PARAMETER ANALYSIS AND SCALING OF PLANT ROOT HYDRAULIC REDISTRIBUTION MODEL

doi:10.17521/cjpe.2006.0124

Abstract

Abstract:

Background and Aims Hydraulic redistribution (HR) is an extension of hydraulic lift. The simulation of hydraulic redistribution done by Ryel et al. (2002) indicated that HR is beneficial for transpiration.

Methods Based on the Ryel Model, we first conducted a sensitivity analysis by varying critical parameters of the model. We scaled the model for time steps of 1 hour to 1 day and soil from 10 cm to greater thicknesses by adjusting the necessary parameters. The scaled model was then applied to field observations of Caragana intermedia in Huangfuchuan Watershed of Inner Mongolia to simulate transpiration with and without HR. Daily changes in transpiration were simulated from April to October in 1998 and 1999.

Key Results and Conclusions The ratio of water redistributed by root to transpiration was strongly negative to soil hydraulic conductivity. The ratio also increased when root hydraulic conductivity increased, but gradually approached a limit. Total transpiration with HR increased when root hydraulic conductivity increased <1 cm·MPa ^-1·h^-1 and decreased when it increased >1 cm·MPa ^-1·h^-1. The result of the scaling indicates that it provides a useful approach to incorporating HR into larger models of soil processes. Total transpiration with HR increased 4.4% more than without HR in 1998, in contrast to total transpiration without HR having increased 2.1% more than with HR. This may be related to high precipitation in 1998.

Key words: Hydraulic redistribution, Transpiration, Root distribution, Scaling

WANG Kun, LIU Ying-Hui, GAO Qiong, MO Xing-Guo. PARAMETER ANALYSIS AND SCALING OF PLANT ROOT HYDRAULIC REDISTRIBUTION MODEL[J]. Chin J Plant Ecol, 2006, 30(6): 969-975.

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URL: https://www.plant-ecology.com/EN/10.17521/cjpe.2006.0124

https://www.plant-ecology.com/EN/Y2006/V30/I6/969

Figures/Tables 8

References 22

[1]	Brooks JR, Meinzer FC, Warren JM, Domec JC, Coulombe R (2006). Hydraulic redistribution in a Douglas-fir forest: lessons from system manipulations. Plant, Cell and Environment, 29,138-150. DOI URL PMID
[2]	Caldwell MM, Dawson TE, Richards JH (1998). Hydraulic lift: consequences of water efflux from the roots of plants. Oecologia, 113,151-161. URL PMID
[3]	Caldwell MM, Richards JH (1989). Hydraulic lift water efflux from upper roots improves effectiveness of water uptake by deep roots. Oecologia, 79,1-5. DOI URL PMID
[4]	Dawson TE (1993). Hydraulic lift and water use by plants: implications for water balance, performace and plant-plant interactions. Oecologia, 95,565-574. DOI URL PMID
[5]	Fan XL(樊小林), Shi WG(石卫国), Cao XH(曹新华) (1995). Hydraulic lift and its effect on soil water potential and nutrient availability. Ⅰ. Hydraulic lift of millet and the effect of HL and root absorption on soil water content. Journal of Soil and Water Conservation (水土保持学报), 9(4),36-42. (in Chinese with English abstract)
[6]	Fan XL(樊小林), Cao XH(曹新华), Guo LB(郭立斌), Qin FL(秦芳玲) (1996). Hydraulic lift and its effect on soil water potential and nutrient availability. Ⅱ. Effect of the interaction of soil water and nutrient and hydraulic lift on the plant growth. Journal of Soil Erosion and Soil and Water Conservation (土壤侵蚀与水土保持学报), 2(4),71-76. (in Chinese with English abstract)
[7]	Gao QZ(高清竹) (2003). Land Use Security Pattern for Farming-Pastoral Zone of North China, a Case Study at Changchuan Watershed(农牧交错带长川流域土地利用安全格局研究). PhD dissertation, Beijing Normal University, Beijing,19-51. (in Chinese with English abstract)
[8]	Han WX(韩文轩), Fang JY(方精云) (2003). Allometry and its application in ecological scaling. Acta Scientiarum Naturalium Universitatis Pekinensis (北京大学学报(自然科学版)), 39,583-593. (in Chinese with English abstract)
[9]	Horton JL, Hart SC (1998). Hydraulic lift—a potentially important ecosystem process. Trends in Ecology and Evolution, 13,232-235. URL PMID
[10]	Jia HK(贾海坤), Liu YH(刘颖慧), Xu X(徐霞), Wang K(王昆), Gao Q(高琼) (2005). Intermedia woodland in Huangfuchuan watershed: relationships among slope, aspect, plant density and soil water content. Acta Phytoecologica Sinica(植物生态学报), 29,910-917. (in Chinese with English abstract)
[11]	King AW (1990). Translating models across scales in the landscape. In: Turner MG, Gardner RH eds. Quantitative Methods in Landscape Ecology, Ecological Studies. Springer, New York, 82,479-517.
[12]	Lee JE, Oliveira RS, Dawson TE, Fung I (2005). Root functioning modifies seasonal climate. Proceedings of National Academy of Sciences of the United States of America, 102,17576-17581.
[13]	Leffler AJ, Peek MS, Ryel RJ, Ivans CY, Caldwell MM (2005). Hydraulic redistribution through the root systems of senesced plants. Ecology, 86,633-642.
[14]	Lü YH(吕一河), Fu BJ(傅伯杰) (2001). Ecological scale and scaling. Acta Ecologia Sinica(生态学报), 21,2096-2105. (in Chinese with English abstract)
[15]	Meinzer FC, Brooks JR, Bucci S, Goldstein G, Scholz FG, Warren JM (2004). Converging patterns of uptake and hydraulic redistribution of soil water in contrasting woody vegetation types. Tree Physiology, 24,919-928. URL PMID
[16]	Richards JH, Caldwell MM (1987). Hydraulic lift: substantial nocturnal water transport between soil layers by Artemisia tridentata roots. Oecologia, 73,486-489. DOI URL PMID
[17]	Ryel RJ, Caldwell MM, Yoder CK, Or D, Leffler AJ (2002). Hydraulic redistribution in a stand of Artemisia tridentata: evaluation of benefits to transpiration assessed with a simulation model. Oecologia, 130,173-184. URL PMID
[18]	Schulze ED, Caldwell MM, Canadell J, Mooney HA, Jackson RB, Parson D, Scholes R, Sala OE, Trimborn P (1998). Downward flux of water through roots (i.e. inverse hydraulic lift)in dry Kalahari sands. Oecologia, 115,460-462. DOI URL PMID
[19]	Smart DR, Carlisle E, Goebel M, Nú†en BA (2005). Transverse hydraulic redistribution by a grapevine. Plant, Cell and Environment, 28,157-166.
[20]	van Genuchten MT (1980). A closed-form equation for predicting the hydraulic conductivity of unsaturated soil. Soil Science Society of America Journal, 44,892-898.
[21]	Yang J(杨吉力), Gao QZ(高清竹), Li GQ(李国强), He LH(何立环), Jin ZP(金争平), Wang ZW(王正文) (2002). A study on the water ecology of dominant artificial shrubs in Huangfuchuan watershed. Journal of Natural Resources (自然资源学报), 17,87-94. (in Chinese with English abstract)
[22]	Zou CB, Barnes PW, Archer S, McMurtry CR (2005). Soil moisture redistribution as a mechanism of facilitation in savanna tree-shrub clusters. Oecologia, 145,32-40. DOI URL PMID

