【作者】 徐少君；

【导师】 曾波；

【作者基本信息】 西南大学 ， 生态学， 2012， 博士

【摘要】 全球变暖是国际社会公认的全球性环境问题,由此引起的气候变化和剧烈波动将对人类的生存、经济和社会发展等方面产生极其深远的影响。植被由于能够吸收和存贮导致全球变暖的温室气体——C02,并表现出巨大的碳汇作用,因而在减缓全球变化中具有不可替代的重要作用,其面积的任何增减、植被组成和质量状况、分布格局和碳汇潜力等,均会对区域环境和全球变化影响很大,因此,研究植被动态变化、格局与碳汇能力,具有重要的理论价值和现实意义。重庆位于三峡库区的心腹地带,是全国重要的水资源战略贮备库,又是中国西南重要碳库区的组成部分；重庆缙云山国家自然保护区是重庆,也是亚热带地区典型的植被资源丰富区域；此外,重庆直辖和三峡库区形成以来,重庆的经济发展和“森林重庆”建设取得了瞩目的成就,所以关注重庆和缙云山植被及其碳储量动态和格局,对于以“增汇减排”和减缓全球变暖为目标的植被和碳汇经营与管理,均具有重要的战略意义,也可以为重庆的发展与规划提供理论和数据上的有益帮助。分别以重庆市和重庆主城区为研究对象,通过重庆市Pathfinder AVHRR NDVI和SPOTVGA NDVI序列数据集及重庆主城区1978、1988、2000和2007年的Landsat卫星遥感影像提取的NDVI,分别对重庆市及主城区近30年植被状况进行水平格局和动态分析。结果显示,重庆市植被有明显的年际变化特征,每年的12月至第二年的2月,植被的生长和活动最不旺盛,而绿期表现在每年的5～10月。近10年来,重庆植被总体处于良好生长状态,增长最明显的区域集中在方斗山、精华山和假角山等渝中北的山脉及渝东南的广大山地区域,负增长主要为重庆主城区、长寿及万州等的城市中心区域。巫溪、城口和綦江三区县植被无退化现象,而重庆主城区植被恶化面积最大,达到了近420km2,其次为长寿和奉节等区县。对重庆主城区近30年的植被动态研究结果显示,主城区的植被生长良好区域集中在东北部及南部地区,主要表现在北部的缙云山、华蓥山、铜锣山和南部的子荡山及圣灯山等山脉,而在西部城市化最为明显的广大城区,植被退化或消失现象较为明显。研究结果表明,重庆市的植被处于良好的增长状态,弥补了城市化过程中局部植被退化或消失的不利影响。而保护好植被发育较好的山区和较大的山脉,以及控制好城市发展过程中对植被的负面影响,是继续保持和提高重庆植被质量、使其处于良好发展态势的关键举措。以重庆缙云山为例,通过面向对象多层次分类的方法介绍和使用,结合对1：10000地形图数字化生产的DEM,建立分类规则对重庆市缙云山自然保护区2010年9月的WorldView-2遥感影像进行解译,提取了研究区域的植被信息,并将其分为常绿阔叶林、针阔混交林、针叶林、针竹(慈竹)混交林、毛竹林、慈竹林和灌木林,分类的初步结果在ArcGIS中进行进—步人工解译、拓扑处理和统计分析。结果显示,基于面向对象多层次图像分类方法并结合人工解译,对缙云山植被具有很高的识别和分类精度,总精度高于89.22%以上,分类的植被结果有明显的边界和均一的内部同质性；研究区域的总面积为3468.41hm2,植被以针叶林为和灌木林为主,面积分别达到了1048.56hm2和729.64hm2,两者占到研究区面积的51%,其次是针阔混交林,面积为537.26hm2,农田、水体、道路和房屋等非植被占7%,面积为242.32hm2。由此可知,高分辨率的遥感影像、高分辨率的地形图,是研究较大尺度上植被空间特征的最有效的工具；结合DEM和基于面向对象的图像解译和分类的方法,及其生产的植被专题图,可以为缙云山植被的空间分布和碳储量研究提供数据和基础技术支持。以重庆缙云山为例,利用高分辨率影像(、VorldView-2)解译植被专题图和1：10000地形图生成数字高程模型,结合野外样方调查、文献中植被生物量回归(经验)模型和碳含量数据资料,在ArcGIS支持下对缙云山自然保护区植被和碳储量密度空间分布进行研究。研究显示,缙云山植被以针叶林为主(30%),人为干扰程度较高的灌木林也占有相当大的比例(21%),地带性顶极植被——常绿阔叶林面积较小(6%)；碳储量密度为针阔混交林(74.23MgC/hm2)>针叶林(62.97MgC/hm2)>常绿阔叶林(62.65MgC/hm2)>针竹混交林(59.84MgC/hm2)>慈竹林(48.72MgC/hm2)>毛竹林(47.88MgC/hm2)>灌木林(10.66MgC/hm2),平均碳储量密度高于全国和同地区的平均值,达到了50.45MgC/hm2；在空间分布上,针叶林在中高海拔(>500m)和斜坡(>15。)以上优势明显,灌木林则相反,针阔混交林、常绿阔叶林的优势随着海拔升高或坡度增大而增加,植被的碳储量密度也随海拔的增高或坡度增大而增势明显。结果表明缙云山积累和存贮了较多的碳,“库”的功能强；而处于演替阶段初期的针叶林及灌木林明显占优,表明其在碳的积累上还有很大的提升空间,具有“汇”的潜能。此外,在较高海拔和较大坡度上的高碳储量密度,与人类的活动频度较小和对植被干扰较轻相关。因此可以推测,随着自然演替和保护区的封育改造、退耕还林及择伐补阔等森林管理措施的进行,将利于森林植被的保护、发育和更新,促使缙云山森林生态系统的碳储量密度进一步增大,碳“汇”潜能进一步增强,生态服务功能和价值得到进一步提高。以重庆缙云山国家自然保护区内亚热带森林演替系列中的灌木林、针叶林、针阔混交林、常绿阔叶林为研究对象,通过分别对各林型生态系统的植被、枯落物和土壤的碳储量密度进行研究,明确不同演替类型植被生态系统的碳储量密度和分配格局特征,并对森林演替过程中碳汇的特点和潜能行进探讨。结果表明：(1)4种演替序列上的植被生态系统碳储量密度与演替序列一致,即常绿阔叶林(347.96MgC/hm2)>针阔混交林(140.19MgC/hm2)>针叶林(107.92MgC/hm2)>灌木林(51.28MgC/hm2)；(2)组成生态系统的植被和枯落物碳储量密度在演替序列上变化一致,均呈增大的趋势,均值从灌木林的10.57MgC/hm2和4.55MgC/hm2分别增加到处于地带性顶极植被——常绿阔叶林的95.55MgC/hm2和191.33MgC/hm2；而针阔混交林、针叶林和灌木林的土壤碳储量密度的均值较为接近,分别为33.31MgC/hm2、32.48MgC/hm2和36.45MgC/hm2,均低于常绿阔叶林的61.03MgC/hm2；(3)生态系统碳储量在各组分格局上差别很大,在演替序列上,除演替顶极的常绿阔叶林外,地上植被所占的比例逐渐增大；土壤碳储量密度所占的比例,随着演替序列呈下降的趋势,其中灌木林土壤碳储量密度所占的比例最高,接近其生态系统的2/3,针叶林约占1/3,针阔混交约为1/4,常绿阔叶林约为1/5；但对不同林型的枯落物而言,在演替序列上增势非常明显,从灌木林的不足1/10到常绿阔叶林的1/2以上。由此可知,缙云山的常绿阔叶林维持着最大的碳储量,枯落物在缙云山的碳库中有着重要的作用；缙云山的植被在今后的发育和演替过程中,有很大的增汇潜能,将主要集中在生态系统的植被和枯落物碳库部分,因此在保护现存植被而增加碳汇的经营和管理中,植被形成的枯落物也是重点保护和管理的对象。根据1km×1km重庆植被专题图,结合数字高程模型(DEM)和文献中不同植被类型的碳储量密度数据,在ArcGIS的空间分析模块中,对重庆市植被及其碳储量密度进行空间格局分析。结果显示,重庆的植被有着明显的空间分异特征,森林植被以常绿阔叶林、针阔混交林为主,两者面积之和达到了31899.38km2,占到了重庆总面积的37.04%,主要集中在渝北和渝南地区,渝中和渝西的条形山脉森林植被也较为丰富；被条形山脉分割的渝中北、渝中和渝西地区地势较低,是重要的农业种植区,农业种植总面积达到了45629.41km2,占到了重庆总面积的52%；灌木林的面积也较大,为5732.49km2。