1 Shapotou Desert Research and Experimental Station, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China; 2 Key Laboratory of Stress Physiology and Ecology in Cold and Arid Regions of Gansu Province, Lanzhou 730000, China; 3 Texas A&M AgriLife Research and Extension Center at Uvalde, Uvalde TX 78801, USA
Topographic differentiations of biological soil crusts and hydraulic properties in fixed sand dunes, Tengger Desert
1 Shapotou Desert Research and Experimental Station, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China; 2 Key Laboratory of Stress Physiology and Ecology in Cold and Arid Regions of Gansu Province, Lanzhou 730000, China; 3 Texas A&M AgriLife Research and Extension Center at Uvalde, Uvalde TX 78801, USA
摘要 Biological soil crusts (BSCs) play an important role in surface soil hydrology. Soils dominated with moss BSCs may have higher infiltration rates than those dominated with cyanobacteria or algal BSCs. However, it is not known whether improved infiltration in moss BSCs is accompanied by an increase in soil hydraulic conductivity or water retention capacity. We investigated this question in the Tengger Desert, where a 43-year-old revegetation program has promoted the formation of two distinct types of BSCs along topographic positions, i.e. the moss-dominated BSCs on the interdune land and windward slope of the fixed sand dunes, and the algal-dominated BSCs on the crest and leeward slopes. Soil water retention capacity and hydraulic conductivity were measured using an indoor evaporation method and a field infiltration method. And the results were fitted to the van Genuchten–Mualem model. Unsaturated hydraulic conductivities under greater pressure (<–0.01 MPa) and water retention capacities in the entire pressure head range were higher for both crust types than for bare sand. However, saturated and unsaturated hydraulic conductivities in the near-saturation range (>–0.01 MPa) showed decreasing trends from bare sand to moss crusts and to algal crusts. Our data suggested that topographic differentiation of BSCs significantly affected not only soil water retention and hydraulic conductivities, but also the overall hydrology of the fixed sand dunes at a landscape scale, as seen in the reduction and spatial variability in deep soil water storage.
Abstract: Biological soil crusts (BSCs) play an important role in surface soil hydrology. Soils dominated with moss BSCs may have higher infiltration rates than those dominated with cyanobacteria or algal BSCs. However, it is not known whether improved infiltration in moss BSCs is accompanied by an increase in soil hydraulic conductivity or water retention capacity. We investigated this question in the Tengger Desert, where a 43-year-old revegetation program has promoted the formation of two distinct types of BSCs along topographic positions, i.e. the moss-dominated BSCs on the interdune land and windward slope of the fixed sand dunes, and the algal-dominated BSCs on the crest and leeward slopes. Soil water retention capacity and hydraulic conductivity were measured using an indoor evaporation method and a field infiltration method. And the results were fitted to the van Genuchten–Mualem model. Unsaturated hydraulic conductivities under greater pressure (<–0.01 MPa) and water retention capacities in the entire pressure head range were higher for both crust types than for bare sand. However, saturated and unsaturated hydraulic conductivities in the near-saturation range (>–0.01 MPa) showed decreasing trends from bare sand to moss crusts and to algal crusts. Our data suggested that topographic differentiation of BSCs significantly affected not only soil water retention and hydraulic conductivities, but also the overall hydrology of the fixed sand dunes at a landscape scale, as seen in the reduction and spatial variability in deep soil water storage.
This research was funded by the National Basic Research Pro-gram of China (2013CB429901), the National Natural Sciences Foundation of China (41471434, 31170385) and the Foundation for Excellent Youth Scholars of CAREERI, Chinese Academy of Sciences.
通讯作者:
ZhiShan ZHANG
E-mail: zszhang@lzb.ac.cn
引用本文:
ZhiShan ZHANG, YongLe CHEN, BinXing XU, Lei HUANG, HuiJuan TAN, XueJun DONG. Topographic differentiations of biological soil crusts and hydraulic properties in fixed sand dunes, Tengger Desert[J]. 干旱区科学, 2015, 7(2): 205-215.
ZhiShan ZHANG, YongLe CHEN, BinXing XU, Lei HUANG, HuiJuan TAN, XueJun DONG. Topographic differentiations of biological soil crusts and hydraulic properties in fixed sand dunes, Tengger Desert. Journal of Arid Land, 2015, 7(2): 205-215.
