黑河中游不同土地覆被类型土壤呼吸及对水热因子的响应

以黑河中游6种典型土地覆被类型（百年灌溉农田、新垦灌溉农田、人工杨树林、人工樟子松林、人工梭梭灌木林和天然荒漠草地）为研究对象，对土壤呼吸及其对土壤含水量和土壤温度的响应进行测定。结果表明：灌溉农田的土壤呼吸速率显著大于人工樟子松林地和杨树林地，人工林地显著大于荒漠草地和梭梭灌木林地。6种土地覆被类型土壤呼吸速率与土壤温度显著正相关性，Q₁₀值1.14~1.31，表明该地区土壤呼吸速率对土壤温度的敏感性低于世界平均水平；土壤呼吸速率与土壤含水量呈显著的指数关系。这表明6种土地覆被类型的土壤呼吸特征存在显著差异，且不同土地覆被类型的土壤呼吸特征与水热因子关系密切，以人类活动为主导的土地覆被变化深刻影响着荒漠绿洲生态系统水土气生的相互作用。

Soil Respiration Characters and Its Response to Hydrothermic Factors over Different Land Cover Types in the Middle Reaches of the Heihe River Basin

The soil respiration and its response to hydrothermic factors over six land cover types (e.g., old irrigation farm land, new irrigation farm land, poplar plantation, pine plantation, Haloxylon ammodendron plantation, and desert grassland) have been studied in the middle reaches of the Heihe River Basin. The results show that the soil respirations are significant different over six land cover types. The soil respiration over irrigation farmland is much larger than that over artificial woods plantation (e.g., poplar plantation, pine plantation); and that over artificial woods plantation is larger than over desert grassland and H. ammodendron plantation. The soil respiration rate is proportional to the surface temperature, with the Q₁₀ value between 1.14 and 1.31, which is below the world average level. Furthermore, the soil respiration shows an exponential increase with soil moisture. The characteristics of soil respiration are closely related to the hydrothermic factors over the six land cover types, indicating that the land changes dominated by human activities can significantly affect the interactions of water, soil, air and biological factors in desert oasis ecological system.