Spatial distribution of palynomorphs in the surface sediments of the Lagoa do Campelo lake, North region of Rio de Janeiro State, Brazil

Acta Botanica Brasilica

Cynthia Fernandes Pinto Da Luz²  Ortrud Monika Barth¹  Cleverson Guisan Silva¹ 

[1] ,Federal do Rio de Janeiro CCMN Instituto de GeociênciasRio de Janeiro RJ ,Brasil

关键词: palynomorphs;    sedimentation;    recent Holocene;    Lagoa do Campelo;    Rio de Janeiro State;    palinomorfos;    sedimentação;    Holoceno recente;    Lagoa do Campelo;    Rio de Janeiro;   

DOI  :  10.1590/S0102-33062005000400009

来源: SciELO

【 摘 要 】

Four samples of the surface sediments of the Lagoa do Campelo lake bottom were collected in a transect of 500 m by 500 m from edge to edge, in a northeast/southwest direction, the dominant wind direction in the region. The analysis of pollen grains, fern spores and algae were used to evaluate their spatial deposition and level of deterioration. In total, 58 types of pollen grains were identified, mainly from herbs as Cyperaceae, Poaceae and Typhaceae. Pollen grains occurred in all the analyzed sediments. The area of highest concentration was the northeast side of the lake. The southwest side showed the highest pollen grain and fern spore degradation and mechanical damage, probably as they were carried across the lake by wind-driven currents, confirming the depositional tendency of damaged palynomorphs in the same direction as the dominant wind. Among the pollen of trees and shrubs, Alchornea, Arecaceae, Cecropia, Celtis, Clethra and Myrtaceae were dominant at more than 1,000 pollen grains per gram of sediment. The quantity of fern spores was practically constant in all samples (± 10% of the total of palynomorphs). The algae Pediastrum tetras (Ehrenberg) Ralfs and Mougeotia occurred in all samples, but Spirogyra only in three of them. The results obtained gave new information about the richness, concentration and distribution of palynomorphs in the lake, representing the local and regional vegetation.

【 授权许可】

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