CH-DAV, Davos


Site Description

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.

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

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

Management

  • Management system: high forest
  • Silvicultural system: group selection
  • Current land use includes little thinning activities.

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)

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

QA/QC Short Report

Short Report – QA/QC Meeting 22 Feb 2024

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

Updated dataset download numbers

In 2023, our datasets were downloaded (at least) 6645 times, which corresponds to 18.2 downloads per day. Most downloaded sites were CH-DAV, Davos, CH-OE2, Oensingen and CH-CHA, Chamau with more than 1300 downloads each. More details including a plot and table can be found on FLUXNET Number Of Downloads ... Read More
Site Updates

Updated site info for CH-DAV

We added more info and restructured the webpage for the forest site CH-DAV, Davos ... Read More

More Info

Last Updated on 14 Feb 2024 03:03