重庆碳储量密度和重庆植被的分布相一致,高密度区集中在渝北和渝南海拔较高的地区,各区县的平均碳储量密度在4.39～54.76MgC/hm2,城口和巫溪有着最高的碳储量密度,分别达到了54.76MgC/hm2和42.31MgC/hm2,渝西的潼南最低,仅为4.39MgC/hm2,全市碳储量密度平均值为21.40MgC/hm2；重庆碳储量密度有明显的垂直分异特征,碳储量密度随着海拔的增加而增势明显,在2000～2200m达到极值(53.29MgC/hm2),然后略有下降,在海拔2600m以上为41.37MgC/hm2。结果表明,常绿阔叶林、针阔混交林和农作物是重庆最主要的植被,对重庆碳储量有着重要的贡献；提高农作物的生产量、合理的利用作物的秸秆等,以及加大灌木林更新和改造将利于重庆地区碳汇功能的提高；在区域格局上对渝北和渝南的植被进行有效的保护和管理,同时对渝中及渝西植被相对薄弱地区适当造林,是重庆地区增加碳汇的最有效措施。综上所述,本论文通过遥感、归一化植被指数数据集和数字高程模型,在地理信息系统的支持下,结合野外实地测量和文献中的数据资料,以及对高分辨率遥感影像的解译和分类,对重庆市、重庆市主城区和重庆缙云山国家自然保护区的植被及其碳储量的动态变化、格局进行了研究,结果表明：近30年来,重庆市的植被总体上处于良好的生长和发展状态,弥补了都市中心区在城市化过程中对植被的负面影响；重庆及缙云山森林植被以针阔混交林和常绿阔叶林为主,且具有较高的碳储量密度,低碳储量密度的灌木林、草丛等也占有重要的比重,重庆的农作物耕种区域主要集中在渝中北、渝中和渝西海拔相对较低的区域,且占有相当大的比重；碳储量密度较高的区域集中海拔较高和人为干扰较轻的区域,如渝北和渝南的广大山区,渝中北、渝中和渝西的条形山脉,且随着海拔梯度的增高呈增加趋势。因此,保护和管理好渝北、渝南广大地区和渝中及渝西主要山脉的森林植被,加快退耕还林、择伐补阔的实施,加速森林发育和更新,以提高森林的质量而起到增加碳汇的目的；在森林植被相对较为薄弱的地区,如渝中和渝西地区,增加人工林的种植面积,并提高农作物的产量和秸秆的利用率,起到进一步增加碳汇的功能。总之,重庆植被已经存贮了较多碳,是西南地区重要的碳库区组成部分；重庆的植被和碳储量动态、格局和碳汇能的特点意味着在未来很长的一段时间内,仍具有重要的碳汇增加潜力。更多还原

【Abstract】 Global warming, one environmental problem recognized by the international community, has resulted in climate fluctuation which would produce a far-reaching impact on human survival, economic and social development. Since plants could absorb and store CO2, one of the main greenhouse gases caused global warming, and the plantation was regarded as a huge carbon sink, the plants play an important and irreplaceable role in global change mitigation. The change of vegetation areas, plantation composition and quality condition, distribution pattern, and potential for carbon sequestration, will impact the regional environment and global change. Therefore, it is essential for theoretical and practical research on dynamics, distribution pattern, and carbon sink capacity of vegetation. Chongqing located in the key zone of the Three Gorges reservoir area, and is the major water resources strategic reserve library in China and an integral part of the important carbon reservoir area in southwest China. The national nature reserve region of Jinyun Mountain is a typical area with rich-resource vegetation in Chongqing and sub-tropical region. In addition, since Chongqing has become direct controlled municipality, the establishments of Three Gorges Reservoir and Chongqing economic development and "foresting Chongqing" construction have made remarkable achievements. Hence, concerning about Chongqing and Jinyun Mountain vegetation, their dynamics and patterns of carbon stocks would have strategic significance to vegetation and carbon sequestration business and management aiming to increase sequestration and slow down global warming, and would provide useful theory and data for the planning and development of Chongqing.Vegetation dynamics of Chongqing and its metropolitan region based on RS,GIS and NDVI Vegetation characteristics of the horizontal pattern and dynamic about nearly30years in Chongqing and its metropolitan region were analyzed through the NDVI of Pathfinder AVHRR and SPOTVGA, The NDVIs were extracted from Landsat satellite remote sensing image at1978a,1988a,2000a and2007a to analyzed vegetation change in the metropolitan region of Chongqing City. The results showed that the Chongqing vegetation had a significant interannual variation. From December to next