摘要
以黄土丘陵区9、23、33、47 a油松人工林为研究对象,分析油松人工林不同发育阶段土壤有机碳质量分数和土壤有机碳密度的变化规律,结合土壤全氮质量分数和土壤密度、枯落物现存量、根系生物量指标,分析其影响因素。结果表明：1）9、23、33和47 a油松人工林0~100 cm土层平均土壤有机碳质量分数分别为4.9、5.9、9.2和6.5g/kg,土壤有机碳密度分别为63.0、66.8、100.7和72.5 mg/hm2,二者均表现为随林龄变化先增大（9~33 a）后减小（33~47 a）的趋势,土壤有机碳质量分数和密度垂直分布规律明显,即随土层深度增加而减小,其中,0~30 cm土层土壤有机碳密度占0~100 cm土层碳密度的48.5%~57.9%;2）相关性分析及拟合结果显示,土壤有机碳质量分数与全氮质量分数、枯落物现存量和根系生物量存在极显著线性正相关关系,与土壤密度呈线性负相关关系,根系生物量、枯落物现存量与土壤有机碳质量分数的相关性随着土层深度的增加逐渐减小,逐步回归分析结果表明,土壤全氮质量分数和枯落物现存量是土壤有机碳质量分数最主要的影响因素。
We analyzed the content and density of soil organic carbon along a chronosequence of Pinus tabulaeformis plantations（ 9,23,33 and 47 years old） in the Loess Hilly Region,and explored the relationships between soil organic carbon content and main factors affecting it,i. e.,total nitrogen,soil particle density,root biomass and litter biomass. The results showed that the average contents of soil organic carbon were 4. 9,5. 9,9. 2 and 6. 5 g / kg,and the densities of soil organic carbon were 63. 0,66. 8,100. 7 and 72. 5 mg / hm2,for 9-,23-,33- and 47-year-old plantations,respectively. Both the content and density of soil organic carbon increased first（ 9- 33 years） and then decreased（ 33- 47years） over stand age. In addition,the content and density of soil organic carbon decreased gradually assoil depth increased. The density of organic carbon in surface soil layer（ 0- 30 cm） accounted for48. 5%- 57. 9% of that of the entire observed soil layer. 2） The soil organic carbon content had a significantly positive correlation with total soil nitrogen,root biomass and litter biomass. However,there was a significantly negative relation between soil organic carbon and soil particle density. The correlation coefficients between soil organic carbon content and root biomass and litter biomass decreased gradually with soil depth increasing. The result of stepwise regression indicated that total soil nitrogen and litter biomass were the main factors affecting soil organic carbon content.
出处
《中国水土保持科学》
CSCD
北大核心
2015年第3期76-82,共7页
Science of Soil and Water Conservation
基金
中国科学院先导专项"中国科学院暖温带落叶阔叶混交林区域陕西省森林固碳现状
速率和潜力研究"(XDA05050203-05)
国家自然科学基金"黄土丘陵区森林植物-凋落物-土壤化学计量特征耦合关系及对非生物环境因子的响应"(41371506)
中国科学院西部之光项目"黄土高原人工林土壤养分平衡与生产力维持机制"(K301021304)
关键词
油松人工林
土壤有机碳质量分数
土壤有机碳密度
影响因素
黄土丘陵区
Pinus tabulaeformis plantations
soil organic carbon content
soil organic carbon density
influencing factors
the Loess Hilly Region
