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

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.

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Modern processes of palynomorph deposition at lakes of the northern region of the Rio de Janeiro State, Brazil

Anais da Academia Brasileira de Ciências ◽

10.1590/s0001-37652010000300016 ◽

2010 ◽

Vol 82 (3) ◽

pp. 679-690 ◽

Cited By ~ 3

Author(s):

Cynthia F.P. da Luz ◽

Ortrud M. Barth ◽

Cleverson G. Silva

Keyword(s):

Rio De Janeiro ◽

Mechanical Damage ◽

Pollen Grains ◽

Northern Region ◽

Palynological Analysis ◽

The North ◽

Pollen Types ◽

Lake Bottom ◽

Superficial Sediments ◽

Janeiro State

Palynological analysis of pollen, Pteridophyta spores and algae deposited in the superficial sediments at Lagoa de Cima and Lagoa do Campelo Lakes, located in the north of Rio de Janeiro state, was used to determine the spatial variation of the palynomorphs deposition. A total of 67 pollen types were identified at Lagoa de Cima, with an expressive contribution of regional arboreous taxa, hydrophytes and ruderal plants of the pastureland. The depositional pattern of palynomorphs depends on the fluvial leakage, the proximity of the local sedimentation to the inlet of the Imbé and Urubu Rivers and the bathymetry of lake bottom. The highest concentrations of palynomorphs were observed in the decentralized and less deeper area, without the interference of the northeastern wind. At Lagoa do Campelo, a total of 58 pollen types were identified, among which the majority of the pollen grains came from hydrophytes, with the highest concentrations found along the northeastern shore. The southeastern shore showed high percentages of pollen and spores with degraded exine and mechanical damage, due to the transport through the lakeby the currents caused by the wind, confirmed by the depositional trend of damaged palinomorphs along the same direction as the prevailing winds.

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Spatial distribution of pollen grains and spores in surface sediments of Guanabara Bay, Rio de Janeiro, Brazil

Anais da Academia Brasileira de Ciências ◽

10.1590/s0001-37652012005000049 ◽

2012 ◽

Vol 84 (3) ◽

pp. 627-644 ◽

Cited By ~ 7

Author(s):

Cintia F. Barreto ◽

Claudia G. Vilela ◽

José A. Baptista-Neto ◽

Ortrud M. Barth

Keyword(s):

Rio De Janeiro ◽

Surface Sediments ◽

Pollen Grains ◽

Source Area ◽

Guanabara Bay ◽

Differential Distribution ◽

Hydrographic Basin ◽

River Transport ◽

Pollen Types ◽

Janeiro State

Aiming to investigate the deposition of pollen grains and spores in Guanabara Bay, Rio de Janeiro State, 61 surface sediment samples were analyzed. The results showed that the current deposition of palynomorphs in surface sediments of Guanabara Bay represents the regional vegetation of this hydrographic basin. The differential distribution of palynomorphs followed a pattern influenced by bathymetry, tidal currents speed, discharge of numerous rivers, and by human activity. The dominance of representatives of Field Vegetation reflects the changes of the original flora caused by intense human activities in the region. The continued presence and richness of pollen types of rain forest in the samples indicates that their source area might be the vegetation from riparian border of rivers in the western sector of the Bay, where the mangrove vegetation is being preserved. The large amount of damaged palynomorphs may be related to abrasion that occurs during river transport, indicating removal or reworking from their areas of origin.

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