February, the vegetation growth and metabolism were inactive, and its activity was presented from May to October in each year. Chongqing vegetation was well-grown in the past10years as a whole. Areas of vegetation growing in an obviously good condition were concentrated in the center-north of Chongqing, such as Fangdou mountain, Jinghua mountain and Jiajiao mountain, and mountain regions of southeastern Chongqing. The negative vegetation growing region appeared in the metropolitan region of Chongqing City, Changshou and Wanzhou District, etc., which were the city center area. Vegetation did not degrade in Wuxi, Chengkou and the Qijiang county. Additionally, the largest area of vegetation deterioration appeared in the metropolitan region of Chongqing City, reached nearly420km, followed by the Changshou and Fengjie county. Study about vegetation dynamics of Chongqing metropolis in nearly30years showed that the vegetation growing area were appeared in northeast and south regions, such as Jinyun mountain, Huaying mountain, Tongluo mountain in the north, and Zidang mountain, Shengden mountain in the south of Chongqing metropolis. On the contrary, the vegetation in west of metropolitan region was more degraded or disappeared. In conclusion, vegetation of Chongqing was in a good condition and compensated for the adverse effects of degradation or disappearance vegetation in the process of urbanization. Protecting the well-developed vegetation in mountain area, as well as controlling the negative impact of urban development on the vegetation, is the key measures to maintaining and improving Chongqing vegetation quality.The vegetation classification using high resolution remote sensing, digital elevation model, geographical information system and object-oriented image classification in Chongqing——a case study on Jinyun MountainIn the vegetation classification study, object oriented multi-level classification was used in interpreting Jinyun vegetation from the high-resolution remote sensing image and1:10000relief maps were used to generate digital elevation model respectively. Then vegetation of study area were exacted from the WorldView-2remote sensing image acquired in September2010. The vegetation types were divided into broad-leaved evergreen, mixed coniferous and broadleaved evergreen, coniferous forest, mixed coniferous and neosinocalsms stand, moso bamboo stand, neosinocalams stand and shrubbery. The preliminary classification results were interpreted, topology pocessed and statistical analyzed in ArcGlS. The results of classification of Jinyun vegetation showed a high recognition and classification accuracy based on object-oriented image multi-level classification approach with manual interpretation. Its overall accuracy was higher than89.22%and the classification results of vegetation had the obvious borders and homogeneous internal homogeneity. The results showed that the study area was3468.41hm2. Coniferous forest and shrubbery stands were dominated vegetation and their areas were reached1048.56hm2and729.64hm2respectively, the ratio of their areas accounted for51%of the study area, followed by mixed coniferous and broad forest, which area is537.26hm2. Water bodies, roads and other artificial surface were accounted for7%, and the total areas are242.32hm2. Therefore, high-resolution