【作者】 应天玉；

【导师】 范文义； 刘丹；

【作者基本信息】 东北林业大学 ， 森林经理学， 2009， 博士

【摘要】 城市森林是城市生态系统中的重要组成部分,它是由城市市区及其周边地区中,以木本植物为主的所有绿色植被组成,它对改善城市生态环境、促进人与自然协调、满足社会发展需求、提高人们的健康和文化生活水平有极为重要作用。以往对城市森林的研究主要局限在城市森林的景观结构上,研究如何提高城市森林的绿化率以及合理的配置城市森林的绿化结构,这是城市森林建设的基本问题之一。随着环境污染的进一步加剧,城市森林的生态功能意义突显,于是突出城市森林建设的生态功能成为城市林业建设的又一基本问题。本研究从城市森林的空间景观结构和生态功能两个方面入手对哈尔滨的城市森林进行了评价。主要开展了如下研究:1、根据城市林业的特点研究其调查监测方法,本研究提出了使用二阶抽样的方法对城市森林进行调查,研究结果表明这种调查方法适用于城市森林。2、在高空间分辨率的航空像片上对哈尔滨的绿地进行提取,结合二阶抽样的方法选择了部分样地进行实地调查,调查因子主要为树种组成、郁闭度、树高、胸径、冠幅等,计算出评价森林生态功能的绿量、生物量和碳储量,进而尺度上推到绿地斑块,组建了哈尔滨市绿地空间数据库。在此数据库的基础之上对哈尔滨森林绿地的空间景观结构进行分析。哈尔滨市建城区绿地覆盖面积约为19777.311hm~2,占全市总面积的约30%。六个市级行政区绿化水平参差不齐,以香坊区的绿地覆盖面积为最大,其他五区的覆盖面积从大到小依次为南岗区,道外区,道里区,松北区,平房区。3、以Landsat系列为基础数据,反演了哈尔滨市的热力场信息,并获得热力场景观指数,从热力场景观指数方面也对热力场进行了分析。哈尔滨的城区空间在1989年至2001年,这11年间迅速扩张,通过利用归一化建筑指数法(Normalization BuildingIndex:NDBI)的原理在与假彩色合成遥感图像相结合,并进行目视判度。分别提取出哈尔滨2001年与1989年城市边界,并进行叠加分析。在获取哈尔滨城区边界的基础上,在市区边界内进行不透水面的提取,再利用光谱混合分析原理从遥感图象中提取不透水面指数,研究了不透水面指数与城市热力场的相关性。4、对哈尔滨的城市森林的功能进行了评价,分别从绿量、生物量和碳储量几个方面来分析。对绿量和生物量的分析结果显示:绿量在2000 m~3以下时绿量每增加120 m~3温度下降1℃,当绿量大于2000 m~3时绿量每增加980 m~3温度下降1℃;当生物量在10000kg以下时生物量每增加760 kg温度下降1℃,当生物量大于10000kg时生物量每增加1650 kg温度下降1℃。因此适当的增加城市森林的绿量和生物量能够有效的降低城市温度。对碳储量的分析表明落叶松和榆树的固碳释氧能力最强,胡桃楸和蒙古栎的固碳释氧能力最弱。据此得出结论哈尔滨市城市森林景观结构基本合理,特别是香坊区和南岗区,但道里和道外区由于老城区规划不合理森林景观结构欠佳。哈尔滨森林绿量为89114863m~3,森林生物量为41601009 kg,森林碳储量为18720454 kg。对上述因子进行分析,哈尔滨森林生态功能发挥不够完善,适当的森林绿量和生物量能够有效的降低城市温度,但哈尔滨市森林绿量和生物量偏小的绿地较多,这些绿地降温效果不明显。从固碳释氧的功能来看,哈尔滨市固碳释氧能力最佳的为榆树和落叶松。更多还原

【Abstract】 Urban forest,mainly composed of all the green vegetations of primary woody plants in or around the urban areas,is an important part of ecosystem in the city,which is also a significant role in improving the urban ecological environment,promoting co-ordination between man and nature,meeting the needs of social development and improving people’s health and levels of culture and living.Previous researches on urban forest were mainly confined to the urban forestry landscape structure,on how to improve the urban green coverage rate or how to allocate a reasonable urban forestry green structure,which is one of the fundamental issues of urban forest construction.With further exacerbated pollution of environment,the significance of urban forestry ecological functions is highlighted.Therefore,it becomes another fundamental issue that giving pronominence to ecological functions of the urban forest construction.In this study,the urban forest of Harbin was evaluated on two aspects:the urban forestry landscape structure and ecological functions.The main research carried out as follows:1.Methods for monitor and investigation were studied according to the characteristics of urban forest.Then the sub-sampling method was proposed for urban forest investigation in this paper,which was very suited.The greenlands of Harbin were identified from high-resolution aerial photograph,combining with some measured sample plots which were selected by subsampling method.The investigated factors of the plots are mainly including tree species compositions,canopy densities,tree heights,breast diameters,crown widths and so on.Then, vegetation quantity,biomass and carbon storage for evaluating forestry ecological functions were calculated and transformed to green patches to build spatial database for Harbin greenlands.Last,the spatial landscape structure of Harbin was analyzed based on it.2.The green coverage area of Harbin city is about 19777.311 hm~2,accounted for 30 percent of the total city areas.And the afforestation levels of the six municipal districts were uneven that the largest green coverage is Xiangfang,the other five areas from large to small are Nangang,Daowai,Daoli,Songbei and Pingfang.3.Thermodynamic field landscape index was retrieved for thermodynamic field analysis based on Landsat data.By using the principle of Normalization Building Index(NDBI) and false color composite image for visual interpretation,it was found that the space of Harbin city zone has been expanded rapidly during the last 11 years.The city boundaries of Harbin in 2001 and 1989 were identified for overlay analysis and the impervious surfaces in the city boundary were extracted.After that,the impervious surface index was retrieved from the image by spectral mixture analysis principle. 4.The urban forestry function of Harbin was evaluated by analyzing vegetation quantity, biomass and carbon storage.The results showed that:if vegetation quantity Was less than 2000m~3,the temperature would decrease one degree for every increased 120m~3 of vegetation quantity;or else the temperature would decrease one degree for every increased 980m~3 of vegetation quantity.If biomass was less than 10000kg,the temperature would decrease one degree for every increased 760kg of biomass;or else the temperature would decrease one degree for every increased 1650kg of biomass.Therefore,the urban temperature can be reduced effectively by properly increasing vegetation quantity and biomass of the urban forest. Analysis of the carbon storage showed that abilities of carbon fixation and oxygen release of larch and elm were the strongest,the weakest were manchurian walnut and mongolian oak.It draw a conclusion that the landscape structure of Harbin urban forest is reasonable, especially Xiangfang district and Nangang district.But Daoli and Daowai districts are poor in landscape structure due to unreasonably planning.The vegetation quantity,forest biomass and forest carbon storage of Harbin are 89114863m~3,41601009kg and 18720454kg respectively. The forestry ecological functions of Harbin did not play perfectly through analyzing the factors above.Even though city temperature can be reduced by proper forest vegetation quantities and biomass,it is very small in Harbin because of the more greenlands with less vegetation quantities and biomass.From the aspect of carbon fixation and oxygen release functions,the best species for carbon fixation and oxygen release in Harbin are elm and larch.更多还原