Anthropogenic Intensity-Determined Assembly and Network Stability of Bacterioplankton Communities in the Le'an River

Bobo Wu; Peng Wang; Adam Thomas Devlin; Yuanyang She; Jun Zhao; Yang Xia; Yi Huang; Lu Chen; Hua Zhang; Minghua Nie; Mingjun Ding

doi:10.3389/fmicb.2022.806036

Anthropogenic Intensity-Determined Assembly and Network Stability of Bacterioplankton Communities in the Le'an River

Front Microbiol. 2022 May 4:13:806036. doi: 10.3389/fmicb.2022.806036. eCollection 2022.

Authors

Bobo Wu^{1

2}, Peng Wang^{1

2}, Adam Thomas Devlin¹, Yuanyang She^{1

2}, Jun Zhao³, Yang Xia^{1

2}, Yi Huang^{1

2}, Lu Chen^{1

2}, Hua Zhang^{1

2}, Minghua Nie^{1

2}, Mingjun Ding^{1

2}

Affiliations

¹ School of Geography and Environment, Jiangxi Normal University, Nanchang, China.
² Key Laboratory of Poyang Lake Wetland and Watershed Research, Ministry of Education, Jiangxi Normal University, Nanchang, China.
³ School of Geography and Ocean Science, Nanjing University, Nanjing, China.

Abstract

Bacterioplankton are essential components of riverine ecosystems. However, the mechanisms (deterministic or stochastic processes) and co-occurrence networks by which these communities respond to anthropogenic disturbances are not well understood. Here, we integrated niche-neutrality dynamic balancing and co-occurrence network analysis to investigate the dispersal dynamics of bacterioplankton communities along human activity intensity gradients. Results showed that the lower reaches (where intensity of human activity is high) had an increased composition of bacterioplankton communities which induced strong increases in bacterioplankton diversity. Human activity intensity changes influenced bacterioplankton community assembly via regulation of the deterministic-stochastic balance, with deterministic processes more important as human activity increases. Bacterioplankton molecular ecological network stability and robustness were higher on average in the upper reaches (where there is lower intensity of human activity), but a human activity intensity increase of about 10%/10% can reduce co-occurrence network stability of bacterioplankton communities by an average of 0.62%/0.42% in the dry and wet season, respectively. In addition, water chemistry (especially NO₃ ^--N and Cl^-) contributed more to explaining community assembly (especially the composition) than geographic distance and land use in the dry season, while the bacterioplankton community (especially the bacterioplankton network) was more influenced by distance (especially the length of rivers and dendritic streams) and land use (especially forest regions) in the wet season. Our research provides a new perspective of community assembly in rivers and important insights into future research on environmental monitoring and classified management of aquatic ecosystems under the influence of human activity.

Keywords: assembly processes; bacterioplankton; human activity intensity; network stability; river.