Drivers of highly diverse planktonic ciliate assemblages in peat bog pools from Tierra del Fuego (Argentina)

G. C. GONZÁLEZ GARRAZA; M.C. MARINONE; G. C. KÜPPERS; R. LOMBARDO; G. MATALONI; M.V. QUIROGA; A. VINOCUR

HYDROBIOLOGIA

SPRINGER

Lugar: Berlin; Año: 2016

0018-8158

Peatlands often encompass shallow pools,wherein dystrophic and colored acid waters host aremarkably diverse biota, with ciliates likely playing akey role in their short trophic webs. In the Sphagnummagellanicum-dominated Rancho Hambre peat bog, a2-year study was conducted in five pools with differentmorphometric and trophic characteristics, in order toidentify main environmental variables driving ciliatespecies richness, abundance, biomass, and diversity.Overall species richness (125 taxa) was much higherthan in northern Hemisphere counterparts. Deepminerotrophic pools hosted the richest communities,showing similar seasonal abundance patterns and thehighest species turnover. Although all pools shared thesame dominant ciliates, similarity in taxonomic compositionamong them was generally low(J = 0.22?0.35). Moreover, IndVal analysis showedthat rare and occasional species were highly indicativeof different pools. Euryoecious, heterotrophic species,occurred in all sites, while mixotrophs were typicalfrom shallow ombrotrophic pools. Rimostrombidiumhyalinum was the most indicative species of a deepombrotrophic pool. A CCA revealed that the abundancesof potential ciliate preys, i.e., picophytoplankton,bacterioplankton, and heterotrophic flagellates,were the most significant regulators of abundances ofthis group. Therefore, ciliate structure and dynamicswere influenced by pool morphometry and physical and chemical features, but foremost by interactionswith other plankton communities.