荒漠河岸林植物木质部导水与栓塞特征及其对干旱胁迫的响应

doi:10.3724/SP.J.1258.2012.00019

摘要/Abstract

摘要：

以同处于干旱区的塔里木河下游(铁干里克)和黑河下游(乌兰图格)断面为研究区, 比较了荒漠河岸林主要建群种胡杨(Populus euphratica)、柽柳(Tamarixspp.)、疏叶骆驼刺(Alhagi sparsifolia)和花花柴(Karelinia caspia)在长期遭受不同干旱胁迫下的根、枝条木质部导水力和栓塞化程度的变化特征, 并分析了木质部导水对干旱胁迫的响应及适应策略。结果表明: 1)黑河下游荒漠河岸林植物的导水能力显著高于塔里木河下游, 其中柽柳、胡杨、疏叶骆驼刺和花花柴根木质部的初始比导率(K_s₀)分别高11.97、6.74、7.10和3.73倍, 枝条的K_s₀分别高9.48、3.65、2.07和1.88倍, 地下水埋深导致的干旱胁迫程度不同是诱发荒漠植物导水能力差异的根本原因; 2)柽柳耐干旱能力最强, 适应范围较宽, 而花花柴、疏叶骆驼刺的耐旱性相对较弱, 适生范围较窄, 这可能与植物的根系分布有关; 3)干旱胁迫较轻时, 枝条木质部是荒漠河岸林植物水分传输的主要阻力部位, 干旱胁迫严重时, 根木质部是限制植株水流的最大阻碍部位; 4)荒漠河岸林植物主要通过调节枝条木质部的水流阻力来适应干旱胁迫, 且其适应策略与干旱胁迫程度有关, 干旱胁迫轻时, 植物通过限制枝条木质部水流来协调整株植物的均匀生长; 干旱胁迫严重时, 植物通过牺牲劣势枝条、增强优势枝条水流来提高植株整体生存的机会。

关键词: 干旱区内陆河流域, 荒漠植物, 栓塞, 导水率, 木质部

Abstract:

Aims Xylem embolism is a physiological response of plant species to adverse environmental factors, such as water deficit. Desert riparian forest plays an important role in the inland river basin of China. Our objectives were to clarify how xylem embolism of desert plants responds to different drought stress and to understand their acclimation mechanism to drought environment.
Methods Desert species, Populus euphratica, Tamarixspp.,Alhagi sparsifolia andKarelinia caspia were chosen to study the response of xylem hydraulic conductivity and embolism of the root and shoot to different drought stress in two riparian areas: Tikanlik, which is located in the lower reaches of the Tarim River, and Ulan Tug, which is located in the lower reaches of the Heihe River. We used a xylem embolism meter. We also examined the effects of soil moisture, groundwater depth and climatic factors in the two areas on the root and shoot xylem hydraulic conductivity and embolism of the desert plants at the same time.
Important findings Xylem hydraulic conductivities of the desert plants in Ulan Tug were significantly higher than those in Tikanlik. For example, the initial specific conductivity (K_s₀) values in the root xylem of Tamarixspp.,P. euphratica, A. sparsifolia andK. caspiaincreased 11.97, 6.74, 7.10 and 3.73 times, respectively, and the shoot xylem K_s₀ values increased 9.48, 3.65, 2.07 and 1.88 times, respectively. The fundamental reason for the different xylem hydraulic conductivities of the plants was the difference in drought stress produced by different groundwater depths in the two regions. The drought resistance of Tamarixspp.was the strongest, meaning the genus could exist in a broad soil moisture environment, but A. sparsifolia andK. caspia only exist in a narrow soil moisture environment because of their weak drought resistance, which might be related to root distribution. The major resistance to water transportation of desert plants was shoot xylem when it encountered moderate drought stress, but it was root xylem when the plant encountered severe drought stress. Desert plants adapt to moderate drought stress through limiting shoot xylem hydraulic conductivity to coordinate the plant growth, but it adapted to severe drought stress through sacrificing inferior shoots and enhancing xylem hydraulic conductivity of the other shoots.

