Effects of Nitrogen Supply on Canopy Structure and Leaf Nitrogen Distribution in Carex Species

Ecology ◽  
1994 ◽  
Vol 75 (5) ◽  
pp. 1482-1490 ◽  
Author(s):  
Rien Aerts ◽  
Hannie de Caluwe
Keyword(s):  
Canopy Structure ◽  
Leaf Nitrogen ◽  
Nitrogen Supply ◽  
Nitrogen Distribution

Canopy structure and leaf nitrogen distribution in a stand of Lysimachia vulgaris L. as influenced by stand density

Oecologia ◽  
1988 ◽  
Vol 77 (2) ◽  
pp. 145-150 ◽  
Author(s):  
T. Hirose ◽  
M. J. A. Werger ◽  
T. L. Pons ◽  
J. W. A. van Rheenen
Keyword(s):  
Canopy Structure ◽  
Stand Density ◽  
Leaf Nitrogen ◽  
Nitrogen Distribution

Nitrogen distribution in young Norway spruce (Picea abies) trees as affected by pedospheric nitrogen supply

1997 ◽  
Vol 101 (4) ◽  
pp. 764-769 ◽  
Author(s):  
Heike Stoermer ◽  
Bettina Seith ◽  
Ulrike Hanemann ◽  
Eckhard George ◽  
Heinz Rennenberg
Keyword(s):  
Picea Abies ◽  
Norway Spruce ◽  
Nitrogen Supply ◽  
Nitrogen Distribution

scholarly journals Coupled carbon-water exchange of the Amazon rain forest, I. Model description, parameterization and sensitivity analysis

2005 ◽  
Vol 2 (2) ◽  
pp. 333-397 ◽  
Author(s):  
E. Simon ◽  
F. X. Meixner ◽  
L. Ganzeveld ◽  
J. Kesselmeier
Keyword(s):  
Stomatal Conductance ◽  
Leaf Area ◽  
Rain Forest ◽  
Canopy Structure ◽  
Leaf Nitrogen ◽  
Optical Parameters ◽  
Amazon Rain Forest ◽  
Leaf Level ◽  
Net Assimilation ◽  
Parameter Values

Abstract. Detailed one-dimensional multilayer biosphere-atmosphere models, also referred to as CANVEG models, are used for more than a decade to describe coupled water-carbon exchange between the terrestrial vegetation and the lower atmosphere. Within the present study, a modified CANVEG scheme is described. A generic parameterization and characterization of biophysical properties of Amazon rain forest canopies is inferred using available field measurements of canopy structure, in-canopy profiles of horizontal wind speed and radiation, canopy albedo, soil heat flux and soil respiration, photosynthetic capacity and leaf nitrogen as well as leaf level enclosure measurements made on sunlit and shaded branches of several Amazonian tree species during the wet and dry season. The sensitivity of calculated canopy energy and CO2 fluxes to the uncertainty of individual parameter values is assessed. In the companion paper, the predicted seasonal exchange of energy, CO2, ozone and isoprene is compared to observations. A bi-modal distribution of leaf area density with a total leaf area index of 6 is inferred from several observations in Amazonia. Predicted light attenuation within the canopy agrees reasonably well with observations made at different field sites. A comparison of predicted and observed canopy albedo shows a high model sensitivity to the leaf optical parameters for near-infrared short-wave radiation (NIR). The predictions agree much better with observations when the leaf reflectance and transmission coefficients for NIR are reduced by 25–40%. Available vertical distributions of photosynthetic capacity and leaf nitrogen concentration suggest a low but significant light acclimation of the rain forest canopy that scales nearly linearly with accumulated leaf area. Evaluation of the biochemical leaf model, using the enclosure measurements, showed that recommended parameter values describing the photosynthetic light response, have to be optimized. Otherwise, predicted net assimilation is overestimated by 30–50%. Two stomatal models have been tested, which apply a well established semi-empirical relationship between stomatal conductance and net assimilation. Both models differ in the way they describe the influence of humidity on stomatal response. However, they show a very similar performance within the range of observed environmental conditions. The agreement between predicted and observed stomatal conductance rates is reasonable. In general, the leaf level data suggests seasonal physiological changes, which can be reproduced reasonably well by assuming increased stomatal conductance rates during the wet season, and decreased assimilation rates during the dry season. The sensitivity of the predicted canopy fluxes of energy and CO2 to the parameterization of canopy structure, the leaf optical parameters, and the scaling of photosynthetic parameters is relatively low (1–12%), with respect to parameter uncertainty. In contrast, modifying leaf model parameters within their uncertainty range results in much larger changes of the predicted canopy net fluxes (5–35%).

