Floristics, structure and soil of insular vegetation in four quartzite-sandstone outcrops of "Chapada Diamantina", Northeast Brazil
Floristics, structure and soil of insular vegetation in four quartzite-sandstone outcrops of "Chapada Diamantina", Northeast Brazil
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DOI：
10.1590/s0100-84042007000400009
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发表时间：
2007-12-01
影响因子：
1.6
通讯作者：
Meirelles, Sergio Tadeu
中科院分区：
文献类型：
--
作者：
Conceição, Abel Augusto;Pirani, José Rubens;Meirelles, Sergio Tadeu
（巴西东北部“查帕达迪亚曼蒂纳”四个石英砂岩露头中岛屿植被的植物区系、结构和土壤）。岩石表面上的土壤岛通常含有由岛屿植物群落组成的聚集植被。这些岛屿是典型的岩石露头，在巴西的各个地区形成所谓的“campos rupestres”植被。在巴西东北部的巴伊亚州选择了四个这样的地点，进行植物区系和植被结构的比较研究：三个地区位于“Parque Nacional da Chapada迪亚曼蒂纳”（Guine、Fumaca和“Gerais da Fumaca”）内，一个位于“Marimbus-Marquara”（“Mae Inacia”）环境保护区的边界。所有发生的植被岛屿进行了研究，在四个随机地块的10 × 10米每个站点。土壤通常较浅，桑迪，呈酸性。确定了维管植物的种类、生活型和冠层覆盖面积。当所有四个站点都被添加时，物种总数为135，每个岛屿的物种数量从2到32不等。214个土岛的面积从0.015到91.9 m2不等，四个地点共计568 m2。单子叶植物科占优势，主要是Velloziaceae，以及兰科，凤梨科，石蒜科和莎草科。在真双子叶植物中，优势科主要是野丁香科、菊科和菊科。生物谱显示，生活型中以高位芽植物和地面芽植物为主，地上芽植物覆盖面积最大。石生和干燥性地生植物组成的最明显的种间协会，并可能与早期的演替过程。彼此距离最近的地点在结构上并不最相似，这表明空间物种丰度可能涉及比距离更相关的其他因素。
(Floristics, structure and soil of insular vegetation in four quartzite-sandstone outcrops of "Chapada Diamantina", Northeast Brazil). Soil islands on rocky surfaces often harbor aggregated vegetation that consists of insular plant communities. These islands are typical of the rocky outcrops and in various parts of Brazil form the so-called "campos rupestres" vegetation. Four of such sites have been selected in the state of Bahia, Northeast Brazil, for this comparative study on floristics and vegetation structure: three areas situated inside the "Parque Nacional da Chapada Diamantina" (Guine, Fumaca and "Gerais da Fumaca") and one is at the border of the Environmental Protection Area of "Marimbus-Iraquara" ("Mae Inacia"). All occurring vegetation islands were studied in four random plots of 10 x 10 m per site. Soil was often shallow, sandy and acidic. Vascular plant species were determined, with respective life forms and canopy coverage areas. The total number of species when all four sites were added was 135, and the number of species per island varied from 2 to 32. The areas of the 214 soil islands varied from 0.015 to 91.9 m(2), totaling 568 m(2) in the four sites. Monocotyledon families were dominant, essentially Velloziaceae, as well as Orchidaceae, Bromeliaceae, Amaryllidaceae and Cyperaceae. Among the eudicotyledons, dominant families were mainly Clusiaceae, Asteraceae and Melastomataceae. The biological spectra revealed that phanerophytes and hemicryptophytes predominated among the life forms, while chamaephytes had the largest coverage area. Epilithic and desiccant chamaephytes composed the most conspicuous interspecific associations, and were probably related to early successional processes. Sites closest to one another were not the most similar in structure, indicating that other factors more relevant than distance might be involved in the abundance of species in space.