Data from: Depth-dependent mechanisms regulate accumulation of plant- and microbial-derived residues under long-term nitrogen addition in a semiarid grassland
Data files
Apr 01, 2026 version files 15.93 KB
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All_data.csv
13.41 KB
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README.md
2.52 KB
Abstract
Plant- and microbial-derived residues constitute the primary sources of soil organic carbon (SOC) in grassland ecosystems. However, their differential responses to chronic nitrogen (N) enrichment and the depth-dependent mechanisms governing their accumulation remain poorly characterized, particularly for water-limited grassland systems.
Based on a 13-year field experiment in a semiarid grassland, we quantified the effects of long-term N addition on the accumulation of plant- (lignin phenols) and microbial-derived (amino sugars) residues.
We found that N addition significantly increased lignin phenol content and its contribution to SOC in the topsoil, whereas lignin phenols exhibited a hump-shaped response peaking under moderate N levels in the subsoil. Amino sugar concentrations and their relative contribution to SOC increased in both soil layers under N addition, but declined at the highest N input. The dominant factors regulating residue accumulation varied with soil depth: in the topsoil, microbial K-/r-traits and community composition primarily explained lignin phenol and amino sugar dynamics, while in the subsoil, mineral-associated protection and microbial composition were the key drivers.
These findings underscore the depth-dependent nature of SOC formation pathways and highlight the importance of incorporating both plant- and microbial-derived residues into Earth System Models to improve projections of carbon-climate feedback under changing nitrogen regimes.
Dataset DOI: 10.5061/dryad.866t1g25j
Description of the data and file structure
This dataset documents the responses of plant- and microbial-derived residues to long-term nitrogen addition across soil depth gradients.
Files and variables
File: All_data.csv
Description: This dataset documents the responses of plant- and microbial-derived residues to long-term nitrogen addition across soil depth gradients.
Variables
- Lignin phenols, mg kg-1
- Lignin phenols in SOC, mg g-1 SOC
- Vanillyls in SOC, mg g-1 SOC
- Syringyls in SOC, mg g-1 SOC
- Cinnamyls in SOC, mg g-1 SOC
- Amino sugars, mg kg-1
- Amino sugars in SOC, mg g-1 SOC
- Fungal glucosamine in SOC, mg g-1 SOC
- Muramic acid in SOC, mg g-1 SOC
- PCI, plant carbon input, g m-2
- pH, pH value, unitless
- DOC, dissolved organic carbon, mg kg-1
- TDN, total dissolved nitrogen, mg kg-1
- DIN, dissolved inorganic nitrogen, mg kg-1
- Clay+silt, proportion of clay and silt fractions in soil, %
- Caexe, exchangeable Ca2+, cmol+ kg-1
- Mgexe, exchangeable Mg2+, cmol+ kg-1
- Fep+Alp, sum of pyrophosphate-extractable Fe/Al oxides, mg kg-1
- Feo+Alo, sum of oxalate-extractable Fe/Al oxides,mg kg-1
- qCO2, microbial metabolic quotient, μg CO2-C mg-1 MBC h-1
- CUE, carbon use efficiency, unitless
- MBC, microbial biomass carbon, mg kg-1
- MBN, microbial biomass nitrogen, mg kg-1
- MBC/MBN, MBC/MBN ratio, unitless
- BG, β-1,4-glucosidase activity, nmol h-1 g-1
- NAG+LAP, sum of N-acetyl-β-D-glucosaminidase and leucine aminopeptidase activity, nmol h-1 g-1
- BG/NAG+LAP, BG/NAG+LAP ratio, unitless
- Fungal_PCoA1, the first dimensional PCoA ordination of taxonomic composition for fungal community, unitless
- Bacterial_PCoA1, the first dimensional PCoA ordination of taxonomic composition for bacterial community, unitless
- Module#1, ecological cluster#1, unitless
- Module#2, ecological cluster#2, unitless
- Module#3, ecological cluster#3, unitless
- Module#4, ecological cluster#4, unitless
- Fungal_O/C, fungal oligotroph/copiotroph ratio, unitless
- Bacterial_O/C, bacterial oligotroph/copiotroph ratio, unitless
- R/L genes, recalcitrant/labile organic carbon degradation gene abundance ratio, unitless