Revised algorithm of ecosystem water use efficiency for semi-arid steppe in the Loess Plateau of China

doi:10.17521/cjpe.2016.0378

Abstract

Abstract:

Aims We evaluated the applicability of different measures of water use efficiency through analyzing the coupled dynamics of GPP and evapotranspiration in the semi-arid steppe in the Loess Plateau of China. Our objective is to explore the applicability of two quantitative measures of ecosystem water use efficiency—inherent water use efficiency (IWUE) and underlying water use efficiency (uWUE) —for the semi-arid steppe and to endeavor necessary modifications.Methods The consistency and stability of three indices of water use efficiency formulations (i.e. WUE, IWUE, uWUE) were calculated and compared at hourly, daily and annual time scales before proposing an optimal water use efficiency (oWUE). These indices were additionally used to quantify their importances in modeling the diel change of gross primary production (GPP). The yielded-accuracy of the prediction was used for justifying their uses.Important findings IWUE and uWUE appeared suitable for examining the coupled water-carbon characteristics of vegetation at hourly and daily scales, whereas WUE was more plausible on the annual and interannual scales. The optimized water use efficiency index did not improve the prediction of the coupled water-carbon characteristics as compared with uWUE, but it improved the prediction of GPP and its dynamics. oWUE and uWUE improved the predictions of GPP in the peak growing period, while WUE predicted the GPP better at the early and late growing season. Interestingly, we found that IWUE was not suitable for predicting GPP and its dynamics. The results will be of great importance in modeling the effects of climate change on the carbon assimilation and water cycle for the future.

http://jtp.cnki.net/bilingual/detail/html/ZWSB201705001

Key words: water use efficiency, inherent water use efficiency, underlying water use efficiency, optimal water use efficiency, predicted gross primary production

Xiao LIU, Chao QI, Yi-Lan YAN, Guo-Fu YUAN. Revised algorithm of ecosystem water use efficiency for semi-arid steppe in the Loess Plateau of China[J]. Chin J Plant Ecol, 2017, 41(5): 497-505.

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URL: https://www.plant-ecology.com/EN/10.17521/cjpe.2016.0378

https://www.plant-ecology.com/EN/Y2017/V41/I5/497

Figures/Tables 7

References 22

[1]	Baldocchi D (1994). A comparative study of mass and energy exchange rates over a closed C3 (wheat) and an open C4 (corn) crop: II. CO2 exchange and water use efficiency.Agricultural and Forest Meteorology, 67(3-4), 291-321.
[2]	Battipaglia G, Saurer M, Cherubini P, Calfapietra C, McCarthy HR, Norby RJ, Cotrufo MF (2013). Elevated CO2 increases tree-level intrinsic water use efficiency: Insights from carbon and oxygen isotope analyses in tree rings across three forest FACE sites.The New Phytologist, 197, 544-554.
[3]	Beer C, Ciais P, Reichstein M, Baldocchi D, Law BE, Papale D, Soussana JF, Ammann C, Buchmann N, Frank D, Gianelle D, Janssens IA, Knohl A, Kostner B, Moors E, Roupsard O, Verbeeck H, Vesala T, Williams CA, Wohlfahrt G (2009). Temporal and among-site variability of inherent water use efficiency at the ecosystem level. Global Biogeochemical Cycles, 23, GB2018. doi: 10.1029/ 2008GB003233.
[4]	Beer C, Reichstein M, Ciais P, Farquhar GD, Papale D (2007). Mean annualGPP of Europe derived from its water balance. Geophysical Research Letters, 34, L05401, doi:10.1029/2006GL029006, 2007.
[5]	Farquhar G (1977). Stomatal function in relation to leaf metabolism and environment: Stomatal function in the regulation of gas exchange.Symposia of the Society for Experimental Biology, 31, 471-505.
[6]	Grossiord C, Gessler A, Granier A, Pollastrini M, Bussotti F, Bonal D (2014). Interspecific competition influences the response of oak transpiration to increasing drought stress in a mixed Mediterranean forest.Forest Ecology and Management, 318, 54-61.
[7]	Hu ZM, Yu GR, Wang QF, Zhao FH (2009). Ecosystem level water use efficiency: A review.Acta Ecologica Sinica, 29, 1498-1507. (in Chinese with English abstract)[胡中民, 于贵瑞, 王秋凤, 赵风华 (2009). 生态系统水分利用效率研究进展. 生态学报, 29, 1498-1507.]
[8]	Keenan TF, Hollinger DY, Bohrer G, Dragoni D, Munger JW, Schmid HP, Richardson AD (2013). Increase in forest water-use efficiency as atmospheric carbon dioxide concentrations rise.Nature, 499, 324-327.
[9]	Legates DR, McCabe GJ (1999). Evaluating the use of “goodness-of-fit” measures in hydrologic and hydroclimatic model validation.Water Resources Research, 35, 233-241.
[10]	Leonardi S, Gentilesca T, Guerrieri R, Ripullone F, Magnani F, Mencuccini M, Noije TV, Borghetti M (2012). Assessing the effects of nitrogen deposition and climate on carbon isotope discrimination and intrinsic water-use efficiency of angiosperm and conifer trees under rising CO2 conditions.Global Chang Biology, 18, 2925-2944.
[11]	Niu SL, Xing XR, Zhang Z, Xia JY, Zhou XH, Song B, Li LH, Wan SQ (2011). Water-use efficiency in response to climate change: From leaf to ecosystem in a temperate steppe.Global Change Biology, 17, 1073-1082.
[12]	Priestley GHB, Taylor RJ (1972). On the assessment of surface heat flux and evaporation using large-scale parameters.Monthly Weather Review, 100, 81-92.
[13]	Scanlon TM, Albertson JD (2004). Canopy scale measurements of CO2 and water vapor exchange along a precipitation gradient in southern Africa.Global Change Biology, 10, 329-341.
[14]	Singh JS, Gupta SR (1977). Plant decomposition and soil respiration in terrestrial ecosystems.Botanical Review, 43, 499-528.
[15]	Wang SG, He GJ, Liu DS, Wang XQ (2008). Advances in carbon cycle model of forest ecosystem.Science & Technology Review, 26(9), 72-77. (in Chinese with English abstract)[王绍刚, 何国金, 刘定生, 汪小钦 (2008). 森林碳循环模型方法研究进展. 科技导报, 26(9), 72-77.]
[16]	Wohlfahrt G, Haslwanter A, Hortnagl L, Jasoni RL, Fenstermaker LF, Arnone JA, Hammerle A (2009). On the consequences of the energy imbalance for calculating surface conductance to water vapour.Agricultural and Forest Meteorology, 149, 1556-1559.
[17]	Yang YT, Long D, Shang SH (2013). Remote estimation of terrestrial evapotranspiration without using meteorological data.Geophysical Research Letters, 40, 3026-3030.
[18]	Yu GR, Wang QF et al.(2010). Ecophysiology of Plant Photosynthesis,Transpiration, and Water Use. Science Press, Beijing. (in Chinese)[于贵瑞, 王秋凤等 (2010). 植物光合、蒸腾与水分利用的生理生态学 . 科学出版社, 北京.]
[19]	Zhang LX, Hu ZM, Fan JW, Shao QQ, Tang FP (2014). Advances in the spatiotemporal dynamics in ecosystem water use efficiency at regional scale.Advances in Earth Science, 29, 691-699. (in Chinese with English abstract)[张良侠, 胡中民, 樊江文, 邵全琴, 唐风沛 (2014). 区域尺度生态系统水分利用效率的时空变异特征研究进展. 地球科学进展, 29, 691-699.]
[20]	Zhao C, Yuan GF, Liu X, Shao MA, Yi XB (2015). Application of cosmic-ray method to soil moisture measurement of grassland in the Loess Plateau.Acta Pedologica Sinica, 52, 1438-1444. (in Chinese with English abstract)[赵纯, 袁国富, 刘晓, 邵明安, 易小波 (2015). 宇宙射线土壤水分观测方法在黄土高原草地植被的应用. 土壤学报, 52, 1438-1444.]
[21]	Zhou S, Yu B, Huang Y, Wang G (2014). The effect of vapor pressure deficit on water use efficiency at the subdaily time scale.Geophysical Research Letters, 41, 5005-5013.
[22]	Zhou S, Yu B, Huang Y, Wang G (2015). Daily underlying water use efficiency for AmeriFlux sites.Journal of Geophysical Research Biogeosciences, 120, 887-902.

