Data are documented in the following article: Gruber A., W. Oberhuber, G. Wieser (2022) Treeline-Quo Vadis? An ecophysiological approach. Forests 2022, 13,857; doi: 10.3390/f13060857. Summary: At high elevation or latitude, the margin of the life-form tree is set by low temperature, with trees defined as upright woody species taller than 2-3 m. As the climate driven limit of the life-form tree at high elevation is set by low temperature, climate warming will cause treelines to move upwards. As shown in a case study in the Central European Alps, open and dense stands at treeline differ with respect to basal area growth. In an open stand recent climate warming triggered an enhancement in basal area increment of solitary Pinus cembra (L.) and Larix decidua (Mill.) trees. In contrary, in a dense stand nearby, an adequate growth response was almost lacking. This suggests that at the alpine treeline, due to competition for light, nutrients and soil water availability, the positive effect of climate warming on individual tree growth is suppressed with increasing tree density.

The data file (BAI_RW.xlsx) contains yearly basal area and ring width series of Swiss stone pine (Pinus cembra L.) and European larch (Larix decidua Mill.) growing in open and dense stands at treeline on Mt. Patscherkofel (Tyrol, Austria). The study was funded by the Austrian Science Fund (FWF), P34706-B.