Community Assembly Mechanisms Underlying the Core and Random Bacterioplankton and Microeukaryotes in a River–Reservoir System

Abstract

Whether bacterioplankton are assembled in the same way as microeukaryotes is a key question that has been answered only partially in microbial ecology. In particular, relating distribution patterns to the underlying ecological processes for plankton communities in highly dynamic ecosystems, such as river–reservoirs subjected to anthropogenic impacts, remains largely unstudied. Here, we analyzed taxonomic distribution patterns, and unraveled community assembly processes underlying the core and random bacterioplankton and microeukaryotes from a subtropical river–reservoir system. These plankton domains were modelled using the spatial abundance distributions (SpADs) of the operational taxonomic units (OTUs) as a proxy for abundant and rare taxa delineation. Both bacterioplankton and microeukaryote plankton communities exhibited significant distance–decay relationships, and samples were grouped depending on reservoir or river habitats. The neutral community model showed that 35–45% of the plankton community variation could be explained by neutral processes. The phylogenetic null model revealed that dispersal limitation accounted for the largest percentage of pairwise comparisons (42–68%), followed by environmental selection (18–25%). We concluded that similar prevalence of ecological processes acting on particular subsets of the bacterioplankton and microeukaryotes might have resulted from similar responses to environmental change, potentially induced by human activities in the watershed.

Contrasting Community Assembly Mechanisms Underlie Similar Biogeographic Patterns of Surface Microbiota in the Tropical North Pacific Ocean

“…Significant distance-decay patterns of bacteria and/or microeukaryotes have been found in rivers ( 12 , 13 ), lakes ( 9 , 14 ), intertidal zones ( 15 ), coastal seas ( 8 , 16 ), and open oceans ( 16 , 17 ). The underling mechanisms responsible for distance-decay patterns have been shown to differ between domains and between ecosystems ( 8 , 13 , 15 ). The fact that environmental factors varied spatially in the TNPO during our study ( Fig.…”

“…Studies of marine microbial biogeography have benefited greatly from the rapid progress that has been made in genomic sequencing and theoretical microbial ecology ( 11 ). Among the various spatial distribution patterns (e.g., latitudinal diversity patterns and taxa-area relationships), distance-decay patterns have frequently been reported based on studies of communities of bacteria and microeukaryotes in a variety of aquatic habitats, including rivers ( 12 , 13 ), lakes ( 9 , 14 ), intertidal zones ( 15 ), coastal ocean ( 8 , 16 ), and open ocean ( 16 , 17 ). However, there have been few studies of microbial biogeographic patterns in oligotrophic marine waters, especially at the trans-basin scale ( 17 ).…”

Community Assembly and Co-occurrence Patterns Underlying the Core and Satellite Bacterial Sub-communities in the Tibetan Lakes

“…The |βNTI|<2 and RC bray <−0.95 or the |βNTI|<2 and RC bray ≥0.95 RCbray were identified as homogenizing dispersal and dispersal limitation, respectively. When the |βNTI|<2 and |RC bray |<0.95 were identified as “Undominated” ( Dini-Andreote et al, 2015 ; Stegen et al, 2015 ; Isabwe et al, 2019 ). To demonstrate which process contributed more to the DDR slopes between the core and satellite sub-communities, samples controlled by dispersal limitation and heterogeneous selection were separately extracted from both sub-communities according to the results of Stegen’s null model.…”

Island area and historical geomorphological dynamics shape multifaceted diversity of barrier island floras

“…These highly dynamic landscapes suffer from plant biomass destruction by stochastic disturbances in addition to large variation in resource availability over a short period of time; processes that may break established environment–plant–ecosystem relationships (Kleyer et al 2014). Studies on rivers and wetlands found that neutral processes and dispersal limitation better explain species diversity in highly dynamic ecosystems than environmental filtering (Isabwe et al 2019, Schöpke et al 2019).…”