<b>Data from:[</b><b>Temporal pattern and metabolic mechanisms of ecosystem carbon fluxes under decadal-long nitrogen enrichment in an alpine grassland</b><b>]</b>

The temporal decline in NEP response was reversed with phosphorus supplementation, providing experimental evidence of aggravated phosphorus limitation under long-term nitrogen loadings. Further analysis demonstrated that plant metabolic traits surpassed the classical traits in mediating productivity response to long-term nitrogen:phosphorus imbalance; the metabolites in Calvin-Benson cycle and pentose phosphate pathway of the dominant species were important predictors of variations in productivity under nutrient additions.

Taken together, our findings imply that prior short-term measurements may overestimate the nitrogen-triggered ecosystem carbon sink, and provide metabolic insights into the nitrogen effects on primary productivity.</p>