ABSTRACT

Besides being one of the most threatened forests, the Brazilian Seasonally Dry Tropical Forest (Caatinga) is the least studied ecosystem in the Northeast Region. Soil composition has an important role in biodiversity conservation since the Caatinga suffers from degradation, salinisation and desertification, mainly caused by non-sustainable agriculture and urbanisation. To identify priority areas for Caatinga preservation, it is necessary to know the nutrient content of the soil and other chemical elements, with information from a consistent and reliable database. The present work aimed at the quantification of Al, Ca, Fe, K, Mg, Mn, Ni, Pb, Si, Sr, Ti and Zn. All chemical elements were determined by Energy Dispersive X-Ray Fluorescence – EDXRF. Multivariate statistical techniques applied to soil identified the correlation between the chemical elements determined in diverse Caatinga soil types. Multivariate analysis when combined with the accumulation index indicates soils where the use of conservation units could be recommended. Research on the behaviour of these elements in the soil, to find solutions or control methods, may lead to a reduction of the risk of environmental degradation.

摘要

除了是最受威胁的森林之一外，巴西季节性干旱热带森林 (Caatinga) 还是东北地区研究最少的生态系统。土壤成分在生物多样性保护中发挥着重要作用，因为卡廷加地区遭受退化、盐碱化和荒漠化，主要是由非可持续农业和城市化造成的。为了确定卡廷加保护的优先区域，有必要了解土壤的养分含量和其他化学元素，以及来自一致和可靠数据库的信息。目前的工作旨在量化 Al、Ca、Fe、K、Mg、Mn、Ni、Pb、Si、Sr、Ti 和 Zn。所有化学元素均通过能量色散 X 射线荧光 - EDXRF 测定。应用于土壤的多元统计技术确定了在不同卡廷加土壤类型中确定的化学元素之间的相关性。与累积指数相结合的多变量分析表明可以推荐使用保护单位的土壤。研究这些元素在土壤中的行为，寻找解决方案或控制方法，可能会降低环境退化的风险。