Water use ratio of
Abstract
Gonghe basin is located in the ecotone from the semi-arid to arid zone on the northeastern Qinghai-Tibetan Plateau. Caragana intermedia and Caragana korshinskii are dominant on sand dunes. Salix psammophila and Salix cheilophila are mainly distributed on interdune. Water source of four desert shrubs was examined by δD and δ18O, and their long-term water use efficiency (WUE) was compared by leaf δ13C. Four desert shrubs used different depths of soil water depending on their availability in different seasons, including shallow soil water recharged by rain in spring or summer and deep soil water recharged by ground water. The reliability on ground water of two Salix shrubs on interdune was more significant than two Caragana shrubs on sand dunes. Moreover, the WUE of four shrubs decreased in drought spring. Two shrubs in Caragana had similar WUE in the growing season. However, the WUE of S. psammophila was always higher than that of S. cheilophila, which might have more adaptability in Gonghe Basin.
Keywords
- water source
- water use efficiency (WUE)
- stable isotope
- soil water
- ground water
1. Introduction
In desert ecosystems, water is a restrictive factor for plant survival and growth because of low and unpredictable precipitation and high evaporation [1, 2]. The ability to use rainwater in spring and summer is important for plant phenology and growth [3]. Additionally, the sustainable water source is necessary for plant growth especially in the drought period, such as deep soil water or ground water [4]. A stable isotope technology is often used to study the water use strategy of desert plants. Generally, there is no stable isotope fractionation during water uptake by root system or water transportation in the xylem of most plant species. Thus, the main water source can be distinguished by comparing the δD or δ18O value of xylem water with that of the potential water source, for example, rain, snow, river, lake, soil water or ground water [1]. Further, leaf δ13C value of C3 plants is positively related to their long-term water-use efficiency (WUE). The δ13C value decreased from spring to autumn in the growing season and increased in the drought period [4].
Previous studies with the stable isotope of hydrogen or oxygen indicated that woody plant species used different water sources in desert or other arid and semi-arid ecosystems. Firstly, many trees and shrubs mainly used shallow soil water recharged by rain, for example,
Gonghe Basin is located in the northeastern Qinghai-Tibetan Plateau, which is the ecotone from semi-arid to arid region, with the altitude varying from 2600 to 3400 m. It contains part of Gonghe County, Guinan County and Xinghai County of Qinghai Province. The dominant vegetation is steppe and desert steppe. The basin is as long as 210 km in East and West, and as wide as 60 km in South and North, with a total area of 13,800 km2. It is one of the most vulnerable land desertification area in Qinghai Province. The area of desertified land is 3530 km2, which accounts for 25.58% of the total area. The ecological security in the upper reaches of Yellow River has been affected significantly by land desertification in Gonghe Basin, especially Longyangxia Reservoir [17]. In order to control and prevent land desertification, large areas were planted with trees and shrubs to form the shelterbelt system in the ecotone between oasis and desert to protect farms, villages and roads in Gonghe Basin. Some trees in
In this chapter, the main water source of four dominant desert shrubs is compared by stable hydrogen and oxygen isotopes in the growing season (May, July and September). The water use ratio of different sources was analysed by Iso-source 1.3.1 software [18]. Two shrubs in
2. Water source and long-term WUE of four desert shrubs
2.1. Four dominant desert shrubs in Gonghe Basin
This study was conducted at Gonghe Desert Ecosystem Research Station, which is located in the mid-west Gonghe Basin and belongs to Shazhuyu Town, Gonghe County (36°16'N, 100°16'E, altitude 2874 m). The mean annual air temperature is only 2.4 °C, and the mean annual forest free day is only 91 days. The mean annual precipitation is 246.3 mm, which is concentrated from July to September. Two shrubs in
2.2. Precipitation in the growing season and soil moisture in four desert shrubs plantation
The total precipitation at the study site was 137.5 mm from May 1 to September 13, 2014. The monthly precipitation was 8.8, 61.6, 37.8 and 28.7 mm in May, June, July and August, respectively (Figure 1). The maximal daily precipitation (18.9 mm) occurred on June 12. Before field sampling in July, 6.4 mm rain occurred on July 8, and in September, the precipitation was only 0.4 mm.
