三江源区高寒草原土壤湿度变化特征及与气候因子的关系

利用青海省三江源区兴海县牧业气象站1999-2016年高寒草原土壤湿度、牧草生育期资料,分析了高寒草原土壤湿度的年、季变化特征以及牧草生长季不同生育期土壤湿度的变化特征及与气候因子的关系。结果表明:高寒草原0-10、10-20、20-30、30-40和40-50 cm土壤湿度均随年际延长呈增加趋势,春季除40-50 cm土层外,其他各层土壤湿度均随年际延长呈显著增加趋势(P<0.05)。高寒草原牧草生长季的土壤相对湿度随年际延长呈显著上升趋势(P<0.05),且与生长季降水量之间呈极显著正相关关系(P<0.01)。随着气候变化,牧草抽穗、开花、成熟和枯黄期的土壤相对湿度随年际延长呈显著增加趋势(P<0.05)。牧草抽穗期、枯黄和全生育期的土壤湿度与气温呈显著负相关关系(P<0.05)。高寒草原牧草生长季土壤湿度的增加有利于草地植被生长。

Alpine grassland soil moisture variation characteristics and its relationship with climate factors in Three River Source

The data supporting this study were collected during 1 9 9 9—2 0 1 6 from the pastureland weather station of Xinghai County,Qinghai Province,at the Three River Source.They included soil moisture content and herbage growth period.We analyzed the changes of alpine meadow soil moisture characteristics,the soil moisture change characteristics at different stages,and their relationship with the herbage growth period.The results showed that the soil moisture content in each layer increased from 0—5 0 cm in the alpine grassland,the soil moisture was sig-nificantly increased trend of each layer in spring 0 to 4 0 cm,the soil moisture increase rate decrease with the in-crease of soil depth.Soil moisture content during growing seasons increased significantly from 1 9 9 9—2 0 1 6,and it correlated significantly with precipitations during the growing seasons.At the flowering stages,soil moisture con-tent was significantly positively correlated with atmospheric temperature.Moreover,at the heading stages and throughout the whole growing season,they were significantly negatively correlated with atmospheric temperatures. The increase of soil moisture content in alpine meadow growth season is beneficial for grassland vegetation growth.