合肥市环城公园城市森林叶面积比较研究

A comparative study on LAI of different urban forest communities in ring parks of Hefei city

应用WinSCANOPY冠层分析仪观测合肥市环城公园不同垂直结构、不同树种组成的城市森林群落的叶面积指数(LAI)。结果表明,合肥市环城公园森林群落的平均LAI为1.95,研究的四大景区拥有叶面积总量为121.7万m2,不同景区对绿量的贡献率与其拥有土地比例不相符。群落的LAI与林分结构及树种组成有关,以银杏、雪松、乌桕、枫杨等为主要冠层树种的群落拥有较高绿量;有针叶树种的单层或复层林分,其绿量一般高于仅为阔叶树种构成的群落。城市森林的功能与LAI有密切的关系,因此建议用LAI作为评价城市森林功能的重要指标,应使城市森林所占的土地面积比重与对绿量的贡献率相适应,使所有的城市森林都能充分发挥其作用。

The ring park is a typical urban forest in Hefei city,WinSCANOPY instrument for canopy analysis was employed in the paper to measure LAI of urban forest stands with different vertical structure and species composition in the park.The result show that the average LAI of the park is 1.95.The four landscape spots of the park totally have 1.217 million m2 of leaf area,but the contribution rate of leaf area that 4 spots have separately is not close match to land proportion they occupied,which indicated that LAI of urban forest stand is interrelated with stand structure and species composition;some stands composed of canopy species such as Ginkgo biloba,Cedrus deodara,Sapium sebiferum and Pterocarya stenoptera that relatively have higher value of LAI;urban forest stands with conifer canopy species for either single vertical layer structure or poly-layer one have more LAI compared to stands with broadleaf species only.Effect of urban forest is correlated with LAI.It is logically to use LAI as an important index for urban forest assessment,so as to make area proportion of green land match their contribution rate of leaf area,and make full use of arban forest.