CH-DAV, Davos


Site Description

The Davos station received the status of an ICOS Class 1 Station in November 2019. It provides the 8th longest time series for CO2 and H2O vapour fluxes globally (since 1997, read more in the station history) and is the only subalpine Class 1 forest Ecosystem station within ICOS. The coniferous forest is located at 1639 m a.s.l. and mainly consists of Norway spruce (Picea abies (L.) Karst.). Trees are on average 17.5 m high, while the tallest trees reach 41 m. The average tree age is 119 years, the oldest tree is estimated to be 350 years old. For the average values, measurements of the ICOS CP and SP plots were weighted by the respective flux contributions (find more details in the published site description). Leaf area index is about 4 m2 m-2. The understorey vegetation is rather patchy, covering roughly 30% of the forest floor, and is mainly composed of dwarf shrubs, primarily Vaccinium myrtillus L. as well as mosses. Davos is part of Swiss FluxNet.

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.

Measurements at the Davos station are jointly organized by ETH Zurich, Swiss Federal Institute for Forest, Snow and Landscape Research (WSL) and Swiss Federal Laboratories for Materials Science and Technology (Empa) / National Air Pollution Monitoring Network (NABEL). The infrastructure is provided by the Federal Office of Environment (FOEN).  Past and ongoing projects cover topics from soil, vegetation, ecosystem to atmosphere. 

The ICOS relevant measurement programme at Davos is organised as follows:

  • Greenhouse gas measurements (CO2, H2O, CH4 and N2O) using the eddy covariance technique and custom-made automated soil chambers, soil meteorology (ETH Zurich)
  • Meteorology (Empa)
  • Measurements of tree growth, stem CO2 exchange as well as leaf area index, biomass, N losses etc.  (WSL)

At the Ecosystem Thematic Centre, the full list of variables measured at an ICOS Class 1 forest station is shown.

Location

The Seehornwald Davos research site is located in the middle range of the subalpine belt in the eastern part of the Swiss Alps.

  • 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

Vegetation

  • The coniferous forest is dominated by Norway spruce (Picea abies (L.) Karst.)
  • Trees are on average 17.5 m high, while the tallest trees reach 41 m. The average tree age is 119 years, the oldest tree is estimated to be 350 years old.
  • Leaf area index (LAI): approx. 4 m2 m-2
  • 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.

Table 1. Biomass characteristics of the research site Seehornwald Davos (CH-DAV). Data refer to SP-, CP plots, or are scaled to the footprint area (80% isoline) with the weighted plot contributions to the eddy covariance signal (FP-weighted). For details see Tab. 2.

Table 2. Calculated contributions of plots to the EC footprint (FP, 80% isoline). Listed are the relative contributions of each plot to the footprint area (%) and the respective values weighted to 100%. Coordinates in the format LV95 indicate the centre of the respective plots (x cor, y cor). The FP was resolved in pixels of one square meter. The last column indicates the number of pixels that was associated with each plot equalling the approximate plot area in m2. To avoid double-counted trees, the plots SP16 and SP17 contain data for that fraction of the plot that is not overlapping with the respective CP plots.

Soil

Management

  • Management system: high forest
  • Silvicultural system: group selection
  • 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.

