【作者】 邢乐杰；

【导师】 王鹏程； 雷静品；

【作者基本信息】 华中农业大学 ， 生态学， 2008， 硕士

【摘要】 随着人类经济的快速发展，环境问题日益突出，尤其是大量使用化石燃料而引发的“温室效应”已成为当今世界面临的最为严峻的全球性环境问题。森林作为陆地生态系统的主体，对维持生态平衡、保护生态安全、防止生态危机起着决定性的作用。三峡库区位于长江流域的咽喉，属生态敏感区，因此，准确预测三峡库区森林生态系统碳储量对研究区域碳循环及碳汇问题意义重大。本文通过研究森林系统三个层次的有机碳储量及碳密度，估算了库区整个森林系统的有机碳储量及碳密度，并以库区分布最广、最具代表性的马尾松林为例，对影响系统有机碳密度的因素进行了研究，主要获得了以下结论：(1)三峡库区森林生态系统共分为11个植被类型，各植被类型植被层生物量密度大小次序依次是：常绿阔叶林>针阔混交林>落叶阔叶林>马尾松林>针叶混交林>杉木林>经济林>竹林>温性松>柏木林>灌木林；各植被类型的生产力大小次序依次是：竹林>常绿阔叶林>杉木林>马尾松林>针叶混交林>落叶阔叶林>温性松林>针阔混交林>经济林>灌木林>柏木林。(2)三峡库区不同植物不同器官含碳率测定结果表明，植物含碳率平均为0．4903，不同树种不同器官的含碳率之间无显著差异。库区森林生态系统植被层总碳储量为58．54×10~6t，各植被类型植被层碳储量分别为：马尾松林21．88×10~6t；柏木林2．11×10~6t；杉木林1．54×10~6t；温性松林0．91×10~6t；针叶混交林5．83×10~6t；针阔混交林6．00×10~6t；常绿阔叶林2．71×10~6t；落叶阔叶林7．72×10~6t；灌木林7．05×10~6t；经济林2．18×10~6t；竹林0．60×10~6t。(3)三峡库区11种森林植被类型下凋落物生物量密度大小顺序为：杉木林>温性松林>落叶阔叶林>常绿阔叶林>马尾松林>针叶混交林>竹林>针阔混交林>柏木林>灌木林>经济林。库区森林生态系统中凋落物现存总量为1755．04×10~4t。各林分凋落物枯落物含碳率平均值为0．3638，含碳率高低次序依次为：马尾松林>杉木林>竹林>温性松林>针叶混交林>针阔混交林>柏木林>落叶阔叶林>常绿阔叶林>灌木林>经济林，凋落物含碳率的高低对其有机碳存量有重要影响。三峡库区森林生态系统凋落物有机碳总储量为667．28×10~4t，各森林植被类型凋落物有机碳库存量分别为：马尾松林265．59×10~4t、灌木林105．84×10~4t、落叶阔叶林88．23×10~4t、针叶混交林64．00×10~4t、针阔混交林47．36×10~4t、杉木林24．92×10~4t、常绿阔叶林20．10×10~4t、温性松林19．60×10~4t、柏木林18．50×10~4t、竹林8．40×10~4t、经济林4．76×10~4t。各植被类型凋落物平均碳密度是2．64t／hm~2，各凋落物有机碳密度大小顺序是：杉木林(4．48t／hm~2)>温性松林(4．02t／hm~2)>马尾松林(3．53 t／hm~2)>针叶混交林(3．02 t／hm~2)>落叶阔叶林(2．99 t／hm~2)>常绿阔叶林(2．94t／hm~2)>竹林(2．55 t／hm~2)>针阔混交林(2．28 t／hm~2)>柏木林(1．51 t／hm~2)>灌木林(1．30 t／hm~2)>经济林(0．42t／hm~2)。(4)三峡库区土壤A层有机碳含量平均值为22．11g/kg，B层为12．57g／kg，土壤A、B层间有机碳含量差异显著。库区植被类型土壤A层有机碳密度平均值为56．3t／hm~2，各植被类型的土壤A层有机碳密度大小顺序为：柏木林>灌木林>落叶阔叶林>温性松林>杉木林>针叶混交林>针阔混交林>常绿阔叶林>马尾松林>竹林>经济林。库区森林土壤B层碳密度平均值为34．7t／hm~2，各植被类型B层有机碳密度大小顺序为：柏木林>杉木林>温性松林>落叶阔叶林>灌木林>经济林>竹林>针叶混交林>针阔混交林>马尾松林>常绿阔叶林；库区土壤有机碳储量总量为2．21×10~8t，其中A层土壤碳储量为1．48×10~8t，B层土壤碳储量0．73×10~8t。(5)三峡库区森林生态系统总有机碳储量为285．97×10~6t，系统平均碳密度为117．31 t／hm~2，各森林植被类型系统碳密度大小排序及密度值为：柏木林(144．08t／hm~2)>杉木林(139．02 t／hm~2)>落叶阔叶林(125．89 t／hm~2)>温性松林(125．33 t/hm~2)>竹林(117．85 t／hm~2)>针叶混交林(113．28 t／hm~2)>经济林(112．54 t／hm~2)>常绿阔叶林(110．25 t／hm~2)>马尾松林(107．08 t/hm~2)>针阔混交林(102．23 t/hm~2)>灌木林(92．87 t／hm~2)，系统有机碳库储量中，系统内各层次所占比例差异较大。植被层有机碳储量所占比例范围在9．33％-36．02％之间，土壤层在61．32％-89．27％之间，凋落物层在0．37％-3．30％之间。(6)对库区马尾松植被类型样地分析发现：系统有机碳密度与土壤养分高低整体上呈一致性；海拔升高与系统碳密度的增加表现为一致性；东西样地有机碳密度差异较小，南北样地有机碳密度差异较大，对不同坡度的样地有机碳密度进行相关分析发现，坡度与系统有机碳密度呈相反趋势。更多还原

【Abstract】 With the development of the society and economy of the human beings, the environmental problem has become increasingly severe. greenhouse effect, which caused by fossil fuel combustion, has become one of the serious global environment problems. As main part of the terrestrial ecosystem, forests play a decisive role in maintaining ecological balance, protecting ecological safety and preventing ecological crisis. Three Gorges Reservoir Area is an ecologically sensitive area, accurately predicting carbon storage is significant for researching regional carbon cycle and carbon sink. In this study, carbon storage and