A dataset of the observations of plant species coverages over a temperate grassland in Inner Mongolia (2015–2020)

Field plots were established in July 2014 following a randomized block design. There were four treatments: control (ambient N condition), and NH₄⁺–N/NO₃^––N at 5:1 (mixtures of NH₄Cl and NH₄NO₃), 1:1 (NH₄NO₃) and 1:5 (mixtures of NH₄NO₃ and Ca(NO₃)₂∙4H₂O) at 10 g N m^–2 year^–1. Each treatment had eight replicates, and each experimental plot was 4 m × 4 m. In 2015, the central 2 m × 2 m in each plot, consisting of four 1 m × 1 m quadrats, was assigned to permanent quadrats. The dataset consist of the coverages of each plant species and the plant community in each 1 m² quadrat. Derived data and code of "Nitrogen input enhances the impacts of emigration and immigration on plant species composition in a temperate grassland" are additionally included here.