FN Archimer Export Format PT J TI Drivers and ecological consequences of dominance in periurban phytoplankton communities using networks approaches BT AF ESCALAS, Arthur Catherine, Arnaud MALOUFI, Selma CELLAMRE, MARIA HAMLAOUI, Sahima YEPREMIAN, Claude LOUVARD, Clarisse TROUSSELIER, Marc BERNARD, Cécile AS 1:1,4;2:1;3:1;4:1,2;5:1;6:1;7:1;8:3;9:1; FF 1:;2:;3:;4:;5:;6:;7:;8:;9:; C1 UMR 7245 MCAM, CNRS-MNHN, Muséum National D’Histoire Naturelle, 12 Rue Buffon, CP 39, 75231, Paris Cedex 05, France Phyto-Quality, 15 Rue Pétrarque, 75116, Paris, France UMR 9190 MARBEC, CNRS-Université de Montpellier-IRD-IFREMER, Place Eugène Bataillon, 34095, Montpellier Cedex 5, France C2 MNHN, FRANCE PHYTO-QUALITY, FRANCE CNRS, FRANCE UNIV MONTPELLIER, FRANCE UM MARBEC IN WOS Cotutelle UMR copubli-france IF 9.13 TC 49 UR https://archimer.ifremer.fr/doc/00508/61962/66081.pdf LA English DT Article DE ;Dominance;Phytoplankton;Co-occurrence network;Community cohesion;Community functioning;Periurban waterbodies AB Evaluating the causes and consequences of dominance by a limited number of taxa in phytoplankton communities is of huge importance in the current context of increasing anthropogenic pressures on natural ecosystems. This is of particular concern in densely populated urban areas where usages and impacts of human populations on water ecosystems are strongly interconnected. Microbial biodiversity is commonly used as a bioindicator of environmental quality and ecosystem functioning, but there are few studies at the regional scale that integrate the drivers of dominance in phytoplankton communities and their consequences on the structure and functioning of these communities. Here, we studied the causes and consequences of phytoplankton dominance in 50 environmentally contrasted waterbodies, sampled over four summer campaigns in the highly-populated Île-de-France region (IDF). Phytoplankton dominance was observed in 32–52% of the communities and most cases were attributed to Chlorophyta (35.5–40.6% of cases) and Cyanobacteria (30.3–36.5%). The best predictors of dominance were identified using multinomial logistic regression and included waterbody features (surface, depth and connection to the hydrological network) and water column characteristics (total N, TN:TP ratio, water temperature and stratification). The consequences of dominance were dependent on the identity of the dominant organisms and included modifications of biological attributes (richness, cohesion) and functioning (biomass, RUE) of phytoplankton communities. We constructed co-occurrence networks using high resolution phytoplankton biomass and demonstrated that networks under dominance by Chlorophyta and Cyanobacteria exhibited significantly different structure compared with networks without dominance. Furthermore, dominance by Cyanobacteria was associated with more profound network modifications (e.g. cohesion, size, density, efficiency and proportion of negative links), suggesting a stronger disruption of the structure and functioning of phytoplankton communities in the conditions in which this group dominates. Finally, we provide a synthesis on the relationships between environmental drivers, dominance status, community attributes and network structure. PY 2019 PD OCT SO Water Research SN 0043-1354 PU Elsevier BV VL 163 UT 000483006400038 DI 10.1016/j.watres.2019.114893 ID 61962 ER EF