Soil water content in
Soil water content in
Soil water content in
Soil water content in
2.3. Water source of four desert shrubs in different seasons
The δ18O ratio of xylem water of
2.3.1. Water source of two Caragana shrubs on sand dunes
On May 27, the value of δD and δ18O in xylem water of
On May 27, the ratio of δD and δ18O in xylem water of
Iso-Source analysis showed that
Water source | May 27 | July 20 | September 11 |
---|---|---|---|
Soil water 10 cm | 22.8 ± 12.2 | 65.7 ± 4.5 | 6.1 ± 5.3 |
25 cm | 22.0 ± 15.3 | 8.8 ± 7.9 | 7.4 ± 6.5 |
50 cm | 15.9 ± 13.8 | 7.6 ± 6.9 | 10.5 ± 9.1 |
75 cm | 10.9 ± 9.3 | 5.8 ± 5.3 | 11.6 ± 1.0 |
100 cm | 10.4 ± 8.9 | 4.5 ± 4.2 | 16.7 ± 14.5 |
150 cm | 8.9 ± 7.5 | 3.7 ± 3.6 | 22.2 ± 16.8 |
Ground water | 9.1 ± 7.8 | 3.8 ± 3.6 | 25.5 ± 12.9 |
Iso-Source analysis showed that
Water source | May 27 | July 23 | September 11 |
---|---|---|---|
Soil water 10 cm | 16.8 ± 9.3 | 9.7 ± 7.3 | 18.2 ± 10.6 |
25 cm | 18.3 ± 12.2 | 12.0 ± 8.1 | 20.9 ± 14.5 |
50 cm | 15.5 ± 13.4 | 17.9 ± 13.9 | 20.0 ± 16.6 |
75 cm | 13.1 ± 11.1 | 13.9 ± 10.8 | 11.1 ± 8.2 |
100 cm | 12.3 ± 10.4 | 10.4 ± 7.6 | 12.8 ± 9.2 |
150 cm | 11.2 ± 9.4 | 28.6 ± 6.1 | 11.6 ± 7.8 |
Ground water | 12.9 ± 11.0 | 7.5 ± 5.8 | 5.4 ± 3.7 |
On sand dunes of Gonghe Basin,
The resource-dependent water use strategy of two
The temporal difference in the main water source for a typical desert shrub is associated with precipitation change in different years. In this study, the ground water table is less than 3 m on interdune.
2.3.2. Water source of two Salix shrubs on interdune
On May 26 and July 17, the value of δD and δ18O in xylem water of
On May 26, the value of δD and δ18O in xylem water of
Iso-Source analysis showed that
Iso-Source analysis showed that
Water source | May 26 | July 17 | September 11 |
---|---|---|---|
Soil water 10 cm | 13.0 ± 8.0 | 26.2 ± 12.0 | 9.0 ± 6.3 |
25 cm | 16.0 ± 12.0 | 23.0 ± 16.9 | 11.3 ± 8.4 |
50 cm | 14.3 ± 11.9 | 9.9 ± 8.6 | 16.8 ± 14.6 |
75 cm | 12.8 ± 10.4 | 8.9 ± 7.7 | 16.1 ± 13.1 |
100 cm | 12.6 ± 10.2 | 8.9 ± 7.7 | 16.2 ± 13.2 |
150 cm | 14.3 ± 11.9 | 9.3 ± 8.0 | 14.4 ± 10.9 |
Ground water | 17.0 ± 14.1 | 13.8 ± 12.0 | 16.1 ± 13.7 |
Water source | May 26 | July 17 | September 11 |
---|---|---|---|
Soil water 10 cm | 16.7 ± 7.1 | 17.0 ± 8.8 | 2.2 ± 2.1 |
25 cm | 31.4 ± 20.2 | 18.8 ± 13.2 | 2.2 ± 2.1 |
50 cm | 9.2 ± 7.7 | 13.1 ± 11.2 | 7.6 ± 6.8 |
100 cm | 7.7 ± 6.4 | 11.5 ± 9.7 | 27.9 ± 19.9 |
150 cm | 6.2 ± 5.2 | 11.7 ± 9.9 | 28.0 ± 19.9 |
200 cm | 6.2 ± 5.2 | 12.3 ± 10.5 | 25.9 ± 19.9 |
Ground water | 22.6 ± 12.2 | 15.6 ± 13.6 | 5.5 ± 5.0 |
On interdune of Gonghe Basin,
The resource-dependent water use strategy of two
2.4. Long-term WUE of four desert shrubs
Leaf carbon discrimination (Δ, ‰) was converted from its δ13C value using an atmospheric carbon dioxide ratio of −8‰ [32]. The leaf Δ value was significantly different (
The long-term WUE is negatively related to the leaf Δ value of C3 plants. There were seasonal dynamics of WUE in two
There were seasonal dynamics of long-term WUE indicated by the leaf Δ value in two
2.5. Conclusion
The water use strategy of four dominant desert shrubs was adapted to the semi-arid climate in Gonghe Basin. They used different water sources depending on their availability in different seasons, including shallow soil water recharged by rain, deep soil water recharged by ground water or ground water. They could use shallow soil water after rain in spring and summer. When shallow soil water was depleted, they turned to use deep soil water or ground water. The reliance of ground water was different for four shrubs in two habitats. Two shrubs in
Acknowledgments
This study was supported by Chinese National Natural Science Foundation (41301095) and the Fundamental Research Funds for the Central Non-profit Research Institute of Chinese Academy of Forestry (CAFYBB2014QB023).
