A modified Jarvis model to improve the expressing of stomatalresponse in a beech forest

0574247 - ÚH 2024 RIV US eng J - Journal Article
Shao, W. - Li, M. - Su, Y. - Gao, H. - Vlček, Lukáš
A modified Jarvis model to improve the expressing of stomatalresponse in a beech forest.
Hydrological Processes. Roč. 37, č. 8 (2023), č. článku e14955. ISSN 0885-6087. E-ISSN 1099-1085
Institutional support: RVO:67985874
Keywords : boundary line analysis * canopy conductance * environmental stress factor * Jarvis model * transpiration
OECD category: Hydrology
Impact factor: 3.2, year: 2022
Method of publishing: Open access
https://onlinelibrary.wiley.com/doi/10.1002/hyp.14955

The Jarvis-type model, which incorporates stress functions, is commonly used todescribe the physiological behaviour of stomatal response in various vegetation species.However, the model has been criticized for its empirically formulated multiplicative equa-tion, which may not accurately capture themutual impact of intercorrelated stress fac-tors, for example, vapour pressure deficit (VPD) and air temperature (Ta). This studyproposedamodifiedJarvismodel that introduces reduction factors in the stress func-tions of VPD andTato provide the description of canopy conductance. We used sapflow data from a beech forest in the mid-latitude region of Centre Europe to inverselyestimate the canopy conductance with optimized stress functions. Our findings revealthat two recommended parameterization strategies for general deciduous broadleaf for-est (DBF) significantly overestimated thetranspiration rate, with a maximum value of 2 mm/day on rainless days. This suggested that the beech forest exhibited a distinctstomatal response compared to the general DBF category. By applying boundary lineanalysis to fit the parameters, both the unmodified and modified Jarvis models providedbetter simulations of transpiration, with relatively high Nash-Sutcliffe Efficiency (NSE)values of 0.75 and 0.77, respectively. These results indicated that modelling transpirationcan be improved by refining the parameterization of canopy conductance, particularlyfor vegetation species with unique stomatal behaviours that deviated from the charac-teristics of their general vegetation type.The modified Jarvis model offers a more accu-rate description of canopy conductance andenhances the modelling of transpiration invegetated areas, especially under dry environment conditions with relatively high VPD.
Permanent Link: https://hdl.handle.net/11104/0344585