remote sensing images, high-resolution topographic maps, are efficient tools for researching large-scale forest vegetation spatial characteristics. Combined with the DEM and based on object-oriented classification and interpretation methods, and using the thematic maps of vegetation, can provide basic technology and useful data to support the researching of spatial distribution vegetation and carbon storage in Jinyun Mountain.Spatial distribution of vegetation and carbon density in Chongqing based on RS/GIS——a case study on Jinyun MountainIn this study, high-resolution remote sensing image and1:10000relief maps were used to generate Jinyun vegetation map and digital elevation model respectively, combining with a non-destructive method to acquire forest biomass by field investigation and the data of carbon content and biomass regression models from the published papers. And then, the spatial characteristics of vegetation and carbon density in Jinyun Mountain Natural Reserve were analyzed by ArcGIS. The results showed that CF was the dominating forest stand, followed by SH (shrub). The vegetation area ranged as CF (coniferous forest,30%)> SH (21%)> MCB (evergreen broad-leaved forest,16%)> NS (neosinocalams stand,11%)> EBF (evergreen broad-leaved, forest6%)> MCN (mixed coniferous and neosinocalsms stand,5%)> MBS (moso bamboo stand,4%). The average vegetation carbon density in Jinyun Mountain was50.45MgC/hm2, which was higher than the average level in China, ranged as MCB (74.23MgC/hm2)> CF (62.97MgC/hm2)> EBF (62.65MgC/hm2)> MCN (59.84MgC/hm2)> NS (48.72MgC/hm2)> MBS (47.88MgC/hm2)> SH (10.66MgC/hm2). Moreover, vegetation and carbon density had clear spatial variations with altitude, slope and aspect. CF dominated in altitude higher than500m and slope>15°, but the shrub was the other way around. The carbon density of MCB and EBF increased with the increasing of altitude and slope. EBF had a large area in the northwest aspect, and MCB had a large distribution in the north, northwest, east and southeast aspects. NS and MCN were the dominating forest stand in the south relatively. CF, dominated with Pinus massoniana, and SH were at the primary stage of forest recovery succession in the Jinyun Mountain. The results indicate that the actual carbon sequestration of Jinyun Mountain is still much lower than the potential value of the zonal climax vegetation in this subtropical area. As we find the carbon storage and density are negatively correlated with human disturbance, forest reserve managements, such as enclosure of forest region, might contribute to conserve and sequester carbon in Jinyun Mountain.The vegetation carbon density of different successional stages in Jinyun MountainIn this study, the different forest ecosystems carbon densities were researched through calculating vegetation, litter and soil carbon density. And the carbon density and its distribution pattern characteristic of different successional series of vegetation ecosystems were also discussed. It was researched that potential carbon stock and its characteristic in succession process as well. The results showed that,(1) carbon density in the four successional vegetation ecosystems were consistent with its sequence of successional stages, ranged by broadleaved evergreen(347.96MgC/hm2)> needle-broadleaved evergreen(140.19MgC/hm2)> coniferous forest(107.92MgC/hm2)> shrubbery(51.28MgC/hm2).