| 摘要: |
| 通过对西江流域肇庆三叉顶市区自然保护区典型样地调查，对比分析了林地(针阔混交林、竹林、马尾松林)、农用地（果园、稻田、旱地)与邻近荒地的0～20cm土壤有机碳含量和密度特征及其影响因子。结果表明：（1）有机碳含量大小顺序为林地(20.71±5.24 g kg-1 )> 农用地 (13.50±6.05 g kg-1 ) >荒地(12.87±4.20g kg-1 )。林地比农用地、荒地表土有机碳含量分别高出34.81％和37.86％。林地表土有机碳含量极显著高于农用地和荒地，而农用地和荒地间则无显著差异。表土有机碳密度差异极显著，有机碳密度大小顺序为林地（3.09±0.88 kg m-2）>荒地（2.99±0.93 kg m-2）>农用地（2.28±1.01 kg m-2）。（2）针阔混交林、竹林、马尾松叶林3种林分类型的表土有机碳含量、密度的大小顺序均为针阔混交林>竹林>马尾松林；在有机碳含量方面，针阔混交林与马尾松林有显著差异；3种林分中，针阔混交林、竹林均与荒地有显著差异，而马尾松林与荒地则无显著差异。在有机碳密度方面，针阔混交林）>竹林>马尾松林，针阔混交林与马尾松林有显著差异。（3）3种农用地有机碳含量大小顺序为果园)>稻田>旱地，果园与旱地之间有显著差异，旱地有机碳含量比果园低58.09%，旱地与水稻田之间无显著差异，3者与荒地均无显著差异。有机碳密度顺序有所变化，大小顺序为果园>旱地 >稻田，3者之间均无显著差异，但旱地、水稻田均与荒地有显著差异。（4）土壤氮水平、电导率对林地、农用地土壤碳固定有正效应，而容重则有负效应；而受施肥和耕作等因素影响，农用地的表土有机碳含量还与石砾含量显著负相关；荒地的土壤有机碳含量则仅与容重显著负相关。 |
| 关键词: 土地利用变化,土壤有机碳含量, 土壤有机碳密度 |
| DOI： |
| 分类号: |
| 基金项目:广东省林业局项目“广东省森林生态效益监测站建设与研究” |
|
| Impact of Different Land Use on Topsoil Organic Carbon in Middle-lower Reacher or West River Basin, Guangdong Province |
|
Zhou Yi
|
| Abstract: |
| Carbon storage and sequestration is considered to be an important issue in study of terrestrial C cycling and global climatic change, Regional C pool estimate is a fundamental data for describing C pool dynamics under human activities. Through comparing the concentration and density of soil organic carbon(SOC)and its distribution in soil profiles under forestry soil(Mixed conifer, Bamboo forest, Pinus forest)，farmland soil(orchard soil, paddy soil ,dryland soil)， and not-till soil in Zhaoqing Sanchading Nature reserve of Zhaoqing city, this paper show (1) there are difference SOC pattern in difference land use, the concentration was in the order of forestry soil (20.71±5.24 g kg-1) > farmland soil (13.50±6.05 g kg-1)> not-till soil (12.87±4.20g kg-1 ) there was significant difference between forestry soil and farmland soil , not-till soil , the concentration of S0C under not-till soil and farmland soil were 34.81％ and 37.86％lower than that under forest soil , respectively. the range order of the soil carbon organic density was forestry soil（3.09±0.88 kg m-2）> not-till soil（2.99±0.93 kg m-2）> farmland soil（2.28±1.01 kg m-2）。there was significant difference between forestry soil , not-till soil and farmland soil.(2) there are difference SOC pattern in difference forestry type, the concentration and density was in the order of Mixed conifer > Bamboo forest> Pinus forest, which last one is 28.13％ lower than that of front one, and comparing with not –till soil ,there was significant difference in mixed conifer ,Bamboo forest and no significant difference with Pinus forest. In density, there was significant difference between Mixed conifer, and Pinus forest, which last one is 2.32 kgm-2of 31.16％ lower than that of front one, which is 3.39kgm-2.(3) In difference farmland type, the concentration was in the order of orchard soil(16.06 gkg-1) > paddy soil(12.24 gkg-1) > dryland soil(9.33 gkg-1), there was significant difference between orchard soil and dryland soil, and no significant difference between paddy soil and Pinus forest, which the lowest is 58.09％ lower than that of the largest . in density, the order of orchard soil(2.63 kgm-2) > dryland soil(1.98 kgm-2) >paddy soil(1.87 kgm-2) there was no significant difference with each other due to human activities. (4) Comparing with not-till soil, that is only negatively correlated with bulk density, forestry land soil and farmland soil, the SOC content is positively correlated with soil nitrogen content and Ce, negatively correlated with bulk density, and the SOC content of farmland soil is negatively correlated with Content of rock fragments due to human activities. |
| Key words: Land use change,Soil organic carbon,Concentration and density |
