摘要
基于 6 1个土壤剖面的数据 ,分析了鼎湖山自然保护区 4种自然植被类型 (沟谷雨林、季风常绿阔叶林、山地常绿阔叶林和山地灌木草丛 )和 4种次生植被类型 (马尾松针叶林、针阔混交林、次生季风常绿阔叶林和常绿灌丛 )的土壤有机碳贮量及其分配特征。结果如下 :(1)各植被类型土壤有机碳含量随深度增加而减少 ,但植被类型不同其减少程度不同。除 >4 0 cm土层外 ,自然植被类型的土壤有机碳含量明显高于次生植被类型。 (2 )土壤碳密度和土壤有机碳含量一样随深度增加而减少。两大植被类型间比较 ,除山地灌木草丛 >4 0 cm土层外 ,自然植被类型各个土层土壤碳密度都高于所有的次生植被类型对应的碳密度。对于整个土层而言 ,各植被类型土壤碳密度在 30 .9～ 12 7.9t/ hm2间 ,总平均为 73.9t/ hm2。 (3)各植被类型的土壤厚度平均为36 .7～ 73.3cm,总平均为 5 6 .4 cm。除了山地常绿阔叶林外 ,土壤厚度基本上沿海拔高度增加而减少。 (4)保护区各植被类型总面积为 10 2 8.4 hm2 ,土壤总碳贮量为 72 2 87.0 t,其中 0～ 10、10～ 2 0、2 0～ 4 0 cm和 >4 0 cm四个土层分别占 32 .0 %、2 0 .6 %、2 5 .8%和 2 1.6 %。自然植被土壤碳贮量在表层 (0～ 2 0 cm)的比重比次生植被的高。所有的植被类型中 ,混交林碳贮量贡献?
Land-use change that influences soil carbon storage and release within the tropics can have large implications for global carbon cycling. Changes in soil carbon following land-use change have become an international policy concern in terms of both sustained production at a local or regional scale, and the global consequences relating to increased emissions of CO_2 from terrestrial systems. There are eight types of vegetation in Dinghushan Biosphere Reserve (DHSBR), Guangdong province, and these vegetations can been divided into two classes: natural vegetation types (Ravine Rain Forest, Monsoon Evergreen Broad-Leaved Forest, Mountain Evergreen Broad-Leaved Forest, and Mountain Shrubby Grassland) and secondary vegetation types (Pine Forest, Pine and Broad-Leaved Mixed Forest, Secondary Monsoon Evergreen Broad-Leaved Forest, and Evergreen Shrub). In this paper, the storage and distribution of soil organic carbon for these classes of vegetation was studied based on 61 soil profiles. The objectives of our study were to provide basic data for the estimation of the soil carbon pool in subtropical China, and to provide information for the evaluation of ecological benefits contributed by nature reserves. The results were as follows: (1) Soil organic carbon concentration generally decreased with depth (2.46%, 1.52%, 0.96% and 0.53% for 0～10, 0～20, 20～40 and >40cm soil depth interval, respectively, with a range of 1.03～3.92%, 0.71～2.64%, 0.43～1.89% and 0.34～0.53%) in all vegetation type. Soil organic carbon concentrations under natural vegetation were significantly higher than that under secondary vegetation (1.7, 2.2 and 2.0 times for 0～10cm, 0～20cm and 20～40cm soil depth interval), except >40cm depth interval.(2) Soil carbon density (t/hm^2) for four soil depth intervals varied from 15.64 to 29.09, 9.25 to 24.86, 10.84 to 33.69 and 4.59 to 34.09, and their mean values (t/hm^2) were 23.46, 16.94, 21.20 and 17.75, respectively. For the whole soil profile, the carbon density was 53.56～111.46 t/hm^2, with a total mean of 73.92 t/hm^2. The highest carbon density value occurred in Pine Forest, and the lowest occurred in Mountain Evergreen Broad-Leaved Forest. Except for the Mountain Shrubby Grassland, soil carbon density in natural vegetation was significantly higher than that in secondary vegetation (1.7 to 2.3 times for four soil depth intervals).(3) The average soil thickness for all types of vegetation was 36.67～73.25cm, with a total mean of 51.99cm, decreasing with altitude. (4) The total carbon storage was 72287.0 t in the area of 1028.4 hm^2, with 32.0%, 20.6%, 25.8% and 21.6% in 0～10, 10～20, 20～40 and >40cm soil depth interval, respectively. It was found that natural vegetation had slightly higher proportion of organic carbon in the top 10cm of soil than the secondary vegetation. Of total soil carbon in DHSBR, 35.0% and 14.5% was contributed by Pine and Broad-leaved Forest and Monsoon Evergreen Broad-Leaved Forest, respectively.(5) By comparisons, DHSBR had lower soil carbon densities, and had higher proportion of carbon contained in the upper 20cm of soil than other regions. These results showed that human impact was one of factors that made soil organic carbon content in secondary vegetation types lower than in natural vegetation types.
出处
《生态学报》
CAS
CSCD
北大核心
2004年第1期135-142,共8页
Acta Ecologica Sinica
基金
国家自然科学基金资助项目 (3 0 2 70 2 83 )
中国科学院知识创新工程领域前沿资助项目
中国科学院华南植物研究所所长基金资助项目
广东省自然科学基金资助项目 (0 2 15 2 4)~~
关键词
土壤有机碳含量
土壤碳密度
碳贮量
碳分配
鼎湖山
soil organic carbon concentration
soil carbon density
carbon storage
carbon distribution
Dinghushan Biosphere Reserve
