外源氮添加对温带荒漠地表凋落物分解及养分释放的影响  

Effects of exogenous nitrogen addition on litter decomposition and nutrient release in a temperate desert

作　　者：张彩云 赵红梅 刘辉 张文太[1,2] 苏延桂 程军回 杨卫君[5] ZHANG Cai-yun;ZHAO Hong-mei;LIU Hui;ZHANG Wen-tai;SU Yan-gui;CHENG Jun-hui;YANG Wei-jun(College of Grassland and Environmental Sciences,Xinjiang Agricultural University,Urumqi 830052,China;Xinjiang Key Laboratory of Soil and Plant Ecological Processes,Urumqi 830052,China;Agricultural Technology Extension Centre of Changji Prefecture,Changji 831100,Xinjiang,China;Institute of Geography Science,Fujian Nor-mal University,Fuzhou 350007,China;College of Agronomy,Xinjiang Agricultural University,Urumqi 830052,China)

机构地区：[1]新疆农业大学草业与环境科学学院,乌鲁木齐830052 [2]新疆土壤与植物生态过程自治区重点实验室,乌鲁木齐830052 [3]昌吉州农业技术推广中心,新疆昌吉831100 [4]福建师范大学地理科学学院,福州350007 [5]新疆农业大学农学院,乌鲁木齐830052

出　　处：《应用生态学报》2020年第11期3631-3638,共8页Chinese Journal of Applied Ecology

基　　金：国家自然科学基金项目(31700423,41761059,31660127,41671115);新疆自然科学基金项目(2016D01A044)资助。

摘　　要：采用分解网袋法,在古尔班通古特沙漠南缘设置对照N0(0 g N·m-2·a-1)、N5(5 g N·m-2·a-1)、N10(10 g N·m-2·a-1)和N20(20 g N·m-2·a-1)4个施N处理,研究外源N添加对多枝柽柳、盐角草及两者混合凋落物分解过程及养分释放的影响,分析氮沉降对荒漠生态系统凋落物分解的影响。结果表明:各物种凋落物的分解速率存在显著差异,经过345 d的分解,多枝柽柳、盐角草及混合物在不同N处理间的分解速率分别为0.64~0.70、0.84~0.99和0.71~0.81 kg·kg-1·a-1。凋落物分解过程中,N、P均表现为养分的直接释放,试验结束时,N0、N5、N10和N20处理单种凋落物及其混合物N分别释放60.6%~67.4%、56.7%~62.6%、57.4%~62.3%、46.8%~63.0%,P分别释放51.9%~77.9%、59.9%~74.7%、53.0%~79.9%、52.3%~76.4%。N处理对单种凋落物及其混合物的分解影响不显著,但各种凋落物的养分动态对N添加的响应不同,N处理抑制了盐角草N、P释放及混合凋落物P释放,而对多枝柽柳无影响。在温带荒漠,适量的N输入对凋落物分解速率影响不大,但可能会延缓个别物种养分向土壤系统的归还。A litterbag decomposition experiment was carried out in southern Gurbantunggut Desert, with four nitrogen treatments: N0(0 g N·m-2·a-1), N5(5 g N·m-2·a-1), N10(10 g N·m-2·a-1) and N20(20 g N·m-2·a-1). The aims were to examine the effects of exogenous nitrogen addition on decomposition rate and nutrient release of Tamarix ramosissima, Salicornia europaea and their mixture. Results showed that decomposition rates were significantly different among litter types. After 345 days, the decomposition rates of T. ramosissima, S. europaea and their mixture under different treatments were 0.64-0.70, 0.84-0.99 and 0.71-0.81 kg·kg-1·a-1, respectively. Both mono-and mixed-litters exhibited nutrient release during decomposition process, with the release rates being 60.6%-67.4%, 56.7%-62.6%, 57.4%-62.3%, 46.8%-63.0% for N, and 51.9%-77.9%, 59.9%-74.7%, 53.0%-79.9%, 52.3%-76.4% for P, respectively for the N0, N5, N10 and N20 treatments. Nitrogen addition did not affect litter decomposition rate. The dynamics of N and P during decomposition of different litter types showed different responses to nitrogen addition. Nitrogen addition inhibited N and P releases of S. europaea litter and P release of the mixed litter, but did not affect the nutrient release of T. ramosissima. The results suggested that nitrogen input would not promote litter decomposition in temperate desert ecosystems, but might retard the nutrient returning to soil system.

关 键 词：凋落物分解 N添加 荒漠生态系统 分解速率 养分释放 

分 类 号：Q948[生物学—植物学]