不同类型园林植物群落冠层的截留能力研究

Canopy Interception Ability of Different Types of Garden Plant Communities

[目的]对不同类型园林植物群落冠层截留能力进行研究,为选择冠层截留效果最优的植物群落配置提供理论依据。[方法]选取7种不同结构的植物群落采用实测法分别测定林外降雨量、林下穿透雨量、树干茎流量,再利用水量平衡法求得冠层截留量,进行分析对比。[结果]单层针阔混交林的冠层截留率达到了49.86%,截留效果最好。单层阔叶灌木截留率为23.66%,截留效果最差。林外降雨量与林下穿透雨量、树干茎流量、冠层截留量呈线性正相关,拟合系数R~2均在0.9左右。对冠层特性与冠层截留能力进行相关性分析的结果为,叶面积指数、郁闭度、冠层厚度、绿化覆盖面积和三维绿量与穿透率呈负相关,与截留率呈正相关。[结论]园林植物群落冠层对雨水有一定的截留能力,且不同类型的群落有一定的差异性,单层阔叶灌木的截留率最低,单层针阔混交林的截留率最高;叶面积指数与郁闭度越高、冠层越厚、绿化覆盖面积与三维绿量越大,园林植物群落的冠层截留能力越好。

[Objective] The canopy interception ability of different types of garden plant communities was determined in order to provide a theoretical basis for selecting the plant community with the best canopy interception effect. [Methods] We selected seven plant communities with different structures, and measured actual throughfall and stem flow. We used the water balance method to obtain canopy interception. [Results] The greatest canopy interception rate(49.86%) was observed for a single-layer coniferous and broad-leaved mixed forest. The lowest interception rate(23.66%) was observed for a single-layer broad-leaved shrub canopy. The throughfall, stem flow, and the canopy interception were linearly and positively correlated with rainfall amount(R~2 of about 0.9). Leaf area index, canopy closure, canopy thickness, green coverage area, and three-dimensional green quantity were negatively correlated with penetration rate, and positively correlated with interception rate. [Conclusion] The canopy of a garden plant community has the ability to retain rainwater, and different types of communities have different abilities. The interception rate of the single-layer broadleaved shrub canopy was the lowest, and that of the single-layer coniferous and broadleaved mixed forest was the greatest. Greater leaf area index and canopy density, thicker canopy, larger green cover area and three-dimensional green quantity all lead to greater canopy interception capacity of a garden plant community.