Nitrogen addition drives local extinction of legumes in meadow steppe

Nitrogen (N) enrichment poses a critical threat to legume diversity through three interlinked mechanisms: stimulating growth of non-leguminous competitors, enhancing community canopy coverage, and inducing light limitation. Canopy management practices such as mowing may partially mitigate these impacts by reducing species dominance and restoring light availability.
Through a decadal field experiment in a meadow steppe, we systematically investigated the interactive effects of chronic N addition and mowing regimes on legume biomass dynamics and species persistence.
Our findings demonstrate a time-dependent relationship between N enrichment and legume species richness. Most legume species, particularly rare and subordinate ones, were eliminated at intermediate-to-late stages when N addition rates exceeded 10 g N m−2 yr−1. This collapse correlated with the progressive suppression of legumes by biomass accumulation in the dominant non-legume species, Leymus chinensis. Beyond this ecological..., , , Description of the data and file structure

The dataset is related to the paper \"Nitrogen Addition Drives Local Extinction of Legumes in Meadow Steppe\". The excel file contains four sheets. The “field experiment” (contains data from 2014-2023), “light transmittance” (2023) and “soil data” (2023) sheets contain data collected from the study site (field), and “greenhouse” sheet contains data collected in 2019 from the greenhouse of *Thermopsis lanceolata*.

**Description:** 

*Variables*

* plot: The nitrogen (N) treatment plot. The study site contains 480 plots, of which 384 are relevant to our study.
* block: Study block. Each block contains 60 plots and total 8 blocks.  
* type: N fertilizer types. This study includes (NH₄)₂SO₄, NH₄HCO₃, urea, slow-release urea.
* dose: the N addition rates. Six rates are included, which are 0, 2, 5,10, 20 and 50 g N m⁻² yr⁻¹.
*  mowing: The mowing treatment.
* year: The study year.
* ANPP: Aboveground net primary productivity in each plot (g m⁻² yr⁻¹)...,