scholarly journals Assessing the ability of three land ecosystem models to simulate gross carbon uptake of forests from boreal to Mediterranean climate in Europe

2007 ◽  
Vol 4 (2) ◽  
pp. 1353-1375 ◽  
Author(s):  
M. Jung ◽  
G. Le Maire ◽  
S. Zaehle ◽  
S. Luyssaert ◽  
M. Vetter ◽  
...  
Keyword(s):  
Eddy Covariance ◽  
Gross Primary Production ◽  
Net Ecosystem Exchange ◽  
Radiation Use Efficiency ◽  
Mean Annual Temperature ◽  
Mediterranean Forests ◽  
Area Index ◽  
Eddy Covariance Measurements ◽  
Use Efficiency ◽  
Radiation Use

Abstract. We evaluate three terrestrial biosphere models (LPJ, Orchidee, Biome-BGC) with respect to their capacity to simulate climate related trends in gross primary production (GPP) of forests in Europe. We compare simulated GPP and leaf area index (LAI) with GPP estimates based on flux separated eddy covariance measurements of net ecosystem exchange (NEE) and LAI measurements along a gradient in mean annual temperature from the boreal to the Mediterranean.The three models capture qualitatively the pattern suggested by the site data: an increase in GPP from boreal to temperate and a subsequent decline from temperate to Mediterranean climates. The models consistently predict higher GPP for boreal and lower GPP for Mediterranean forests. Based on a decomposition of GPP into absorbed photosynthetic active radiation (APAR) and radiation use efficiency (RUE), the overestimation of GPP for the boreal zone appears to be primarily related to too high simulated LAI - and thus light absorption (APAR) – rather than too high radiation use efficiency. On average, the models compare similarly well to the site GPP data (RMSE of ~30% or 420 gC/m2/yr) but differences are apparent for different ecosystem types. Given uncertainties about the accuracy in model drivers, a potential representation bias of the eddy covariance sites, and uncertainties related to the method of deriving GPP from eddy covariance measurements data, we find the agreement between site data and simulations acceptable, providing confidence in simulations of GPP for European forests.

scholarly journals Assessing the ability of three land ecosystem models to simulate gross carbon uptake of forests from boreal to Mediterranean climate in Europe

2007 ◽  
Vol 4 (4) ◽  
pp. 647-656 ◽  
Author(s):  
M. Jung ◽  
G. Le Maire ◽  
S. Zaehle ◽  
S. Luyssaert ◽  
M. Vetter ◽  
...  
Keyword(s):  
Eddy Covariance ◽  
Model Comparison ◽  
Gross Primary Production ◽  
Radiation Use Efficiency ◽  
Mediterranean Forests ◽  
Area Index ◽  
Limited Region ◽  
Eddy Covariance Measurements ◽  
Use Efficiency ◽  
Radiation Use

Abstract. Three terrestrial biosphere models (LPJ, Orchidee, Biome-BGC) were evaluated with respect to their ability to simulate large-scale climate related trends in gross primary production (GPP) across European forests. Simulated GPP and leaf area index (LAI) were compared with GPP estimates based on flux separated eddy covariance measurements of net ecosystem exchange and LAI measurements along a temperature gradient ranging from the boreal to the Mediterranean region. The three models capture qualitatively the pattern suggested by the site data: an increase in GPP from boreal to temperate and a subsequent decline from temperate to Mediterranean climates. The models consistently predict higher GPP for boreal and lower GPP for Mediterranean forests. Based on a decomposition of GPP into absorbed photosynthetic active radiation (APAR) and radiation use efficiency (RUE), the overestimation of GPP for the boreal coniferous forests appears to be primarily related to too high simulated LAI - and thus light absorption (APAR) – rather than too high radiation use efficiency. We cannot attribute the tendency of the models to underestimate GPP in the water limited region to model structural deficiencies with confidence. A likely dry bias of the input meteorological data in southern Europe may create this pattern. On average, the models compare similarly well to the site GPP data (RMSE of ~30% or 420 gC/m2/yr) but differences are apparent for different ecosystem types. In terms of absolute values, we find the agreement between site based GPP estimates and simulations acceptable when we consider uncertainties about the accuracy in model drivers, a potential representation bias of the eddy covariance sites, and uncertainties related to the method of deriving GPP from eddy covariance measurements data. Continental to global data-model comparison studies should be fostered in the future since they are necessary to identify consistent model bias along environmental gradients.

