Seasonal variation and occurrence of algal turf community in Lake Ladik, Turkey.

ABSTRACT

The composition and seasonal variation of the algal turf of Lake Ladik were studied using samples collected from one station between June 2000 and May 2001. 50 taxa of diatoms were identified in the epiphyton. Navicula veneta, N. halophila, Nitzschia fonticola and Aulacoseira distans were particularly important on turf community. During the October month several Navicula species become progressively more important. Gomphonema lateripunctatum was particularly notable. Other diatoms were occasionally abundant, including Cymbella affinis, C. silesiaca, Navicula cryptocephala, Gomphonema olivaceum and Cyclotella ocellata. Also Navicula lanceolata and Anomoeoneis brachysira were conspicuous, owing to their large size, but were never numerically abundant. Fragilaria ulna and Nitzschia palea were found in low numbers in study area and this pointed out there has not been a remarkable abundance of algal pollution in Lake Ladik. The associations between July and August with bonds to June, January and February with bonds to April were most significant in the study period obtained by cluster analysis. Shannon diversity and evenness presented small variations during the study period. Lake Ladik presented low values of species richness particularly during summer period and highest values were recorded in April. According to canonical correspondence analysis, there was association between some Navicula and Nitzschia species with PO4-, NH3-N. Also the multivariate analysis showed, temperature as the most important factor in the distribution and abundance of diatoms on turf biomass.