochemical model coordinated approximately weekly time scale. Transpiration (T) is then calculated via acclimated conductance, with no need plant type- or biome-specific parameters. finally from T using empirical function light, temperature, soil content foliage cover predict T/ET ratio at each site. The GPP estimates were well supported (weekly) data 20 widely distributed eddy-covariance flux sites (228 site-years), correlation coefficients (r) = 0.81 root-mean-square error (RMSE) 18.7 gC week?1 Nash-Sutcliffe efficiency (NSE) 0.61. Predicted was also supported, r =0.85, RMSE 5.5 mm week–1 NSE 0.66. Estimated ratios (0.43–0.74) showed significant positive relationships radiation, precipitation green vegetation negative temperature modelled (r 0.84). Aspects could improved, notably estimation T/ET. Nonetheless, see application principles a promising direction resources research, eliminating uncertainty introduced specify multiple parameters, leveraging power remotely sensed key indicator ecosystem function.
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ژورنال
عنوان ژورنال: Environmental Research Letters
سال: 2021
ISSN: ['1748-9326']
DOI: https://doi.org/10.1088/1748-9326/ac29eb