scholarly journals Solar radiation use efficiency by soybean under field conditions in the Amazon region

2009 ◽  
Vol 44 (10) ◽  
pp. 1211-1218 ◽  
Author(s):  
Paulo Jorge de Oliveira Ponte de Souza ◽  
Aristides Ribeiro ◽  
Edson José Paulino da Rocha ◽  
José Renato Bouça Farias ◽  
Renata Silva Loureiro ◽  
...  
Keyword(s):  
Solar Radiation ◽  
Leaf Area ◽  
Biomass Production ◽  
Amazon Region ◽  
Field Conditions ◽  
Radiation Use Efficiency ◽  
Area Index ◽  
Natural Field ◽  
Use Efficiency ◽  
Radiation Use

The objective of this work was to evaluate the efficiency of soybean (Glycine max) in intercepting and using solar radiation under natural field conditions, in the Amazon region, Brazil. The meteorological data and the values of soybean growth and leaf area were obtained from an agrometeorological experiment carried out in Paragominas, Pará state, during 2007 and 2008. The radiation use efficiency (RUE) was obtained from the ratio between the above-ground biomass production and the intercepted photosynthetically active radiation (PAR) accumulated to 99 and 95 days after sowing, in 2007 and 2008, respectively. Climatic conditions during the experiment were very distinct, with reduction in rainfall in 2007, which began during the soybean mid-cycle, due to the El Niño phenomenon. An important reduction in the leaf area index and biomass production was observed during 2007. Under natural field conditions in the Amazon region, the values of RUE were 1.46 and 1.99 g MJ-1 PAR in the 2007 and 2008 experiments, respectively. The probable reason for the differences found between these years might be associated to the water restriction in 2007 coupled with the higher air temperature and vapor pressure deficit, and also to the increase in the fraction of diffuse radiation that reached the land surface in 2008.

Leaf development, radiation interception and radiation-use efficiency of kale crops supplied with different rates of banded or broadcast phosphorus fertiliser

2011 ◽  
Vol 62 (10) ◽  
pp. 840 ◽  
Author(s):  
E. Chakwizira ◽  
D. J. Moot ◽  
W. R. Scott ◽  
A. L. Fletcher ◽  
S. Maley
Keyword(s):  
Radiation Use Efficiency ◽  
Yield Response ◽  
Area Index ◽  
Radiation Interception ◽  
Degree Day ◽  
Use Efficiency ◽  
P Application ◽  
Leaf Appearance ◽  
Radiation Use ◽  
P Supply

Inadequate phosphorus (P) supply at crop establishment can reduce dry matter (DM) accumulation. A field experiment quantified the effects of banded or broadcast P fertiliser (0, 20, 40 or 60 kg P/ha) applied at establishment to moderately fertile soils on growth and development of ‘Regal’ kale (Brassica oleracea var. acephala L.) crops. DM yield increased from 8710 to ~11 400 kg/ha by the addition of P fertiliser but was unaffected by the method of P application. The control crops accumulated 630 kg DM/100 degree-day (degree-day-accumulated heat available for crop growth) compared with ~800 kg/100 degree-day for the P-fertilised crops. The yield response to P was caused by an increased rate of development of leaf area index (LAI) and consequently earlier canopy closure that led to higher accumulated radiation interception (RIcum). The maximum LAI for the control crops was 3.80 or 24% lower than for fertilised crops. At the final harvest total RIcum for P-fertilised crops was 22% higher than the 592 MJ/m2 for the control, and this accounted for 80% of their yield differences. Leaf appearance rates were unaffected by P supply, with a common phyllochron of 109 degree-day. There was a consistent relationship between light interception and LAI, with a critical LAI of 3.40, extinction coefficient of 0.90 and radiation-use efficiency of 1.56 g/MJ photosynthetically active radiation. Overall, these results support a starter P application of at least 20 kg P/ha at establishment to maximise yields for kale crops when initial soil Olsen P levels ranged from 9 to 17 mg/kg soil.

