Long-term forest inventory dataset: Haggen afforestation site, Haggen, Tyrol, Austria

This dataset comprises long-term forest inventory data collected from an upper elevation afforestation site near the community of Haggen in the Sellrain Valley, Tyrol, Austria. Data were recorded during four separate thinning application years: 1995, 2000, 2008, and 2024. The study area includes six permanent monitoring plots established along an altitudinal gradient ranging from 1,730 to 1,900 meters above sea level. The plots encompass pure and mixed stands of Pinus cembra L. (Swiss stone pine) and Larix decidua Mill. (European larch), two native conifer species typical of the central Alps. The dataset includes detailed measurements of individual tree growth attributes, specifically: Tree height (m) Root collar diameter (cm) Diameter at breast height (DBH) (cm) Crown width (m) Height to crown base (m) These attributes were recorded to monitor tree growth responses to thinning treatments, stand composition and environmental conditions over time. We thank the Forest and Engineering Service in Torrent and Avalanche Control (WLV), section Tyrol, for the past 60 years of study site management and for conducting the thinning prescriptions.