禁牧放牧下温湿度对西藏那曲地区高寒草甸土壤碳矿化的影响

发布时间：2018-04-09 08:55

本文选题：土壤温度　切入点：土壤湿度　出处：《北京师范大学学报(自然科学版)》2017年05期

【摘要】：土壤碳矿化速率具有很多的影响因素,为检测不同温度和湿度梯度对土壤碳矿化的效应,本实验以西藏那曲地区高寒草甸禁牧和放牧2种管理方式的土样为研究对象,开展室内非原状土培养实验,分别设置了5个温度梯度(5、10、15、20、25℃)和2个湿度梯度(40%和60%土壤持水力),探讨了温度和湿度对土壤碳矿化速率的影响,并结合土壤相关指标的测定,探索土壤碳矿化速率在不同水平温度和湿度下的响应机制.结果表明土壤碳矿化速率主要受温湿度的影响.放牧类型60%土壤持水力的土壤碳矿化速率在温度较低时与禁牧类型没有明显差异,随着温度的增加土壤碳矿化速率显著增加(P0.05);同一温度下,放牧类型40%土壤持水力的土壤碳矿化速率显著高于禁牧类型(P0.05).放牧类型40%土壤持水力的土壤碳矿化速率平均值为(0.66±0.03)μmol·g-1·s-1,比60%土壤持水力的高73.7%;禁牧类型60%土壤持水力的平均值为(0.27±0.01)μmol·g-1·s-1,比40%土壤持水力的高3.8%.除了温湿度的直接影响外,改变土壤微生物群落的数量和活性以及土壤的理化指标,也会影响土壤碳矿化速率.随着温度的增加,培养前期及培养后期微生物量碳的变化较小,而培养中期微生物量碳显著增加(P0.05).不同管理方式下土壤可溶性有机碳的变化也不一致.
[Abstract]:The rate of soil carbon mineralization is affected by many factors. In order to detect the effect of different temperature and humidity gradient on soil carbon mineralization, soil samples from alpine meadow grazing and grazing management in Naqu area, Tibet, were studied in this experiment.In this paper, five temperature gradients (5) and two moisture gradients (40% and 60%) were set up in non-native soil culture experiments. The effects of temperature and humidity on soil carbon mineralization rate were discussed, and the related soil indexes were measured.To explore the response mechanism of soil carbon mineralization rate at different levels of temperature and humidity.The results showed that the soil carbon mineralization rate was mainly affected by temperature and humidity.The soil carbon mineralization rate of 60% soil water holding capacity of grazing type was not significantly different from that of forbidden grazing type when the temperature was low, and the rate of soil carbon mineralization increased significantly with the increase of temperature, while at the same temperature, the soil carbon mineralization rate increased significantly.The soil carbon mineralization rate of 40% soil water holding capacity of grazing type was significantly higher than that of forbidden grazing type (P0.05).In addition to the direct effect of temperature and humidity, changing the number and activity of soil microbial communities and soil physical and chemical indexes will also affect the rate of soil carbon mineralization.With the increase of temperature, the change of microbial biomass carbon in the early and late stage of culture was small, while the biomass carbon of microorganism increased significantly in the middle period of culture.The changes of soil soluble organic carbon under different management methods were also inconsistent.
【作者单位】：北京师范大学地理科学学部地表过程与资源生态国家重点实验室;
【基金】：国家重点研发计划资助项目(2017YFC0503805) 国家自然科学基金资助项目(31770519)
【分类号】：S812.2

【相似文献】