scholarly journals Radiation Use Efficiency for Cowpea Subjected to Different Irrigation Depths Under the Climatic Conditions of the Northeast Of Pará State

2018 ◽  
Vol 33 (4) ◽  
pp. 579-587
Author(s):  
Denis de Pinho Sousa ◽  
Paulo Jorge Oliveira Ponte de Souza ◽  
Vivian Dielly da Silva Farias ◽  
Hildo Giuseppe Caldas Nunes ◽  
Denílson Pontes Ferreira ◽  
...  
Keyword(s):  
Water Deficit ◽  
Dry Matter ◽  
Climatic Conditions ◽  
Radiation Use Efficiency ◽  
Crop Evapotranspiration ◽  
Area Index ◽  
Active Radiation ◽  
Use Efficiency ◽  
Radiation Use ◽  
Absorbed Photosynthetically Active Radiation

Abstract This study aims to determine the cowpea efficiency in absorbing and using solar radiation according to different irrigation depths under the climatic conditions of the northeast of Pará State. The experiment was carried out on 2014 and 2016 in an experimental design of randomized blocks, which consisted in six blocks with four treatments, in which different irrigation depths the reproductive phase were applied, as follows: T100, T50, T25 e T0, that corresponded to 100%, 50%, 25% e 0% of the crop evapotranspiration, respectively. The absorbed photosynthetically active radiation, leaf area index (LAI), total aerial dry matter (TADM) and grain yield were measured. The extinction coefficient (k) was obtained by nonlinear regression between the fraction of absorbed PAR (fPARinter) and the LAI. The radiation use efficiency (RUE) was calculated by linear regression between the TADM and the accumulated absorbed PAR. The water deficit imposed by the treatments had a significant influence on the LAI, TADM and cowpea yields. The water deficit did not significantly influenced k – it ranged between 0.83 for T100 and 0.70 for T0. The RUE showed significant behaviors regarding the treatments with adequate water supply and treatments under water deficit, ranging from 2.23 to 1.64 g·MJ-1, respectively.

scholarly journals Study on Radiation Interception and Use in Some Mustard Varieties

2020 ◽  
pp. 11-23
Author(s):  
M. A. Awal ◽  
M. O. Gani
Keyword(s):  
Solar Radiation ◽  
Seed Yield ◽  
Block Design ◽  
Winter Season ◽  
Radiation Use Efficiency ◽  
Branch Number ◽  
Area Index ◽  
Radiation Interception ◽  
Use Efficiency ◽  
Radiation Use

Aim: Solar radiation is the unique source of energy which drives the photosynthesis of green plants for producing biomass to living being. Use efficiency of solar radiation to produce biomass has been quantified for many crops in field condition but no study is undertaken for mustard although it is an important oil seed crop in the world as well as in Bangladesh. Therefore, the present study was undertaken to evaluate the radiation-use efficiency of mustard crop. Study Design: The experiment was laid out in a Randomized Complete Block Design (RCBD) with three replicates. Place and Duration of Study: The experiment was conducted in the Crop Botany Field Laboratory, Bangladesh Agricultural University, Mymensingh during the winter season extended from November 2011 to March 2012. Methodology: Treatments comprised six mustard varieties viz. BINAsarisha-3, BINAsarisha-4, BINAsarisha-5, BINAsarisha-6, BINAsarisha-7 and BINAsarisha-8 which were grown following standard cultivation techniques to optimize the growth and development. Radiation measurements along the growing season were carried out during solar noon on some sunny days with a Radiometer connected to a 1 m long Line Quantum Sensor. Results: Mustard varieties showed wide variation in terms of plant height, branch number, leaf area index (LAI), dry matter (DM) accumulation, yield components and yield and radiation interception and use. BINAsarisha-6 showed better performance on the aforesaid traits followed by BINAsarisha-7 while lower performance was observed in BINAsarisha-3 and BINAsarisha-4. The higher seed yield (2.41 t ha-1) was obtained in the BINAsarisha-6, the variety also showed higher radiation-use efficiency, RUE (3.75 g MJ-1 PAR) whereas the lower seed yield (about 2.1 t ha-1) was observed in the BINAsarisha-3 or BINAsarisha-4, the varieties also showed the lower RUE (<3 g MJ-1 PAR) which indicate that the higher accumulation of DM in BINAsarisha-6 variety as influenced by higher utilization of solar radiation effectively constitute the seed yield. The temporal RUE showed much fluctuated pattern in all the varieties and higher RUEs were observed at the later part of the crop growth. The variety BINAsarisha-6 also showed the higher seasonal mean RUE whereas BINAsarisha-4 showed the lower. Conclusion: Mustard varieties showed wide variation in growth, yield and radiation interception and use. Higher biomass production as well as higher seed yield is associated with higher utilization of solar radiation.

