Spatial variation in the structure and composition of the herbaceous community in a semiarid region of northeastern Brazil

Brazilian Journal of Biology

Ka. Silva¹  Jmff. Santos²  Dm. Santos²  Emn. Ferraz²  El. Araújo² 

[1] ,Universidade Federal de Pernambuco Centro Acadêmico de Vitória Laboratório de BiodiversidadeVitória de Santo Antão PE ,Brazil

关键词: dry forest;    phytosociology;    herb;    soil;    caatinga;    microhabitat;    floresta seca;    fitossociologia;    erva;    solo;    caatinga;    micro-habitat;   

DOI  :  10.1590/S1519-69842013000100015

来源: SciELO

【 摘 要 】

In the arid and semiarid environments of the world, microhabitats serve as models for the structure of vegetation communities. The goal of this study was to identify differences in the structures of the herbaceous communities growing on a crystalline substrate and those growing on a sedimentary substrate in a semiarid region of northeastern Brazil. One hundred 1 × 1 m plots were established in each area for quantitative sampling, with 69 species recorded in the crystalline area and 76 in the sedimentary area. The average plant density was higher in the sedimentary area, and average diameters and heights were greater in the crystalline area. The families and species with a high Importance Value Index (IVI) and a high Mixed Ecological Value Index (MEVI) differed between the areas. Of the species with high densities, only four were found in both areas. Shannon-Weiner diversity index values in the crystalline (2.96 nats/ind.-1) and sedimentary (2.89 nats/ind.-1) areas were similar. Evenness values on both substrates were also similar (0.72 and 0.71 in the crystalline and sedimentary areas, respectively). This study shows that variations in plant establishment conditions between crystalline and sedimentary areas in a semiarid region of northeastern Brazil should be considered as structure-modeling factors for the herbaceous community.

【 授权许可】

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