Similar community assembly mechanisms underlie similar biogeography of rare and abundant bacteria in lakes on Yungui Plateau, China

Abstract

The revolution of molecular techniques in the field of microbial ecology not only allows an in-depth exploration of abundant bacteria, but also confirms the existence of "rare biosphere." However, the mechanisms underlying the assembly process of abundant and rare bacteria in plateau lakes are still poorly understood. In the present study, distribution of abundant and rare bacteria in 21 lakes on Yungui Plateau, China and the relative importance of deterministic and neutral factors to their biogeographic patterns were examined. Results surprisingly showed that similar biogeographic patterns of rare and abundant taxa were generally shaped via similar assembly mechanisms. For both bacterial groups, deterministic process strongly influenced the distribution, while neutral process was not at play. In addition, they both exhibited a weak distance-decay relationship. Nevertheless, environmental drivers of rare and abundant taxa and their importance were not exactly the same. Water physicochemical property was the most dominant driver shaping the biogeographic pattern of rare taxa, followed by lake morphology and watershed land-use, while for abundant taxa, watershed land-use was the most dominant driver and lake morphology did not play a significant role. This study suggested that rare bacteria in high-altitude aquatic ecosystems might experience equally low extinction risk and respond to environmental changes in a similar manner to abundant ones, but their ecological niches and functions were not identical. To fully understand the assembly mechanism of bacterial community, it is necessary to differentiate the community by traits of taxa.Bacteria are typically diverse and complex organisms crucial to ecosystem function for their vital roles in global biogeochemical cycles (Xia et al. 2010;Newton et al. 2011;Liao et al. 2015a;Cao et al. 2016). The revolution of highthroughput sequencing and increasing sampling efforts have confirmed the existence of "rare bacterial biosphere," which is composed of massive species with a few individuals . These rare bacteria exhibit characteristic metabolic activities (Jones and Lennon 2010;Campbell et al. 2011), carry out particular metabolic functions important for the turnover of certain elements (Pester et al. 2010; Pedr osAli o 2012), and can be regarded as a propagule bank (Grime 1998). Compared to rare bacteria, abundant ones have been explored to a deeper degree. They appear to contribute a major function to ecosystems (Kim et al. 2013). Considering the importance of rare and abundant taxa, it is necessary to unveil their biogeographic patterns, which will provide more useful information for functional and ecological investigations (Herlemann et al. 2011;Hanson et al. 2012;Liu et al. 2015). However, it is still under debate whether rare bacterial taxa share similar biogeography with abundant ones. In order to resolve this dispute and also to interpret a global map of bacterial diversity, more efforts are in demand to characterize the biogeographic patterns of rare and ab...

Abundant and Rare Bacterioplankton in Freshwater Lakes Subjected to Different Levels of Tourism Disturbances

“…This result suggests that rare taxa are a significant contributor to alpha diversity [49,59]. The abundance of any given bacterial species is the results of balance between its growth rate and loss factors [29,60]. Low abundance could actually protect rare taxa from active loss by both viral lysis and predation [61]; then, rare taxa are likely to experience a low risk of extinction as equally as abundant taxa [31,60].…”

“…The abundance of any given bacterial species is the results of balance between its growth rate and loss factors [29,60]. Low abundance could actually protect rare taxa from active loss by both viral lysis and predation [61]; then, rare taxa are likely to experience a low risk of extinction as equally as abundant taxa [31,60]. Relative to rare taxa, abundant ones are generally detected to a deeper degree [60,62].…”

“…Low abundance could actually protect rare taxa from active loss by both viral lysis and predation [61]; then, rare taxa are likely to experience a low risk of extinction as equally as abundant taxa [31,60]. Relative to rare taxa, abundant ones are generally detected to a deeper degree [60,62]. However, with the aid of advanced molecular techniques and increasing sampling efforts, rare bacteria have been successfully explored in oceans [63], soils [49], wastewater treatment reactors [30], coastal lakes [33], and plateau lakes [60].…”

Introductory Chapter: The Main Directions and Tasks of Pure and Applied Biogeography in Solving the Global Problems of Our Time

“…Climate change and biodiversity crisis issues have a particularly large impact on water, aquatic ecosystems and wet habitats such as oceanic biotopes [36], surface freshwater [37,38], or groundwater [39]. The state of river water vegetation also has a fundamental effect on animal communities [40].…”

Causes and consequences of soil bacterial rarity

“…However, studies attempting to quantify the relative importance of niche differences and environmental variation vs. dispersal and stochastic events find variable results (Östman et al 2010(Östman et al , Jeraldo et al 2012. Still, niche processes have been demonstrated often to be the dominant mechanism indicating significant ecological differences between species (Powell et al 2015, Liao et al 2017. In support of the niche theory, Koch (2001) proposed the oligotrophic-copiotrophic concept for bacteria.…”