Physiological Responses of Amaranthus Cruentus L. to Drought Stress Under Sufficient- and Deficient-Nitrogen Conditions

2021 ◽  
Author(s):  
Inês Cechin ◽  
Laura Prado da Silva ◽  
Elisa Teófilo Ferreira ◽  
Sarah Corrêa Barrochelo ◽  
Fernanda Pereira de Souza Rosa de Melo ◽  
...  
Keyword(s):  
Water Stress ◽  
Plant Growth ◽  
Photosynthetic Pigments ◽  
Dry Matter ◽  
Nitrogen Availability ◽  
Leaf Nitrogen ◽  
Nitrogen Supply ◽  
Plant Performance ◽  
In Planta ◽  
Phenolic Contents

Abstract Water and nitrogen availability are environmental factors that can impair plant growth, and when they are combined their effects can be intensified or reduced. The objective of this study was to analyse the influence of nitrogen availability on the responses of Amaranthus cruentus’s metabolisms to water stress. The plants were cultivated in plastic pots filled with vermiculite and kept under greenhouse conditions and were watered with 70% of full strength nitrogen-free Long Ashton solution, containing 1.97 or 9.88 kg N ha−1 as ammonium nitrate, three times a week. Photosynthetic parameter were evaluated in planta and leaves were harvested for chemical analysis of proline and phenolic contents. Higher nitrogen supply increased the shoot dry matter, photosynthetic pigments, photosynthesis, stomatal conductance, transpiration, total leaf nitrogen, proline, nitrate and ammonium but reduced the concentration of flavonoids and total phenols. Water stress for 6 days did not affect dry matter, photosynthetic pigments, leaf nitrogen, ammonium or specialized metabolites but increased the proline and affected negatively the other variables. The observed interactions between nitrogen and water supply resulted in no alleviation of the negative effects of drought on amaranth. Although the increase in nitrogen supply had benefits on plant performance, it intensified the negative effect of water stress. The study shows the importance of choosing the correct level of nitrogen fertilization in order to obtain satisfactory results in terms of plant growth under drought conditions.

scholarly journals Coupled carbon-water exchange of the Amazon rain forest, I. Model description, parameterization and sensitivity analysis

2005 ◽  
Vol 2 (3) ◽  
pp. 231-253 ◽  
Author(s):  
E. Simon ◽  
F. X. Meixner ◽  
L. Ganzeveld ◽  
J. Kesselmeier
Keyword(s):  
Stomatal Conductance ◽  
Leaf Area ◽  
Rain Forest ◽  
Canopy Structure ◽  
Leaf Nitrogen ◽  
Optical Parameters ◽  
Amazon Rain Forest ◽  
Leaf Level ◽  
Net Assimilation ◽  
Parameter Values