类型 Type	符号 Symbol	代号 Code	表达式 Formulation	单位 Unit
水分利用效率 Water use efficiency	WUE	WUE₀	GPP/ET	g ·kg^-1
内在水分利用效率 Inherent water use efficiency	IWUE	WUE_1.0	GPP × VPD /ET	g hPa·kg^-1
固有水分利用效率 Underlying water use efficiency	uWUE	WUE_0.5	GPP × VPD^0.5/ET	g hPa^0.5·kg^-1
优化水分利用效率 Optimal water use efficiency	oWUE	WUE_k*	GPP × VPD^k^*/ET	g hPa^k^*·kg^-1

类型 Type	符号 Symbol	代号 Code	表达式 Formulation	单位 Unit
水分利用效率 Water use efficiency	WUE	WUE₀	GPP/ET	g ·kg^-1
内在水分利用效率 Inherent water use efficiency	IWUE	WUE_1.0	GPP × VPD /ET	g hPa·kg^-1
固有水分利用效率 Underlying water use efficiency	uWUE	WUE_0.5	GPP × VPD^0.5/ET	g hPa^0.5·kg^-1
优化水分利用效率 Optimal water use efficiency	oWUE	WUE_k*	GPP × VPD^k^*/ET	g hPa^k^*·kg^-1

时间尺度 Time scales	水分利用效率 WUE	内在水分利用效率 IWUE	固有水分利用效率 uWUE
小时尺度 Hourly time scales
日尺度 Daily time scales
年尺度 Yearly time scales

时间尺度 Time scales	水分利用效率 WUE	内在水分利用效率 IWUE	固有水分利用效率 uWUE
小时尺度 Hourly time scales
日尺度 Daily time scales
年尺度 Yearly time scales

年份 Year	水分利用效率 WUE				内在水分利用效率 IWUE				固有水分利用效率 uWUE
年份 Year	相关系数 r	变异系数 Cv	日平均值 Mean daily value	年值 Yearly value	相关系数 r	变异系数 Cv	日平均值 Mean daily value	年值 Yearly value	相关系数 r	变异系数 Cv	日平均值 Mean daily value	年值 Yearly value
2014	0.70	0.40	1.655 5	1.523 5	0.81	0.54	20.534 4	23.639 5	0.83	0.38	5.563 9	5.829 7
2015	0.55	0.33	1.134 4	1.075 7	0.81	0.42	16.993 5	18.173 0	0.83	0.30	4.274 9	4.327 4
2016	0.38	0.41	1.177 5	1.097 0	0.77	0.63	8.763 6	10.264 1	0.84	0.38	2.943 6	3.137 0