carbon density of forestry ecosystem in Three Gorges Reservoir Area had been estimated by researching carbon storage and carbon density in three layers of the forestry ecosystem. Masson pine forest, which was the widest in distribution in Three Gorges Reservoir Area, was taken for example, the main factors that influenced the system carbon density were studied. Our results indicated that:(1) Vegetation ecosystems in Three Gorges Reservoir Area were divided into 11 types, the biomass density in vegetation layer of diverse vegetation types showed an order : evergreen broad-leaved forest>coniferous-deciduous mixed forest> deciduous broad-leaved forest>Masson pine forest>coniferous mixed forest> Chinese-fir forest >bamboo forest>economic forest> temperate pine forest>Cypress forest>shrubbery. The sequence of NPP was that: bamboo forest>evergreen broad-leaved forest>Chinese-fir forest>Masson pine forest>coniferous-deciduous mixed forest>deciduous broad-leaved forest>coniferous mixed forest>economic forest>temperate pine forest>Cypress forest>shrubbery.(2) The mean vegetation layer carbon content rate of diverse vegetation types in Three Gorges Reservoir Area was 0.4903, and tissues carbon content rate were similar among of diverse tree species. The total carbon storage of vegetation layer was 58.70×10~6t, and Masson pine forest was 21.88×10~6t, Cypress forest was 2.11×10~6t, Chinese-fir forest was 1.54×10~6t, temperate pine forest was 0.91×10~6t, coniferous mixed forest was 5.83×10~6t, coniferous-deciduous mixed forest was 6.00×10~6t, evergreen broad-leaved forest was 2.71×10~6t, deciduous broad-leaved forest was 7.72×10~6t, shrubbery was 7.05×10~6t, economic forest was 2.18×10~6t, and bamboo forest was 0.60×10~6t, respectively.(3) The biomass density in litter of 11 vegetation types from high to low was that: Chinese-fir forest>temperate pine forest>deciduous broad-leaved forest>evergreen broad-leaved forest>Masson pine forest>coniferous mixed forest>bamboo forest> coniferous-deciduous mixed forest>Cypress forest>shrubbery>economic forest. The total litter biomass of vegetation types in Three Gorges Reservoir Area was 17.55×10~6t. The mean litter carbon content rate of diverse vegetation types was 0.3638, the sequence was that: Masson pine forest>Chinese-fir forest>bamboo forest >temperate pine forest>coniferous mixed forest>coniferous-deciduous mixed forest>Cypress forest>deciduous broad-leaved forest>evergreen broad-leaved forest >shrubbery>economic forest, and the carbon content rate of litter was significant for its organic carbon content. The total litter carbon storage of vegetation types in Three Gorges Reservoir Area was 667.28×10~4t, and Masson pine forest was 265.59×10~4t, Cypress forest was 18.50×10~4t, Chinese-fir forest was 24.92×10~4t, temperate pine forest was 19.60×10~4t, coniferous mixed forest was 64.00×10~4t, coniferous-deciduous mixed forest was 47.36×10~4t, evergreen