Abstract. Detailed one-dimensional multilayer biosphere-atmosphere models, also referred to as CANVEG models, are used for more than a decade to describe coupled water-carbon exchange between the terrestrial vegetation and the lower atmosphere. Within the present study, a modified CANVEG scheme is described. A generic parameterization and characterization of biophysical properties of Amazon rain forest canopies is inferred using available field measurements of canopy structure, in-canopy profiles of horizontal wind speed and radiation, canopy albedo, soil heat flux and soil respiration, photosynthetic capacity and leaf nitrogen as well as leaf level enclosure measurements made on sunlit and shaded branches of several Amazonian tree species during the wet and dry season. The sensitivity of calculated canopy energy and CO2 fluxes to the uncertainty of individual parameter values is assessed. In the companion paper, the predicted seasonal exchange of energy, CO2, ozone and isoprene is compared to observations. A bi-modal distribution of leaf area density with a total leaf area index of 6 is inferred from several observations in Amazonia. Predicted light attenuation within the canopy agrees reasonably well with observations made at different field sites. A comparison of predicted and observed canopy albedo shows a high model sensitivity to the leaf optical parameters for near-infrared short-wave radiation (NIR). The predictions agree much better with observations when the leaf reflectance and transmission coefficients for NIR are reduced by 25–40%. Available vertical distributions of photosynthetic capacity and leaf nitrogen concentration suggest a low but significant light acclimation of the rain forest canopy that scales nearly linearly with accumulated leaf area. Evaluation of the biochemical leaf model, using the enclosure measurements, showed that recommended parameter values describing the photosynthetic light response, have to be optimized. Otherwise, predicted net assimilation is overestimated by 30–50%. Two stomatal models have been tested, which apply a well established semi-empirical relationship between stomatal conductance and net assimilation. Both models differ in the way they describe the influence of humidity on stomatal response. However, they show a very similar performance within the range of observed environmental conditions. The agreement between predicted and observed stomatal conductance rates is reasonable. In general, the leaf level data suggests seasonal physiological changes, which can be reproduced reasonably well by assuming increased stomatal conductance rates during the wet season, and decreased assimilation rates during the dry season. The sensitivity of the predicted canopy fluxes of energy and CO2 to the parameterization of canopy structure, the leaf optical parameters, and the scaling of photosynthetic parameters is relatively low (1–12%), with respect to parameter uncertainty. In contrast, modifying leaf model parameters within their uncertainty range results in much larger changes of the predicted canopy net fluxes (5–35%).

The Optimal Allocation of Nitrogen Within the C3 Photosynthetic System at Elevated CO2

1996 ◽  
Vol 23 (5) ◽  
pp. 593 ◽  
Author(s):  
BE Medlyn
Keyword(s):  
Elevated Co2 ◽  
Optimal Allocation ◽  
Co2 Concentration ◽  
Leaf Nitrogen ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Nitrogen Distribution ◽  
Photosynthetic System ◽  
Light Regimes ◽  
Nitrogen Contents

The distribution of nitrogen among compounds involved in photosynthesis varies in response to changes in environmental conditions such as photon flux density. However, the extent to which the nitrogen distribution within leaves adjusts in response to increased atmospheric CO2 is unclear. A model was used to determine the nitrogen distribution which maximises photosynthesis under realistic light regimes at both current and elevated levels of CO2, and a comparison was made with observed leaf nitrogen distributions reported in the literature. The model accurately predicted the distribution of nitrogen within the photosynthetic system for leaves grown at current levels of CO2, except at very high leaf nitrogen contents. The model predicted that, under a doubling of CO2 concentration from its current level, the ratio of electron transport capacity to Rubisco activity (Jmax : Vcmax) should increase by 40%. In contrast, measurements of Jmax : Vcmax taken from the literature show a slight but non-significant increase in response to an increase in CO2. The discrepancy between predicted and observed Jmax : Vcmax suggests that leaf nitrogen distribution does not acclimate optimally to elevated CO2. Alternatively, the discrepancy may be due to effects of CO2 which the model fails to take into account, such as a possible decrease in the conductance to CO2 transfer between the intercellular spaces and the sites of carboxylation at elevated CO2.

scholarly journals A meta-analysis of leaf nitrogen distribution within plant canopies

2016 ◽  
Vol 118 (2) ◽  
pp. 239-247 ◽  
Author(s):  
Kouki Hikosaka ◽  
Niels P. R. Anten ◽  
Almaz Borjigidai ◽  
Chiho Kamiyama ◽  
Hidemitsu Sakai ◽  
...  
Keyword(s):  
Meta Analysis ◽  
Leaf Nitrogen ◽  
Nitrogen Distribution ◽  
Plant Canopies

Assessing the effects of subtropical forest fragmentation on leaf nitrogen distribution using remote sensing data

2013 ◽  
Vol 28 (8) ◽  
pp. 1479-1491 ◽  
Author(s):  
Moses Azong Cho ◽  
Abel Ramoelo ◽  
Pravesh Debba ◽  
Onisimo Mutanga ◽  
Renaud Mathieu ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Forest Fragmentation ◽  
Remote Sensing Data ◽  
Leaf Nitrogen ◽  
Subtropical Forest ◽  
Nitrogen Distribution ◽  
Sensing Data
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