摘要
通过调查和对比不同密度土壤碳在亚热带森林生态系统土壤剖面中的垂直分布规律,分析和探讨森林生态系统不同类型土壤在分解、分馏、沉积和保存碳元素方面发挥的重要作用。本研究在云南哀牢山亚热带湿性常绿阔叶原生林生态系统中进行,以上游森林生态系统原生土和下游草地生态系统淤积土为研究土壤类型,采用分层取样的方法,观察土壤剖面中根层土壤(0~45 cm)不同密度有机碳的垂直分布规律,并对比分析土壤碳密度分级法和重铬酸钾氧化法测定土壤全碳含量的差异。研究结果表明:在6个土壤剖面、2种不同类型的土壤剖面中,土壤轻组碳、中组碳、重组碳和全碳均呈衰减式指数分布,且4个测定指标在淤积土土壤剖面的各个土层中的含量明显高于原生土土壤剖面相对应的各个土层中的含量,说明单位体积淤积土在沉积土壤碳方面发挥的作用比原生土要大。在所测定的3种不同密度的土壤碳中,轻组碳含量最低,中组碳次之,重组碳最高,说明大部分土壤碳与矿物质形成团聚体而不能被土壤微生物、土壤动物和植物根系直接利用;3种不同密度土壤碳占土壤全碳的比例数据中,轻组碳和中组碳的比例随着土层深度的增加而减少,重组碳的比例则随着土层深度的增加而增加,说明不同土层在沉积和保存不同密度土壤碳方面发挥的作用有异。本研究成果为全球热带和亚热带森林生态系统不同密度土壤碳在各种不同类型土壤剖面中的沉积速率和储量等方面的研究工作扩展新的调查内容和研究方向。
By investigating and comparing the vertical distribution pattern of soil carbon with different densities along the soil profile in the subtropical forest ecosystem,this study analyzed the important role of different types of soil in the decomposition,fractionation,deposition and preservation of carbon elements with varying densities in the forest ecosystem.This study was carried out in the subtropical moist evergreen broad-leaved primary forest ecosystem in Ailao Mountains of Yunnan Province.It took the primary soil of the upstream forest ecosystem and the warp soil of the downstream grassland ecosystem as the research soil types.With the stratified sampling method,we collected soil samples,and observed the vertical distribution pattern of soil organic carbon with different densities in the root layer(0-45 cm) in the soil profile.The study further compared and analyzed the differences between the soil carbon density fractionation method and the potassium dichromate oxidation method for determining soil total carbon.The results showed that the light carbon,middle carbon,heavy carbon and soil total carbon all were distributed in a decaying exponential pattern in the six soil profiles and two soil types,and the contents of the four measurement indicators in each soil layer of the warp soil profile were significantly higher than those of the primary soil profile in the corresponding depth of the soil layer,indicating that the unit volume of warp soil played a greater role in depositing soil carbon than the primary soil.Among the three kinds of soil carbon with different densities,the light carbon content was the lowest,the middle carbon content was the second,and the heavy carbon content was the highest.This finding indicated that most of the soil carbon formed soil aggregates with minerals and could not be directly used by soil microorganisms,soil animals and plant roots.Among the proportions of the three soil carbons with different densities in total soil carbon,the proportions of light carbon and middle carbon decreased with the increase of soil depth,and the proportion of heavy carbon increased with the increase of soil depth,indicating that different soil layers played different roles in depositing and preserving soil carbon with varying densities.The results of this study expand the scope and dimension of the research on the deposition rate and storage of soil carbon with different densities in various types of soil profiles in tropical and subtropical forest ecosystems.
作者
孔令迁
刘宪斌
李云
KONG Lingqian();LIU Xianbin;LI Yun(School of Chemistry,Biology and Environment,Yuxi Normal University,Yuxi,Yunnan 653100;Institute of Biology and Environmental Engineering,Yuxi Normal University,Yuxi,Yunnan 653100)
出处
《中国农学通报》
2023年第23期8-16,共9页
Chinese Agricultural Science Bulletin
基金
云南省教育厅大学生创新创业训练计划项目“森林凋落物和根系分泌物对土壤活性碳的影响”(2021A024)
云南省教育厅科学研究基金项目“季节性干旱对云南次生常绿阔叶林碳库和养分循环的影响”(教师类项目:2019J0739)。
关键词
土壤剖面
土壤轻组碳
土壤中组碳
土壤重组碳
多钨酸钠
哀牢山亚热带湿性常绿阔叶林
原生土
淤积土
soil profile
soil light carbon
soil middle carbon
soil heavy carbon
sodium polytungstate
subtropical moist evergreen broad-leaved forest in Ailao Mountains
primary soil
warp soil