Key words: arid inland river basin, desert plant, embolism, hydraulic conductivity, xylem

周洪华, 李卫红, 木巴热克∙阿尤普, 徐茜. 荒漠河岸林植物木质部导水与栓塞特征及其对干旱胁迫的响应. 植物生态学报, 2012, 36(1): 19-29. DOI: 10.3724/SP.J.1258.2012.00019

ZHOU Hong-Hua, LI Wei-Hong, AYUP Mubarek, XU Qian. Xylem hydraulic conductivity and embolism properties of desert riparian forest plants and its response to drought stress. Chinese Journal of Plant Ecology, 2012, 36(1): 19-29. DOI: 10.3724/SP.J.1258.2012.00019

导出引用管理器 EndNote|Ris|BibTeX

链接本文: https://www.plant-ecology.com/CN/10.3724/SP.J.1258.2012.00019

https://www.plant-ecology.com/CN/Y2012/V36/I1/19

图/表 7

图1 乌兰图格断面和铁干里克断面地下水埋深对比分析。W1-W7代表乌兰图格断面的7个监测点; T1-T7代表铁干里克断面的7个监测点。

Fig. 1 Comparative analysis of groundwater depth in section of Tikanlik and Ulan Tug. W1-W7 represent seven monitoring points of Ulan Tug section; T1-T7 represent seven monitoring points of Tikanlik section.

图2 铁干里克和乌兰图格气候因素对比分析。

Fig. 2 Comparative analysis of climate factors in Tikanlik and Ulan Tug.

图3 荒漠河岸林植物叶片最低水势对比分析(平均值±标准误差)。HA, 乌兰图格骆驼刺; HK, 乌兰图格花花柴; HP, 乌兰图格胡杨; HT, 乌兰图格柽柳; TA, 铁干里克骆驼刺; TK, 铁干里克花花柴; TP, 铁干里克胡杨; TT, 铁干里克柽柳。

Fig. 3 Comparative analysis of the lowest water potential in the leaves of desert riparian forest plants (mean ± SE). HA, Alhagi sparsifolia in Ulan Tug; HK, Karelinia caspia in Ulan Tug; HP, Populus euphratica in Ulan Tug; HT, Tamarix spp. in Ulan Tug; TA, Alhagi sparsifolia in Tikanlik; TK, Karelinia caspia in Tikanlik; TP, Populus euphratica in Tikanlik; TT, Tamarix spp. in Tikanlik.

图4 荒漠河岸林植物根木质部比导率(平均值±标准误差)。Ks0, 初始比导率; Ksmax, 最大比导率; HA, 乌兰图格骆驼刺; HK, 乌兰图格花花柴; HP, 乌兰图格胡杨; HT, 乌兰图格柽柳; TA, 铁干里克骆驼刺; TK, 铁干里克花花柴; TP, 铁干里克胡杨; TT, 铁干里克柽柳。

Fig. 4 Xylem specific conductivity in the roots of desert riparian forest plants (mean ± SE). K s0, initial specific conducti- vity; Ksmax, maximal specific conductivity; HA, Alhagi sparsifolia in Ulan Tug; HK, Karelinia caspia in Ulan Tug; HP, Populus euphratica in Ulan Tug; HT, Tamarix spp. in Ulan Tug; TA, Alhagi sparsifolia in Tikanlik; TK, Karelinia caspia in Tikanlik; TP, Populus euphratica in Tikanlik; TT, Tamarix spp. in Tikanlik.

