Effects of forest type and environmental factors on the soil organic carbon pool and its density fractions in a seasonally dry tropical forest
Effects of forest type and environmental factors on the soil organic carbon pool and its density fractions in a seasonally dry tropical forest
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DOI：
10.1016/j.foreco.2014.09.037
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发表时间：
2015
影响因子：
3.7
通讯作者：
Jumpei Toriyama;M. Hak;A. Imaya;K. Hirai;Y. Kiyono
中科院分区：
文献类型：
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作者：
Jumpei Toriyama;M. Hak;A. Imaya;K. Hirai;Y. Kiyono
密度分级现在是区分森林生态系统中不同土壤有机碳（SOC）库功能的潜在方法。季节性干旱热带地区常绿和落叶森林类型的共存有利于阐明高温条件下不同植物功能性状对 SOC 库大小和质量的影响。我们研究了森林类型（落叶与常绿）、矿物因子（铝和氧化铁）和气候条件（温度和降水）是否影响东南亚大陆季节性干燥热带森林中土壤中有机碳库的大小和质量以及密度分数。森林类型和矿物质因素分别影响 SOC 库的质量和规模。森林类型对凋落物碳氮（C:N）比和游离轻组分有显着影响。然而，无论森林类型和降水模式如何变化，0-30 cm 深度的 SOC 库大小和每个表土密度分数的变化都完全由矿物因素（即酸性草酸铵可提取的氧化铝）来解释。表明粘土矿物表面积是研究区SOC储存能力的主导因素。铝和相关氧化物还可能增加轻馏分的吸留形式的聚集体内空间。尽管气候因素对 SOC 库的影响（包括湿热带地区对 SOC 组成的影响仍然是未来研究的主题），但尚未发现显着水平的影响。具有 SOC 和土壤有机氮变量的线性模型可以很好地估计轻组分中碳和氮库的大小，与森林类型无关。这些回归模型有助于估计植物碎屑形式不稳定 SOC 池的大范围分布及其数字绘图，并结合大量 SOC 含量数据集。它将通过对碳排放减排效果进行空间界定的评估，为季节性干旱热带森林森林管理下的碳固存实践提供激励。
Density fractionation is now a potential approach for distinguishing among the functions of different soil organic carbon (SOC) pools in a forest ecosystem. The co-existence of evergreen and deciduous forest types in seasonally dry tropics is favorable for clarifying the effect of contrasting plant functional trait on the size and quality of SOC pools under the high temperature regime. We examined whether forest type (deciduous vs. evergreen), mineral factor (aluminum and iron oxide) and climatic condition (temperature and precipitation) affect the size and quality of SOC pools in bulk soil and density fractions in a seasonally dry tropical forest of continental Southeast Asia. The forest type and mineral factor affected the quality and size, respectively, of SOC pools. The forest type had significant effects on carbon-to-nitrogen (C:N) ratios of leaf litter and free form of light fraction. However, variations in the size of the SOC pools at a depth of 0–30 cm and in each topsoil density fraction were explained exclusively by the mineral factor, i.e., aluminum oxide extractable by acid ammonium oxalate, regardless of variations in forest type and precipitation pattern. It was suggested that the surface area of clay mineral was the dominant factor for the storage capacity of SOC in the study area. The aluminum and related oxides might also increase intra-aggregate space for occluded form of light fraction. The impact of the climatic factor on the SOC pools was not found in a significant level though its effect including humid tropics on the composition of SOC remains a subject of future investigation. The linear models with variables of SOC and soil organic nitrogen favorably estimated the size of the C and N pools in the light fraction independent of the forest type. These regression models help to estimate the wide-area distribution of labile SOC pools of plant detritus form and its digital mapping, combined with a dataset of bulk SOC content. And it will provide incentives for C sequestration practice under forest management in seasonally dry tropical forests through the spatially-defined assessment of reduction effect of C emissions.