Neutral community model explains the bacterial community assembly in freshwater lakes

Abstract

Over the past decade, neutral theory has gained attention and recognition for its capacity to explain bacterial community structure (BCS) in addition to deterministic processes. However, no clear consensus has been drawn so far on their relative importance. In a metacommunity analysis, we explored at the regional and local scale the effects of these processes on the bacterial community assembly within the water column of 49 freshwater lakes. The BCS was assessed using terminal restriction fragment length polymorphism (T-RFLP) of the 16S rRNA genes. At the regional scales, results indicated that the neutral community model well predicted the spatial community structure (R(2) mean = 76%) compared with the deterministic factors - which explained only a small fraction of the BCS total variance (less than 14%). This suggests that the bacterial compartment was notably driven by stochastic processes, through loss and gain of taxa. At the local scale, the bacterial community appeared to be spatially structured by stochastic processes (R(2) mean = 65%) and temporally governed by the water temperature, a deterministic factor, even if some bacterial taxa were driven by neutral dynamics. Therefore, at both regional and local scales the neutral community model appeared to be relevant in explaining the bacterial assemblage structure.

Neutral processes and high inter-annual turnover shape the assembly of soil bacterial communities in a Mediterranean watershed

“…Since the watershed has not recently experienced severe disturbances (e.g., fires, land use change, droughts), the observed shifts have likely arisen by variations of climatic factors which, in turn, have affected the strength of individual mechanisms of assembly (e.g., dispersal, drift, selection) in the soils. A similar temporal trend has been reported in lakes, where the importance of neutral processes increased over a triennial period and that trend was accompanied by an increase in immigration coefficient (Roguet et al 2015).…”

Nitrotoga is selected over Nitrospira in newly assembled biofilm communities from a tap water source community at increased nitrite loading

“…This suggests that including the rare taxa in the source community (not detected with our sampling method or sequencing) increases the support of the NCM. Others report much higher support of the NCM but in all these studies composition of the source community is not directly measured but estimated by averaging the composition of multiple communities (Sloan et al ., ; Ofiteru et al ., ; Burns et al ., ; Roguet et al ., ). We believe that such approach may provide misleading confidence in the NCM.…”

Insights into protist diversity and biogeography in intertidal sediments sampled across a range of spatial scales

“…Normally, neutral processes can also shape biological communities. Neutral community models have been well explored in bacterial community structure, such as in wastewater treatment plants (Ofiteru et al ), bioreactors (Zhou et al ), lakes (Roguet et al ), soils (Powell et al ), and subtropical bays (Mo et al ). Recently, it was found that this model is also helpful in explaining microeukaryote community structure (Dolan et al ; Chen et al ).…”