图5 荒漠河岸林植物枝条木质部比导率(平均值±标准误差)。Ks0, 初始比导率; Ksmax, 最大比导率; HA, 乌兰图格骆驼刺; HK, 乌兰图格花花柴; HP, 乌兰图格胡杨; HT, 乌兰图格柽柳; TA, 铁干里克骆驼刺; TK, 铁干里克花花柴; TP, 铁干里克胡杨; TT, 铁干里克柽柳。

Fig. 5 Xylem specific conductivity in the shoots of desert riparian forest plants (mean ± SE). K s0, initial specific conductivity; Ksmax, maximal specific conductivity; HA, Alhagi sparsifolia in Ulan Tug; HK, Karelinia caspia in Ulan Tug; HP, Populus euphratica in Ulan Tug; HT, Tamarix spp. in Ulan Tug; TA, Alhagi sparsifolia in Tikanlik; TK, Karelinia caspia in Tikanlik; TP, Populus euphratica in Tikanlik; TT, Tamarix spp. in Tikanlik.

图6 荒漠河岸林植物根和枝条木质部导水率损失百分率 (平均值±标准误差)。HA, 乌兰图格骆驼刺; HK, 乌兰图格花花柴; HP, 乌兰图格胡杨; HT, 乌兰图格柽柳; TA, 铁干里克骆驼刺; TK, 铁干里克花花柴; TP, 铁干里克胡杨; TT, 铁干里克柽柳。

Fig. 6 Percentage loss of hydraulic conductivity of roots and shoots of desert riparian forest plants (mean ± SE). HA, Alhagi sparsifolia in Ulan Tug; HK, Karelinia caspia in Ulan Tug; HP, Populus euphratica in Ulan Tug; HT, Tamarix spp. in Ulan Tug; TA, Alhagi sparsifolia in Tikanlik; TK, Karelinia caspia in Tikanlik; TP, Populus euphratica in Tikanlik; TT, Tamarix spp. in Tikanlik.

图7 铁干里克和乌兰图格土壤含水量的变化(平均值±标准误差)。

Fig. 7 Changes of soil moisture in Tikanlik and Ulan Tug (mean ± SE).

