Naslov
The Influence of the Lotic and Lentic Stretches on the Zooseston Flux through the Plitvice Lakes (Croatia)

Autori
Špoljar, Maria ; Habdija, Ivan ; Primc-Habdija, Biserka

Izvornik
Annales de Limnologie (0003-4088) 43 (2007), 1; 29-40

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
Karstic lake; Lotic; Lentic; Zooseston; Rotifers

Sažetak
The influence of the lotic and the lentic stretches on zooseston flux was studied during the year 2000. Three investigated stretches of the karstic barrage of the Plitvice Lakes (Croatia) were selected: 1. a channel on the barrier with low inclination ; 2. water flow through a deep lake (retention) and 3. a channel with cascades and sharp barrier inclination. At all sampling points of the three investigated stretches, zooseston reached maximum abundance in September (up to 147, 392 ind/m3). Rotifers dominated in both zooseston abundance (58 to 80%) and diversity (66 taxa), followed by crustaceans (23 taxa), mostly represented with Cladocera and Copepoda. Results of the Kruskal-Wallis test suggest that statistically significant differences exist between the lentic stretch and two lotic stretches in the biomass net flux of euplanktonic organisms. Also, the net flux of benthic organism biomass and change of the biodiversity index were significantly different between the lentic stretch and lotic stretch with high inclination. Lotic stretches had a greater influence on the increase of abundance and biomass of benthic and semiplanktonic organisms than on the decrease of euplanktonic organisms. The first two axes in the Principal Components Analysis explained 65% of the variance in the interaction of environmental variables and zooseston biomass. The oligochaets, insect larvae, nematodes, bdelloids and total zooseston were associated with axis 1, meaning that their biomass is negatively correlated with discharge and dissolved oxygen concentration and positively with temperature. Biomass of Cladocera, Copepoda, T. birostris, Polyarthra spp. and rotifers was associated with component 2 and positively correlated with chl-a, POM and DOM values. The species K. cochlearis was also associated with component 2, but was negatively correlated to food resources. The inference is that zooseston flux through Plitvice Lakes is a function of the hydrological and physiographical features of the stretches, as well as food resources from the lakes.

Izvorni jezik
Engleski

Znanstvena područja
Biologija

POVEZANOST RADA