悬铃木行道树夏季垂直降温效应测析

Measurement and Analysis of Vertical Cooling Effect on Platanus acerifolia Street Tree in Summer

在上海地区的夏季典型高温日,通过垂直实测空气温湿度的实验方法,对悬铃木行道树进行垂直方向的有遮荫与无遮荫对比实测,以了解植物的遮荫与蒸腾作用对垂直方向的空气温湿度分层影响机制。实验发现:无遮荫垂直方向的温湿度日变化受太阳辐射与空气流动影响,没有与高度相关的明显变化规律;悬铃木行道树垂直温湿度日变化受树冠层的遮荫与蒸腾作用影响,从下垫面到树冠表面的各高度分层中,日最高温度位于树冠表面,且使垂直方向上的温差加大,树冠表面和林荫下人活动层的垂直温差最高达到10℃,同时因为蒸腾作用对周围环境产生的降温使与树冠表面同高度水平方向的无遮荫测点温差达到5. 1℃。研究结果为研究植物改善室外小气候舒适性在垂直分层高度的空间作用规律提供参考。

In summer typical high temperature day in Shanghai, according to the vertical measurement of airtemperature and humidity experimental method, the comparison measurement of Platanus acerifolia in verticaldirection has been carried out with shady and shady-free condition, The purpose of this measurement is to understandthe mechanism between the shady and transpiration of plants and the temperature and humidity of air in verticaldirection, It was found that the daily change of temperature and humidity in the vertical direction without shade wasaffected by solar radiation and air flow, and there was no obvious change rule related to height, The daily variation ofvertical temperature and humidity with shade measuring point is affected by the shading and transpiration of thecanopy, In the stratification from the underlying surface to the canopy surface, the daily maximum temperature islocated on the canopy surface and the temperature difference in the vertical direction is increased, The verticaltemperature difference between the canopy surface and the active layer under the shade is up to 10 °C, At the sametime, the temperature difference caused by transpiration to the surrounding environment makes the temperaturedifference of the unshaded measuring point in the same horizontal direction as the surface of the canopy reach 5, 1 °C,This research provides a reference for studying the spatial action law of plants to improve the outdoor microclimatecomfort in vertical stratification height.