A global meta-analysis database of elevated CO ₂ , warming and altered precipitation regimes on grassland nitrogen and carbon cycles

Grasslands are the largest terrestrial ecosystems on Earth, providing essential ecosystem services to human society through biogeochemical cycles. Despite their significance, the response of grassland nitrogen cycling to climate change remains inadequately understood on a global scale. To address this, we selected 513 field-based grassland studies that simulate climate change, from which we extracted a total of 4,632 experimental observations sourced from published studies to construct a comprehensive dataset. This dataset presents experimental data on the responses of various nitrogen cycling variables, along with some carbon cycle-related variables, to individual climate change factors, including elevated CO2 concentrations, climate warming, increased precipitation, and decreased precipitation. The database includes detailed research information, location data, vegetation information, experimental conditions, variable response ratios, and variance, providing valuable insights into the independent effects of individual climate change factors on the grassland nitrogen cycle. It also offers a data foundation for predicting nitrogen budgets under future climate change scenarios. The data is available on the Figshare platform (https://doi.org/10.6084/m9.figshare.28702616.v2).