Responses of growing-season ecosystem carbon flux components to nitrogen addition and precipitation manipulation in an alpine meadow

Understanding how their carbon exchange responds to global change drivers is essential for accurately assessing the regional carbon budget. To quantify the main and interactive effects of nitrogen deposition and altered precipitation patterns on ecosystem carbon fluxes, we conducted a field manipulation experiment at the National Field Research Station for Haibei Alpine Grassland Ecosystem in Qinghai Province, established in 2017.

The experiment used a randomized complete block design with a full factorial combination of nitrogen addition (10 g·m-2·a-1) and precipitation manipulation (±50% of ambient rainfall). Monthly soil respiration, ecosystem respiration, gross primary productivity (GPP), and net ecosystem productivity (NEP) were measured using static chambers coupled with an infrared gas analyzer during the growing season of 2025.