TY - JOUR

T1 - How does structure matter? Comparison of canopy photosynthesis using one- and three-dimensional light models

T2 - A case study using greenhouse cucumber canopies

AU - Pao, Yi Chen

AU - Kahlen, Katrin

AU - Chen, Tsu Wei

AU - Wiechers, Dirk

AU - Stützel, Hartmut

N1 - Funding Information: This work was supported by Deutsche Forschungsgemeinschaft (DFG, project numbers 19247411, 225572701, 403510751)

PY - 2021

Y1 - 2021

N2 - One-dimensional light models using the Beer-Lambert equation (BL) with the light extinction coefficient k are simple and robust tools for estimating light interception of homogeneous canopies. Functional-structural plant models (FSPMs) are powerful to capture light-plant interactions in heterogeneous canopies, but they are also more complex due to explicit descriptions of three-dimensional plant architecture and light models. For choosing an appropriate modelling approach, the trade-offs between simplicity and accuracy need to be considered when canopies with spatial heterogeneity are concerned. We compared two light modelling approaches, one following BL and another using ray tracing (RT), based on a framework of a dynamic FSPM of greenhouse cucumber. Resolutions of hourly step (HS) and daily step (DS) were applied to simulate light interception, leaf-level photosynthetic acclimation and plant-level dry matter production over growth periods of 2-5 weeks. Results showed that BL-HS was comparable to RT-HS in predicting shoot dry matter and photosynthetic parameters. The k used in the BL approach was simulated using an empirical relationship between k and leaf area index established with the assistance of RT, which showed variation up to 0.2 in k depending on canopy geometry under the same plant density. When a constant k value was used instead, a difference of 0.2 in k resulted in up to 27 % loss in accuracy for shoot dry matter. These results suggested that, with the assistance of RT in k estimation, the simple approach BL-HS provided efficient estimation for long-term processes.

AB - One-dimensional light models using the Beer-Lambert equation (BL) with the light extinction coefficient k are simple and robust tools for estimating light interception of homogeneous canopies. Functional-structural plant models (FSPMs) are powerful to capture light-plant interactions in heterogeneous canopies, but they are also more complex due to explicit descriptions of three-dimensional plant architecture and light models. For choosing an appropriate modelling approach, the trade-offs between simplicity and accuracy need to be considered when canopies with spatial heterogeneity are concerned. We compared two light modelling approaches, one following BL and another using ray tracing (RT), based on a framework of a dynamic FSPM of greenhouse cucumber. Resolutions of hourly step (HS) and daily step (DS) were applied to simulate light interception, leaf-level photosynthetic acclimation and plant-level dry matter production over growth periods of 2-5 weeks. Results showed that BL-HS was comparable to RT-HS in predicting shoot dry matter and photosynthetic parameters. The k used in the BL approach was simulated using an empirical relationship between k and leaf area index established with the assistance of RT, which showed variation up to 0.2 in k depending on canopy geometry under the same plant density. When a constant k value was used instead, a difference of 0.2 in k resulted in up to 27 % loss in accuracy for shoot dry matter. These results suggested that, with the assistance of RT in k estimation, the simple approach BL-HS provided efficient estimation for long-term processes.

KW - Canopy geometry

KW - Dry matter

KW - Functional-structural plant model (FSPM)

KW - Light extinction coefficient

KW - Light interception

KW - Photosynthetic acclimation

UR - http://www.scopus.com/inward/record.url?scp=85121264640&partnerID=8YFLogxK

U2 - 10.1093/insilicoplants/diab031

DO - 10.1093/insilicoplants/diab031

M3 - Article

AN - SCOPUS:85121264640

VL - 3

SP - 1

EP - 17

JO - In Silico Plants

JF - In Silico Plants

SN - 2517-5025

IS - 2

ER -