TY - JOUR
T1 - Fine sediment and flow velocity impact bacterial community and functional profile more than nutrient enrichment
AU - Juvigny-Khenafou, Noël P.D.
AU - Piggott, Jeremy J.
AU - Atkinson, David
AU - Zhang, Yixin
AU - Wu, Naicheng
AU - Matthaei, Christoph D.
N1 - Funding Information:
We thank Qinsheng Zhu and the Jiulongfeng Nature Reserve director, Xinhua Cao, and all his staff for their help and assistance during the setting‐up of the ExStream system and the running of this project; Yili Chen, Xiao Zhou, and Liangping Long for logistical assistance as well as laboratory analysis. This work was supported by the Research Development Fund of Xi’an Jiaotong‐Liverpool University (RDF‐15‐01‐50) to Y. X. Zhang, D. Atkinson, and J. J. Piggott with a PhD scholarship to N. P. D. Juvigny‐Khenafou, by the Natural Science Foundation of Jiangsu Province (BK20171238) to Y. X. Zhang, and by a University of Otago "Priming Partnerships" grant to C. D. Matthaei, J. J. Piggott, and Y. X. Zhang.
Publisher Copyright:
© 2020 by the Ecological Society of America
PY - 2021/1
Y1 - 2021/1
N2 - Freshwater ecosystems face many simultaneous pressures due to human activities. Consequently, there has been a rapid loss of freshwater biodiversity and an increase in biomonitoring programs. Our study assessed the potential of benthic stream bacterial communities as indicators of multiple-stressor impacts associated with urbanization and agricultural intensification. We conducted a fully crossed four-factor experiment in 64 flow-through mesocosms fed by a pristine montane stream (21 d of colonization, 21 d of manipulations) and investigated the effects of nutrient enrichment, flow-velocity reduction and added fine sediment after 2 and 3 weeks of stressor exposure. We used high-throughput sequencing and metabarcoding techniques (16S rRNA genes), as well as curated biological databases (METAGENassit, MetaCyc), to identify changes in bacterial relative abundances and predicted metabolic functional profile. Sediment addition and flow-velocity reduction were the most pervasive stressors. They both increased α-diversity and had strong taxon-specific effects on community composition and predicted functions. Sediment and flow velocity also interacted frequently, with 88% of all bacterial response variables showing two-way interactions and 33% showing three-way interactions including nutrient enrichment. Changes in relative abundances of common taxa were associated with shifts in dominant predicted functions, which can be extrapolated to underlaying stream-wide mechanisms such as carbon use and bacterial energy production pathways. Observed changes were largely stable over time and occurred after just 2 weeks of exposure, demonstrating that bacterial communities can be well-suited for early detection of multiple stressors. Overall, added sediment and reduced flow velocity impacted both bacterial community structure and predicted function more than nutrient enrichment. In future research and stream management, a holistic approach to studying multiple-stressor impacts should include multiple trophic levels with their functional responses, to enhance our mechanistic understanding of complex stressor effects and promote establishment of more efficient biomonitoring programs.
AB - Freshwater ecosystems face many simultaneous pressures due to human activities. Consequently, there has been a rapid loss of freshwater biodiversity and an increase in biomonitoring programs. Our study assessed the potential of benthic stream bacterial communities as indicators of multiple-stressor impacts associated with urbanization and agricultural intensification. We conducted a fully crossed four-factor experiment in 64 flow-through mesocosms fed by a pristine montane stream (21 d of colonization, 21 d of manipulations) and investigated the effects of nutrient enrichment, flow-velocity reduction and added fine sediment after 2 and 3 weeks of stressor exposure. We used high-throughput sequencing and metabarcoding techniques (16S rRNA genes), as well as curated biological databases (METAGENassit, MetaCyc), to identify changes in bacterial relative abundances and predicted metabolic functional profile. Sediment addition and flow-velocity reduction were the most pervasive stressors. They both increased α-diversity and had strong taxon-specific effects on community composition and predicted functions. Sediment and flow velocity also interacted frequently, with 88% of all bacterial response variables showing two-way interactions and 33% showing three-way interactions including nutrient enrichment. Changes in relative abundances of common taxa were associated with shifts in dominant predicted functions, which can be extrapolated to underlaying stream-wide mechanisms such as carbon use and bacterial energy production pathways. Observed changes were largely stable over time and occurred after just 2 weeks of exposure, demonstrating that bacterial communities can be well-suited for early detection of multiple stressors. Overall, added sediment and reduced flow velocity impacted both bacterial community structure and predicted function more than nutrient enrichment. In future research and stream management, a holistic approach to studying multiple-stressor impacts should include multiple trophic levels with their functional responses, to enhance our mechanistic understanding of complex stressor effects and promote establishment of more efficient biomonitoring programs.
KW - 16S rRNA
KW - China
KW - Exstream system
KW - METAGENassist
KW - mesocosms
KW - microbiome
KW - multiple stressors
UR - http://www.scopus.com/inward/record.url?scp=85091724875&partnerID=8YFLogxK
U2 - 10.1002/eap.2212
DO - 10.1002/eap.2212
M3 - Article
C2 - 32754996
AN - SCOPUS:85091724875
SN - 1051-0761
VL - 31
JO - Ecological Applications
JF - Ecological Applications
IS - 1
M1 - e02212
ER -