城市不同绿地类型对土壤温度的调控作用

为评价城市不同绿地类型降温的差异,选择陕西渭南市具有代表性的林草混合、林地、草地及对比裸地进行地温测量,测量深度为5,10,15,20,25 cm,测量时段为14:00—16:00,20:00—22:00.结果表明,不同深度土温随时间变化而变化,两个时段各类型绿地地温都较裸地高,但晚上深层土壤差异较小;各样地相比,平均地温/深度变化斜率为裸地草地林地林草.对于林地而言,郁闭度0.9的林地5 cm深度地温较郁闭度0.65,0.55分别低出2.8℃,3.8℃,林地郁闭度对降温效应影响明显.研究证明,城市绿地的降温效应与绿地类型层次、树木郁闭度有关.

The Effective Regulation of Different Types of Urban Green Space on Soil Temperature

To evaluate the differences in the cooling effect of different types of urban green space, collecting typical grass-forest mixed, grassland and contrasted bare land sites, we analyzed the ground temperatures in depth of 5 cm, 10 cm, 15 cm, 20 cm and 25 cm at 14： 00-16： 00, 20： 00-22： 00. The results suggest the ground temperatures in different depths change over time, and each type of green space at two times is higher than bare land, but at night the difference is limited. Compared to each site, the slope of ground temperature/depth suggests bare land〉grassland〉forest land〉grass- forest mixed land. For forest land, the ground temperature at 5 cm depth of crown density 0.9 forest is lower to 2.8 ℃and 3.8℃than crown density 0.65 and 0.55, so the crown density can affect cooling effect obviously. Research proves that the cooling effect of urban green space is controlled by green space types and trees crown density.