ISSN:
1573-5125
Schlagwort(e):
biomass
;
phytoplankton
;
seasonal distribution
;
tropical lake
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Biologie
Notizen:
Abstract Seasonal changes in the pytoplankton community was studied in Lake Xolotlán (Managua). Cyanophyta were found to be dominant throughout the year. Phytoplankton biomass was estimated by volume (wet weight) and by chlorophyll-a at two localities. Seasonal biomass fluctuations were monthly measured for two years. The lowest annual phytoplankton biomass was observed at the end of the rainy season (October-November), and the highest during the dry period (January–February). Short-term studies (3–14 days) on daily biomass changes were also performed. Significant variations in total biomass over short time spans were detected at both localities. Horizontal distribution of phytoplankton was also determined during 30 months. It proved that the lake was quite homogeneous. The results also revealed a great homogeneity with regard to species composition throughout the year. Biomass was permanently high (15.75±5.89 mg.l−1 wet weight, annual average) in front of Managua city where anthropogenic influence is more immediate, whereas the north central region has a comparatively lower biomass (9.07±2.4 mg.l−). Lake Xolotlán may be considered as hypertrophic, taking into account its high chlorophyll-a concentration (79 μg.l−1 as annual average for 1987–1988).
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/BF02291243
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