Landscape-driven environmental variability largely determines abiotic characteristics and phytoplankton patterns in peat bog pools (Tierra del Fuego, Argentina)

MATALONI, G.; GONZÁLEZ GARRAZA, G.; VINOCUR, A.

HYDROBIOLOGIA

SPRINGER

Lugar: Berlin; Año: 2015

0018-8158

Ombrotrophic peat bogs from Tierra delFuego are characteristically raised, dome-shaped, fedby precipitation, and nutrient-poor. Their landscapepattern consists of a Sphagnum magellanicum matrixencompassing pools with different morphometric andtrophic features. Within the framework of a 2-yearlimnological survey in five pools from Rancho Hambrepeat bog, we analyzed phytoplankton communitiesunder the hypothesis that taxonomic compositionwould show a spatial pattern driven by ultimatelylandscape-controlled environmental features such aspH and trophic status, while temperature and weatherdependentfeatures would account for seasonalchanges in abundance and structure. Among the 305taxa recorded, most were Conjugatophyceae andBacillariophyceae, and were strongly associated tocircumneutral pH and minerotrophic conditions,though limited superficial connectivity among poolsaccounted for dissimilar taxonomic compositions.Despite such differences, phytoplankton of pools withsimilar morphometry and trophic status showed similardominant and richest taxonomic groups undergoingparalell changes over time. Seasonal temperaturefluctuations were modulated by pool size and modifiednot only abiotic properties but also phytoplanktonabundance, with different taxa showing strong summerpeaks in different pools. An interpretative modelis proposed which will be tested as a tool for predictingcommunity strategy and temporal variation patterns asresponses to different environmental templates.