摘要
【目的】选择与林内小气候舒适度相关的城市森林冠层结构指数,为进一步优化城市森林结构、改善城市森林热环境提供参考。【方法】以与城市森林降温效应相关度较高的一维度冠层结构指标(包括叶面积指数、平均叶倾角、冠层厚度、枝下高、冠高比和冠层通透度)为基础,从林内外空气流动和能量交换的角度,构建多维度城市森林冠层结构指数,通过相关分析筛选对小气候舒适度解释度较高的城市森林冠层结构指数。【结果】一维度冠层结构指标与林内舒适度(S)、舒适度相对变化(Sd)呈弱度相关关系,对S的解释力为0~30.5%,对Sd的解释力为0~53.5%;多维度冠层结构指数对S和Sd的解释程度明显提升,对S的解释力为0~37.5%,对Sd的解释力为30.9%~55.1%;热垂直扩散结构指数和热水平扩散结构指数的协同作用对S的解释程度相对较高(43.5%);垂直冠层指数和树冠垂直均匀指数的协同作用对Sd的解释程度最高(63.9%)。【结论】城市森林舒适度和舒适度相对变化受多个冠层结构指标和指数共同影响,所构建的多维度冠层结构指数(包括热垂直扩散结构指数、热水平扩散结构指数、综合热扩散结构指数、垂直冠层指数、树冠均匀指数、树冠垂直均匀指数和冠层综合指数)与林内小气候舒适度及其相对变化相关性较高。
【Objective】In order tooptimizethe structure of the urban forestsand to improve thermal environment,canopy structure indices related to comfort of microclimate were constructed and screened.【Method】One dimension canopy structure indicators(including leaf area index,mean tilt angle of leat,canopy thickness,under branch height,ratio of canopy thickness to tree height,and the permeability of the canopy),highly correlatedwith urban forest cooling effect,were selected to construct multidimensional canopy structure indices on the basis of both air flow and energy exchange in and out of the forests.Furthermore,correlation analysis was used to select canopy structure indices with high explanation to the microclimate comfort in the forests.【Result】The one dimension canopy structure indicators were weakly correlated with the comfort degree in the forest(S)and the relative variationin comfort(Sd),whose explanatory power to S was between 0 and 30.5%and the explanatory power to Sd was between 0 and 53.5%;The multidimensional canopy structure indices significantly improved the interpretation to S and Sd,which were 0 to 37.5%and 30.9%to 55.1%respectively;The synergistic effect on S of the structure index for vertical heat diffuse and the structure index for horizonta heat diffuse was 43.5%relatively large.The synergistic effect on Sd of the vertical canopy index and the canopy vertical evenness index was 63.9%,the highest,among others.【Conclusion】The comfort and the relative variationin comfortin urban forests are influenced by several structureindicators and indices jointly.The multidimensional canopy structure indices(including structure index for vertica heat diffuse,structure index for horizontal heat diffuse,comprehensive structure index for heat diffuse,vertical canopy index,canopy uniformity index,canopy vertical evenness index and comprehensive canopy index),constructed in this paper are highly correlated with comfort degree and its relative variation,providing a reference for the optimization of urban forest structure.
作者
刘海轩
吴鞠
许丽娟
徐程扬
Liu Haixuan;Wu Ju;Xu Lijuan;Xu Chengyang(College of Forestry, Beijing Forestry University ,Beijing 100083)
出处
《林业科学》
EI
CAS
CSCD
北大核心
2020年第2期32-39,共8页
Scientia Silvae Sinicae
基金
林业公益性行业专项(20140430102)
关键词
城市森林
降温效应
舒适度
冠层结构
叶面积指数
urban forest
cooling effect
degree of comfort
canopy structure
leaf area index