干旱区生态环境知识资源中心(Arid): First assessment of the plant phenology index (PPI) for estimating gross primary productivity in African semi-arid ecosystems

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DOI	10.1016/j.jag.2019.01.018
	First assessment of the plant phenology index (PPI) for estimating gross primary productivity in African semi-arid ecosystems
	Abdi, A. M.1,2; Boke-Olen, N.2; Jin, H.1; Eklundh, L.1; Tagesson, T.1; Lehsten, V 1,3; Ardo, J.1
通讯作者	Abdi, A. M.
来源期刊	INTERNATIONAL JOURNAL OF APPLIED EARTH OBSERVATION AND GEOINFORMATION
ISSN	0303-2434
出版年	2019
卷号	78 页码:249-260
英文摘要	The importance of semi-arid ecosystems in the global carbon cycle as sinks for CO2 emissions has recently been highlighted. Africa is a carbon sink and nearly half its area comprises and and semi-arid ecosystems. However, there are uncertainties regarding CO2 fluxes for semi-arid ecosystems in Africa, particularly savannas and dry tropical woodlands. In order to improve on existing remote-sensing based methods for estimating carbon uptake across semi-arid Africa we applied and tested the recently developed plant phenology index (PPD. We developed a PPI-based model estimating gross primary productivity (GPP) that accounts for canopy water stress, and compared it against three other Earth observation-based GPP models: the temperature and greenness (T-G) model, the greenness and radiation (GoR) model and a light use efficiency model (MOD17). The models were evaluated against in situ data from four semi-arid sites in Africa with varying tree canopy cover (3-65%). Evaluation results from the four GPP models showed reasonable agreement with in situ GPP measured from eddy covariance fltut towers (EC GPP) based on coefficient of variation (R-2), root-mean-square error (RMSE), and Bayesian information criterion (BIC). The Gott model produced R-2 = 0.73, RMSE = 1.45 g C m(-2) d(-1), and BIC = 678; the T-G model produced R-2 = 0.68, RMSE = 1.57 g C m(-2) d(-1), and BIC = 707; the MOD17 model produced R-2 = 0.49, RMSE = 1.98 g C and BIC = 800. The PPI-based GPP model was able to capture the magnitude of EC GPP better than the other tested models (R-2 = 0.77, RMSE = 1.32 g C Mm(-2) d(-1), and BIC = 631). These results show that a PPI-based GPP model is a promising tool for the estimation of GPP in the semi-arid ecosystems of Africa.
英文关键词	Plant phenology index PPI Gross primary productivity GPP Land surface temperature LST Vapor pressure deficit VPD Drylands Semi-arid FLUXNET Eddy covariance MODIS
类型	Article
语种	英语
国家	Sweden ; Switzerland
开放获取类型	Green Accepted, Green Submitted
收录类别	SCI-E
WOS记录号	WOS:000463131700022
WOS关键词	LAND-SURFACE TEMPERATURE ; TERRESTRIAL GROSS ; VEGETATION INDEX ; CHLOROPHYLL CONTENT ; REMOTE ESTIMATION ; EXCHANGE FLUXES ; CLIMATE-CHANGE ; CARBON FLUXES ; MODIS ; SAVANNA
WOS类目	Remote Sensing
WOS研究方向	Remote Sensing
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/216343
作者单位	1.Lund Univ, Dept Phys Geog & Ecosyst Sci, Solvegatan 12, SE-22362 Lund, Sweden; 2.Lund Univ, Ctr Environm & Climate Res, Solvegatan 37, SE-22362 Lund, Sweden; 3.Swiss Fed Inst Forest Snow & Landscape Res WSL, Zurcherstr 11, CH-8903 Birmensdorf, Switzerland
推荐引用方式 GB/T 7714	Abdi, A. M.,Boke-Olen, N.,Jin, H.,et al. First assessment of the plant phenology index (PPI) for estimating gross primary productivity in African semi-arid ecosystems[J],2019,78:249-260.
APA	Abdi, A. M..,Boke-Olen, N..,Jin, H..,Eklundh, L..,Tagesson, T..,...&Ardo, J..(2019).First assessment of the plant phenology index (PPI) for estimating gross primary productivity in African semi-arid ecosystems.INTERNATIONAL JOURNAL OF APPLIED EARTH OBSERVATION AND GEOINFORMATION,78,249-260.
MLA	Abdi, A. M.,et al."First assessment of the plant phenology index (PPI) for estimating gross primary productivity in African semi-arid ecosystems".INTERNATIONAL JOURNAL OF APPLIED EARTH OBSERVATION AND GEOINFORMATION 78(2019):249-260.