scholarly journals EFISIENSI PENGGUNAAN RADIASI SURYA DAN SEBAGAI DASAR DALAM MODEL JARAK PAGAR(RADIATION USE EFFICIENCY AS BASIS THE CROPS MODELING OF JATROPHA)

Agromet ◽  
2008 ◽  
Vol 22 (2) ◽  
pp. 108
Author(s):  
Gusti Rusmayadi ◽  
. Handoko ◽  
Yonny Koesmaryono ◽  
Didiek Hadjar Goenadi
Keyword(s):  
Nitrogen Fertilizer ◽  
Plant Density ◽  
Crop Growth ◽  
Radiation Use Efficiency ◽  
Growth And Yield ◽  
Area Index ◽  
Rainfall Condition ◽  
Use Efficiency ◽  
Four Levels ◽  
Radiation Use

Plant growth interpretation in term of accumulated intercepted solar radiation and the radiation use efficiency (RUE) was used to study the growth and analysis of Jatropha (Jatropha curcas L.). A number of crop growth simulation models have been developed using the RUE concept to predict crop growth and yield in various environments. These models generally calculate daily biomass production as the product of the quantity of radiation intercepted and RUE. This research was carried out to quantify the RUE, biomass and leaf area index on Jatropha under rainfall condition, four levels of nitrogen fertilizer (N) and three population densities (P) planted twice. The experiments used a systematic Nelder fan design with 9 spokes and 4 – 5 rings were conducted at SEAMEO-BIOTROP field experiment in 2007. Data from the first experiment were used for parameterization and calibration and the second experiment data for model validation. Values of RUE were determined by nitrogen fertilizer and plant density. Based on parameterization, we found that RUE for prediction above ground biomass accumulation of Jatropha were 0.94 (r=0.83) g MJ-1 to 1.3 (r=0.75) g MJ-1. Validation between model prediction and field experimental data showed that model can simulate crop growth and development of Jatropha.

scholarly journals Biomass accumulation and radiation use efficiency of winter wheat under deficit irrigation regimes

2009 ◽  
Vol 55 (No. 2) ◽  
pp. 85-91 ◽  
Author(s):  
Q. Li ◽  
M. Liu ◽  
J. Zhang ◽  
B. Dong ◽  
Q. Bai
Keyword(s):  
Winter Wheat ◽  
Grain Yield ◽  
Deficit Irrigation ◽  
Biomass Accumulation ◽  
Growing Season ◽  
Radiation Use Efficiency ◽  
Area Index ◽  
Irrigation Regimes ◽  
Use Efficiency ◽  
Radiation Use

