青藏高原冻融一水蚀凹陷对高寒沼泽草甸土壤呼吸的影响  

Effects of Depressions Formed by Freeze-Thaw and Water Erosion on Soil Respiration in Alpine Marsh Meadow in Qinghai-Tibet Plateau

作　　者：丁俊霞 周贵尧[2] 陈克龙[3,4] 陈生云 崔航[1,3] Ding Junxia;Zhou Guiyao;Chen Kelong;Chen Shengyun;Cui Hang(College of Geographical Sciences,Qinghai Normal University,Xi’ning,Qinghai 810008,China;School of Ecology and Environmental Science,East China Normal University,Shanghai 200241,China;MOE Key Laboratory of Tibetan Plateau Land Surface Processes and Ecological Conservation,Qinghai Normal University,Xi’ning,Qinghai 810008,China;Science and Technology Department,Qinghai Normal University,Xi’ning,Qinghai 810008,China;Sate Key Laboratory of Cryospheric Science,Northwest Institute of Eco-envirorment and Resources,Chinese Academy of Sciences,Lanzhou,Gansu 730000,China)

机构地区：[1]青海师范大学地理科学学院,青海西宁810008 [2]华东师范大学生态与环境科学学院,上海200241 [3]青海师范大学青藏高原地表过程与生态保育教育部重点实验室,青海西宁810008 [4]青海师范大学科技处,青海西宁810008 [5]中国科学院西北生态环境资源研究所冰冻圈科学国家重点实验室,甘肃兰州730000

出　　处：《水土保持通报》2020年第1期17-23,共7页Bulletin of Soil and Water Conservation

基　　金：国家自然科学基金项目“青海湖内陆高寒湿地景观尺度碳库动态测定与模拟”(41661023);青海省科技计划项目基金(2014-ZJ-723);青海省科技计划项目基金(2018-ZJ-T09);青海省科技计划项目基金(2019-SF-A12)。

摘　　要：[目的]探究青藏高原长期的冻融与水蚀造成的凹陷对高寒沼泽草甸土壤呼吸的影响,为探讨和评估高寒沼泽草甸碳循环过程提供一定的科学依据.[方法]以青海湖北岸冻融—水蚀凹陷的高寒沼泽草甸为研究对象,选取了非冻融—水蚀凹陷区和冻融—水蚀凹陷区,2019年5月监测土壤呼吸、5 cm土壤温度、5 cm土壤含水量及空气温度和空气相对湿度,2018年8月观察了植被群落特征(优势种、地上生物量、植物高度、群落盖度).[结果]①冻融水蚀凹陷区的平均土壤呼吸速率显著低于非冻融水蚀凹陷样区.②冻融水蚀造成地表下陷,下陷的洼地微生态系统具有类似盆地的聚温保湿效应,因此在凹陷样区中空气相对湿度显著增加,空气温度降低,5 cm土壤温度显著增加(p<0.05),以上环境要素的变化深刻影响着土壤呼吸.[结论]青藏高原冻融水蚀过程形成的凹陷改变了高寒沼泽草甸土壤环境,使原生系统的土壤呼吸发生变化,进而影响高寒沼泽草甸生态系统碳循环.[Objective]The effects of depression caused by long-term freezing-thawing and water erosion on soil respiration in Qinghai-Tibet Plateau were studied to provide a scientific basis for the evaluation of carbon cycling process at an alpine marsh meadow.[Methods]We conducted a field experiment at an alpine marsh meadow with a depression and a non-depression in Qinghai-Tibet Plateau.We measured the air temperature,relative air humidity,soil respiration,soil temperature,and moisture content at 5 cm depth in May 2019,and investigated plant traits,such as dominant species,above-ground biomass,plant height,and community coverage in August 2018.[Results]①The average rate of soil respiration in the depression caused by freezing-thawing and water erosion was significantly lower than those in non-depression regions;②Freezing-thawing and water erosion causeed the surface sink,leading to an increase in relative air humidity and a decrease in air temperature,which was similar to the polythermal effects of basin regions.The depression caused by freezing-thawing and water erosion increased soil temperatures at 5 cm depth,and had a profound impact on soil respiration.[Conclusion]The depression caused by natural freezing-thawing and water erosion processes of Qinghai-Tibet Plateau changes the soil environment and the soil respiration in the primary system,which further modifies the carbon cycle of alpine marsh meadow ecosystem.

关 键 词：土壤呼吸 冻融—水蚀凹陷 高寒沼泽草甸 

分 类 号：K903[历史地理—人文地理学] P463.23[天文地球—大气科学及气象学]