Almog R, Yair A. 2007. Negative and positive effects of topsoil biological crusts on water availability along a rainfall gradient in a sandy arid area. Catena, 70: 437–442.Belnap J. 2006. The potential roles of biological soil crusts in dryland hydrologic cycles. Hydrological Processes, 20: 3159–3178.Berndtsson R, Chen H S. 1994. Variability of soil water content along a transect in a desert area. Journal of Arid Environments, 27: 127–139. Brotherson J D, Rushforth S R. 1983. Influence of cryptogamic crusts on moisture relationships of soils in Navaip National Monument. Great Basin Naturalist, 43: 73–78.Duan Z H, Xiao H L, Li X R, et al. 2004. Evolution of soil properties on stabilized sands in the Tengger Desert, China. Geomorphology, 59: 237–246. Eldridge D J, Zaady E, Shachak M. 2000. Infiltration through three contrasting biological soil crusts in patterned landscapes in the Negev, Israel. Catena, 40: 323–336.Eldridge D J, Zaady E, Shachak M. 2002. Microphytic crusts, shrub patches and water harvesting in the Negev Desert: the Shikim system. Landscape Ecology, 17: 587–597.Eldridge D J, Bowker M A, Maestre F T, et al. 2010. Interactive effects of three ecosystem engineers on infiltration in a semi-arid Mediterranean grassland. Ecosystems, 13: 499–510. FAO/UNESCO. 1974. Soil Map of the World 1:5,000,000. Volume 1. Paris: UNESCO.George D B, Roundy B A, St. Clair L L, et al. 2003. The effects of microbiotic soil crusts on soil water loss. Arid Land Research and Management, 17: 113–125.Halbertsma J M, Veerman G J. 1997. Determination of the unsaturated conductivity and water retention characteristics using the Wind’s evaporation method. In Stolte J. Manual for Soil Physical Measurements. Wageningen: DLO Winand Staring Centre, 47–55.Hu C X, Liu Y D, Zhang D L, et al. 2002. Cementing mechanism of algal crusts from desert area. Chinese Science Bulletin, 47: 1361–1368. Hu W, Shao M A, Wang Q J, et al. 2009. Temporal changes of soil hydraulic properties under different land uses. Geoderma, 149: 355–366.Kidron G J, Yair A, Vonshak A, et al. 2003. Microbiotic crust control of runoff generation on sand dunes in the Negev Desert. Water Resource Research, 39: 1108–1112.Kidron G J. 2007. Millimeter-scale microrelief affecting runoff yield over microbiotic crust in the Negev Desert. Catena, 70: 266–273. Li T, Xiao H L, Li X R. 2001. Modeling the effects of crust on rain infiltration in vegetated sand dunes in arid desert. Arid Land Research and Management, 15: 41–48.Li X R, Ma F Y, Xiao H L, et al. 2004. Long-term ecosystem effects of vegetation on soil water content of sand dunes in arid region of Northern China. Journal of Arid Environments, 57: 1–16.Li X R, Jia X H, Long L Q, et al. 2005. Effect of biological soil crusts on seed bank, germination and establishment of two annual plant species in the Tengger Desert (China). Plant and Soil, 27: 375–385.Li X R, He M Z, Stefan Z, et al. 2010. Micro-geomorphology determines community structure of BSCs at small scale. Earth Surface Processes and Landforms, 35: 932–940.Li X R, Jia R L, Chen Y W, et al. 2011. Association of ant nests with successional stages of biological soil crusts in the Tengger Desert, NorthernChina. Applied Soil Ecology, 47: 59–66.Li X R, GaoY H, Su J Q, et al. 2014. Ants mediate soil water in arid desert ecosystems: Mitigating rainfall interception induced by biological soil crusts? Applied Soil Ecology, 78: 57–64. Liu L C, Song Y X, Gao Y H, et al. 2007. Effects of microbiotic crusts on evaporation from the revegetated area in a Chinese desert. Australia Journal of Soil Research, 45: 1–6. Maestre F T, Huesca M T, Zaady E, et al. 2002. Infiltration, penetration resistance and microphytic crust composition in contrasted microsites within a Mediterranean semi-arid steppe. Soil Biology and Biochemistry, 34: 895–898.Malam I O, Défarge C, Trichet J, et al. 2009. Microbiotic soil crusts in the Sahel of western Niger and their influence on soil porosity and water dynamics. Catena, 77: 48-55.Mualem Y. 1976. A new model for predicting the hydraulic condu-ctivity of unsaturated porous media. Water Resource Research, 12: 513-522.Shapotou Desert Research and Experiment Station, Chinese Academy of Sciences. 1991. Study on Shifting Sand Control in Shapotou Region of Tengger Desert (2). Yingchuan: Ningxia People’s Press, 101–106. (in Chinese).Šimûnek J, Wendroth O, van Genuchten M T. 1998. A parameter estimation analysis of the evaporation method for determining soil hydraulic properties. Soil Science Society of America Journal, 62: 894–905. Su Y G, Li X R, Cheng Y W, et al. 2007. Effects of biological soil crusts on emergence of desert vascular plants in North China. Plant Ecology, 191: 11–19.van Genuchten M T H. 1980. A close-form equation for predicting the hydraulic conductivity of unsaturated soils. Soil Science Society of America Journal, 44: 892–898.Wang X P, Li X R, Xiao H L, et al. 2006. Evolutionary characteristics of the artificially revegetated shrub ecosystem in the Tengger Desert, Northern China. Ecological Research, 21: 415–424.Wang X P, Young H M. Yu Z, et al. 2007a. Long-term effects of restoration on soil hydraulic properties in revegetation stabilized desert ecosystems. Geophysical Research Letters, 34: L24S22.Wang X P, Li X R, Xiao H L, et al. 2007b. Effects of surface characteristics on infiltration patterns in an arid shrub desert. Hydrological Processes, 21: 72–79.Warren S D. 2003. Synopsis: influence of biological soil crusts on arid land hydrology and soil stability. In: Belnap J, Lange O L. Biological Soil Crusts: Structure, Function, and Management. Berlin: Springer-Verlag, 349–360.West N E. 1990. Structure and function of microphytic soil crusts in wildland ecosystems of arid to semi-arid regions. Advances in Ecological Research, 20: 179–223.Williams J D, Dobrowolski J P, West N E. 1999. Microbiotic crust influence on unsaturated hydraulic conductivity. Arid Soil Research and Rehabilitation, 13:145–154.Zhang Y M, Wu N, Zhang B C, et al. 2010. Species composition, distribution patterns and ecological functions of biological soil crusts in the Gurbantunggut Desert. Journal of Arid Land, 2: 180–189. Zhang Z S, Liu L C, Li X R, et al. 2008. Evaporation properties of a revegetated area of the Tengger Desert, North China. Journal of Arid Environments, 72: 964–973.
2015, Vol. 7 
