CH-DAV, Davos
Contents
Site Description
- ICOS Class 1 ecosystem station since Nov 2019
- Part of ICOS Switzerland
The Seehornwald Davos research site is located at 46°48’55.2” N, 9°51’21.5” E (Google Maps) at 1639 m a.s.l. in the middle range of the subalpine belt in the eastern part of the Swiss Alps.
The coniferous forest is dominated by Norway spruce (Picea abies (L.) Karst.) with a mean canopy height of 9.9 m in the eddy covariance footprint area (tallest trees reach 41 m), and a leaf area index of about 4 m2 m-2. The average tree age in the eddy covariance footprint is approx. 60 years, with some specimens reaching over 350 years. The understorey vegetation is rather patchy, covering roughly 30% of the forest floor, and is mainly composed of dwarf shrubs, primarily Vaccinium myrtillus and Vaccinium gaulterioides as well as mosses.
The research site offers a unique combination of ongoing long-term measurements of regional climate, CO2 and microclimate profiles through the forest, tree physiological records such as sap flow and continuous stem radius changes, turbulent fluxes by eddy covariance, continuous atmospheric NOx, SO2 and O3 concentrations, and multiple properties of the vegetation (e.g. crown transparency, litterfall, rain deposition) and soil structure. Check the history of the Seehornwald Davos research site to get more information about the equipment installed.
The long continuous track record of measurements makes this research site a predestined location for investigations about (missing) links between climate change and tree physiological adaptations and to a hot spot for addressing questions about the ecosystem carbon balance in relation to soil related components and tree physiological processes under changing environmental conditions.
Current land use includes little thinning activities. In 2006, an area of 25 x 70 m (1750 m2) within the NE-part of the footprint of the EC site was harvested at the end of October.
- A list of past and ongoing projects can be found here: Past and ongoing projects at Davos Station
- Additional info about the tower and tower sharing: Tower Sharing (CH-DAV)
- Map (2018)
Location
- Altitude: 1639 m a.s.l.
- Altitudinal zone: subalpine
- Country: Switzerland (Canton Graubünden)
- Coordinates: 46°48’55.2″N / 9°51’21.5″E (46.815333, 9.855972) (Google Maps)
- FLUXNET identifier: CH-Dav
Climate
Air Temperature
- Mean annual air temperature: 4.32°C (1997-2022)
- 5 warmest years: 2022 (5.6°C), 2018 (5.3°C), 2020 (5.2°C), 2015 (5.1°C), 2011 (5.1°C)
- 5 coolest years*: 2010 (2.9°C), 2005 (3.2°C), 2004 (3.7°C), 1999 (3.7°C), 2013 (3.7°C)
- Lowest number of half-hours < 0°C: 2014 (4256), 2011 (4272), 2015 (4490), 2022 (4543), 2020 (4548)
- Highest number of half-hours > 20°C: 2003 (689), 2015 (619), 2022 (565), 2017 (516), 2006 (501)
- Highest number of half-hours > 25°C: 2019 (98), 2015 (56), 2013 (55), 2012 (33), 2022 (29)
- Highest measured air temperature: 28.7°C (26 Jun 2019, half-hourly average between 14:00 and 14:30)
- Lowest measured air temperature: -25.0°C (4 Feb 2012, half-hourly average between 8:30 and 9:00)
Precipitation
- Mean annual precipitation: 876 mm (1997-2022)
Nearby meteo stations
- Meteoswiss: Davos (Google Maps) Data since: 1 Jan 1864 | 1594 m a.s.l. | in 1 km distance
- Meteoswiss: Klosters (Google Maps) Data since: 1 Jan 1864 | 1186 m a.s.l. | in 5 km distance
Vegetation
Where available, numbers are given separately for ICOS sparse measurement plots (SP plots) and ICOS continuous plots (CP plots).
There are differences between these two types of plots, which originatee from the fact that the CP plots, which have been operated for more than 25 years (starting before ICOS), have never been thinned, while the surrounding forest is continuously harvested, thus management keeps the stand smaller and also younger.
The SP plots are located within the eddy covariance footprint area.
- Vegetation: coniferous forest
- Land cover (IGBP classification): Evergreen Needleleaf Forests (ENF)
- Main tree species: Picea abies (L.) Karst
- Mean tree age Picea abies:
- SP plots: 60 yrs (some specimens reaching 350 yrs)
- CP plots: 106 yrs
- Mean tree height:
- SP plots: 9.9 m (max. 41 m)
- CP plots: 18.3 m
- Top-height diameter (quadratic average diameter of the 100 thickest trees per ha): 47.0 cm
- Woodland association after EK72: 58: Larici-Piceetum
- Leaf area index (LAI): 4 m2 m-2
- Average number of stems per hectar:
- SP plots: 1061
- CP plots: 995
- Average stem diameter at breast height:
- SP plots: 12.5 cm
- CP plots: 22 cm
- Average basal area of stems per hectar:
- SP plots: 40.6 m2
- CP plots: 54.7 m2
- Average radial stem growth per year:
- CP plots: 1.2 mm yr-1, 23 µm d-1
- On average, the trees grow 220 hours yr-1, mainly at night with the highest growth at 5:00 in the morning.
- Long-term Forest Ecosystem Research (LWF):
- LWF Date of installation: 15 Jun 2006
- LWF Number of trees BHD >= 12 cm (2006): 498
- LWF Size of the plot: 0.6 ha
Soil
- C stock (ICOS): Computing C stock (online)
- The analysis can also be downloaded as pdf:
Management
- Management system: high forest
- Silvicultural system: group selection
- Current land use includes little thinning activities.
Data
Current Flux Products
Available Level-1 Fluxes
- For info about the different flux levels, see Flux Processing Chain
Eddy covariance raw data files
- Overview of eddy covariance raw data files since 1997: EC Raw Binary Format (CH-DAV)
Additional data information
- Dataflow flowchart (2018)
- Timing of ICOS Dataflow
- Example dataflow (2018): Datalogger: CR1000
- Files Generated On-Site
- Variables Logged On-Site (2021)
- Near-realtime data for this station can be downloaded from the ICOS Carbon Portal
Photos
Video
25 years of CO2 flux measurements in Davos (2022)
More videos can be found on Videos (CH-DAV).
Webcam
- 360° view from top of the Davos station which is part of the external research project SwissPhenocam
- Most recent images from the main tower and Forest Floors 1-5
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Fieldbook
News
Short Report – QA/QC Meeting 21 Mar 2024
Short Report – QA/QC Meeting 22 Feb 2024
Updated dataset download numbers
More Info
- Publication list @ETH Grassland Sciences
- CH-DAV@WSL: Swiss Federal Institute of Forest, Snow and Landscape Research WSL
- CH-DAV@ICOS Switzerland: Class 1 Ecosystem Station – Davos
- CH-DAV@ICOS Carbon Portal: https://meta.icos-cp.eu/resources/stations/ES_CH-Dav
Last Updated on 14 Feb 2024 03:03