Patterns of Floristic Differentiation among Atlantic Forests in Southeastern Brazil and the Influence of Climate 1
Patterns of Floristic Differentiation among Atlantic Forests in Southeastern Brazil and the Influence of Climate 1
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巴西东南部大西洋森林区系分化模式及气候影响1
DOI：
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发表时间：
2000
期刊：
影响因子：
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通讯作者：
M. Fontes
中科院分区：
文献类型：
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作者：
A. Oliveira;M. Fontes
从两个主要方面调查了巴西东南部大西洋森林的乔木植物区系：(A)通过对125个现有的植物区系清单进行多元分析，从地理和气候变量的角度分析了雨林和半落叶森林植物区系组成的变化；(B)评估了雨林和半落叶森林与亚马逊森林和Cerrados(伍迪稀树草原)的联系。所有的分析都是在物种、属和科的水平上进行的。获得的125个林区信息被组织成一个包含地理和气候记录的环境数据库，以及一个包含106科、520属、2532种的二进制存在记录的植物区系数据库。典型对应分析(CCA)被用来评估地理和气候变量与树木区系组成之间的关系。使用维恩图和聚类分析来评估与亚马逊森林和塞拉多的植物区系联系。在所有三个分类层面上都发现了下列模式：(A)雨林和半落叶林的区系分化在植物区系上是一致的，并与降雨状况密切相关，尽管过渡可能是突然或渐进的；(B)雨林和半落叶林都存在南北分化，这可能是由于温度和降雨状况的变化；(C)半落叶林的植物区系也随着距离海洋的增加和相关的降雨季节性的增加而变化；(D)海拔和相关的温度与雨林和半落叶林的内部分化密切相关。在相当大的程度上，半落叶森林的树木植物群是雨林植物群的一个子集，可能提取出能够应对较长旱季的物种。在物种层面上，大西洋雨林和半落叶森林之间的植物区系相似性比这些森林和亚马逊雨林或塞拉多斯之间的任何一种都要大。尽管如此，半落叶森林和Cerrados显示出更强的联系，特别是在属和家族一级。因此，认为大西洋热带雨林比邻近的半落叶森林更接近亚马逊雨林的植物区系依据很少。对于巴西东南部的雨林和半落叶林，最合适的观点是树种分布的连续体。我们建议，大西洋森林的定义应与亚马逊森林的定义一样全面。
The tree flora of southeastern Brazilian Atlantic forests was investigated according to two main aspects: (a) the variations in floristic composition of bodi rain and semi‐deciduous forests were analyzed in terms of geographic and climatic variables by performing multivariate analyses on 125 existing floristic checklists; and (b) the links of both rain and semi‐deciduous forests to Amazonian forests and Cerrados (woody savanna) were assessed. All analyses were performed at the species, genus, and family levels. The information obtained for the 125 forest areas was organized into an environmental database containing geographic and climatic records, and a floristic database containing binary presence records for 2532 species, 520 genera, and 106 families. Canonical correspondence analyses (CCA) were utilized to assess the relationship between geographic and climatic variables, and tree flora composition. Venn diagrams and cluster analyses were used to assess the floristic links to Amazonian forests and Cerrados. The following patterns were detected at all three taxonomic levels: (a) the differentiation between rain and semi‐deciduous forests is floristically consistent and strongly correlated with rainfall regime, although transitions may be abrupt to gradual; (b) a north–south differentiation exists for both rain and semi‐deciduous forests, probably caused by variations in both temperature and rainfall regime; (c) The flora of semi‐deciduous forests also changes with increasing distance from the ocean and the associated increasing rainfall seasonality; and (d) elevation and associated temperatures are strongly correlated with the internal differentiation of both rain and semi‐deciduous forests. To a considerable extent, the tree flora of semi‐deciduous forests is a subset of the rain forest flora, probably extracting species that are able to cope with a longer dry season. There is greater floristic similarity at the species level between Atlantic rain and semi‐deciduous forests than between any of these and either Amazonian rain forests or Cerrados. Nevertheless, semi‐deciduous forests and Cerrados show stronger links, particularly at the generic and familial levels. Therefore, rhere is little floristic ground for viewing Atlantic rain forests as being closer to their Amazonian counterparts than to the adjacent semi‐deciduous forests. The most appropriate view of rain and semi‐deciduous forests in southeastern Brazil is that of a continuum in tree species distribution. We suggest that the definition of Atlantic forests should be as comprehensive as that of Amazonian forests.