An application of plot-scale NDVI in predicting carbon dioxide exchange and leaf area index in heterogeneous subarctic tundra

2010 ◽  
Vol 36 (sup1) ◽  
pp. S111-S123 ◽  
Author(s):  
Jennifer Dagg ◽  
Peter Lafleur
Keyword(s):  
Carbon Dioxide ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Carbon Dioxide Exchange ◽  
Area Index

NET CARBON DIOXIDE EXCHANGE RATES IN PHASEOLUS VULGARIS L. AS INFLUENCED BY TEMPERATURE, LIGHT INTENSITY, LEAF AREA INDEX, AND AGE OF PLANT

1964 ◽  
Vol 42 (4) ◽  
pp. 393-401
Author(s):  
Douglas P. Ormrod
Keyword(s):  
Carbon Dioxide ◽  
Phaseolus Vulgaris ◽  
Light Intensity ◽  
Exchange Rates ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Planting Density ◽  
Carbon Dioxide Exchange ◽  
Area Index ◽  
Light Intensities

Plants of Phaseolus vulgaris were grown under controlled conditions for 10 to 60 days and then transferred to light intensities of from 0 to 12,000 ft-c at temperatures of 4 to 38 °C for measurement of net carbon dioxide exchange by means of an infrared analyzer. The net carbon dioxide exchange was not markedly influenced by temperature at higher light intensities, particularly with older plants and the greater planting density, but was strikingly influenced by temperature in darkness or low light intensity. The leaf area index affected the rate at which the maximum net carbon dioxide exchange rates were attained. The compensation point increased with aging and with denser planting. The net assimilation decreased at the onset of fruiting. Several features of the experimental method are discussed.

Hyperspectral characteristics and leaf area index monitoring of rice (Oryza sativa L.) under carbon dioxide concentration enrichment

2021 ◽  
Vol 54 (3) ◽  
pp. 231-243
Author(s):  
Chao Liu ◽  
Zhenghua Hu ◽  
Rui Kong ◽  
Lingfei Yu ◽  
Yuanyuan Wang ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Oryza Sativa ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Oryza Sativa L ◽  
Carbon Dioxide Concentration ◽  
Area Index

Characteristics of the canopy, root system and grain yield of a crop of Lupinus angustifolius cv. Unicrop

1975 ◽  
Vol 26 (3) ◽  
pp. 497 ◽  
Author(s):  
EAN Greenwood ◽  
P Farrington ◽  
JD Beresford
Keyword(s):  
Carbon Dioxide ◽  
Grain Yield ◽  
Leaf Area ◽  
Time Course ◽  
Dry Weight ◽  
Grain Filling ◽  
Main Axis ◽  
Carbon Dioxide Exchange ◽  
Area Index ◽  
Plant Parts

The time course of development of a lupin crop was studied at Bakers Hill, Western Australia. The aim was to gain insight into the crop factors influencing yield. Weekly measurements were made of numbers and weights of plant parts, and profiles of roots, leaf area and light interception. A profile of carbon dioxide in the crop atmosphere was taken at the time of maximum leaf area, and the net carbon dioxide exchange (NCE) of pods was estimated for three successive weeks. The crop took 10 weeks to attain a leaf area index (LAI) of 1 and a further 9 weeks to reach a maximum LAI of 3.75, at which time only 33% of daylight reached the pods on the main axis. Once the maximum LAI was attained at week 19, leaf fall accelerated and rapid grain filling commenced almost simultaneously on all of the three orders of axes which had formed pods. Measurements of NCE between pods on the main axis and the air suggest that the assimilation of external carbon dioxide by the pods contributed little to grain filling. Grain dry weight was 2100 kg ha-1 of which 30%, 60% and 10% came from the main axis, first and second order apical axes respectively. Only 23% of the flowers set pods and this constitutes an important physiological limitation to grain yield.

Photosynthesis of wheat under field conditions. III. Seasonal trends in carbon dioxide uptake of crop communities

1971 ◽  
Vol 22 (1) ◽  
pp. 1 ◽  
Author(s):  
DW Puckridge
Keyword(s):  
Carbon Dioxide ◽  
Grain Yield ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Dry Weight ◽  
Field Conditions ◽  
Wheat Cultivars ◽  
Area Index ◽  
Carbon Dioxide Uptake ◽  
Assimilation Chamber

Photosynthesis of two wheat cultivars grown in the field was examined during three seasons by use of a portable field assimilation chamber. There were large differences in dry weight, leaf area, and carbon dioxide uptake between seasons. Variations in carbon dioxide uptake by the community were related mainly to changes in leaf area index (LAI). There were changes in carbon dioxide uptake per unit LAI with time, and between the two cultivars in the first season, but the effects of these changes were small compared with the effects of LAI. Differences in grain yield were correlated with LAI and carbon dioxide uptake in the period after anthesis.

Photosynthesis of wheat under field conditions. IV. The influence of density and leaf area index on the response to radiation

1971 ◽  
Vol 22 (1) ◽  
pp. 11 ◽  
Author(s):  
DW Puckridge ◽  
DA Ratkowsky
Keyword(s):  
Carbon Dioxide ◽  
Solar Radiation ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Net Photosynthesis ◽  
Good Prediction ◽  
Area Index ◽  
Rectangular Hyperbola ◽  
Carbon Dioxide Uptake ◽  
Good Agreement

The photosynthesis of two cultivars of wheat at three densities of sowing was measured during the growing season of 1968. When the data were plotted as carbon dioxide uptake versus leaf area index (LAI) (leaf laminae and green stem) for a fixed value of solar radiation, it was found that all of the data could be fitted by a single curve, irrespective of variety, sowing density, or time of season when the measurements were made. Since the curve was of continuously decreasing slope, the carbon dioxide uptake per unit LAI was highest for the low values of LAI and was reduced with the increased light interception at high LAI. For a solar radiation of 0.6 cal/cm2/min the approximate maximum net photosynthesis was 4.5 g CO2/m2/hr for an LAI of 6. A mathematical model for photosynthesis was found to give good prediction of carbon dioxide uptake versus solar radiation for most of the period of measurement. For each plot, a rectangular hyperbola was fitted to the data. When the parameters of the model were subsequently plotted as a function of LAI, then within a given variety, it was found that lines of common slope but differing intercepts could be drawn through the points for different sowing densities. From these fitted lines together with the measured values of LAI and respiration, carbon dioxide uptake was then predicted as a function of solar radiation by employing the rectangular hyperbola model. Good agreement between predicted and measured values of photosynthesis was obtained.

GLOBAL LEAF AREA INDEX DATA FROM FIELD MEASUREMENTS, 1932-2000

2001 ◽  
Author(s):  
G. P. ASNER ◽  
S. T. GOWER ◽  
J. M. O. SCURLOCK
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Field Measurements ◽  
Area Index ◽  
Index Data

Application of an Improved Method in Retrieving Leaf Area Index Combined Spectral Index with PLSR in Hyperspectral Data Generated by Unmanned Aerial Vehicle Snapshot Camera

2017 ◽  
Vol 43 (4) ◽  
pp. 549
Author(s):  
Lin GAO ◽  
Gui-Jun YANG ◽  
Chang-Chun LI ◽  
Hai-Kuan FENG ◽  
Bo XU ◽  
...  
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Unmanned Aerial Vehicle ◽  
Spectral Index ◽  
Hyperspectral Data ◽  
Improved Method ◽  
Area Index ◽  
Aerial Vehicle
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