Mangrove Soil in Physiographic Zones in the Sao Francisco River Estuary

ABSTRACT Mangrove ecosystem dynamics and diverse human activities have led to a need for studies that give us a better understanding of the peculiarities of their soils. The objective of this study was to evaluate the physical and chemical soil attributes of mangrove forests located in the São Francisco River estuary, related to local ecological conditions. Two stations, divided into three forest types (fringe, basin and transition) were selected and five composite soil samples were collected from each forest type. Soil samples were submitted for chemical and physical analysis. The soil presented a sandy texture, with high organic matter and element content in the following order: Mg2+>Na+>Ca2+ >H+>K+>P>Al3+ and Fe2+ >Zn2+>Cu2+>Mn2+, respectively, with variations between the forests and stations. In general, the mangrove forests presented high fertility, especially in the basin forest, provided by vegetation development, showing a zoning trend for species in relation to soil fertility.

摘要 红树林生态系统动态与多样人类活动使得学界亟需开展相关研究，以深入认知其土壤的独特属性。本研究旨在评估圣弗朗西斯科河河口（São Francisco River estuary）的红树林土壤理化属性，以关联当地生态条件。研究选取两个采样站位，在其中划分出三种林型（边缘林、盆地林与过渡林），并从每种林型中采集5份混合土壤样品，随后对土壤样品开展理化分析。结果显示，研究区域土壤质地为砂质，有机质与各元素含量依次呈现如下排序：阳离子组为Mg²⁺>Na⁺>Ca²⁺>H⁺>K⁺>P>Al³⁺，铁族元素组为Fe²⁺>Zn²⁺>Cu²⁺>Mn²⁺，且不同林型与站位间存在显著差异。总体而言，红树林土壤整体肥力较高，其中盆地林肥力尤为突出，这得益于植被的良好发育，且物种分布呈现出与土壤肥力相关的分带趋势。