(2) As the main ecosystem constituents of ecosystem carbon sinks, vegetation and litter carbon density in the succession sequence showed an increasing tendency with the successional times. The mean value of vegetation and litter carbon density increased from10.57MgC/hm2and4.55MgC/hm2of shrub to95.55MgC/hm2and191.33MgC/hm2of the broadleaved evergreen respectively. And soil carbon density of needle-broadleaved evergreen, coniferous forest and shrubbery were closed, ranged as33.31MgC/hm2,32.48MgC/hm2and36.45MgC/hm2respectively, and were much lower than that of broadleaved evergreen(61.03MgC/hm2).(3) Ecosystem carbon density pattern of vegetation were very different. The proportion of the vegetation carbon storage above the ground gradually increased with succession sequence, except for the zonal top forest and broadleaved forest evergreen. The proportion of soil carbon storage density showed a downward trend with the succession sequence. The proportion of shrub soil carbon density, closed to2/3of the ecosystem, was the highest. And that of the coniferous forest was about1/3of its ecosystem and that of the needle-broadleaved evergreen was closed1/4, and then that of the broadleaf evergreen was about1/5. On the contrary, the litter carbon storage proportion was increased obviously with the successional sequence, and the ratio increased from less than1/10of the shrubbery to1/2of the broad-leaved evergreen. Therefore, the broadleaved evergreen in Jinyun Mountain maintained the largest carbon reserves, and litter carbon storage played an important role in the carbon pools in this region. The vegetation in Jinyun Mountain would have a great potential increasing carbon storage in the future development and succession process, and its increasing carbon sink will mainly lead to increasing of vegetation and litter carbon pool of the ecosystem. The result also showed that the litter transformed from vegetation should be protected and managed effectively.The spatial distribution of Chongqing vegetation and carbon density based on GIS/DEM/RSIn the study, Chongqing vegetation and carbon density spatial pattern were analyzed by using1km×1km Chongqing vegetation map, combined with the data of different vegetation carbon density from the published papers and DEM, and with the ArcGIS spatial analysis module. The results showed that vegetation in Chongqing were obviously spatial distributing, with the main forest vegetation type of broadleaved evergreen and needle-leaved evergreen. These two types accounted for37.04%of the total area of Chongqing. Their areas were31899.38km2and mainly distributed in the north and south region of Chongqing, and some strip-mountains of the west and center Chongqing. West, center and north-center regions, segmented by the strip-mountains, were major agricultural areas. The total planted area reached to45629.41km2, accounting for52%of the total Chongqing area. The shrubbery area was also very large-about5732.49km2. The spatial distribution of carbon density was similar to Chongqing vegetation. High carbon density areas were concentrated in the higher elevation of north and south region. The average carbon density values of counties were from4.39MgC/hm2to54.76MgC/hm2. Chengkou