Bavarian Alps / pre-Alps Observatory
The Bavarian Alps/pre-Alps Observatory is jointly coordinated by the Karlsruhe Institute of Technology (KIT) and Helmholtz Center Munich (HMGU). This observatory comprises the “River Ammer catchment”, the long term silvicultural research platform ”Höglwald Forest“, and the long term agricultural research farm “Scheyern“.
Picture 1: Overview of the Bavarian Alps/pre-Alps Observatory
The main objectives followed at this observatory are characterization and quantification of climate change effects on
- Coupled C-/N-cycles and C-/N-storage
- Biosphere-atmosphere exchange (trace gases/energy flux/albedo)
- Vegetation and microbial biodiversity and of the temporal dynamics of matter turnover and exchange associated with this change in biodiversity
- Terrestrial hydrology (alpine water budget, precipitation variability, extreme hydrometeorological events (floods/droughts), seepage water quality/quantity, water retention capacity) in prealpine ecosystems particularly sensitive to changes in climate, nutrient deposition and land use/management (wet grasslands/fens, forests and agricultural systems).
The “River Ammer catchment” is located in Bavaria, southern Germany, covering an area of 709 km2. The highest point is at 2185 m a.s.l. in the Ammergau Alps and the outflow is at 533 m a.s.l. Due to the complex topography, the catchment is characterised by large north-south differentiations in soils, land-use and climate. Long-term mean annual precipitation in the northern part is around 1100 mm/a while the southern part with the summits of the Ammer Alps receives more than 2000 mm/a. Maximum precipitation is in summer. The mean annual temperature is around 7-8 °C in the alpine forelands and approx 4-5 °C in the southern mountainous part of the catchment. Its area includes the Hohenpeissenberg and thereby benefits from the long-term hydrometeorological observations of the DWD observatory (since 1781).
At the River Ammer catchment a lysimeter network is realized (36 lysimeters), in which soil monoliths with grassland vegetation are transplanted along the existing natural gradient in temperature and precipitation, in order to gain - in a frame work of a long-term in situ study - information about the effects of regional climate change on the coupled C and N cycles, the plant biological and microbial processes/populations/biodiversity involved in C and N-cycling as well as C- and N-trace gas production, consumption and emission, and on terrestrial hydrology and water quality.
Picture 2: Installation of 18 lysimeters at the Fendt site within the “River Ammer catchment”
For this, the Ammer catchment region at three elevations will be equipped with climate stations, eddy covariance systems, 36 lysimeters, isotope laser systems for determination of water vapour and CO2 fluxes, TDL-systems for N2O and CH4 flux measurements and closed chamber measuring systems for determination of CO2, N2O and CH4 fluxes at the soil atmosphere interface, and a rain radar.
Picture 3: Installation of EC station at the Fendt site within the “River Ammer catchment”
Picture 4: X-Band rain radar in Geigersau (Mount Kirnberg) within the “River Ammer catchment”
In cooperation with the Bavarian Avalanche Alert Service and Bavarian environmental and water authorities, detailed snow measurements will be performed.
The “Höglwald Forest” observation platform (11°11’E and 48°30’N) is an approx. 100 years old spruce plantation located 40 km north-west of the city of Munich. At this platform the long term effects of atmospheric N input and the consequences of forest conversion on greenhouse gas balances are studied. The climate is suboceanic, with a mean annual precipitation for the period 1984 to 2001 of 933 mm and a mean annual temperature of 7.7°C. The forest is part of a region which is characterized by an intensive mixture of forested and intensively used agricultural areas.
The Höglwald-Forest long term research platform is equipped since 1993 with fully automated measuring systems (chambers) for continuous year round flux measurements of N2O, CH4, CO2, NO/NO2 between the soil and the atmosphere at three experimental sites; tower (50 m high) based EC measurements for determination of water vapour and net ecosystem CO2-exchange are running continuously since 2004.
Picture 5: Measuring tower at the “Höglwald” Forest site
In order to study trace gas fluxes/exchange at the agro-forest interface, an identical set of fully automated chamber systems for determination of trace gas fluxes at the soil/atmosphere interface will be installed in an agricultural field in direct vicinity to the forest site. Furthermore, a NH3-TDLAS-instrument will be set up which will be used e.g. for the determination of NH3 deposition from the agricultural fields into the forest site.
The research farm “Scheyern” is a 150 ha cloister estate located 40 km north of the city of Munich at an altitude of 445-498 above sea level. The farm land is used already since more than 5 centuries and is situated in the tertiary hills, a landscape demonstrating typical problems associated with intensive agricultural use, such as erosion, soil compaction, groundwater contamination, impoverishment of flora and fauna. Since 1992 two farming systems, an integrated crop production and an organic farm system, were installed and permanently monitored to analyse the ecological and economical sustainability of the agricultural systems. In particular the impact of reduced N input on the production systems itself and neighbouring ecosystems is studied. Average annual precipitation is 803 mm and mean annual temperature is 7.4°C.
The research farm Scheyern is equipped since 1992 with hydrological observation systems and automated chambers to measure N2O, CH4, CO2 concentrations at the soil surface. The measurement systems include soil hydrological stations, groundwater multi-level wells, groundwater gages, weirs and drains, surface runoff and erosion measurement devices and several plots to monitor crop production systems depending on soil cultivation type. To study trace gas fluxes between soil and atmosphere the research farm will be equipped for TERENO with additional climate stations, a rainscanner, TDL-systems for N2O and CH4 flux measurements, runoff and soil erosion observation systems, a wireless soil moisture sensor network, a lysimeter station and a soil heating system.