【摘要】 明确生长季不同土地覆被类型土壤呼吸变化规律及其对水热因子的响应,对于干旱区土壤碳循环研究有重要意义。为此,采用LI-COR 8100土壤呼吸观测系统对河西走廊荒漠–绿洲过渡区荒漠梭梭(Haloxylon ammodendron)林地、绿洲农田、人工杨树(Populus gansuensis)林地生长季的土壤呼吸进行测定,分析3种土地覆被类型土壤呼吸变化特征及其对水热因子的响应。结果表明,荒漠梭梭林地、绿洲农田、人工杨树林地生长季土壤呼吸速率分别为0.59、2.67和3.16μmol·(m2·s)–1。生长季土壤呼吸的月变化受土壤温度和土壤水分的共同影响,其中土壤呼吸与土壤温度的关系用线性模型和指数模型均拟合较好,而与土壤水分的关系较复杂,呈二项式函数关系。生长季不同土地覆被类型土壤呼吸日变化过程呈单峰曲线,主要受土壤温度日变化的影响。更多还原

【Abstract】 For the study of soil carbon cycling,it is important to investigate the effects of hydrothermal factors on soil respiration under different land cover types in arid areas.In this study,soil respiration during the growing season under three land cover types(Haloxylon ammodendron plantation,oasis field,and poplar plantation) was measured in a desert-oasis ecotone in Northwest China.The response of soil respiration to hydrothermal factors under the three land cover types was analyzed.There were differences in monthly soil respiration among the three land cover types.From April to September in 2016,soil respiration was 0.59 μmol·(m2·s)–1 in the H.ammodendron plantation,2.67 μmol·(m2·s)–1 in the oasis field,and3.16 μmol·(m2·s)–1 in the poplar plantation.The monthly variation in soil respiration was influenced by both soil temperature and soil moisture.The relationship between soil temperature and soil respiration can be simulated by linear and exponential equations,whereas the relationship between soil moisture and soil respiration was more complex and had a quadratic function.For all three land-cover types,the diurnal variation in soil respiration showed a single-peak curve,which was mainly affected by soil temperature.更多还原