Norway Spruce-Fir-Red Beech Forest on Limestone

The experimental site Mühleggerköpfl is located on the northern edge of the Alps and receives air pollutants that are transported over long distances, by predominant westerly winds; local emissions from rural settlements are low. The LTER site has an area of 20 hectares. It is a privately owned mature montane forest rich in Norway spruce in the Northern Limestone Alps at 920 m a.s.l. on a north–north-east facing slope of a mountain (47° 34’ 50” N; 11° 38’ 21” E). The site on an isolated calcareous outcrop in the valley of Achenbach represents a watershedsmall catchment. Routinely measured parameters over the years have included climate (air temperature, precipitation, and air humidity), soil temperature, soil water content, soil solution chemistry, nutrient content of Norway spruce needles, air quality, deposition of N, and surface runoff. The climate is cool and mesic with maximum precipitation in summer and a snow-free period from April/May to November/December. The mean annual air temperature and precipitation from on-site measurements are 6.8°C and 1580 mm, respectively. The annual variability of the precipitation is small. Moist conditions are also evident from the high relative air humidity.