DOI: 10.5061/dryad.z612jm6n3
title: Data from: Precipitation and nitrogen enrichment impact carbon exchange and stability: From antagonism to synergy with increasing shrub encroachment

description: Shrub encroachment in arid and semi‐arid grasslands is increasing due to
 global environmental changes, leading to greater vegetation and soil
 heterogeneity that threatens carbon sequestration. Alterations in global
 precipitation patterns and nitrogen (N) deposition impact water and
 nutrient availability, affecting carbon dynamics in these ecosystems.
 Despite this, existing research mainly focuses on traditional steppe
 ecosystems, with limited understanding of variations across different
 stages of shrub encroachment and within heterogeneous patches.This study
 utilized a 4‐year (2020–2023) experimental approach in Inner
 Mongolia's shrub‐encroached grasslands, involving water and nitrogen
 (N) additions, to investigate carbon exchange parameters (NEE, GEP and ER)
 within both shrub and herbaceous patches. It assessed the effects of
 increased precipitation and N enrichment on carbon exchange and stability
 (resistance, resilience and temporal stability) across different stages of
 encroachment (non‐encroached, light, moderate and severe).Water addition
 significantly enhanced net ecosystem carbon exchange (NEE) in
 shrub‐encroached grasslands, particularly during dry years (2020 and
 2022). Although N addition had a minor impact on NEE, its effect varied
 with the extent of shrub encroachment. Herbaceous patches were more
 responsive to water addition, while shrub patches showed stronger
 responses to N addition.The interaction between water and N was modulated
 by interannual precipitation variability and the level of shrub
 encroachment. Co‐additions of water and N promoted carbon sequestration
 during dry years with synergistic effects but exhibited antagonistic
 effects during wet and normal years. As shrub encroachment
 increased  the impact of water–N interaction on NEE transitioned
 from antagonistic to synergistic or additive. Notably, water addition
 enhanced drought resistance in shrub patches. Despite greater stability in
 shrub patches compared to herbaceous patches, the post-drought resilience
 of ecosystem decreased with increasing encroachment intensity. These
 findings provide insights into the long‐term impacts of shrub encroachment
 on ecosystem stability. Future assessments should consider differential
 responses across encroachment stages and heterogeneous patches to better
 understand how changes in precipitation and N deposition affect the
 structure, function and stability of shrub‐encroached grasslands. This
 study offers a novel perspective on the carbon cycling mechanisms in these
 ecosystems, informing evaluations of their carbon sequestration potential.
description: # Data from: Precipitation and nitrogen enrichment impact carbon exchange
 and stability: From antagonism to synergy with increasing shrub
 encroachment
 [https://doi.org/10.5061/dryad.z612jm6n3](https://doi.org/10.5061/dryad.z612jm6n3) ## Description of the data and file structure * Carbon_flux.xlsx were obtained through field monitoring using a Li-cor 840 instrument combined with a homemade transparent photosynthesis assimilation chamber, and were monitored five times a year from June to August, and then used for analysis of variance (ANOVA), linear mixed modeling, and regression analyses with the data on plant community and soil physicochemical properties; * Drought_stability.xlsx was calculated using carbon flux data and then used in ANOVA, linear mixed model analysis, and regression analysis with soil physicochemical properties. * In the above two files, there is some unavailable information (i.e., cells filled with “null”) because there are no shrubs in the typical stepp (i.e., stage named "TS"), so the data observation cannot be carried out. We use “null” to replace the empty cells. - Plant_community_and_soil_properties.xlsx were obtained through field collection of samples and then brought back to the laboratory for measurement in a single run in mid-August each year, then used in ANOVA and regression analysis with carbon flux data; In this file, there is some unavailable information (i.e., cells filled with “null”), which means that the data observation was not made in the corresponding patch because of the difficulty of the operation, and we use “null” to replace the empty cells. ### Files and variables #### File: Functional\_ecology\_\_2024\_Zhu\_et\_al.zip **Description:**  The ratio of SOC to TN: C/N (unitless) Soil organic carbon: SOC (%) Soil total phosphorus: TP (%) Soil total nitrogen: TN (%) Soil available nitrogen: AN (mg kg-1) Soil moisture: SM (%) Soil temperature: ST (°C) Ratio of annuals and biennials (AB) to perennial grasses (PG) biomass: AB/PG (unitless) Root biomass: RB (g m-3) Aboveground net primary productivity: ANPP (g m-2) Interannual variability (CV) (unitless) Post-drought resilience (unitless) Drought resistance (unitless) Gross ecosystem productivity: GEP (umol m-2 s-1) Ecosystem respiration: ER (umol m-2 s-1) Net ecosystem CO2 exchange: NEE (umol m-2 s-1) ## Code/software These can be viewed using software that can view zip as well as xlsx format files, such as excel et al.