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This content will become publicly available on April 12, 2019

Title: Nitrogen enrichment suppresses other environmental drivers and homogenizes salt marsh leaf microbiome

Microbial community assembly is affected by a combination of forces that act simultaneously, but the mechanisms underpinning their relative influences remain elusive. This gap strongly limits our ability to predict human impacts on microbial communities and the processes they regulate. Here, we experimentally demonstrate that increased salinity stress, food web alteration and nutrient loading interact to drive outcomes in salt marsh fungal leaf communities. Both salinity stress and food web alterations drove communities to deterministically diverge, resulting in distinct fungal communities. Increased nutrient loads, nevertheless, partially suppressed the influence of other factors as determinants of fungal assembly. Using a null model approach, we found that increased nutrient loads enhanced the relative importance of stochastic over deterministic divergent processes; without increased nutrient loads, samples from different treatments showed a relatively (deterministic) divergent community assembly whereas increased nutrient loads drove the system to more stochastic assemblies, suppressing the effect of other treatments. These results demonstrate that common anthropogenic modifications can interact to control fungal community assembly. As a result, our results suggest that when the environmental conditions are spatially heterogeneous (as in our case, caused by specific combinations of experimental treatments), increased stochasticity caused by greater nutrient inputs can reduce the importancemore » of deterministic filters that otherwise caused divergence, thus driving to microbial community homogenization.« less
ORCiD logo [1] ;  [1] ;  [2] ; ORCiD logo [3] ;  [1] ;  [1] ;  [4]
  1. Instituto de Investigaciones Marinas y Costeras (Argentina)
  2. Kansas State Univ., Manhattan, KS (United States)
  3. Kansas State Univ., Manhattan, KS (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
  4. Duke Univ., Beaufort, NC (United States)
Publication Date:
Grant/Contract Number:
Accepted Manuscript
Journal Name:
Additional Journal Information:
Journal Volume: 99; Journal Issue: 6; Journal ID: ISSN 0012-9658
Ecological Society of America (ESA)
Research Org:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org:
Country of Publication:
United States
54 ENVIRONMENTAL SCIENCES; deterministic vs. neutral processes; leaf fungal communities; microbial community assembly; nutrient loading; salt marshes; Spartina
OSTI Identifier: