Monitoring and Modelling of Surface-Atmosphere-Interactions: The Tharandt Cluster Institute of Hydrology and Meteorology, Department of Meteorology
Ch. Bernhofer, V. Goldberg, T. Grünwald, B. Köstner
Introduction
Monitoring
Modelling
Since 1996 and in context with different research projects (e.g., BMBF VERTIKO, BMBF LandCaRe 2020, CarboEurope-IP) flux, meteorological, biomass and soil related variables of the dominant land-use types (spruce, crop rotation, grassland, beech) are observed on different time scales at 5 continuous observation sites and 2 monitored watersheds in and around the Tharandt Forest (20 km SW of the city of Dresden).
At all sites:
HIRVAC
• eddy covariance flux:
• vegetation-boundary layer model • vertical highly resolved (120 layers up to 2 km) • coupled with a mechanistic photosynthesis model (University Bayreuth) and a hydrological soil module • studies of differentiated landuse-atmosphere interactions and feedbacks on energy, water and carbon budgets
CO2, latent heat, sensible heat, momentum • meteorological measurements: full radiation budget including Photosynthetic Active Radiation (PAR), air temperature and air humidity, wind speed (horizontal and vertical) and wind direction, precipitation
These long-term flux datasets and a long history of meteorological, hydrological and phenological observations (back to the 1950ies) allow the quantification (monitoring as well as SVAT and Atmospheric boundary layer modelling) of land surface-atmosphere-interactions of carbon, water and energy budgets on different spatial and temporal scales against the background of land-use changes (climate related, forest management, storms, drought effects).
SVAT-CN
At selected sites: • snow mass and snow density • biomass and soil variables: soil respiration, soil temperature and moisture, bole temperature, bole increment, litter fall, sap flow, stem flow, above-ground biomass, LAI
• multilayer SVAT • based on the process-oriented gas exchange model PROXEL (University of Bayreuth) • Simulation of mass (carbon, water, nitrogen) and energy exchange from leaf to landscape scale • combine multilayer vegetation and soil water model
Monitoring Sites Landberg (440 m a.s.l.): Beech • Mean stand height 25 m • Measuring Tower 28 m • Monitoring since 2005
Tharandt (220 m a.s.l.): Climate • Extended climatology (including radiation, soil temperature and moisture and pan evaporation) • Monitoring since 1951
Dresden
IPG (365 m a.s.l.): Phenology • 28 plant species observed • Monitoring since 1960, since 1999 Global Phenological Monitoring Program Tharandt IHM
Landberg
Wildacker (385 m a.s.l.): Climate • Standard climatology • Monitoring since 1959
Tharandt (385 m a.s.l.): Spruce • Mean stand height: 28 m • Measuring Tower height: 42 m • Monitoring since 1991
IPG Wernersbach Catchment
Klingenberg (480 m a.s.l.): Crop Rotation • Crop rotation: maize, rapeseed, winter wheat, winter barley • Measuring Tower height: 2 m • Monitoring since 2004
Anchor Station Tharandt / Wildacker
Wernersbach: Catchment Hydrology • 323-424 m a.s.l., 4,6 km² • 6 sites for precipiation, 5 sites for runoff monitoring • 11 sites for soil moisture, 26 sites for manual runoff measurements • Monitoring since 1968
Grillenburg
Oberbärenburg (735m a.s.l.): Spruce • Mean stand height: 15-20 m • Measuring Towers: 18 m (since 1985), 22 m (1998-2007), 30 m (since 2004) • Monitoring since 1985 (climate), 1994 (micrometeorology)
Klingenberg
Oberbärenburg
Grillenburg (385 m a.s.l.): Grass • Mean stand height 0,3 m • Measuring Tower height 2 m • Monitoring since 2002
Rotherdbach: Catchment Hydrology 0,09 km², 690-750 m a.s.l., measurements since 1996
