Contrasting Phytoplankton Structure and Morphologically Based Functional Groups of Reservoirs That Differ in the Adjacent Surrounding

Abstract

Increasing human activity has resulted in the transformation of waters and their landscape leading to fragmentation and degradation of natural ecosystems. We hypothesized that adjacent surrounding structures of water reservoir is weighty factor explaining changes in phytoplankton. The aim of the study was to find what level of identification is adequate to routine analyses and assess the best criteria that reflect structure of adjacent surrounding of reservoirs. Lithuanian and Polish reservoirs located in similar climatic conditions and of similar morphology were studied. The adjacent land use was described based on Corine Land Cover 2006. The physico‐chemical parameters of waters, structure and biomass of phytoplankton, Shannon index and obligatory autotrophic to mixotrophic species ratio were analyzed. The main difference between reservoirs was natural (Lithuanian reservoir: 67.8%) and agricultural landscape structure (Polish reservoir: 78.4%). Both ecosystems showed significant statistical differences in a few chemical features and in phytoplankton taxonomic and morphologically based functional groups (MBFG), Shannon index and autotrophic to mixotrophic species ratio. The dominant phytoplankton groups and MBFG better reflected stresses resulted differences of adjacent surrounding structure, compared with single species. In conclusion, the best criteria indicated the differences in the structure of adjacent surrounding of water ecosystems are MBFG and autotrophic to mixotrophic species ratio were presented.