DOI: 10.5061/dryad.95x69p8xr
title: Data from: Extreme wetness reduces soil microbial residue carbon more substantially than extreme drought across grassland ecosystems

description: Soil microbial residue carbon (MRC) represents a significant component of
 soil carbon pools and regulates the response of soil carbon sequestration
 to precipitation changes. However, how soil MRC content responds to
 extreme drought and wetness, and the underlying mechanisms in regional
 grassland ecosystems, remains unclear. Here, we quantified the responses
 of soil MRC content to extreme drought and wetness, and identified the key
 drivers using a coordinated precipitation change experiment across nine
 alpine and temperate grassland ecosystems in China. Extreme drought (-50%
 precipitation) reduced MRC content by 8% on average. In contrast, extreme
 wetness (+50% precipitation) unexpectedly caused a pronounced 24% average
 decline in MRC content. Under extreme drought, reduced plant biomass
 inhibited soil MRC formation, and soil microbial N enzymes accelerated
 soil MRC decomposition. Moreover, wetter ecosystems exhibited greater
 losses of soil MRC, while drier ecosystems experienced a more moderate
 decline. Under extreme wetness, increased soil microbial N enzyme activity
 accelerated the decomposition and utilization of microbial residue due to
 intensified microbial nitrogen limitation, resulting in a reduction in
 MRC. Our findings challenged the conventional understanding that extreme
 wetness promotes MRC accumulation by revealing a stronger reduction in MRC
 content under extreme wetness than under extreme drought. By uncovering
 distinct mechanisms driving MRC responses to extreme drought and wetness,
 our study provides critical insights into the dynamics of
 microbial-derived carbon in grassland ecosystems under future climate
 change.
description: # Data from: Extreme wetness reduces soil microbial residue carbon more
 substantially than extreme drought across grassland ecosystems #### Data
 Description Data.xlsx: Contains measurements of variables for each sample,
 along with the associated Site and Treatment. Each row represents an
 individual sample (Sample), corresponding to one measurement or sampling
 event. Each column represents a variable (Sample, Site, Treatment, pH...)
 describing sample attributes or measurements. **Variable Descriptions**
 3.1 Sample ID Type: String Description: Name of the sample. Format
 Example: A1.1, A1.2... Note: The letter (A–C) denotes the Treatment plot.
 The first digit (1-9) indicates the Site number. The last digit (1-3 or 4)
 indicates the Block number. 3.2 Site Type: String Description: Name of the
 sampling Site. Example: Dangxiong... 3.3 Treatment Type: String
 Description: Experimental Treatment plot. Examples: Control, -50%Pre,
 +50%Pre 3.4 Plant, Soil, Microbial variables Type: Numeric Description:
 Measurement value and unit SWC: Soil Water Content change (%) MRC:
 microbial residue carbon, g kg^-1 ANPP: aboveground net primary
 productivity, g m^-2 SOC: soil organic carbon, g kg^-1 DOC: dissolved
 organic carbon, mg kg^-1 TN: total nitrogen, g kg^-1 AN: available
 nitrogen, mg kg^-1 TP: total phosphorus, g kg^-1 Bacterial: bacterial
 biomass, nmol g^-1 Fungal: fungal biomass, nmol g^-1 Microbial: microbial
 biomass, nmol g^-1 βG: β-1,4-glucosidase, nmol g^-1 h^-1 NAG:
 β-N-acetylglucosaminidase, nmol g^-1 h^-1 LAP: leucine aminopeptidase,
 nmol g^-1 h^-1 AP: alkaline phosphatase, nmol g^-1 h^-1 Oxidase: soil
 microbial oxidase enzyme, µmol g^-1 h^-1