参考文献 40

[1]	Aloni R, Griffith M (1991). Functional xylem anatomy in root-shoot junctions of six cereal species. Planta, 184,123-129. DOI URL PMID
[2]	Ayup M, Hao X, Chen Y, Li W, Su R (2011). Changes of xylem hydraulic efficiency and native embolism of Tamarix ramosissima Ledeb. seedlings under different drought stress conditions and after rewatering. South African Journal of Botany, . DOI URL PMID
[3]	Chen YN (陈亚宁), Chen YP (陈亚鹏), Li WH (李卫红), Zhang HF (张宏锋) (2003). Proline accumulation of Populus euphratica and its response to groundwater depth in the lower reaches of the Tarim River. Chinese Science Bulletin (科学通报), 48,958-961. (in Chinese with English abstract)
[4]	Chen YP (陈亚鹏), Chen YN (陈亚宁), Xu CC (徐长春), Li WH (李卫红), Fu AH (付爱红) (2011). Effects of groundwater depth on the gas exchange and chlorophyll fluorescence of Populus euphratica in the lower reaches of Tarim River. Acta Ecologica Sinica(生态学报), 31,344-353. (in Chinese with English abstract)
[5]	Cochard H, Barigah ST, Kleinhentz M, Eshel A (2008). Is xylem cavitation resistance a relevant criterion for screening drought resistance among Prunus species? Journal of Plant Physiology, 165,976-982. DOI URL PMID
[6]	Cochard H, Herbette S, Hernández E, Hölttä T, Mencuccini M (2010). The effects of sap ionic composition on xylem vulnerability to cavitation. Journal of Experimental Botany, 61,275-285. DOI URL PMID
[7]	Domec JC, Scholz FG, Bucci SJ, Meinzer FC, Goldstein G, Villalobos-Vega R (2006). Diurnal and seasonal variation in root xylem embolism in neotropical savanna woody species: impact on stomatal control of plant water status. Plant, Cell & Environment, 29,26-35. DOI URL PMID
[8]	Ennajeh M, Tounekti T, Vadel AM, Khemira H, Cochard H (2008). Water relations and drought-induced embolism in olive ( Olea europaea) varieties ‘Meski’ and ‘Chemlali’ during severe drought. Tree Physiology, 28,971-976. URL PMID
[9]	Ewers FW, Fisher JB, Chiu ST (1991a). Water transport in the liana Bauhinia fassoglensis (Fabaceae). Plant Physiology, 91,1625-1631. URL PMID
[10]	Ewers FW, Fisher JB, Fichtner K (1991b). Water flux and xylem structure in vines. In: Putz FE, Mooney HA eds. The Biology of Vines. Cambridge University Press, Cambridge, UK. 119-152.
[11]	Fan DY (樊大勇), Xie ZQ (谢宗强) (2004). Several controversial viewpoints in studying the cavitation of xylem vessels. Acta Phytoecologica Sinica(植物生态学报), 28,126-132. (in Chinese with English abstract)
[12]	Fu AH, Chen YN, Li WH (2006). Analysis on water potential of Populus euphratica Oliv. and its meaning in the lower reaches of Tarim River, Xinjiang. Chinese Science Bulletin, 51(Supp.1),221-228.
[13]	Fu AH (付爱红), Chen YN (陈亚宁), Li WH (李卫红) (2007). Stems water potential of Tamarix ramosissima Lbd. and influencing factors in the lower reaches of Tarim River, Xinjiang. Arid Land Geography (干旱区地理), 30,108-114. (in Chinese with English abstract)
[14]	Gullo MAL, Salleo S, Piaceri EC, Rosso R (1995). Relations between vulnerability to xylem embolism and xylem conduit dimensions in young trees of Quercus corris. Plant, Cell & Environment, 18,661-669.
[15]	Huang JY (黄菊莹), Yu HL (余海龙), Zhang SX (张硕新) (2009). Effects of potassium addition and water supply on xylem embolism in Acer truncatum and Ligustrum lucidum. Chinese Journal of Plant Ecology(植物生态学报), 33,1199-1207. (in Chinese with English abstract)
[16]	Jacobsen AL, Pratt RB, Davis SD, Ewers FW (2008). Comparative community physiology: nonconvergence in water relations among three semi-arid shrub communities. New Phytologist, 180,100-113.
[17]	Jiang XH (蒋晓辉), Liu CM (刘昌明) (2009). The response of vegetation to water transport in the lower reaches of the Heihe River. Acta Geographica Sinica (地理学报), 64,791-797. (in Chinese with English abstract)
[18]	Ladjal M, Huc R, Ducrey M (2005). Drought effects on hydraulic conductivity and xylem vulnerability to embolism in diverse species and provenances of Mediterranean cedars. Tree Physiology, 25,1109-1117. DOI URL PMID
[19]	Li JQ (刘嘉麒), Qin XG (秦小光) (2005). Evolution of the environmental framework and oasis in the Tarim River Basin. Quaternary Sciences(第四纪研究), 25,533-539. (in Chinese with English abstract)