To better understand the potential for improving biomass accumulation and radiation use efficiency (RUE) of winter wheat under deficit irrigation regimes, in 2006–2007 and 2007–2008, an experiment was conducted at the Luancheng Experimental Station of Chinese Academy of Science to study the effects of deficit irrigation regimes on the photosynthetic active radiation (PAR), biomass accumulation, grain yield, and RUE of winter wheat. In this experiment, field experiment involving winter wheat with 1, 2 and 3 irrigation applications at sowing, jointing, or heading stages was conducted, and total irrigation water was all controlled at 120 mm. The results indicate that irrigation 2 or 3 times could help to increase the PAR capture ratio in the later growing season of winter wheat; this result was mainly due to the changes in the vertical distributions of leaf area index (LAI) and a significant increase of the LAI at 0–20 cm above the ground surface (LSD, <i>P</i> < 0.05). Compared with irrigation only once during the growing season of winter wheat, irrigation 2 times significantly (LSD, <i>P</i> < 0.05) increased aboveground dry matter at maturity; irrigation at sowing and heading or jointing and heading stages significantly (LSD, <i>P</i> < 0.05) improved the grain yield, and irrigation at jointing and heading stages provided the highest RUE (0.56 g/mol). Combining the grain yield and RUE, it can be concluded that irrigation at jointing and heading stages has higher grain yield and RUE, which will offer a sound measurement for developing deficit irrigation regimes in North China.

Impact of water deficit on light interception, radiation use efficiency and leaf area index in a potato crop (Solanum tuberosumL.)

2015 ◽  
Vol 154 (4) ◽  
pp. 662-673 ◽  
Author(s):  
D. C. CAMARGO ◽  
F. MONTOYA ◽  
M. A. MORENO ◽  
J. F. ORTEGA ◽  
J. I. CÓRCOLES
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Potato Crop ◽  
Irrigation Treatment ◽  
Ground Cover ◽  
Absorption Efficiency ◽  
Radiation Use Efficiency ◽  
Area Index ◽  
Use Efficiency ◽  
Radiation Use

SUMMARYThe aim of the current research was to analyse the effect of four water irrigation treatments (1·20, 1·00, 0·80 and 0·60 of the crop water requirement) on the relationships among leaf area index (LAI), radiation use efficiency (RUE) and green canopy cover in a potato crop (Solanum tuberosumL.) cv. Agria. The crop was established in a commercial plot irrigated with a centre pivot system in Southeast Spain during the 2011 and 2012 seasons. In both seasons, the highest light absorption efficiency values occurred at the LAI value of 3 that corresponded to maximum ground cover. With regard to the irrigation treatment, a significant linear response was indicated for RUE. The results indicate that the 1·00 irrigation treatment produced the best result, improving water resources management without reducing crop yield.

scholarly journals Effect of tillage, residue and nitrogen management on radiation interception, radiation use efficiency and evapotranspiration partitioning

2021 ◽  
Vol 22 (3) ◽  
pp. 285-294
Author(s):  
KOUSHIK BAG ◽  
K.K. BANDYOPADHYAY ◽  
V.K. SEHGAL ◽  
A. SARANGI ◽  
P. KRISHNAN
Keyword(s):  
Leaf Area ◽  
Photosynthetically Active Radiation ◽  
Crop Residue ◽  
Radiation Use Efficiency ◽  
Area Index ◽  
Radiation Interception ◽  
Active Radiation ◽  
Biomass Yields ◽  
Use Efficiency ◽  
Radiation Use

In this study, we have evaluated the effect of different tillage (conventional tillage (CT) and no tillage (NT)), residue (with crop residue mulch (R+) and without residue (R0)) and nitrogen (60, 120 and 180 kgN ha-1) interaction for radiation interception, radiation use efficiency (RUE), evapotranspiration (ET) partitioning and yield of wheat in a split-split plot design for 2017-18 and 2018-19. Results showed that Leaf Area Index (LAI), Leaf area duration (LAD), Total intercepted photosynthetically active radiation (TIPAR), Grain and Biomass yields were higher in R+ during both the years of study. With increasing Ndoses LAI, LAD, TIPAR, RUE, grain and biomass yields increased and extinction coefficient decreased significantly in both the years. Fraction intercepted photosynthetically active radiation (fIPAR) followed a similar trend with LAI. Seasonal ET was partitioned into soil evaporation (Ep) and crop transpiration (Tp) to take into account the productive transpiration effects on crop growth and yield. It was found that NT and residue could reduce Ep (6% and 5.6%) and increased Tp (2.6% and 2.4%) over CT and no mulch treatments, respectively. With higher N-dose, Ep decreased while Tp increased significantly. Thus besides higher nitrogen doses, NT and crop residue mulching could be a better strategy to harness higher radiation interception vis-a-vis higher crop productivity.

