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通过野外样方实测,研究长春城市森林群落结构特征对城市森林降温作用的影响.结果表明:不同郁闭度等级城市森林温度随时间呈现相同的波动上升趋势;群落郁闭度越高,城市森林温度越低;城市森林群落结构特征影响城市森林降温效应的大小,其中,郁闭度、叶面积指数、树高对降温效应的影响最显著,而胸径、密度、树干基部断面积与城市森林降温作用关系不显著;郁闭度及树高与降温强度呈线性正相关,郁闭度每增加10%,降温效应增加0.5℃,树高每增加10 cm,降温效应增加0.05℃;叶面积指数与降温强度呈非线性正相关,叶面积指数对降温调节功能存在作用阈值,为0.23~2.3,叶面积指数位于该阈值内时,降温强度随叶面积的增加而迅速提高.
The results showed that the urban forest temperature in different canopy density cities showed the same fluctuation trend with time; the higher the community canopy density was, the higher the urban forest The lower the temperature is, the lower the temperature is. The structure of urban forest community affects the cooling effect of urban forest. Among them, canopy density, leaf area index and tree height have the most significant effects on the cooling effect, while the DBH, density, There was a linear positive correlation between canopy density and tree height and cooling intensity. For every 10% increase in canopy density, the cooling effect increased by 0.5 ℃. For every 10 cm increase in tree height, the cooling effect increased by 0.05 ℃. Leaf area index The cooling intensity showed a non-linear positive correlation, and the leaf area index had a threshold of 0.23 ~ 2.3 for the function of cooling regulation. When leaf area index was within this threshold, the cooling intensity increased rapidly with the increase of leaf area.