【作者】 张波；

【导师】 王文杰；

【作者基本信息】 东北林业大学 ， 植物学， 2017， 硕士

【摘要】 实地观测研究城市森林遮荫、降温增湿功能及其影响因素,是构建具有更高环境效益的城市绿化工程的基础,而一个系统的大尺度的调查还很有限。本研究分别分析了哈尔滨和长春市城市森林4类林型——单位附属林、道路林、风景游憩林和生态公益林。分别测量每一样地内主要树种的测树因子(树高、枝下高、冠幅、胸径周长)和绿地内外环境因子(光照强度、空气温度、土壤温度、空气湿度、树木冠层温度及冠下温度),定量研究了不同林型在遮荫、降温、增湿效应之间的差异及其与外界环境、测树因子之间的关系,以便为城市森林生态服务功能评估和管理提供科学依据。比较两城市间城市微气候调节功能、测树因子和外界气候条件之间的差异,为指导城市树木管理、优化城市森林结构提供理论依据。主要研究成果如下:(1)哈尔滨城市森林遮荫、增湿程度分别为77%~90%、4.5%;水平平均降温约2.95 ℃左右、土壤降温1~2 ℃左右,而垂直降温能力较弱;4类不同林型遮荫、降温、增湿效应差异显著,总效益综合得分排名风景游憩林明显比其它三类林分平均高19%;香坊区城市森林遮荫、降温(水平、垂直、土壤)效果好于其他行政区,而松北区增湿效果最好。城市森林遮荫、降温、增湿等生态服务功能在高温、晴朗和低湿环境下更强;树高、枝下高、冠幅和胸径周长对树木遮荫、降温增湿效果也有显著影响,且多表现为高大树木具有更明显的生态服务功能,但较环境因素作用小;不同森林类型具有明显的微气候调节相关生态服务功能差异,对于风景游憩林应继续维持其高生态服务功能,对于环境调节能力较低的森林类型应加强管理。(2)长春城市森林可以阻挡掉入射太阳光的74%~86%;空气相对湿度平均增加3%~7%;水平可降温3.5℃;垂直降温方面表现为冠层温度低于冠下温度1 ℃左右;土壤降温在1 ℃内。4类林分类型遮荫、降温和增湿效应差异显著,综合得分表现为:单位附属林>道路林>生态公益林>风景游憩林。空间分布图显示市中心微气候调节功能较差,朝阳区最好;回归分析表明,长春城市森林在高光强、高温、低湿时有较强的调节作用,高大的树木在微气候调节功能方面也存在一定的作用。(3)哈尔滨与长春市城市森林树木长势大小较一致,均以小树居多(<10m),大树较少,但两城市相比较,哈尔滨树木显著高于长春树木21cm,冠幅显著大于长春树木约25m~2,胸径周长也显著高出约25cm。长春外界气候较哈尔滨热,光辐射量是哈尔滨1.45倍,气温高哈尔滨1.1℃。长春城市森林除土壤降温外其他微气候调节功能均高于哈尔滨。冗余分析表明,城市森林微气候调节功能与外界气候条件的相关性比测树因子强,且随着光强、温度、测树因子的增大,其生态服务功能增强。城市森林微气候调节功能发挥最主要的限制因子是裸地光强。更多还原

【Abstract】 Field observation on urban forests shading,cooling humidification effect and its influencing factors,is a foundation to build an urban greening engineering with better environmental effect,while a systematic large-scale study is limited.The study analyzed the 4forest types of urban forests in Harbin and Changchun city respectively(Affiliated Forests,Roadside Forests,Landscape Forests and Ecological Welfare Forests).Tree growth-related parameters and environmental factors(inside and outside the forest)were measured simultaneously.The quantitative studied of differences between 4 forests types in shading,cooling and humidifying effects and their associations with the environmental and tree growth characteristics.The aims of this study were to provide scientific basis for the evaluation and management of urban forest ecological service functions.This paper compared the differences between urban forests ecological service functions,tree size and external climatic conditions between Harbin and Changchun city,which provides the theoretical basis for the management of urban trees and the optimization of urban forests structure.This study reached the following results:(1)Urban forests produced a 77%~90%reduction of sun lights(shading effect)and 4.5%increases in relative humidity(humidifying effect).The horizontal average cooling effect was2.95 ℃ lower than open sites(outside forests).Soil cooling effect was about 1~2 ℃ lower under canopy than outside forests.But the vertical cooling was poor.Shading,cooling and humidifying effects were significant differences among 4 different forest types.The comprehensive scores for all these microclimate regulations demonstrated that LF was 19%higher than the other 3 forest types on average.Xiangfang District urban forests shading,cooling(horizontal,vertical,soil)effect was better than other administrative regions,and the best humidifying effect in Songbei District.Urban forests had much stronger regulating functions at high air temperature,low air humidity sunny days.Moreover,4 tree-growth factors[tree height,canopy area,under branch height and DBH(diameter at breast height)]had significant influences on temperature reduction and relative humidity increase,and the general patterns were that larger trees usually accompany with higher regulating functions,but its influence was less than environmental factors.Our findings highlight that different forest types in different urban regions had dramatically different ecological service functions,and comparison among forest types facilitates urban tree management for maximizing microclimate regulations functions.For the landscape forests,we should continue to maintain its high ecological service functions and strengthen the management of the forest types with low environmental regulation ability.(2)Urban forests could reduce 74%~86%of incident sun lights,3%~7%increase in air relative humidity in Changchun city.The horizontal average cooling effect was 3.5 ℃;Soil cooling effect was about 1℃ lower under canopy than outside forests.The vertical cooling effect characterized as canopy temperature about 1℃ lower than under canopy temperature.Shading,cooling and humidifying effects significantly differed among the 4 forest types located at different urban regions,and comprehensive scores for all these microclimate regulations showed a peak value in AF.The overall score is expressed as AF>RF>EF>LF.The spatial distribution map showed that microclimate regulation functions of the city center was poor,the best in Chaoyang Distric.Regress analyses and redundancy analysis revealed that urban forests had much stronger regulating functions at high air temperature,low air humidity sunny days,while a general pattern of larger trees usually accompany with higher regulating function in cooling,shading and humidifying effects.(3)Urban forest trees were small and mostly in Harbin and Changchun city(<10m),which may lead to their low ecological service functions and could not give full play to their ecological benefits.Compared with the two cities,the trees size of Harbin was significantly higher than that of the Changchun 21cm,and the canopy size was significantly larger than that of Changchun 25m~2,and the DBH was significantly higher than that of about 25cm.The external climate of Changchun was hotter than Harbin.Changchun city light radiation was1.45-fold higher than Harbin,the temperature was 1.1℃ higher than Harbin.The shading of Harbin urban forests was significantly higher than that of Changchun,but it was lower than that of Changchun in terms of cooling(horizontal and vertical)and humidifying effects.更多还原