DOI: 10.5061/dryad.xwdbrv1n4
title: Data from: Distinct N-cycling microbial communities contribute to microtopographic variation in soil N2O emissions

description: Climate change is increasing the frequency and intensity of large
 precipitation events that flood soils and establish anoxic conditions that
 promote microbial denitrification, a predominant source of atmospheric
 nitrous oxide (N2O, a strong greenhouse gas). Denitrification may be
 favored within topographic depressions in otherwise flat fields that are
 prone to ponding, establishing “hotspots” of N2O emissions. The location
 of N2O hotspots may also depend on the distribution of soil microbial
 communities that are responsible for the production and consumption of N2O
 in soils. Yet, relating soil microbial community composition to N2O
 emissions remains challenging. To assess how spatial variation in soil
 microbial communities affects N2O emissions, we measured the community
 composition of active microorganisms using amplicon-based sequencing of
 cDNA generated from mRNA transcripts associated with N-cycling processes
 in response to experimentally flooding and draining soils in the lab. We
 also used stable isotope tracers to relate microbial communities to
 process rates. Consistent with the hypothesis that denitrifying microbial
 communities are not functionally redundant, we found that the diversity of
 microbial taxa expressing nitrite reduction genes (nirK) and N2O reduction
 genes (Clade I nosZ) were correlated with denitrifier-derived N2O
 emissions. Depressional soils had more diverse active N2O consuming
 communities (assessed using Clade I nosZ) under flooded conditions,
 limiting net N2O emissions compared to upslope soils. Furthermore,
 non-flooded depressional soils maintained higher rates of dissimilatory
 nitrate reduction to ammonia (DNRA), limiting nitrate available to
 denitrifiers. Our results show that depressional soils maintain distinct
 microbial communities that likely promote higher rates of N2O reduction
 and DNRA compared to upslope soils. Soil microtopography can, therefore,
 select for distinct microbial communities that emit different amount of
 N2O in response to large precipitation events.
description: Please see the methods in the associated publication for detailed
 methods. Briefy, we collected soil cores from depressional and upslops
 soils within three agricultural fields in central Illinois. We used stable
 isotopes to emasure dentirifciation and ntirification derived N2O
 emissions as well as rates of dissimilary nitrate reductionto ammonium. We
 also sequenced mRNA transcrips from genes involved in various steps of
 dentirification and DNRA. We used these data to link microbial community
 composition to microbial process rates. 
description: # Data from: Distinct N-cycling microbial communities contribute to
 microtopographic variation in soil N2O emissions
 [https://doi.org/10.5061/dryad.xwdbrv1n4](https://doi.org/10.5061/dryad.xwdbrv1n4) This dataset presents data from the publication entitled "Distinct N-cycling microbial communities contribute to microtopographic variation in soil N2O emissions". The dataset includes data on soil N2O emissions, soil microbial community composition, and soil properties presented in the manuscript. Please refer to the publication for methodologies used to generate these data and for the experimental design. ## Description of the data and file structure File list (filenamesand brief description of all data files): combined_data.csv: This file contains the cDNA transcript richness, initial soil properties, N transformation rates, and N2O emission data from the experiment described in the manuscript. Variable_Descriptions.csv: This file includes the units and description of all variables presented in the combined_data.csv data file. Raw sequence reads are available at the National Centre for Biotechnology Sequence Read Archive under BioProject accession number PRJNA1101905.