黑河上游天涝池流域不同植被类型下露水凝结规律

Dew condensation of different vegetation types in Tianlaochi catchment in the upper reaches of the Heihe river

选择祁连山中段黑河上游天涝池小流域作为研究区,在草地、灌丛冠层和下层、青海云杉林1.8、1.0 m和地面(苔藓)处进行露水凝结量的观测,并用相应的公式对草地、灌丛冠层和青海云杉林实际露水量进行了估算.结果表明:非降雨日露日数较多,露日频数大.除青海云杉林下层(苔藓)外,其他观测到的露水强度都有两个峰值,一个出现在6月下半月,另一个出现在8月.草地、金露梅和鬼箭锦鸡儿冠层生长季估算露水量所占同期降雨量的比例分别为5.58%、6.67%、3.65%;青海云杉林距地面1.8、1.0、0 m观测的露水量分别占同期降雨量的2.28%、2.82%、3.16%.总体来看,研究区降雨事件较多,非降雨日中出现露水的概率较大.草地和灌丛的露水量大于青海云杉林地面层(苔藓)的,青海云杉林1.8、1.0 m处的露水量最小.草地、灌丛和青海云杉林3种生态系统进行比较,露水对青海云杉林生态系统的作用至关重要,因为苔藓是青海云杉林生态系统的重要组成部分.

The study area is located in Tianlaochi catchment in the upper reaches of Heihe river. The ex- periments were conducted in grassland, shurblands and Qinghai spurce forest. Then, some formulas were used to calculate the actual dewfall. The results showed that the number of dew days was more in non rainfall day. There were two peaks of dewfall appearing in later June and August except for the Qinghai spruce understory （moss mats）. The estimated dewfall in grassland, Potentilla fruticosa and Caragana jubata accounted for 5.58%, 6.67% and 3.65% of rainfall in the same period respectively. And the dew- fall of Qinghai spruce from the ground 1.8 m, 1.0 m and 0 m accounted for 2.28%, 2.82% and 3.16% of rainfall, respectively. On the whole, there were more rainfall events in the study area, and there was a greater probability of dew in non rainy days. The dewfall of grass and shrubs was greater than that of Qin- ghai spruce forest understory. And compared with other places, the dewfall of Qinghai spruce from the ground 1.8 m and 1 m was the smallest. The dew and atmospheric humidity had played a key role in the growth of moss. Because moss was an important part of Qinghai spruce forest, the effect of dew on the ecosystem of Qinghai spruce was greater than shrub and grassland.