DOI: 10.5061/dryad.1g1jwstx3
title: Data from: Grazing and nitrogen addition restructure the spatial heterogeneity of soil microbial community structure and enzymatic activities

description: 1. In grassland ecosystems, large herbivorous animal grazing
 activity and increasing nitrogen deposition strongly
 alters microbial community structure and function.
 Understanding the effects of grazing and nitrogen
 addition on the spatial heterogeneity in soil
 microbial community structure, enzymatic activities and the
 underlying mechanisms are crucial for making
 better predictions of soil organic matter dynamics and
 nutrient cycling.  2. We examined the spatial
 heterogeneity of soil microbial community
 structure and enzymatic activity associated with changes
 in soil microclimate, soil characteristics, plant biomass and
 soil nutrient responses to grazing and nitrogen
 addition using a manipulative experiment with
 control (CK), grazing (G), nitrogen addition (N) and
 grazing plus nitrogen addition (NG) treatments in a Leymus
 chinensis meadow steppe, in northeastern China.  3. The
 results demonstrated that soil microbial community structure and enzymatic
 activities showed a high level of spatial dependence [C/(C +
 C0)≥0.9] in the CK plot. G, N and
 NG treatments not only reduced the spatial variability
 ofsoil microbial community structure and enzymatic activities, but also
 reshaped the spatial links between enzymes
 activities and microbial community
 structure. Litter biomass, soil temperature and soil
 nutrients (soil dissolved inorganic nitrogen or soil
 dissolved organic carbon) explained 21-27% of the spatial
 variability of soil microbial community structure in the CK
 treatment and pH was the strongest
 driver for the spatial variability of soil
 enzymatic activities. Meanwhile, the homogenization in soil water
 content induced by the N addition treatment was
 a determinant of the reduction in spatial
 heterogeneity of the microbial community structure. The
 combination of soil physicochemical properties (bulk density, soil pH and
 soil dissolved inorganic nitrogen), soil
 temperature and root biomass explained 32-43% of the
 spatial variability of the microbial community structure
 in the G treatment, and N and G treatments
 had additive effects on the spatial heterogeneity of total
 PLFAs by homogenizing root biomass. Plant biomass and
 microbial community structure were the major drivers for the
 spatial heterogeneity of enzymatic activities under G, N and NG.
 In NG, the change in spatial variability of enzymatic
 activities was dominated by N addition. Regardless of grazing,
 N addition facilitated the spatial correlation between
 microbial community structure and enzyme activities.  4.
 Overall, our results revealed the drivers of soil microbial
 community structure and enzymatic
 activities spatial pattern shift due to grazing and N
 addition, highlighting the
 role that spatial variability in soil microbial
 community structure and enzymatic
 activities has on the L.
 chinensis meadow steppe.
description: To examine how
 spatial
 heterogeneity of soil microbial community structure and enzymatic activities respond to grazing and nitrogen addition at a small scale of 15 ×15 m, we established a field experiment with control (CK), grazing (G), nitrogen addition (N) and grazing plus nitrogen addition (NG) treatments in a <i>Leymus chinensis </i>meadow steppe, in northeastern China. We explored the mechanisms of shifting spatial variability in microbial community structure and enzyme activities by measuring associated changes in soil microclimate and characteristics (soil temperature, soil water content, bulk density and pH), plant biomass (aboveground biomass, AB; root biomass, RB; litter biomass, LB) and soil nutrients (soil dissolved inorganic nitrogen, TIN; soil dissolved organic carbon, DOC; soil organic carbon, SOC; soil total nitrogen, TN) of 75 samples within each treatment. We replaced blank rows with null.