Comparison of the USO and CAP stomatal control approaches using JSBACH

Forskningsoutput: KonferensbidragPoster

Sammanfattning

The land surface model JSBACH may be modified to use different stomatal control functions to determine the exchange of carbon dioxide and water between vegetation and its environment. These different functions yield different predictions for gross photosynthetic production (GPP), evapotranspiration (ET) and canopy conductance on a given grid cell, which can then be compared to observations by hindcasting. In this study, prediction performances of several stomatal models based on the CAP optimisation hypothesis are compared to that of the more widely used Unified Stomatal Optimisation (USO) model. The CAP hypothesis implies a direct downregulation of photosynthesis with decreasing leaf water potential, thus coupling water transport in the xylem with carbon dioxide assimilation in the leaves. The hindcasting is done using eddy covariance data for boreal Scots pine (Pinus sylvestris) stands from two sites in Finland (Hyytiälä and Sodankylä). Preliminary results indicate that while performance regarding GPP and ET is similar, CAP-based models give a higher canopy conductance that is more sensitive to drought.
Originalspråkengelska
StatusPublicerad - nov 2019
MoE-publikationstypEj behörig
Evenemang11th International Workshop on Sap Flow - Hyytiälä, Juupajoki, Finland
Varaktighet: 7 okt 201911 okt 2019
Konferensnummer: 11
https://www.ishs.org/symposium/528

Konferens

Konferens11th International Workshop on Sap Flow
LandFinland
OrtJuupajoki
Period07/10/201911/10/2019
Internetadress

Vetenskapsgrenar

  • 114 Fysik
  • 4112 Skogsvetenskap

Citera det här

Mauranen, A., Mäkelä, J., Hölttä, T., Salmon, Y., & Vesala, T. (2019). Comparison of the USO and CAP stomatal control approaches using JSBACH. Poster presenterad vid 11th International Workshop on Sap Flow, Juupajoki, Finland.
Mauranen, Aleksanteri ; Mäkelä, Jarmo ; Hölttä, Teemu ; Salmon, Yann ; Vesala, Timo. / Comparison of the USO and CAP stomatal control approaches using JSBACH. Poster presenterad vid 11th International Workshop on Sap Flow, Juupajoki, Finland.
@conference{ae7bb634967341c787e371267129b4a6,
title = "Comparison of the USO and CAP stomatal control approaches using JSBACH",
abstract = "The land surface model JSBACH may be modified to use different stomatal control functions to determine the exchange of carbon dioxide and water between vegetation and its environment. These different functions yield different predictions for gross photosynthetic production (GPP), evapotranspiration (ET) and canopy conductance on a given grid cell, which can then be compared to observations by hindcasting. In this study, prediction performances of several stomatal models based on the CAP optimisation hypothesis are compared to that of the more widely used Unified Stomatal Optimisation (USO) model. The CAP hypothesis implies a direct downregulation of photosynthesis with decreasing leaf water potential, thus coupling water transport in the xylem with carbon dioxide assimilation in the leaves. The hindcasting is done using eddy covariance data for boreal Scots pine (Pinus sylvestris) stands from two sites in Finland (Hyyti{\"a}l{\"a} and Sodankyl{\"a}). Preliminary results indicate that while performance regarding GPP and ET is similar, CAP-based models give a higher canopy conductance that is more sensitive to drought.",
keywords = "114 Physical sciences, 4112 Forestry",
author = "Aleksanteri Mauranen and Jarmo M{\"a}kel{\"a} and Teemu H{\"o}ltt{\"a} and Yann Salmon and Timo Vesala",
year = "2019",
month = "11",
language = "English",
note = "null ; Conference date: 07-10-2019 Through 11-10-2019",
url = "https://www.ishs.org/symposium/528",

}

Mauranen, A, Mäkelä, J, Hölttä, T, Salmon, Y & Vesala, T 2019, 'Comparison of the USO and CAP stomatal control approaches using JSBACH', 11th International Workshop on Sap Flow, Juupajoki, Finland, 07/10/2019 - 11/10/2019.

Comparison of the USO and CAP stomatal control approaches using JSBACH. / Mauranen, Aleksanteri; Mäkelä, Jarmo; Hölttä, Teemu; Salmon, Yann; Vesala, Timo.

2019. Poster presenterad vid 11th International Workshop on Sap Flow, Juupajoki, Finland.

Forskningsoutput: KonferensbidragPoster

TY - CONF

T1 - Comparison of the USO and CAP stomatal control approaches using JSBACH

AU - Mauranen, Aleksanteri

AU - Mäkelä, Jarmo

AU - Hölttä, Teemu

AU - Salmon, Yann

AU - Vesala, Timo

PY - 2019/11

Y1 - 2019/11

N2 - The land surface model JSBACH may be modified to use different stomatal control functions to determine the exchange of carbon dioxide and water between vegetation and its environment. These different functions yield different predictions for gross photosynthetic production (GPP), evapotranspiration (ET) and canopy conductance on a given grid cell, which can then be compared to observations by hindcasting. In this study, prediction performances of several stomatal models based on the CAP optimisation hypothesis are compared to that of the more widely used Unified Stomatal Optimisation (USO) model. The CAP hypothesis implies a direct downregulation of photosynthesis with decreasing leaf water potential, thus coupling water transport in the xylem with carbon dioxide assimilation in the leaves. The hindcasting is done using eddy covariance data for boreal Scots pine (Pinus sylvestris) stands from two sites in Finland (Hyytiälä and Sodankylä). Preliminary results indicate that while performance regarding GPP and ET is similar, CAP-based models give a higher canopy conductance that is more sensitive to drought.

AB - The land surface model JSBACH may be modified to use different stomatal control functions to determine the exchange of carbon dioxide and water between vegetation and its environment. These different functions yield different predictions for gross photosynthetic production (GPP), evapotranspiration (ET) and canopy conductance on a given grid cell, which can then be compared to observations by hindcasting. In this study, prediction performances of several stomatal models based on the CAP optimisation hypothesis are compared to that of the more widely used Unified Stomatal Optimisation (USO) model. The CAP hypothesis implies a direct downregulation of photosynthesis with decreasing leaf water potential, thus coupling water transport in the xylem with carbon dioxide assimilation in the leaves. The hindcasting is done using eddy covariance data for boreal Scots pine (Pinus sylvestris) stands from two sites in Finland (Hyytiälä and Sodankylä). Preliminary results indicate that while performance regarding GPP and ET is similar, CAP-based models give a higher canopy conductance that is more sensitive to drought.

KW - 114 Physical sciences

KW - 4112 Forestry

M3 - Poster

ER -

Mauranen A, Mäkelä J, Hölttä T, Salmon Y, Vesala T. Comparison of the USO and CAP stomatal control approaches using JSBACH. 2019. Poster presenterad vid 11th International Workshop on Sap Flow, Juupajoki, Finland.