The landscape around the Tharandt forest (Landsat TM) - the Tharandt cluster consist of 5 continuous observation sites covering spruce (Anchor Station Tharandt, Oberbärenburg), beech (Landberg), grass (Grillenburg) and crop rotation (Klingenberg)
Selected Results:
Gross Prim ary Productivity N et Ecosystem Productivity C arbon export (harvest)
450
600 400
1400
300 300 250 200 200 100 150 0 100
-2 -1
350 400
-100 50 -200
01 .0 1. 20 04 01 .0 1. 20 05 01 .0 1. 20 06 01 .0 1. 20 07 01 .0 1. 20 08 01 .0 1. 20 04 01 .0 1. 20 05 01 .0 1. 20 06 01 .0 1. 20 07 01 .0 1. 20 08
0
3,8
soil moisture net carbon sink
800
evapotranspiration
600
sensible heat flux
400
bowen ratio
200
C sink
-30 -20 -10 0 10 20 30 40 50 60 relative change of the 2003 value compared to the mean values of the 1997- 2007 period (%)
-400 -600
Klingenberg
3,0
50
2,8 2,6
40
2,4 2,2
30
2,0 1,8
20 30
40 50 60 70 Test area width [m]
80
Crown Temperature [deg C]
80
70
30
70
29 28
60
27
50
26 25
40
24
30
23
29 28
60
27
50
26 25
40
24
30
23
22
20
21
1,6
20
Relative change of different meteorological and flux variables of the dry year 2003 compared to the 1997-2007 period at the Anchor Station Tharandt (Spruce)
Net Biome Productivity of different crops affected by rural management at the Klingenberg site
Surface Temperature [deg C]
20
30
40 50 60 Test area width [m]
70
80
Expertise and Perspective The unique concentration of long-term flux and climate measurements over different land use types in the Tharandt cluster as well as the combined application of micrometeorological and SVAT models is an excellent base to study the interactions between different land surface types and changing atmospheric “boundary” conditions.
light use efficiency
C source
-200
3,4 3,2
water use efficiency
0
30
3,6
60
vapour pressure deficit
maize
1000
80
Test area length [m]
Test area length [m]
Modelling
Leaf Area Index
70
precipitation air temperature
winter wheat
rapeseed
1200
Carbon im port (m anure) Net Biom e Productivity
-800
Yearly cumulated carbon dioxide exchange (Net Ecosystem Productivity – left) and evapotranspiration (right) of different land use (2004-2007)
80
Carbon Exchange (gCm a )
500
cumulated ETR [mm]
cumulated NEP [gCm-2]
Monitoring
700
rapeseed winter wheat maize
Test area length [m]
old spruce grassland winter barley
Carbon, Water and Climate
22
20
Left: Biomass distribution (leaf area index) of a heterogeneous 135 years old beech stand (Duebener Heide, North Saxony) in July Middle: Distribution of surface temperature inside a 135 years old beech forest Right: Distribution of crown temperature inside a 135 years old beech forest
The combination of monitoring and modelling allows to study effects of the changing number of natural “disasters” on land surface water and carbon budget. The aim is to find new strategies in land use management. In this context, historical events as, e.g., summer drought in 2003 and storm Kyrill in 2007 are well documented by the measurements and can serve as reference to estimate the potential range of ecosystem response (average and extremes) under changing future climate conditions.
21
20
30
40 50 60 Test area width [m]
Contact / Department Prof. Dr. Christian Bernhofer Kontakt Technische Universität Dresden, Institute of Hydrology and Meteorology, Department of Meteorology Prof. Dr. Christian Bernhofer Pienner Str. 23, 01737 Tharandt, Germany Technische Universität Dresden, Chair of Meteorology e-mail:
[email protected] Pienner Str. 23, 01737 Tharandt Internet: http://tu-dresden.de/meteorologie
e-mail:
[email protected]; Internet: http://tu-dresden.de/meteorologie
70
80
EN ENVIRONMENT AND FORESTS UNDER CHANGING CONDITIONS
F R Change
