Predicting the Photosynthetic Capacity and Leaf Nitrogen of Woody Bioenergy Crops from Hyperspectral Reflectance Models

2021 ◽  
Author(s):  
Thu Ya Kyaw ◽  
Heidi Renninger ◽  
Courtney Siegert ◽  
Padmanava Dash ◽  
Krishna Poudel
Keyword(s):  
Photosynthetic Capacity ◽  
Leaf Nitrogen ◽  
Bioenergy Crops ◽  
Hyperspectral Reflectance

scholarly journals Leaf Photosynthetic Capacity of Sunlit and Shaded Mature Leaves in a Deciduous Forest

Forests ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 318
Author(s):  
Guangman Song ◽  
Quan Wang ◽  
Jia Jin
Keyword(s):  
Close Relationships ◽  
Deciduous Forest ◽  
Photosynthetic Capacity ◽  
Leaf Gas Exchange ◽  
Nitrogen Concentration ◽  
Leaf Traits ◽  
Leaf Nitrogen ◽  
Leaf Mass Per Area ◽  
Clear Understanding ◽  
Equivalent Water Thickness

A clear understanding of the dynamics of photosynthetic capacity is crucial for accurate modeling of ecosystem carbon uptake. However, such dynamical information is hardly available and has dramatically impeded our understanding of carbon cycles. Although tremendous efforts have been made in coupling the dynamic information of photosynthetic capacity into models, using “proxies” rooted from the close relationships between photosynthetic capacity and other available leaf parameters remains the popular selection. Unfortunately, no consensus has yet been reached on such “proxies”, leading them only applicable to limited cases. In this study, we aim to identify if there are close relationships between the photosynthetic capacity (represented by the maximum carboxylation rate, Vcmax) and leaf traits for mature broadleaves within a cold temperature deciduous forest. This is based on a long-term in situ dataset including leaf chlorophyll content (Chl), leaf nitrogen concentration (Narea, Nmass), leaf carbon concentration (Carea, Cmass), equivalent water thickness (EWT), leaf mass per area (LMA), and leaf gas exchange measurements from which Vcmax was derived, for both sunlit and shaded leaves during leaf mature periods from 2014 to 2019. The results show that the Vcmax values of sunlit and shaded leaves were relatively stable during these periods, and no statistically significant interannual variations occurred (p > 0.05). However, this is not applicable to specific species. Path analysis revealed that Narea was the major contributor to Vcmax for sunlit leaves (0.502), while LMA had the greatest direct relationship with Vcmax for shaded leaves (0.625). The LMA has further been confirmed as a primary proxy if no leaf type information is available. These findings provide a promising way to better understand photosynthesis and to predict carbon and water cycles in temperate deciduous forests.

Effect of leaf nitrogen and water regime on the photosynthetic capacity of kenaf (Hibiscus cannabinus L.) under field conditions

1990 ◽  
Vol 41 (5) ◽  
pp. 845 ◽  
Author(s):  
RC Muchow
Keyword(s):  
Water Deficit ◽  
Photosynthetic Capacity ◽  
N Uptake ◽  
Quantitative Information ◽  
Leaf Nitrogen ◽  
Hibiscus Cannabinus ◽  
High Rate ◽  
N Application ◽  
Area Index ◽  
The Relationship

To understand the influence of nitrogen (N) supply on the productivity of kenaf (Hibiscus cannabinus L.), the dependence of photosynthetic capacity, measured as light-saturated leaf CO2 assimilation rate (CA) and crop radiation use efficiency (RUE), on specific leaf nitrogen (SLN) was examined under well-watered conditions in the field. Photosynthetic capacity increased hyperbolically with SLN and was most responsive at SLN values less than c. 1.5 g m-2. The relationship reached a plateau at a maximum CA of 37 8mol m-2 s-1 and a maximum RUE of 1.5 g MJ-1 Increasing N application from 0 to 24 g N m-2 increased both RUE and SLN. Where ample N was applied, RUE and SLN were higher in those plots which previously experienced water deficit than in those that were always fully irrigated. The stimulation in growth following alleviation of water deficit was directly associated with the increase in SLN during water deficit. SLN varied according to differences in N uptake, the proportion of N allocated to leaves and the leaf area index. In particular, N application had much less effect on SLN and consequently RUE, than on N uptake, due to lower N partitioning to leaves and higher LAI where a high rate of N was applied. The importance of quantitative information on the relationship between photosynthetic capacity and SLN, in order to predict crop performance under varying environmental conditions, is discussed.

scholarly journals Genetic variation for photosynthetic capacity and efficiency in spring wheat

2019 ◽  
Vol 71 (7) ◽  
pp. 2299-2311 ◽  
Author(s):  
Viridiana Silva-Pérez ◽  
Joanne De Faveri ◽  
Gemma Molero ◽  
David M Deery ◽  
Anthony G Condon ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Stomatal Conductance ◽  
Photosynthetic Capacity ◽  
Genotypic Variation ◽  
Genotypic Diversity ◽  
Dry Mass ◽  
Co2 Assimilation ◽  
Leaf Nitrogen ◽  
Yield Potential

Abstract One way to increase yield potential in wheat is screening for natural variation in photosynthesis. This study uses measured and modelled physiological parameters to explore genotypic diversity in photosynthetic capacity (Pc, Rubisco carboxylation capacity per unit leaf area at 25 °C) and efficiency (Peff, Pc per unit of leaf nitrogen) in wheat in relation to fertilizer, plant stage, and environment. Four experiments (Aus1, Aus2, Aus3, and Mex1) were carried out with diverse wheat collections to investigate genetic variation for Rubisco capacity (Vcmax25), electron transport rate (J), CO2 assimilation rate, stomatal conductance, and complementary plant functional traits: leaf nitrogen, leaf dry mass per unit area, and SPAD. Genotypes for Aus1 and Aus2 were grown in the glasshouse with two fertilizer levels. Genotypes for Aus3 and Mex1 experiments were grown in the field in Australia and Mexico, respectively. Results showed that Vcmax25 derived from gas exchange measurements is a robust parameter that does not depend on stomatal conductance and was positively correlated with Rubisco content measured in vitro. There was significant genotypic variation in most of the experiments for Pc and Peff. Heritability of Pc reached 0.7 and 0.9 for SPAD. Genotypic variation and heritability of traits show that there is scope for these traits to be used in pre-breeding programmes to improve photosynthesis with the ultimate objective of raising yield potential.

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