Distinct Factors Shape Aquatic and Sedimentary Microbial Community Structures in the Lakes of Western China

Abstract

Little is known about the relative importance of spatial and environmental factors to structuring aquatic and sedimentary microbial biogeography in lakes. Here, we investigated the microbial community composition (MCC) of the water (n = 35) and sediment (n = 35) samples from 16 lakes in western China (salinity: freshwater to salt saturation; pairwise geographical distance: 9–2027 km) using high-throughput sequencing and evaluated the relative importance of spatial and environmental factors to microbial (including total, abundant, and rare) distributions. Our results showed that spatial factors were more important than environmental factors in shaping the biogeography of aquatic and sedimentary microbial communities in the studied lakes, and spatial factors on abundant microbial community was stronger than that on the total/rare microbial communities. Moreover, sedimentary rare MCC might be more sensitive to environmental factors than its aquatic counterpart. Such different biogeography responses of total, abundant, and rare communities to environmental and spatial factors could be ascribed to different physiochemical properties between water and sediment. Collectively, this study expands our understanding of factors shaping microbial biogeography of total, abundant, and rare communities between waters and sediments of lakes.

Factors influencing aquatic and terrestrial bacterial community assembly

“…() found rare bacteria to be to a greater extent randomly assembled and, finally, Yang et al . () found that spatial factors were most important for both. Further, it has been shown that assembly mechanisms can differ between habitat generalists and specialists (Szekely and Langenheder, ; Liao et al ., ; Wu et al ., ).…”

“…Although community assembly mechanisms have rarely been directly coupled to traits, several authors have shown that dominant assembly mechanisms differ among bacterial groups (e.g., Barberan and Casamayor, ; Bissett et al ., ; Drakare and Liess, ; Szekely and Langenheder, ; Fujii et al ., ; Liao et al ., ). Moreover, several authors have made comparisons between rare and abundant members of lake communities, which could, for example, vary because of differences in their risk of extinction and likelihood for dispersal (Liu et al ., ; Niño‐Garcia et al ., ; Yang et al ., ; Liao et al ., ). It is, however, hard to draw general conclusions from those studies since widely different results have been obtained, partly perhaps because different definitions of rare and abundant taxa were used: for example, Liao et al .…”

“…2. This work should also be done for different habitat types (e.g., water or sediments, lakes or oceans or soil, free-living or biofilm-associated) because of differences in the range of dispersal distances in bacteria that are associated with them (Lindström and Langenheder, 2012;Wang et al, 2013;Yang et al, 2016). Generalizations among studies are difficult until this has been achieved, but our hope is that a framework similar to the one presented in Fig.…”

“…Although community assembly mechanisms have rarely been directly coupled to traits, several authors have shown that dominant assembly mechanisms differ among bacterial groups (e.g., Barberan and Casamayor, 2010;Bissett et al, 2010;Drakare and Liess, 2010;Szekely and Langenheder, 2014;Fujii et al, 2015;Liao et al, 2016). Moreover, several authors have made comparisons between rare and abundant members of lake communities, which could, for example, vary because of differences in their risk of extinction and likelihood for dispersal (Liu et al, 2015;Niño-Garcia et al, 2016b;Yang et al, 2016;Liao et al, 2017). It is, however, hard to draw general conclusions from those studies since widely different results have been obtained, partly perhaps because different definitions of rare and abundant taxa were used: for example, Liao et al (2017) showed that species sorting was the most important assembly mechanism for both rare and abundant taxa, but that different environmental variables were important; Liu et al (2015) found that local environmental factors had a stronger effect on rare lake bacteria as opposed to abundant ones; Niño-Garcia et al (2016b) found rare bacteria to be to a greater extent randomly assembled and, finally, Yang et al (2016) found that spatial factors were most important for both.…”

“…Moreover, several authors have made comparisons between rare and abundant members of lake communities, which could, for example, vary because of differences in their risk of extinction and likelihood for dispersal (Liu et al, 2015;Niño-Garcia et al, 2016b;Yang et al, 2016;Liao et al, 2017). It is, however, hard to draw general conclusions from those studies since widely different results have been obtained, partly perhaps because different definitions of rare and abundant taxa were used: for example, Liao et al (2017) showed that species sorting was the most important assembly mechanism for both rare and abundant taxa, but that different environmental variables were important; Liu et al (2015) found that local environmental factors had a stronger effect on rare lake bacteria as opposed to abundant ones; Niño-Garcia et al (2016b) found rare bacteria to be to a greater extent randomly assembled and, finally, Yang et al (2016) found that spatial factors were most important for both. Further, it has been shown that assembly mechanisms can differ between habitat generalists and specialists (Szekely and Langenheder, 2014;Liao et al, 2016;Wu et al, 2018).…”