scholarly journals Identification of a general light use efficiency model for gross primary production

2010 ◽  
Vol 7 (5) ◽  
pp. 7673-7726 ◽  
Author(s):  
J. E. Horn ◽  
K. Schulz
Keyword(s):  
Large Scale ◽  
Gross Primary Production ◽  
Daily Basis ◽  
Climatic Conditions ◽  
Model Parameters ◽  
Light Use Efficiency ◽  
Meteorological Forcing ◽  
Use Efficiency ◽  
Study Sites ◽  
Light Use Efficiency Model

Abstract. Non-stationary and non-linear dynamic time series analysis tools are applied to multi-annual eddy covariance and micrometeorological data from 45 FLUXNET sites to derive a light use efficiency model on a daily basis. The extracted typical behaviour of the canopies in response to meteorological forcing leads to a model formulation allowing a variable influence of the model parameters modulating the light use efficiency. Thereby, the model is applicable to a broad range of vegetation types and climatic conditions. The proposed model explains large proportions of the variation of the gross carbon uptake at the study sites while the optimized set of six parameters is well defined. With the parameters showing explainable and meaningful relations to site-specific environmental conditions, the model has the potential to serve as basis for general regionalization strategies for large scale carbon flux predictions.

scholarly journals Identification of a general light use efficiency model for gross primary production

2011 ◽  
Vol 8 (4) ◽  
pp. 999-1021 ◽  
Author(s):  
J. E. Horn ◽  
K. Schulz
Keyword(s):  
Primary Production ◽  
Large Scale ◽  
Gross Primary Production ◽  
Daily Basis ◽  
Climatic Conditions ◽  
Environmental Drivers ◽  
Light Use Efficiency ◽  
Meteorological Forcing ◽  
Use Efficiency ◽  
Light Use Efficiency Model

Abstract. Non-stationary and non-linear dynamic time series analysis tools are applied to multi-annual eddy covariance and micrometeorological data from 44 FLUXNET sites to derive a light use efficiency model for gross primary production on a daily basis. The extracted typical behaviour of the canopies in response to meteorological forcing leads to a model formulation allowing for a variable influence of the environmental drivers temperature and moisture availability modulating the light use efficiency. Thereby, the model is applicable to a broad range of vegetation types and climatic conditions. The proposed model explains large proportions of the variation of the gross carbon uptake at the study sites while the optimized set of six parameters is well defined. With the parameters showing explainable and meaningful relations to site-specific environmental conditions, the model has the potential to serve as basis for general regionalization strategies for large scale carbon flux predictions.

scholarly journals Light Use Efficiency of Aboveground Biomass Production of Norway Spruce Stands

2017 ◽  
Vol 65 (1) ◽  
pp. 9-16
Author(s):  
Michal Bellan ◽  
Irena Marková ◽  
Andrii Zaika ◽  
Jan Krejza
Keyword(s):  
Norway Spruce ◽  
Aboveground Biomass ◽  
Photosynthetically Active Radiation ◽  
Climatic Conditions ◽  
Light Use Efficiency ◽  
Active Radiation ◽  
Spruce Stands ◽  
Use Efficiency ◽  
Study Sites ◽  
Radiation Use

Light use efficiency (LUE or photosynthetically active radiation use efficiency) in production of young spruce stands aboveground biomass was determined at the study sites Rájec (the Drahanská vrchovina Highland) and Bílý Kříž (the Moravian‑Silesian Beskids Mountains) in 2014 and 2015. The LUE value obtained for the investigated spruce stands were in the range of 0.45 – 0.65 g DW MJ–1. The different LUE values were determined for highland and mountain spruce stand. The differences were caused by growth and climatic conditions and by the amount of assimilatory apparatus (LAI).

scholarly journals Integration of Sentinel-3 OLCI Land Products and MERRA2 Meteorology Data into Light Use Efficiency and Vegetation Index-Driven Models for Modeling Gross Primary Production

2021 ◽  
Vol 13 (5) ◽  
pp. 1015
Author(s):  
Fengji Zhang ◽  
Zhijiang Zhang ◽  
Yi Long ◽  
Ling Zhang
Keyword(s):  
Primary Production ◽  
Eddy Covariance ◽  
Large Scale ◽  
Vegetation Index ◽  
Gross Primary Production ◽  
Regional Scale ◽  
Reanalysis Data ◽  
Light Use Efficiency ◽  
The Us ◽  
Use Efficiency

