咸水灌溉对凋落物分解及土壤有机碳矿化的影响  

Effects of saline water irrigation on litter decomposition and soil organic carbon mineralization

作　　者：韩欢 袁萍 李从娟[1] 赵红梅 HAN Huan;YUAN Ping;LI Congjuan;ZHAO Hongmei(Key Laboratory of Ecological Safety and Sustainable Development in Arid Lands/National Engineering Technology Research Center for Desert-Oasis Ecological Construction,Xinjiang Institute of Ecology and Geography,Chinese Academy of Sciences,Urumqi 830011,Xinjiang,China;University of Chinese Academy of Sciences,Beijing 100049,China;College of Resources and Environment,Xinjiang Agricultural University,Urumqi 830052,Xinjiang,China;Xinjiang Key Laboratory of Soil and Plant Ecological Processes,Urumqi 830052,Xinjiang,China)

机构地区：[1]中国科学院新疆生态与地理研究所,干旱区生态安全与可持续发展重点实验室/国家荒漠-绿洲生态建设工程技术研究中心,新疆乌鲁木齐830011 [2]中国科学院大学,北京100049 [3]新疆农业大学资源与环境学院,新疆乌鲁木齐830052 [4]新疆土壤与植物生态过程实验室,新疆乌鲁木齐830052

出　　处：《干旱区地理》2024年第12期2030-2040,共11页Arid Land Geography

基　　金：新疆维吾尔自治区杰出青年基金(2022D01E97);国家自然科学基金(32360300)资助。

摘　　要：咸水是塔克拉玛干塔中植物园和沙漠公路防护林植被唯一灌溉用水,不仅决定着塔中植物园和防护林人工植被的正常生命运转,而且影响着植物-土壤之间的物质循环,探究咸水灌溉对凋落物分解及土壤有机碳矿化的影响对于理解极端环境物质循环和土壤有机碳固定有重要意义。以塔中植物园胡杨和杜梨叶凋落物为研究对象,结合室内培养的方式,动态研究不同盐浓度咸水添加下凋落物分解特征及土壤有机碳过程。结果表明:(1)相对于淡水而言,咸水添加通过影响土壤的理化性质而限制凋落物分解速率,尤其是高浓度咸水严重抑制凋落物的分解。(2)在土壤有机碳的累积矿化过程中,淡水作用下土壤有机碳累积矿化量最大,而15.0g·L^(-1)的咸水添加下土壤有机碳的累积矿化量最小。(3)凋落物的添加提高了土壤有机碳含量,且土壤有机碳含量处于动态变化过程。总之,适宜浓度的咸水通过影响土壤理化性质和微生物的活动进而限制了凋落物分解和矿化过程,有利于土壤有机碳积累。Plant litter plays a pivotal role in the material and energy cycles of terrestrial ecosystems,serving as a primary source of plant-derived soil carbon,which is fundamental to the carbon cycle.The decomposition of litter releases CO2 into the atmosphere,provides nutrients and energy essential for subterranean ecosystems,and significantly contributes to the maintenance of geochemical element cycling.In arid zone ecosystems,moisture serves as a crucial limiting factor,influencing both the abundance and activity of soil microorganisms and the geochemical processes within subsurface ecosystems.In the Taklimakan Desert Botanical Garden,plants are primarily irrigated with saline groundwater to support their growth and development,which in turn affects litter decomposition and the transformation of soil organic carbon.Although research on the effects of saline water irrigation on soil physicochemical properties in desert ecosystems has expanded,studies examining soil organic carbon mineralization and litter decomposition under saline water conditions remain limited.To address this gap,two indoor incubation experiments were conducted to investigate the decomposition characteristics of Populus euphratica and Pyrus betulifolia litter and the rate of soil organic carbon mineralization under the influence of saline water with varying salt concentrations(0,7.5 g·L^(-1),15.0 g·L^(-1),22.5 g·L^(-1),and 30.0 g·L^(-1)).The key findings are as follows:(1)Saline water at different salt concentrations altered soil physicochemical properties.Soil conductivity increased with rising salt concentrations,while pH remained relatively stable.The decomposition rate of litter was influenced by saline water concentration,with the litter mass residual rate of both plant species showing a decreasing trend over time.The litter mass residual rate of P.betulifolia increased with higher saline water concentrations,whereas the decomposition of P.euphratica was faster than that of P.betulifolia.(2)The highest soil organic carbon mineralization rat

关 键 词：凋落物分解 咸水灌溉 土壤有机碳 矿化速率 

分 类 号：S153.6[农业科学—土壤学]