中亚热带土地利用方式对土壤易氧化有机碳及碳库管理指数的影响

发布时间：2018-11-11 20:57

【摘要】：为了解土地利用方式对中亚热带土壤易氧化有机碳(ROC)及碳库管理指数(CMI)的影响,采用KMn O4氧化法,对湘中丘陵区6种土地利用类型:石栎(Lithocarpus glaber)-青冈(Cyclobalanopsis glauca)次生林、杉木(Cunninghamia lanceolata)人工林、毛竹(Phyllostachys edulis)林、苗圃、农用旱地、水田土壤ROC含量及其季节动态变化进行测定,以石栎-青冈次生林土壤为参照,计算土壤CMI,分析土壤ROC含量、CMI与土壤理化性状的关系。结果表明,同一土层ROC含量、ROC分配比例在不同土地利用类型之间差异显著,ROC含量表现为石栎-青冈次生林毛竹林水田杉木人工林农用旱地苗圃,ROC分配比例为水田石栎-青冈次生林毛竹林农用旱地苗圃杉木人工林;与石栎-青冈次生林相比,毛竹林、水田、杉木人工林、农用旱地、苗圃土壤ROC含量依次下降了9.8%~15.6%、22.0%~36.3%、27.6%~40.1%、47.4%~51.2%、58.0%~65.5%,水田、毛竹林、杉木人工林、农用旱地、苗圃土壤CMI依次下降了11.6%~18.4%、9.1%~20.9%、40.0%~44.1%、48.6%~51.5%和59.3%~66.6%;6种土地利用类型土壤ROC含量的季节变化节律基本一致,表现为春夏季较秋冬季高,夏季最高,冬季或秋季最低;土壤ROC含量、CMI与土壤SOC、全N、全P、水解N、有效P含量之间呈显著或极显著正相关,与土壤p H呈极显著负相关,与土壤含水率、全K、速效K不相关。土地利用方式对土壤ROC含量、CMI影响显著,次生林转变为人工林或农用地后,土壤碳库稳定性和生物可利用性下降。
[Abstract]:In order to understand the effects of land use patterns on (ROC) and (CMI), a method of KMn O 4 oxidation was used to study the effects of land use patterns on soil oxidable organic carbon (OOC) and carbon pool management index (CMI) in middle subtropical soils. Six types of land use in hilly areas of central Hunan were studied: (Lithocarpus glaber)-(Cyclobalanopsis glauca) secondary forest, (Cunninghamia lanceolata) plantation of Chinese fir, (Phyllostachys edulis) forest of Phyllostachys pubescens, nursery, agricultural dryland, The content of ROC in paddy soil and its seasonal dynamic changes were determined. The relationship between soil ROC content, CMI and soil physical and chemical properties was calculated by calculating soil CMI, as a reference to the soil of Quercus lanceolata (Quercus-Cyclobalanopsis) secondary forest. The results showed that there were significant differences in ROC content and ROC distribution ratio among different land use types in the same soil layer. The ROC content of the same soil layer was as follows: Quercus lanceolata-Cyclobalanopsis pubescens secondary forest, Phyllostachys lanceolata plantation, agricultural dryland nursery. The distribution ratio of ROC was the plantation of Chinese fir in the secondary forest of Quercus arborescens and Phyllostachys pubescens in paddy field. Compared with the secondary forest of Quercus lanceolata, Phyllostachys pubescens, paddy fields, Chinese fir plantation, agricultural dryland and nursery soil, the ROC content of soil decreased in turn by 9.8% 15.60.20% and 36.30.30% and 40.1%, respectively. 47.4 the CMI in the paddy field, the bamboo forest, the Chinese fir plantation, the agricultural dryland, and the nursery soil CMI decreased by 11.6and 18.49.1in turn. 48.6% 51.5% and 59.3% 66.6%; The seasonal variation rhythm of soil ROC content in 6 land use types was basically the same, showing that spring and summer were higher than autumn and winter, summer was highest, winter or autumn was the lowest. The content of soil ROC, CMI and soil SOC, total P, hydrolyzed N, and available P content were significantly or significantly positively correlated, but negatively correlated with soil pH, but not correlated with soil moisture content, total K, available K. The effects of land use patterns on soil ROC content and CMI content were significant. The soil carbon pool stability and bioavailability decreased after secondary forest was converted to artificial forest or agricultural land.
【作者单位】：中南林业科技大学材料科学与工程学院;中南林业科技大学生命科学与技术学院;南方林业生态应用技术国家工程实验室;
【基金】：国家林业公益性行业科研专项(201504411) 中南林业科技大学引进高层次人才科研启动基金项目(2014YJ019)
【分类号】：S153.6

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