scholarly journals Índices Morfofisiológicos e Uso de Radiação Solar por um Cultivo de Cana-de-Açúcar Irrigada no Semiárido Brasileiro (Morphophysiological Indices and Radiation Use by an Irrigated Sugarcane Crop in the Brazilian Semi-Arid)

2014 ◽  
Vol 7 (4) ◽  
pp. 764
Author(s):  
Thieres George Freire da Silva ◽  
Magna Soelma Beserra de Moura ◽  
Sérgio Zolnier ◽  
Luciana Sandra Bastos de Souza ◽  
José Francisco Alves do Carmo
Keyword(s):  
Extinction Coefficient ◽  
Growth Patterns ◽  
Photosynthetic Active Radiation ◽  
Radiation Use Efficiency ◽  
Area Index ◽  
Active Radiation ◽  
Maximum Value ◽  
Use Efficiency ◽  
Radiation Use ◽  
Semi Arid

Os índices morfofisiológicos e parâmetros de eficiência do uso de radiação foram determinados para a cana-de-açúcar irrigada, RB92579. O experimento foi conduzido no município de Juazeiro-BA, Semiárido brasileiro. Foram obtidas medições de biomassa seca acumulada pelas folhas, colmos e total da parte aérea, e do índice de área foliar. Adicionalmente, dados de radiação solar global e de radiação fotossinteticamente ativa foram medidos acima e abaixo do dossel da cultura. Por meio desses dados foram calculados os índices morfofisiológicos, a fração da radiação fotossinteticamente ativa (fRFA), o coeficiente de extinção (ke), o uso eficiente de radiação (UER) e a eficiência fotossintética (EFT). A taxa de crescimento absoluto aumentou substancialmente até atingir o valor máximo de 41,8 g m-2 d-1 aos 200 dias após o corte (DAC). O valor máximo de fRFA foi em torno de 99%, permanecendo constante dos 213 DAC até o final do ciclo. A magnitude do parâmetro ke foi 0,72. Baseado nas medições do BSTPA verificou-se que os valores aproximados de EFT e UER foram 2,67 g MJ-1 e 1,29 g MJ-1, respectivamente. Os resultados mostraram que a cana-de-açúcar irrigada no Semiárido brasileiro possui padrões de crescimento superiores aos de outros ambientes de cultivo registrados na literatura.  A B S T R A C T The morphphysiological indices and parameters of radiation use efficiency were determined for irrigated sugarcane, RB92579 cultivar. The experiment was carried out in the district of Juazeiro, State of the Bahia, located in the Brazilian semi-arid. Measurements of dry biomass accumulated by leaves, stalk and total shoot, and leaf area index (LAI) were carried out. Additionally, global solar radiation and photosynthetic active radiation were measured above and below the crop canopy. Using these data, morphphysiological indices, the photosynthetic active radiation fraction (fPAR), the extinction coefficient (ke), the radiation efficient use (REU) and the photosynthetic efficiency (PTE) were calculated. The absolute growth rate tended to increase substantially until reaching the maximum value of 41.8 g m-2 d-1, which was observed 200 days after cutting (DAC). The maximum value of the fPAR was around 99%, remaining constant from 213 DAC until the end of the crop cycle. The magnitude of the ke parameter was 0.72. Based on measurements of DBTS, it was verified that the approximate values of the PTE and REU were 2.67 g MJ-1 and 1.29 g MJ-1, respectively. Results showed that the irrigated sugarcane has excellent growth patterns when cultivated under semi-arid conditions when compared to others environments cited in literature. Keywords: growth, extinction coefficient, radiation use efficiency.  

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