参数名称 Parameters	符号 Symbol	数值 Value	单位 Unit
饱和容积含水量 Volumetric soil water content at saturation	θ_s	0.5	cm³·cm^-3
剩余容积含水量 Residual volumetric soil water content	θ_r	0.02	cm³·cm^-3
土壤饱和导水率 Soil hydraulic conductivity	K_s	0.247	cm·h^-1
全部活跃根系的最大径向导度 Root conductivity for water for all roots	C_RT	0.097	cm·MPa^-1·h^-1
根系导度降至50%时的土壤水势 Soil ψ/water potential where root conductivity reduced by 50%	ψ₅₀	-1.0	MPa
最大蒸腾速率 Maximum transpiration rate	E_RT_,max	1	cm·d^-1
形状指数 Shaping parameter	b	3.22
土壤水分特征曲线拟合参数 Fitting parameter for soil water retention curve	a	0.001 851	cm^-1
土壤水分特征曲线拟合参数 Fitting parameter for soil water retention curve	n	1.429 2

参数名称 Parameters	符号 Symbol	数值 Value	单位 Unit
饱和容积含水量 Volumetric soil water content at saturation	θ_s	0.5	cm³·cm^-3
剩余容积含水量 Residual volumetric soil water content	θ_r	0.02	cm³·cm^-3
土壤饱和导水率 Soil hydraulic conductivity	K_s	0.247	cm·h^-1
全部活跃根系的最大径向导度 Root conductivity for water for all roots	C_RT	0.097	cm·MPa^-1·h^-1
根系导度降至50%时的土壤水势 Soil ψ/water potential where root conductivity reduced by 50%	ψ₅₀	-1.0	MPa
最大蒸腾速率 Maximum transpiration rate	E_RT_,max	1	cm·d^-1
形状指数 Shaping parameter	b	3.22
土壤水分特征曲线拟合参数 Fitting parameter for soil water retention curve	a	0.001 851	cm^-1
土壤水分特征曲线拟合参数 Fitting parameter for soil water retention curve	n	1.429 2

参数名称 Parameters	原模型 Model	尺度转换后 Scaling
饱和水分导度 Soil hydraulic conductivity	0.247 cm·h^-1	0.247×24 cm·h^-1
根系的最大水分导度 Root conductivity for water for all roots	0.097 cm·MPa^-1·h^-1	0.097×24 cm·MPa^-1·h^-1
最大蒸腾速率 Maximum transpiration rate	1/24 cm·d^-1	1 cm·d^-1
根系水力再分配调节系数 Multiplier for day (1) or night (0)	1(10 h)~0(14 h)	10/24

参数名称 Parameters	原模型 Model	尺度转换后 Scaling
饱和水分导度 Soil hydraulic conductivity	0.247 cm·h^-1	0.247×24 cm·h^-1
根系的最大水分导度 Root conductivity for water for all roots	0.097 cm·MPa^-1·h^-1	0.097×24 cm·MPa^-1·h^-1
最大蒸腾速率 Maximum transpiration rate	1/24 cm·d^-1	1 cm·d^-1
根系水力再分配调节系数 Multiplier for day (1) or night (0)	1(10 h)~0(14 h)	10/24