Forests, groundwater and a deep unsaturated zone: The TERENO Observatory Lake Hinnensee/Fuerstensee in the NorthEastern German Lowlands
Abstract
As the Northeastern German Lowlands were identified to be particularly vulnerable to global change, the observatory TERENO-NE was established in 2011 as part of the Helmholtz-funded TERENO initiative to investigate the regional impact of climate and land use change. Six sites were chosen for comprehensive monitoring, covering forest, intense agriculture, lakes and wetlands. This poster will present one site in detail: the observatory at Lake Hinnensee/Fuerstensee in the Muritz National Park.
The landscape in this region is dominated by forests and lakes. As groundwater and lake water levels have been declining in recent decades, the main questions asked at this site are: what is the effect of different forest stands on groundwater recharge? Which environmental controls can we reconstruct from tree ring archives? Are currently observed weather phenomena and groundwater fluctuations still in the range of the natural variability or have we moved beyond that? The groundwater-dominated lake system and its catchment are located in a glacial outwash plain of the last glaciation, soils are sandy and the depth of the unsaturated zone ranges from 1 to 30 m. Our 15 monitoring sites cover different topographic positions and forest stands: a pure mature beech stand (125 years of age) and a pure mature pine stand (70 years), a young beech (40 years) and a young pine stand (35 years) and 9 mixed stands (100-170 years). The mixed stands cover varying degrees of depth to groundwater (3 - 30 m), while groundwater influence at the pure stands is minimal. The monitoring network includes 7 plots measuring throughfall and stemflow at high temporal resolution (35 trough systems and 50 stemflow collars), 6 plots measuring sapflow and tree growth on 4 trees per plot, 15 plots with 5 soil moisture profiles each (down to a depth of 2m), sapflow, leaf wetness and basic meteorological data, 2 weather stations, 17 deep wells and numerous piezometers surrounding the lake. A DTS fiber optic cable is installed on the lake bottom to investigate lacustrine groundwater discharge patterns. The observatory furthermore includes several instruments which provide data at the field scale: a superconducting field gravimeter to measure total water storage dynamics as well as cosmic ray neutron sensors and GNSS reflectometry to measure soil moisture.- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFMPA13B1015B
- Keywords:
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- 0439 Ecosystems;
- structure and dynamics;
- BIOGEOSCIENCES;
- 1848 Monitoring networks;
- HYDROLOGY;
- 6329 Project evaluation;
- POLICY SCIENCES & PUBLIC ISSUES;
- 6610 Funding;
- PUBLIC ISSUES