青南青北寒冻雏形土地温状况比较及对牧草产量的影响

青海南北二地寒冻雏形土分布区，由于海拔高度及地理环境不同，气候变化差异显著。但分析二地地温变化特征发现，青南青北地温分布趋势基本相似，差异不甚明显。这主要与二地土壤质地和湿度、植被覆盖程度不同等有关。表明地温变化是在气候引起变化的基础上叠加了局地土壤-植被性状影响下的结果。当年冬春地温低时，对应牧草产量较高，而地温较高的年份则牧草产量低，究其原因可能与地温低，土壤冻结深厚坚实，地表蒸发减小，易贮存较多的土壤水分有关。

The Mat-acryic Cambisols Ground Temperature and Its Influence on Herbage Yield in South and North Qinghai

The climate change difference of Mat-Cryic Cambisols and area in south and north Qinghai is significant because of different elevation and geological environment. Based on the variation features of ground temperature, the distribution of ground temperature are basically similar because of soil structure, soil moisture and vegetation coverage. Because of low annual and monthly mean temperature from June to September of soil at the depth of 50 cm, the soils in south and north belong to Mat-Cryic Cambisols. The annual difference of soil temperature of north is more obvious than that of south. The results also show that the variation of ground temperature resutts from ground-temperature features in limited area on the basis of the fluctuation caused by climate change. The herbage yield is higher with low ground temperature while it is lower with high ground temperature in winter and spring. Maybe the reasons are correlated with low ground temperature, the depth and stiffness of frozen soil, the dwindled evaporation of ground surface, more stored soil water.