References
- 1.
Ehleringer JR. Carbon and water relations in desert plants: an isotopic perspective. In: Ehleringer JR, Hall AE, Farquhar GD, editors. Stable Isotope and Plant Carbon–Water Relations. 1st ed. San Diego: Academic Press; 1993. p. 155–172. DOI: 10.1016/B978-0-08-091801-3.50018-0 - 2.
Schwinning S, Starr BI, Ehleringer JR. Dominant cold desert plants do not partition warm season precipitation by event size. Oecologia. 2003; 136 :252–260. DOI: 10.1007/s00442-003-1255-y - 3.
Ogle K, Reynolds JF. Plant responses to precipitation in desert ecosystems: integrating functional types, pulses, thresholds, and delays. Oecologia. 2004; 141 :282–294. DOI: 10.1007/s00442-004-1507-5 - 4.
Lin G. Stable Isotope Ecology. 1st ed. Beijing: Higher Education Press; 2013. 492 p. - 5.
Cheng X, An S, Li B, Chen J, Lin G, Liu Y, Luo Y, Liu S. Summer rain pulse size and rainwater uptake by three dominant desert plants in a desertified grassland ecosystem in northwestern China. Plant Ecology. 2006; 184 :1–12. DOI: 10.1007/s11258-005-9047-6 - 6.
West AG, Hultine KR, Burtch KG, Ehleringer JR. Seasonal variation in moisture use in a piňon-juniper woodland. Oecologia. 2007; 153 :787–798. DOI: 10.1007/s00442-007-0777-0 - 7.
Li S-G, Romero-Saltos H, Tsujimura M, Sugimoto A, Sasaki L, Davaa G, Oyunbaatar D. Plant water sources in the cold semiarid ecosystem of the upper Kherlen River catchment in Mongolia: a stable isotope approach. Journal of Hydrology. 2007; 333 :109–117. DOI: 10.1016/j.jhydrol.2006.07.020 - 8.
Kowaljow E, Fernández RJ. Different utilization of a shallow-water pulse by six shrub species in the Patagonian steppe. Journal of Arid Environments. 2011; 75 :211–214. DOI: 10.1016/j.jaridenv.2010.10.004 - 9.
Zhu Y, Jia Z, Yang X. Resource-dependent water use strategy of two desert shrubs on interdune, Northwest China. Journal of Food, Agriculture and Environment. 2011; 9 :832–835. - 10.
Kray JA, Cooper DJ, Sanderson JS. Groundwater use by native plants in response to changes in precipitation in an intermountain basin. Journal of Arid Environments. 2012; 83 :25–34. DOI: 10.1016/j.jaridenv.2012.03.009 - 11.
Dai Y, Zheng X-J, Tang L-S, Li Y. Stable oxygen isotopes reveal distinct water use patterns of two Haloxylon species in the Gurbantonggut Desert. Plant and Soil. 2015;389 :73–87. DOI: 10.1007/s11104-014-2342-z - 12.
Ohte N, Koba K, Yoshikawa K, Sugimoto A, Matsuo N, Kabeya N, Wang L. Water utilization of trees in semiarid desert of Inner Mongolia, China. Ecological Applications. 2003; 13 :337–351. DOI: 10.1890/1051-0761 - 13.
Pataki DE, Bush SE, Gardner P, Solomon DK, Ehleringer JR. Ecohydrology in a Colorado River riparian forest: implications for the decline of Populus fremontii . Ecological Applications. 2005;15 :1009–1018. DOI: 10.1890/04-1272 - 14.
Su H, Li Y, Liu W, Xu H, Sun OJ. Changes in water use with growth in Ulmus pumila in semiarid sandy land of northern China. Trees: Structure and Function. 2014;28 :41–52. DOI: 10.1007/s00468-013-0928-3 - 15.
Song L, Zhu J, Li M, Yu Z. Water utilization of Pinus sylvestris var.mongolica in a sparse wood grassland in the semiarid sandy region of Northeast China. Trees: Structure and Function. 2014;28 :971–982. DOI: 10.1007/s00468-014-1010-5 - 16.
