The Höglwald is a Norway spruce-dominated forest of about 370 ha surrounded by farmland in the hilly landscape of Southern Bavaria, approx. 70 km north of the Alps and 40 km west of Munich at 11° 5' E and 48°18' N. The Höglwald site (560 m asl) is operated by IMK-IFU permanently since 1993. The site is characterized by chronically high loads of atmospheric nitrogen deposition (~30 kg N ha-1 yr-1 in wet deposition). The site is equipped with 3 fully automated, remotely controlled measuring and data acquisition systems in standard containers for continuous quantification of net exchange of trace gases (CO2, N2O, CH4, NOX) at the soil-atmosphere interface in high temporal resolution using static and dynamic chamber techniques. In addition, the site is equipped with two towers (3 m and 50 m height) for quantification of net ecosystem exchange of CO2, H2O and sensible heat. The measurements are complemented by sensors for precipitation, N-input via wet and dry deposition, soil temperature, soil moisture, stem temperature, soil heat flux, radiation as well as the vertical profiles of temperature, wind speed and wind direction.
Starting in 1993, measurements concentrated on the effect of soil liming, N-deposition, tree species, and distance from the stems of trees on the magnitude of trace gas exchange. In 1999, the focus of measurements was changed to the longterm effect of different forest management practices (clear-cutting vs. selective cutting) on trace gas exchange and the impact on the resources atmosphere and groundwater.
The Höglwald site was/is part of the EU Projects NOFRETETE and NitroEurope IP, and the Helmholtz Initiative TERENO.