broad-leaved forest was 20.10×10~4t, deciduous broad-leaved forest was 88.23×10~4t, shrubbery was 105.84×10~4t, economic forest was 4.76×10~4t, and bamboo forest was 8.40×10~4t, respectively. The mean litter carbon density of diverse vegetation types was 2.64 t/hm~2, and Chinese-fir forest(4.48t/hm~2)> temperate pine forest(4.02t/hm~2)>Masson pine forest(3.53t/hm~2)>coniferous mixed forest(3.02t/hm~2)>deciduous broad-leaved forest(2.99t/hm~2)>evergreen broad-leaved forest(2.94t/hm~2)>bamboo forest(2.55 t/hm~2)>coniferous-deciduous mixed forest(2.28t/hm~2)>cypress forest( 1.51 t/hm~2)>shrubbery( 1.30t/hm~2)>economicforest(0.42t/hm~2).(4) Carbon content in the soil at two levels(A and B) were various, the mean carbon content of layer A was 22.11g/Kg, and layer B was only 12.57 g/Kg. The mean layer A carbon density of diverse vegetation types was 56.3 t/hm~2, and the sequence of carbon density in layer A of diverse vegetation types was that: cypress forest>shrubbery>deciduous broad-leaved forest>temperate forest>Chinese-fir forest>coniferous mixed forest>coniferous-deciduous mixed forest>evergreen broad-leaved forest>Masson pine forest>bamboo forest>economic forest. The mean layer B carbon density of diverse vegetation types was 34.7 t/hm~2, and the sequence of carbon density in layer B of diverse vegetation types was that: cypress forest>Chinese-fir forest>temperate forest>deciduous broad-leaved forest>shrubbery>economic forest>bamboo forest>coniferous mixed forest>coniferous-deciduous mixed forest>Masson pine forest>evergreen broad-leaved forest. The total soil carbon storage of vegetation types in Three Gorges Reservoir Area was 2.21×10~8t, layer A was 1.48×10~8t and layer B was 0.73×10~8t, respectively.(5) The total forestry ecosystem carbon storage of Three Gorges Reservoir Area was 285.97×10~6 t.The mean carbon density of forestry ecosystems was 117.31 t/hm~2, the sequence of diverse vegetation types was that: cypress forest( 144.08 t/hm~2)> Chinese-fir forest(1 39.02 t/hm~2)>deciduous broad-leaved forest(125.89t/hm~2)>temperate pine forest(125.33 t/hm~2)>bamboo forest(117.85 t/hm~2)> coniferous mixed forest(113.28 t/hm~2)>economic forest(112.54 t/hm~2)> evergreen broad-leaved forest(110.25 t/hm~2)> Masson pine forest( 107.08 t/hm~2)>coniferous-deciduous mixed forest( 102.23 t/hm~2)> shrubbery(92.87 t/hm~2). The ratio of diverse layers to system carbon storage were various, vegetation layer ranged from 9.33% to 36.02%, litter layer ranged from 0.37% to 3.30%, and soil layer ranged from 61.32% to 89.27%, respectively.(6) Masson pine forest plots were studied, it suggested that system carbon density showed an obverse linear relationship with nutrient, an inverse linear relationship with slope angle, and a weak tendency to increase with altitude. Plot carbon density was similar from East to West, but variously from South to North in Three Gorges Reservoir Area.更多还原