and Wuxi had the highest carbon density and its mean values were54.76MgC/hm2and42.31MgC/hm2respectively. Tongnan, one county of Chongqing west, had only4.39MgC/hm2, and Chongqing average carbon density value was21.40MgC/hm2. Moreover. Chongqing carbon density had a vertical differentiation characteristic. The values of carbon density increased with increasing altitude remarkably and reached peak(53.29MgC/hm2) at2000～2200m and then decreased slightly. At an altitude of above2600m, the value was41.37MgC/hm2. The results showed that the broadleaved evergreen, needle-leaved evergreen and crops, dominated vegetation in Chongqing, made an important contribution to carbon storage. Increasing crop production and rational utilization of crop straw, as well as updating and transforming the shrubbery to the forest would be advantageous to the improvement carbon sink in Chongqing. Effectively protecting and managing forest in north and south of Chongqing, and afforesting in the west and center region timely should be the effective measures for the increasing Chongqing carbon sink. In summary, this paper aimed to study the vegetation dynamics, pattern and spatial distribution of its carbon density in Chongqing, metropolitan area of Chongqing City and national nature reserve of Jinyun Mountain, using RS, NDVI, DEM, GIS, and the data from field surveying and published papers, as well as interpreting and classifying the vegetation from the high-resolution remote sensing images. The results showed that:in the past30years, Chongqing vegetation has been in good growing and developing condition, and has been made up for the negative impact of the vegetation decreasing in the urban central area in the process of urbanization. The broadleaved evergreen and needle-broadleaved evergreen were the dominated vegetation in Chongqing and had a higher carbon density. Shrubs and herbaceous held the relatively low carbon density accounted for an important proportion. The crop cultivation area in Chongqing was mainly distributed in the low altitude area of the east and west of Chong, and occupied a large area. High carbon density areas were appeared on higher elevations where was disturbed lightly, such as the vast mountain in the north and south of Chongqing, and the strip-mountains in the center-north, center and west of Chongqing. Carbon density was increased with the increasing of elevation.Therefore, protecting and managing the forest in the north and south of Chongqing and in the mountains of the center-north, center and west of Chongqing can increase the carbon sinks effectiveness, with the measures of returning farmland to forests, replacing low carbon density plants with broadleaved evergreen and accelerating forest development rate and improving forest quality. In relatively fewer vegetation areas, such as east and west of Chongqing, afforestation, enhancing crop yield and using straw effectively would increase carbon sinks. In conclusion, carbon has been stored more by Chongqing vegetation, and it has been an important carbon pool in southwestern China. The features of Chongqing vegetation and carbon storage changing dynamics, patterns and variation tendency of carbon density present that Chongqing would still have an important carbon sink potential in the future for a long time.更多还原