A soil geochemical background for northeastern Brazil
A soil geochemical background for northeastern Brazil
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巴西东北部土壤地球化学背景
DOI：
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发表时间：
2012
期刊：
影响因子：
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通讯作者：
C. Reimann
中科院分区：
文献类型：
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作者：
J. Matschullat;Silke T. Höfle;Juscimar da Silva;J. Mello;Germano Melo;A. Plessow;C. Reimann
南半球具有区域代表性的土壤地球化学数据很少。巴西东北部的一个次大陆尺度(1.7×106平方公里)的化探采样考察队为非人为影响地区(主要是牧场)提供了101个具有代表性的复合土壤样本(30-50厘米深)。从岩性、土壤类型、生物群类型、气候和土地利用等方面对WD-XRF测定的主要、次要和选定的微量元素进行了讨论。除了硅以外，这些元素的浓度变化高达两个数量级(≅系数2.6)。与全球平均水平相比，硅的丰度很高，而大多数其他成分显示出相当大的不足。与从巴西南部和澳大利亚获得的结果相比，出现了显著的偏差--南半球为数不多的代表性数据就是一个例子。人为影响似乎可以忽略不计。除土地利用外，所有环境参数都对形成地球化学成分起着积极的作用。由于年龄的原因，岩性似乎部分地与土壤脱钩。土壤成分反映了土壤类型、生物群类型和风化的影响。大多数植物养分，尽管它们绝对耗尽，但在卡廷加土壤中显示出最高的值，在大西洋森林土壤中显示出最低的值。新的数据形成了一个强大而有价值的工具，以支持未来的土地利用管理。
Very few area-representative soil geochemical data exist for the southern hemisphere. A sub-continental scale (1.7 × 106 km2) geochemical sampling expedition in northeastern Brazil delivered 101 representative composite soil samples (30–50 cm depth) for non-anthropogenically influenced areas (mainly pasture land). Major, minor, and selected trace elements, determined by WD-XRF, are discussed with respect to lithology, soil type, biome type, climate and land use. These element concentrations vary up to two orders of magnitude, except for Si (factor ≅ 2.6). Silicon is strongly enriched compared to global averages, whereas most other components show a considerable deficiency. Significant deviations occur compared to results obtained from southern Brazil and from Australia – examples for the few representative data from the southern hemisphere. Anthropogenic influences appear negligible. All environmental parameters, except for land use, play an active role in shaping the geochemical composition. Lithology appears to be partly decoupled from the soils due to their age. The soil composition reflects soil type, biome type, and weathering influences. Most plant nutrients, despite their absolute depletion, show the highest values in Caatinga soils, and the lowest in Atlantic Forest soils. The new data form a robust and valuable tool to support future land use management.