Accurately and reliably estimating total terrestrial gross primary production (GPP) on a large scale is of great significance for monitoring the carbon cycle process. The Sentinel-3 satellite provides the OLCI FAPAR and OTCI products, which possess a higher spatial and temporal resolution than MODIS products. However, few studies have focused on using LUE models and VI-driven models based on the Sentinel-3 satellites to estimate GPP on a large scale. The purpose of this study is to evaluate the performance of Sentinel-3 OLCI FAPAR and OTCI products combined with meteorology reanalysis data in estimating GPP at site and regional scale. Firstly, we integrated OLCI FAPAR and meteorology reanalysis data into the MODIS GPP algorithm and eddy covariance light use efficiency (EC-LUE) model (GPPMODIS-GPP and GPPEC-LUE, respectively). Then, we combined OTCI and meteorology reanalysis data with the greenness and radiation (GR) model and vegetation index (VI) model (GPPGR and GPPVI, respectively). Lastly, GPPMODIS-GPP, GPPEC-LUE, GPPGR, and GPPVI were evaluated against the eddy covariance flux data (GPPEC) at the site scale and MODIS GPP products (GPPMOD17) at the regional scale. The results showed that, at the site scale, GPPMODIS-GPP and GPPEC-LUE agreed well with GPPEC for the US-Ton site, with R2 = 0.73 and 0.74, respectively. The performance of GPPGR and GPPVI varied across different biome types. Strong correlations were obtained across deciduous broadleaf forests, mixed forests, grasslands, and croplands. At the same time, there are overestimations and underestimations in croplands, evergreen needleleaf forests and deciduous broadleaf forests. At the regional scale, the annual mean and maximum daily GPPMODIS-GPP and GPPEC-LUE agreed well with GPPMOD17 in 2017 and 2018, with R2 > 0.75. Overall, the above findings demonstrate the feasibility of using Sentinel-3 OLCI FAPAR and OTCI products combined with meteorology reanalysis data through LUE and VI-driven models to estimate GPP, and fill in the gaps for the large-scale evaluation of GPP via Sentinel-3 satellites.

Biogeographical Patterns of Light Use efficiency?

2021 ◽  
Author(s):  
David Sandoval ◽  
Iain Colin Prentice
Keyword(s):  
Maximum Rate ◽  
Spatial Organization ◽  
Gross Primary Production ◽  
Incident Light ◽  
Direct Consequence ◽  
Theoretical Explanation ◽  
Light Use Efficiency ◽  
Mountain Regions ◽  
Use Efficiency ◽  
Photosynthetic Traits

<p>The emergent spatial organization of ecosystems in elevational gradients suggest that some ecosystem processes, important enough to shape morphological traits, must show similar patterns.</p><p>The most important of these processes, gross primary production (GPP), usually (albeit with some exceptions) decreases with elevation. This was previously thought to be a direct consequence either of the decrease in temperature, or the decrease of incident light due to cloud cover. However, some recent developments in photosynthetic theory, plus the unprecedented availability of ecophysiological data, support the hypothesis that plants acclimate (optimize) their photosynthetic traits to the environment. In this new theoretical context, the temperature is no longer considered as a major constraining factor, except when either freezing or excessively high temperatures inhibit plant function generally.</p><p>Two of the most important photosynthetic traits, the maximum rate of carboxylation (V<sub>CMAX</sub>) and the intrinsic quantum efficiency (φ<sub>o</sub>), vary in opposite directions with increasing elevation. Plants tend to increase V<sub>CMAX</sub> to compensate for a decrease in the ratio leaf-internal to ambient partial pressures of CO<sub>2</sub>, while φ<sub>o</sub> increases with temperature up to a plateau. To explore how these different responses, documented at leaf level, converge in emergent spatial patterns at ecosystem scale we considered how elevation shape light use efficiency (defined as the ratio of CO<sub>2</sub> assimilated over light absorbed) over mountain regions worldwide. We used data from eddy-covariance flux towers, from different networks, located in mountain regions around the world, adding up to 618 station-years of record. To complement our analysis, we included theoretical predictions using an optimality model (P-model) and evaluated changes in the spatial pattern with simulation experiments.</p><p>Empirically we found an asymptotic response of LUE to the average daytime temperature during the growing season with increasing elevation, and a small, but globally consistent effect of elevation on LUE. We propose a theoretical explanation for the observation that temperature differences have little impact on the biogeographical pattern of LUE, but we also find that different assumptions on the acclimation of the maximum rate of electron transport (J<sub>MAX</sub>) and φ<sub>o</sub> change this pattern.</p>

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