Liu S, Chen Y, Chen Y, Chen Y, Friedman JM, Hati JHA, Fang G. Use of 2H and 18O stable isotopes to investigate water sources for different ages of Populus euphratica along the lower Heihe River. Ecological Restoration. 2015;30 :581–587. DOI: 10.1007/s11284-015-1270-6 - 17.
Zhang D, Gao S, Shi M, Hasi E, Yan P, Lu R. Land Desertification and Its Control in Plateau of Qinghai. 1st ed. Beijing: Science Press; 2009. 194 p. - 18.
Phillips DL, Gregg JW. Source partitioning using stable isotopes: coping with too many sources. Oecologia. 2003; 136 :261–269. DOI: 10.1007/s00442-003-1218-3 - 19.
Liu YX, editor. Flora in Desertis Reipublicae Populorum Sinarum. Tomus 2. 1st ed. Beijing: Science Press; 1987. 464 p. - 20.
Jia Z, Zhu Y, Liu L. Different water use strategies of juvenile and adult Caragana intermedia plantations in the Gonghe Basin, Tibet Plateau. PLoS One. 2012;7 :e45902. DOI: 10.1371/journal.pone.0045902 - 21.
Liu SW, editor. Flora Qinghaiica. Volume 1. 1st ed. Xining: Qinghai Pepole’s Publishing House; 1997. 544 p. - 22.
Liu J, He X, Bao H, Zhou C. Distribution of fine roots of Salix psammophila and its relationship with soil moisture in Mu Us Sandland. Journal of Desert Research. 2010;30 : 1362-1366. - 23.
Ma YQ, editor. Flora Intramongolica. Volume 1. 1st ed. Huhhot: Inner Mongolia People Press; 1985. 294 p. - 24.
Yu Y, Jia Z, Zhu Y, Zhao S, Liu H, Li Q, Wei D. Root distribution of Salix cheilophila along a chronosequence in high-cold sandland. Journal of Desert Research. 2014;34 :67–74. DOI: 10.7522/j.issn.1000-694X.2013.00188 - 25.
Chimner RA, Cooper DJ. Using stable oxygen isotopes to qualify the water source used for transpiration by native shrubs in San Luis Valley, Colorado USA. Plant and Soil. 2004; 260 :225–236. DOI: 10.1023/B:PLSO.0000030190.70085.e9 - 26.
Yang H, Auerswald K, Bai Y, Han X. Complementarity in water sources among dominant species in typical steppe ecosystems of Inner Mongolia, China. Plant and Soil. 2011; 340 :303–313. DOI: 10.1007/s11104-010-0307-4 - 27.
Xing X, Chen H, Zhu J, Chen T. Water sources of five dominant desert species in Nuomuhong area of Qaidam Basin. Acta Ecologica Sinica. 2014; 34 :6277–6286. DOI: 10.5846/stxb201310092427 - 28.
Zhu Y, Jia Z, Lu Q, Hao Y, Zhang J, Li L, Qi Y. Water use strategy of five shrubs in Ulanbuh Desert. Scientia Silvae Sinicae. 2010; 46 :15–21. DOI: 10.11707/j.1001-7488.20100403 - 29.
Wei YF, Fang J, Liu S, Zhao XY, Li SG. Stable isotope observation of water use source of Pinus sylvestris var.mongolica in Horqin Sandy Land, China. Trees: Structure and Function. 2013;27 :1249–1260. DOI: 10.1007/s00468-013-0873-1 - 30.
Gong G, Chen H, Duan D. Comparison of the methods using stable hydrogen and oxygen isotope to distinguish the water source of Nitraria tangutorum . Acta Ecologica Sinica. 2011;31 :7533-7541 - 31.
IPCC, editor. Climate Change 2013. The Physical Science Basis. New York: Cambridge University Press; 2013. 152 p. - 32.
West AG, Bowen GJ, Cerling TE, Ehleringer JR. Stable isotopes as one of nature’s ecological recorders. TRENDS in Ecology and Evolution. 2006; 21 :408-414. DOI: 10.1016/j.tree.2006.04.002 - 33.
Cao S, Feng Q, Si J, Chang Z. Research on characteristics of water use efficiency variations of Populus euphratica during the growing season in extremely arid region of China. Journal of Desert Research. 2012;32 :724–729. - 34.
Liu H, Li J, Zhao Y, Huang K. Study on δ13C values of desert plant Salix psammopphila and water use efficiency. Arid Zone Research. 2008;25 :514–518.