摘要
干旱区人工防护林植物采用滴灌的方式补给水分以促进人工生态屏障的建成和稳定性维持,然而持续滴灌导致表层土壤盐分累积,最终威胁人工防护林的生长和生态功能。本研究通过测定塔克拉玛干沙漠南缘防护林和自然群落多枝柽柳(Tamarix ramosissima)的茎水、各潜在水源(土壤水和地下水)的稳定氢(δD)氧(δ18O)同位素值,以及叶片氮(N)、磷(P)含量和稳定碳同位素(δ13C)值,探究滴灌补水对多枝柽柳叶片养分特征和水分利用策略的影响。结果表明:滴灌群落多枝柽柳对中层土壤水(40~100 cm)的利用率高于自然群落,但其主要水分来源仍然是地下水,说明其根系已经深达地下水层;滴灌群落多枝柽柳叶片N、P含量显著高于自然群落,表明水分的补给影响了植物对养分元素的吸收和转移;滴灌群落多枝柽柳长期水分利用效率显著高于自然群落,可能与灌溉造成的盐分胁迫或其叶片N、P含量较高有关,但盐分胁迫尚未对多枝柽柳造成毒害。防护林建成后可以减少灌溉用水量或停止滴灌,从而节约防护林长期建设的用水量和维护防护林生态屏障的稳定性。
The establishment and maintenance of artificial ecological barriers in arid areas require drip irrigation to replenish water to plants on artificial shelterbelt. However,continuous drip irrigation leads to the accumulation of salt in the surface soil,which would threaten the growth and ecological function of artificial shelterbelts. To examine the effects of drip irrigation on leaf nutrient characteristics and water use strategies of desert plants in arid regions,we measured leaf nutrient content,water use efficiency,stable hydrogen isotope( δD) and stable oxygen isotope( δ18 O) values of stem water and assessed potential water sources( soil water and groundwater) of Tamarix ramosissima growing in the shelterbelt and natural communities on the southern margin of the Taklimakan Desert. The results showed that the utilization rate for middle-layer soil water( 40-100 cm) in T. ramosissima of the shelterbelt community was higher than that in the natural community,while groundwater was the main water source,indicating that root system of drip irrigated T. ramosissima could reach the groundwater layer. Foliar N and P concentrations of T. ramosissima in the shelterbelt community were significantly higher than those in the natural community,indicating that water supply affected the absorption and transfer of key nutrients. The long-term water use efficiency of T. ramosissima in the shelterbelt community was significantly higher than that in the natural community,which may be related to salt stress caused by irrigation or higher foliar N and P concentrations. The drip irrigation associated salt stress had not caused toxicity to T. ramosissima. After the successful establishment of shelterbelt plants,irrigation can be reduced or stopped,which would facilitate to water conservation and the maintenance of shelterbelt stability.
作者
孟德坤
闵孝君
臧永新
马剑英
MENG De-kun;MIN Xiao-jun;ZANG Yong-xin;MA Jian-ying(CAS Key Laboratory of Biogeography and Bioresource in Arid Land,Xinjiang Institute of Ecology and Geography,Urumqi 830011,China;Fukang Station of Desert Ecology,Chinese Academy of Sciences,Fukang 831505,Xinjiang,China;University of Chinese Academy of Sciences,Beijing 100049,China)
出处
《生态学杂志》
CAS
CSCD
北大核心
2019年第11期3245-3253,共9页
Chinese Journal of Ecology
基金
中国科学院特色研究所主要服务项目5课题1(TSS-2015-014-FW-5-1)、中国科学院“西部之光”交叉团队(2019)资助
国家自然科学基金面上项目(41671207)
