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Mechanisms of soil acidification under leguminous fast growing tree plantations in the humid tropics and its prediction

湿热带豆科速生林土壤酸化机制及其预测

基本信息

批准号：
15255014
负责人：
OHTA Seiichi
金额：
$ 24.63万
依托单位：
Kyoto University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A)
财政年份：
2003
资助国家：
日本
起止时间：
2003 至 2006
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-15255014/
关键词：
humid tropics soil acidification leguminous fast growing tree industrial tree plantation Acacia mangium elements cycling nutrients pool forest ecosystem 湿潤熱帯 Acacia mangium 産業造林

项目摘要

This study was conducted in the Acacia mangium plantation in the Province of South Sumatra, Indonesia for the purpose of elucidating the possibility of soil acidification caused by establishment of leguminous fast growing tree plantation in the humid tropics and its mechanism, and to develop the methodology to predict the acidification. The progresses obtained are the followings.1)Based on the multipoint soil survey covering relatively large area, we illustrated in an empirical way that conversion of degraded Imperata grassland into Acacia tree plantation causes obvious soil acidification, and the decline in exchangeable base cations in soils resulted from nutrients trans location from soil to growing tree biomass is the major cause of the acidification. Furthermore, it was indicated that effective cation exchange capacity of the humid tropical soils containing minerals of variable charge characteristics might decline with soils acidification, and it may possibly accelerate further soi … More l acidification.2)For the two 7-year-old Acacia stands respectively on a heavy clay soil and a light clay soil, allometry formulas were developed by destructive measurements, and nutrients concentrations were determined for every organ of trees. Based on these information, nutrients export through tree harvest was estimated, and possible number of replanting-harvest rotation was simulated on a supposition that nutrients is input only through precipitation. The results of simulation suggested that Ca and K will become deficient in near future and its magnitude is different by the soil characteristics especially clay content.3)Nutrients transported by litterfall, throughfall, stemflow and water percolation through litter layers (Ao horizon, 0 horizon), and nutrients and dissolved organic matter released from litter decomposition were monitored for 3 years at the permanent plot, and the results showed every related parameters display obvious seasonality between drier and wetter seasons mostly in conjunction with each other.4)A model to predict the soil acidification was formulated based on ion balance and mass balance, and soil change during a period of three rotations was predicted by using data collected by field observation. The simulation output by the model indicated possible rapid and significant soil acidification, however also it became clear that the model still have weakness to be improved. Less

本研究以印度尼西亚南苏门答腊省马占相思种植园为研究对象，旨在阐明在热带湿润地区建立豆科速生种植园引起土壤酸化的可能性及其机理，并建立预测酸化的方法。主要研究成果如下：1）通过大面积多点土壤调查，实证分析了退化白茅草地改建为相思人工林后，土壤酸化现象明显，养分从土壤向生长林木转移导致土壤交换性盐基阳离子减少是导致土壤酸化的主要原因。此外，还表明，含可变电荷矿物的热带湿润土壤的有效阳离子交换量可能随着土壤酸化而下降，并可能加速土壤的进一步酸化 ...更多信息 2）以重粘和轻粘土壤上的2个7年生相思林分为研究对象，通过破坏性测定，建立了相思林分的异速生长公式，并测定了相思树各器官养分含量。在此基础上，估算了林木收获过程中养分的输出量，并在假定养分仅通过降水输入的情况下，模拟了可能的补植-收获轮作次数。模拟结果表明，Ca、K在不久的将来将出现亏缺，亏缺的幅度因土壤性质特别是粘粒含量的不同而不同（Ao层，0层），并对固定样地凋落物分解释放的养分和溶解性有机质进行了3年的监测，结果表明，各相关参数均表现出明显的干湿季节性，且多为联合作用。4）建立了基于离子平衡和质量平衡的土壤酸化预测模型，并利用野外观测数据对3个轮作周期内的土壤变化进行了预测。模型的模拟结果表明，土壤酸化可能会迅速而显著，但也表明模型仍存在不足之处。少