Dataset for 'Tracking a decade of change: plant diversity decline parallels nutrient enrichment in Alpine semi-natural grasslands'

While long-term biodiversity loss is well documented, short-term ecological changes remain poorly understood. Here, we assess ecological changes in Alpine semi-natural grasslands over a decade.</p><p dir="ltr">We surveyed 55 grassland sites covering 392.7 ha across eight Alpine areas in northern Italy in 2014 and 2024.

We mapped vegetation types and land-use categories in both years and quantified changes in surface-weighted plant species richness and nitrogen fertilisation. We modelled changes in relation to elevation and slope, assessed clusters of vegetation types of different naturalness value, and developed a Naturalness Index combining species richness and management intensity to identify conservation and restoration priorities.</p><p dir="ltr">Over a decade, mean weighted plant species richness declined from 31.5 to 28.9 species, while nitrogen fertilisation increased by 10.9 kg N ha⁻¹ yr⁻¹.