Le Noac'h, Philippe; Ouellet Jobin, Vincent et Beisner, Beatrix E.
(2021).
« Effects of Vertical Spatial Overlap on Phytoplankton Diversity under Experimentally Altered Lake Stratification Regimes ».
Microorganisms, 9(2447), pp. 1-14.
Fichier(s) associé(s) à ce document :
Résumé
In phytoplankton communities, competitive exclusion might occur when functionally
similar species are impeded from regulating their positions along light and nutrient gradients to
reduce niche overlap. Greater spatial overlap (SO) between species due to water column mixing could
thus promote competitive exclusion, reducing community taxonomic diversity. However, greater
SO could also promote coexistence of functionally different taxa. Using data from a whole-lake
experiment, we investigated the effects of SO and other relevant environmental factors on phytoplankton
diversity across the water columns of lake basins with different thermocline manipulations.
We estimated SO using an in situ fluorometer, and overall community diversity microscopically.
Using structured equation models, we estimated directional relationships between phytoplankton
diversity, SO, the lake physical structure and the zooplankton community. No significant effect of
SO on phytoplankton taxonomic diversity was observed, but higher SO was associated with greater
functional diversity. Change in lake physical structure and in the zooplankton community also
affected diversity, with a negative response to increased top-down interactions. Overall, despite
the fact that the alteration of water column stratification structure and top-down interactions were
stronger drivers of phytoplankton diversity in our system, some effect of spatial overlap on the
outcome of inferred competitive interactions were observable.
RECHERCHER
PARCOURIR
LIBRE ACCÈS