Data

Current Flux Products

Available Level-1 Fluxes

wdt_ID Site & Year SA GA CO2 H2O N2O CH4 Current Version EFDC Version EFDC Upload EFDC Calcs Details
37 CH-DAV 2016 R350/HS50 IRGA72/75 CO2 H2O FF-202101 FF-202101 30 Jun 2021 UPDATE
38 CH-DAV 2017 HS50 IRGA72 CO2 H2O FF-201902 FF-201902 28 Mar 2019 NEW
39 CH-DAV 2018 HS50 IRGA72 CO2 H2O FF-201902 FF-201902 28 Mar 2019 NEW
40 CH-DAV 1998 R2 IRGA62 CO2 H2O FF-201606 FF-201606 04 Oct 2016 NEW
41 CH-DAV 1997 R2 IRGA62 CO2 H2O FF-201606 FF-201606 04 Oct 2016 NEW
43 CH-DAV 2014 R350/HS50 IRGA72/75 CO2 H2O FF-202101 FF-202101 30 Jun 2021 UPDATE
45 CH-DAV 2012 R350 IRGA75 CO2 H2O FF-201606 FF-201606 30 Jun 2021 UPDATE
46 CH-DAV 2011 R350 IRGA75 CO2 H2O FF-201606 FF-201606 30 Jun 2021 UPDATE
47 CH-DAV 2010 R350 IRGA75 CO2 H2O FF-201606 FF-201606 30 Jun 2021 UPDATE
48 CH-DAV 2009 R350 IRGA75 CO2 H2O FF-201606 FF-201606 30 Jun 2021 UPDATE
49 CH-DAV 2008 R350 IRGA75 CO2 H2O FF-201606 FF-201606 30 Jun 2021 UPDATE
50 CH-DAV 2007 R350 IRGA75 CO2 H2O FF-201606 FF-201606 30 Jun 2021 UPDATE
51 CH-DAV 2006 R2/R350 IRGA75 CO2 H2O FF-201606 FF-201606 30 Jun 2021 UPDATE
52 CH-DAV 2005 R2 IRGA62/75 CO2 H2O FF-201606 FF-201606 30 Jun 2021 UPDATE
53 CH-DAV 2004 R2 IRGA62 CO2 H2O FF-201606 FF-201606 04 Oct 2016 NEW
54 CH-DAV 2003 R2 IRGA62 CO2 H2O FF-201606 FF-201606 04 Oct 2016 NEW
55 CH-DAV 2002 R2 IRGA62 CO2 H2O FF-201606 FF-201606 04 Oct 2016 NEW
56 CH-DAV 2001 R2 IRGA62 CO2 H2O FF-201606 FF-201606 24 Sep 2020 UPDATE
57 CH-DAV 2000 R2 IRGA62 CO2 H2O FF-201606 FF-201606 04 Oct 2016 NEW
58 CH-DAV 1999 R2 IRGA62 CO2 H2O FF-201606 FF-201606 04 Oct 2016 NEW
60 CH-DAV 2016 HS50 QCL N2O CH4 FF-201908 FF-201908 30 Aug 2019 NEW
61 CH-DAV 2017 HS50 QCL N2O CH4 FF-201908 FF-201908 30 Aug 2019 NEW
62 CH-DAV 2013 R350 IRGA72/75 CO2 H2O FF-202101 FF-202101 30 Jun 2021 UPDATE
63 CH-DAV 2015 R350/HS50 IRGA72/75 CO2 H2O FF-202101 FF-202101 30 Jun 2021 UPDATE
65 CH-DAV 2019 HS50 IRGA72 CO2 H2O FF-202005 FF-202005 15 Oct 2020 NEW
66 CH-DAV 2020 HS50/HS100 IRGA72 CO2 H2O FF-202101 FF-202101 13 Apr 2021 UPDATE
137 CH-DAV 2022 NEW
136 CH-DAV 2021 HS50/HS100 IRGA72 CO2 H2O FF-202208 NEW
Site & Year SA GA CO2 H2O N2O CH4 Current Version EFDC Version EFDC Upload EFDC Calcs Details

Eddy covariance raw data files

Additional data information

Photos

You are here: CH-DAV, Davos

Video

25 years of CO2 flux measurements in Davos (2022)

https://www.youtube.com/watch?v=by-CERkxde0

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

Fieldbook

News

Flux Product News

Now Available: new FLUXNET / ICOS datasets

New FLUXNET datasets are available for 6 Swiss FluxNet sites and shared under the CC-BY-4.0 license. Datasets include flux and meteo data until 2023. All datasets can be downloaded from the ICOS data portal, the direct link to the respective site data is given below. New FLUXNET datasets are available ... Read More
QA/QC Short Report

Short Report – QA/QC Meeting 19 Sep 2024

The new Short Report with an overview of recent fluxes and meteo data can be downloaded from here: Short Report - QAQC Meeting 19 Sep 2024 ... Read More
QA/QC Short Report

Short Report – QA/QC Meeting 22 Aug 2024

The new Short Report with an overview of recent fluxes and meteo data can be downloaded from here: Short Report - QAQC Meeting 22 Aug 2024 ... Read More

More Info

Last Updated on 20 Dec 2024 22:35