Data from: Labile carbon input alleviates nitrogen-induced community instability in a meadow steppe

Global nitrogen (N) deposition continues to threaten plant diversity and
ecosystem stability despite a recent slowdown in its increasing rates.
Labile carbon (C) may help reduce excess N by alleviating microbial C
starvations, but their role in mitigating the harmful effects of N
enrichment remains unclear. In a meadow steppe in northern China, we
conducted a 9-year (2014-2022) field experiment with six levels of
historical N addition (0, 2, 5, 10, 20, and 50 g N m–2 yr–1, 2014-2019)
and three levels of labile C (0, 200, and 2000 g C m-2 yr-1). Three years
after ceasing N treatments (2020-2022), aboveground net primary
productivity (ANPP) remained high under N addition. However, species
richness and community stability continued to decline with increasing N
addition rates. Labile C addition reduced the dominance of certain plant
species within the community while it enhanced species asynchrony and
belowground net primary productivity (BNPP). Boosted regression tree
models indicated that the high levels of labile C inputs improved
community stability by enhancing BNPP, which increased the relative
importance of BNPP to the community stability from 7.5% to 27.4% as labile
C input rose. Synthesis. Our results highlight how labile C inputs can
counteract the negative impacts of N enrichment on community stability via
enhancing plant-microbe competition and increasing belowground biomass
allocation.