Wyniki wyszukiwania - BazTech

Ograniczanie wyników

2 Polish Journal of Ecology

Powiadomienia systemowe

Sesja wygasła!

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Sortuj według:

Ogranicz wyniki do:

Response of periohyton community to salinity gradient in tropical estuary, Niger Delta

Chindah A. C.

Polish Journal of Ecology

2004

Vol. 52, nr 1

83-89

Studies on periphyton of Crinium plants were conducted in the estuary (New Calabar River) of the Niger Delta at 4 different locations during the two major seasons (rainy and dry season). Periphyton samples were collected from an area (of 2 cm by 2 cm) in 3 sets of 3 replicates for biomasses (AFDW-ash free dry weight and chlorophyll a) and for numerical abundance. Physicochemical parameters such as temperature, pH, conductivity, hardness and salinity were also collected from the respective stations. Temperature was considerably uniform but conductivity, hardness and salinity showed increasing graduation in concentration down stream. A total of 110 periphyton species were recorded with diatoms constituting 54% of the occurring species followed by Euglenophyta (21%0, Chlorophyta (17%), Cyanophyceae (6%) and Rhodophyta (1.8%). There were strong similarities in the values obtained for species richness, periphyton abundance, and chlorophyll a, AFDW (ash free dry weight) for wet and dry season indicating no seasonal influence. However, the periphyton abundance, chlorophyll a and ash free dry weight distribution suggested strongly influence by the salinity gradient. The values for periphyton abundance ranged from 2621 ([plus-minus] 168.5) to 3452.8 ([plus-minus] 715.9) indiv. cm^-2. In addition, the combined mean values for chlorophyll a, and ash free dry weight in the system were 8.443 [plus-minus] 2.51 mg cm^-2 and 0.32 [plus-minus] 0.07 g cm^-2, respectively.

Epipelic algal of tropical estuary : case of stable and invariable seasonally community

Chindah A. C., Braide S. A.

Polish Journal of Ecology

2003

Vol. 51, nr 1

91-99

The physicochemical and epipelic algal analyses in the catchment of lower Bonny river, Nigeria, was carried out between September 1998 and February 1999. A total of 51 species were observed of which Bacillariophyceae had 28 species followed by Cyanophyceae (19 species), Chlorophyceae (2 species), and Euglenophyceae (2 species) respectively. The epipelic algal abundance ranged from 3.2 [plus minus] 0.8 x 108 indiv. cm-2 to 6.3 [plus minus] 0.6 x 108 indiv. cm-2 in wet season and 3.9 [plus minus] 0.3 x 108 indiv. cm-2 to 6.9 [plus minus] 0.6 x 108 indiv. cm-2 in dry season. In addition, chlorophyll a values range from 0.85 [plus minus] 0.15 to 2.61 [plus minus] 0.42 mg cm-2 in wet season and 1.02 [plus minus] 0.12 to 4.45 [plus minus] 0.88 mg cm-2 in dry seasons respectively. This range of variation was relatively narrow and the whole community seems to be persistent and stable during wet and dry seasons.