【作者】 王光华；

【导师】 刘琪璟；

【作者基本信息】 北京林业大学 ， 森林经理学， 2012， 博士

【摘要】 在应对全球气候变化背景下,森林碳汇成为当前研究的核心内容之一。现阶段有关北京山地森林和城市园林绿地碳储量的数据主要基于森林资源清查资料及以往建立的有关模型计算而来,缺乏森林碳储量估算所需的针对北京地区的基础参数(如生物量转化和扩展系数、单木生物量模型),所得的估算值存在较大不确定性,仍未形成一套适合北京实际的森林碳汇计量和监测技术体系。本研究以北京山地森林和城市园林绿地乔木为研究对象,采用嵌套回归方法无损测定样木生物量,建立适用于北京地区的12种主要树种单木生物量方程；同时,基于“北京市植物种质资源调查项目”的调查资料(2007—2009),建立侧柏林、刺槐林、桦树林、阔叶树林、栎树林、落叶松林、杨树林和油松林等北京8种主要森林类型生物量转化和扩展系数(BCEF),以及基于2009年TM影像建立8种主要森林类型的碳储量遥感估算模型；在此基础上,基于2005年北京森林资源二类调查资料(2004)和2009年TM影像分别估算了2004年和2009年北京山地森林碳储量,基于2005年北京市城市园林绿化普查资料和2009年崇文区园林绿地乔木调查数据估算了2005年和2009年崇文区园林绿地乔木碳储量以及2005年北京城市园林绿地乔木碳储量,并估算了2011—2015年北京森林植被固定的碳。主要研究结果如下：(1)2004年和2009年北京山地森林碳储量分别为5240 490.8 tC和6158970.6tC,平均碳密度分别为12.03 tC·hm-2和14.14 tC·hm-2(含地上和地下部分)；8种森林类型中,栎树林、杨树林、油松林的碳储量较大,刺槐林和落叶松林的碳储量较小；从空间分布特征来看,2009年北京山地森林碳储量主要分布在密云、延庆和怀柔3个区县；从0-10、10-20、20-30和>30tC·hm-2四个碳密度区间来看,多数森林分布在10-20 tC·hm-2区间,主要分布在北部山区。(2)2005年和2009年崇文区园林绿地乔木碳储量分别为8022.09和8541.29 tC,根据2005年的园林绿地面积(539.96 hm2),碳密度分别为14.86和15.82tC·hm-2。(3)2005年北京全市园林绿地乔木碳储量约为122.07×104tC,按园林绿地面积计算碳密度,全市平均碳密度为31.40 tC·hm-2,16个区县的平均碳密度与其碳储量不成正相关；16个区县中,碳储量比较多的区县主要是城市功能扩展区所在区县,约占总碳储量的70%。(4)基于库—差别方法估算得到2004年至2009年北京山地森林的碳汇为0.42tC·hm-2·year-1,2005年至2009年北京崇文区园林绿地乔木的碳汇为0.24 tC·hm-2·year-1。据此估算得到,2011年至2015年北京山地森林和北京城市园林绿地乔木固定的碳分别为914550.0 tC和46453.08 tC,年平均固定的碳分别为182910.0 tC和9330.62 tC,2011—2015年二者合计固定的碳达961003.08 tC。更多还原

【Abstract】 In local and global contexts of attempting to mitigate climate change, carbon sequestration by the world’s forests is a focus of global climate change researches. At present, estimated values of carbon storage by mountain forests and urban landscape in Beijing are derived from forest inventory data and models developed pastly. However, there is significant uncertainty in these estimations because of lacking correspondingly basic parameters suitable for the Beijing region, including biomass conversion and expansion factors and allometric models, and thus a useful technique framework for estimating and monitoring carbon sequestration by Beijing’s forests is now lacking.The major research objects of this study are mountain forests and trees in urban green spaces in the whole Beijing area. Diameter-based aboveground biomass equations were developed for twelve tree species using a non-destructive method, named as the nested sampling method, in Beijing, and biomass conversion and expansion factors and TM-based models for estimating carbon stored by eight major forest types, including Platycladus orientalis forest, Robinia pseudoacacia forest, Betula forest, Broad-leaved forest, Quercus forest, Larix principis-rupprechtii forest, Populus forest and Pinus tabulaeformis forest, on the basis of data from the program "Beijing plant germplasm resources survey" (2007-2009) and TM images acquired in 2009. Then, carbon stock in mountain forests in 2004 and 2009 were estimated based on 2005 Beijing forest inventory data and TM images acquired in 2009, and carbon storages by trees in urban green spaces in Chongwen District in 2005 and 2009 and in the whole study area in 2005 were also estimated, respectively, based on 2005 Beijing City urban green space census and 2009 tree survey data in Chongwen District’s urban green spaces. Carbon sequestered by Beijing’s forests from 2011 to 2015 was projected depending on Beijing’s forest carbon storage estimates of this study. The main results include as follows:(1) Beijing’s mountain forest carbon stocks in 2004 and 2009 were 5 240 490.8 tonnes carbon and 6 158 970.6 tonnes carbon (including above- and belowground carbon storage), respectively, with mean carbon storage densities of 12.03 tC·hm-2 and 14.14 tC·hm-2. Among the eight forest types, carbon storages were higher in Quercus forest, Populus forest and Pinus tabulaeformis forest and lower in Robinia pseudoacacia forest and Larix principis-rupprechtii forest. According to four carbon storage densities of 0-10,10-20,20-30 and >30 tC·hm-2, Beijing’s mountain forest carbon storage densities mostly varied from 10 tC·hm-2 to 20 tC·hm-2 in 2009, mainly found in the northern mountains.(2) Urban trees in Chongwen District in 2005 and 2009 stored 8 022.09 and 8 541.29 tonnes carbon, respectively, with average carbon densities of 14.86 tC·hm-2 and 15.82 tC·hm-2 based on the district’s green space area of 539.96 hm2 in 2005.(3) Urban trees in Beijing’s 16 districts and counties stored roughly 1 220 700.00 tonnes carbon with mean carbon density of 31.40 tC·hm-2, and average carbon densities of the 16 cities were not directly proportional to their carbon stocks. Among the 16 cities, urban trees in the cities belonging to urban capability expansion region stored the most carbon accounting for 70% of total carbon storage.(4) Based on an pool-difference method, it was estimated that carbon sequestration rates of Beijing’s mountain forests (from 2004 to 2009) and Chongwen District’s urban trees (from 2005 to 2009) were 0.42 tC·hm-2·year-1 and 0.24 tC·hm-2·year-1, respectively. Mountain forests and urban trees in the whole study area will sequester 914 550.00 tonnes carbon and 46 453.08 tonnes carbon from 2011 to 2015, respectively, amount to 961 003.08 tonnes carbon, with average carbon sequestered per year of 182 910.0 tonnes carbon and 9 330.62 tonnes carbon.更多还原