[20]	Li JY (李吉跃), Zhai HB (翟洪波) (2000). Hydraulic architecture and drought resistance of woody plants. Chinese Journal of Applied Ecology (应用生态学报), 11,301-305. (in Chinese with English abstract)
[21]	Mrema AF, Granhall U, Sennerby-Forsse L (1997). Plant growth, leaf water potential, nitrogenase activity and nodule anatomy in Leucaena leucocephala as affected by water stress and nitrogen availability. Trees-Structure and Function, 12,42-48.
[22]	Nardini A, Tyree MT, Salleo S (2001). Xylem cavitation in the leaf of Prunus laurocerasus and its impact on leaf hydraulics. Plant Physiology, 125,1700-1709. URL PMID
[23]	Pockman WT, Sperry JS (2000). Vulnerability to xylem cavitation and the distribution of sonoran desert vegetation. American Journal of Botany, 87,1287-1299. URL PMID
[24]	Raimondoa F, Trifilò P, Gulloa MAL, Buffab R, Nardinic A, Salleo S (2009). Effects of reduced irradiance on hydraulic architecture and water relations of two olive clones with different growth potentials. Environmental and Experimental Botany, 66,249-256.
[25]	Rice KJ, Matzner SL, Byer W, Brown JR (2004). Patterns of tree dieback in Queensland, Australia: the importance of drought stress and the role of resistance to cavitation. Oecologia, 139,190-198. DOI URL PMID
[26]	Salleo S, Gullo MAL (1986). Xylem cavitation in nodes and internodes of whole Chorisia insignis H. B. et K. plants subjected to water stress: relations between xylem conduit size and cavitation. Annals of Botany, 58,431-441.
[27]	Salleo S, Gullo MAL, Trifilò P, Nardini A (2004). New evidence for a role of vessel-associated cells and phloem in the rapid xylem refilling of cavitated stems of Laurus nobilis L. Plant, Cell & Environment, 27,1065-1076.
[28]	Song YD (宋郁东), Fan ZL (樊自立), Lei ZD (雷志栋) (2000). Water Resources and Ecological Problems in the Tarim River, China (中国塔里木河水资源与生态问题研究). Xinjiang People’s Publishing House, Ürümqi.
[29]	Sperry JS, Tyree MT (1990). Water-stress-induced xylem embolism in three species of conifers. Plant, Cell & Environment, 13,427-436.
[30]	Trifilò P, Gullo MA, Nardini A, Pernice F, Salleo S (2007). Rootstock effects on xylem conduit dimensions and vulnerability to cavitation of Olea europaea L. Trees- Structure and Function, 21,549-556.
[31]	Tyree MT, Alexander JD (1993). Hydraulic conductivity of branch junctions in three temperate tree species. Trees- Structure and Function, 7,156-159.
[32]	Tyree MT, Sperry JS (1988). Do woody plants operate near the point of catastrophic xylem dysfunction caused by dynamic water stress? Answers from a model. Plant Physiology, 88,574-580. DOI URL PMID
[33]	Yao JM (姚济敏), Gao XQ (高晓清), Feng Q (冯起), Zhang XY (张小由), Gu LL (谷良雷) (2006). The photosynthe- tically active radiation during dust storm day in Ejina Oasis. Acta Energiae Solaris Sinica (太阳能学报), 27,484-488. (in Chinese with English abstract)
[34]	Ye ZX (叶朝霞), Chen YN (陈亚宁), Li WH (李卫红) (2007). Ecological water demand of vegetation based on eco- hydrological processes in the lower reaches of Tarim River. Acta Geographica Sinica (地理学报), 62,451-461. (in Chinese with English abstract)
[35]	Zhang SX (张硕新), Shen WJ (申卫军), Zhang YY (张远迎), Zhou XX (周新霞) (1997). The vulnerability of xylem embolism in twigs of some drought-resistent tree species. Journal of Northwest Forestry University (西北林学院学报), 12(2),2-7. (in Chinese with English abstract)
[36]	Zhao CY (赵传燕), Li SB (李守波), Feng ZD (冯兆东) (2010). Modeling of spatiotemporal distribution of groundwater level in water table fluctuant belt of the lower Heihe River reaches: (I) Division of study area and groundwater evaporation. Journal of Desert Research (中国沙漠), 20,198-203. (in Chinese with English abstract)
[37]	Zhao QW (赵其文), Pan LP (潘丽萍), Li Y (李彦) (2006). Adaptative morphological responses of plant water- conducting system to soil texture and radiation. Acta Botanica Boreali-Occidentalia Sinica (西北植物学报), 26,976-982. (in Chinese with English abstract)
[38]	Zimmermann MH (1978). Hydraulic architecture of some diffuse-porous trees. Canadian Journal of Botany, 56,2286-2295. DOI URL
[39]	Zimmermann MH (1983). Xylem Structure and the Ascent of Sap. Springer-Verlag, Berlin.
[40]	Zotz G (1997). Hydraulic architecture, and water relation of a flood-tolerant tropical tree, Annona glabra. Tree Physiology, 17,359-365. DOI URL PMID