DOI: 10.1016/j.jag.2015.03.016
Scopus记录号: 2-s2.0-84943620864
论文题名: Leaf chlorophyll constraint on model simulated gross primary productivity in agricultural systems
作者: Houborg R ; , McCabe M ; F ; , Cescatti A ; , Gitelson A ; A
刊名: International Journal of Applied Earth Observation and Geoinformation
ISSN: 15698432
出版年: 2015
卷: 43 起始页码: 160
结束页码: 176
语种: 英语
英文关键词: Agriculture
; Community Land Model
; Landsat
; Leaf chlorophyll content
; Leaf photosynthetic capacity
; Nitrogen
; Rubisco
; Vmax
Scopus关键词: agriculture
; chlorophyll
; Landsat
; nitrogen
; parameterization
; photosynthesis
; primary production
; remote sensing
; Glycine max
; Zea mays
英文摘要: Leaf chlorophyll content (Chll) may serve as an observational proxy for the maximum rate of carboxylation (Vmax), which describes leaf photosynthetic capacity and represents the single most important control on modeled leaf photosynthesis within most Terrestrial Biosphere Models (TBMs). The parameterization of Vmax is associated with great uncertainty as it can vary significantly between plants and in response to changes in leaf nitrogen (N) availability, plant phenology and environmental conditions. Houborg et al. (2013) outlined a semi-mechanistic relationship between Vmax 25 (Vmax normalized to 25 °C) and Chll based on inter-linkages between Vmax 25, Rubisco enzyme kinetics, N and Chll. Here, these relationships are parameterized for a wider range of important agricultural crops and embedded within the leaf photosynthesis-conductance scheme of the Community Land Model (CLM), bypassing the questionable use of temporally invariant and broadly defined plant functional type (PFT) specific Vmax 25 values. In this study, the new Chll constrained version of CLM is refined with an updated parameterization scheme for specific application to soybean and maize. The benefit of using in-situ measured and satellite retrieved Chll for constraining model simulations of Gross Primary Productivity (GPP) is evaluated over fields in central Nebraska, U.S.A between 2001 and 2005. Landsat-based Chll time-series records derived from the Regularized Canopy Reflectance model (REGFLEC) are used as forcing to the CLM. Validation of simulated GPP against 15 site-years of flux tower observations demonstrate the utility of Chll as a model constraint, with the coefficient of efficiency increasing from 0.91 to 0.94 and from 0.87 to 0.91 for maize and soybean, respectively. Model performances particularly improve during the late reproductive and senescence stage, where the largest temporal variations in Chll (averaging 35-55 μg cm-2 for maize and 20-35 μg cm-2 for soybean) are observed. While prolonged periods of vegetation stress did not occur over the studied fields, given the usefulness of Chll as an indicator of plant health, enhanced GPP predictabilities should be expected in fields exposed to longer periods of moisture and nutrient stress. While the results support the use of Chll as an observational proxy for Vmax25, future work needs to be directed towards improving the Chll retrieval accuracy from space observations and developing consistent and physically realistic modeling schemes that can be parameterized with acceptable accuracy over spatial and temporal domains. © 2015 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/79469
Appears in Collections: 气候变化事实与影响
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作者单位: Water Desalination and Reuse Center, Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Saudi Arabia; European Commission, Joint Research Centre, IES, Ispra, Italy; Center for Advanced Land Management Information Technology (CALMIT), School of Natural Resources, University of Nebraska-Lincoln, Lincoln, NE, United States
Recommended Citation:
Houborg R,, McCabe M,F,et al. Leaf chlorophyll constraint on model simulated gross primary productivity in agricultural systems[J]. International Journal of Applied Earth Observation and Geoinformation,2015-01-01,43