SMEAR II - Station for Measuring Ecosystem-Atmosphere Relations


Open-air Platform

Parent institution: University of Helsinki
Active since 1995
Active through 1995 - current

Co-located with

  • ICOS
  • LTER

Fields of study

  • Atmospheric chemistry and physics
  • Isotopic chemistry
  • Climatology, Climate Change
  • Environmental sciences, Pollution
  • Soil science
  • Mapping, GIS
  • Microbiology
  • Hydrology
  • Terrestrial biology, Ecology
  • Limnology

Contact Information

Bäck, Jaana

The SMEAR II station is designed for multidisciplinary research on ecosystem-atmosphere interactions, established in 1995. The site is a Level I ICOS ecosystem and atmosphere site, and hosts the LTER Hyytiälä (LTER_EU_FI_007). The site consists of a tall mast (137 m), 2 Eddy towers for GHG, aerosol and trace gas fluxes, and several walk-in towers for access to canopy.

The Location

Country: Finland

Latitude: 61.8500000

Longitude: 24.2833333

Nearest town: Korkeakoski

Distance from neaerst town: 6 km

Relevant Research Questions

Interactions between climate, ecosystems and atmosphere; exchange of GHGs, trace gases (incl. O3, SO2, VOCs) and aerosols between ecosystems and atmosphere - effects of different forest management methods on ecosystem processes and biogeochemical cycles.


The site has a comprehensive set of ongoing long-term ecosystem measurements operated on a continuous basis, 24/7. It also has strong scientific and operational links between ICOS, ACTRIS, AnaEE and LTER (co-location). The Hyytiälä Forest research station is able to accommodate 130 person during summer time and ca 80 ppl during winter time. Cafeteria, office space, small lab, storage and technical assistance available.


As the site is a long-term ecosystem and atmosphere site (ICOS), large-scale destructive measurements should be avoided, or conducted outside the actual SMEAR II stand. The on-site laboratory facilities (equipment) are rather basic, and in need of some upgrading.

Experimental Capabilities

Experimental Facilities

portable gas analyzers

Experiments duration: Months, Weeks, Years, Decades;

Experimental Aerea

Total area: 10000 m²

from leaf scale to stand scale

Available area: 10000 m²

Experimental Unit Size

unit size: 1 m²

Area depends on the specific type and site of intended manipulations, larger areas are available outside the existing core measurement sites.


Replicates number: 20

the number is dependent on experiments.

Cross-Ecosystem Manipulation

Catchment areas (forest –lake, forest-wetland, lake-wetland)

Manipulation Techniques

Trenching (tree-soil interactions), fertilization (nutrient availability), ditching (water table level), prescribed burning, a choice of various forest management practices, manipulation of gas concentration in shoot chambers

Temporary storage

  • Drying oven
  • Freezer
  • Liquid N
  • Refrigerator
  • Other

Available Instruments

  • Basic field sampling instruments
  • Enclosures for manual measurements (many sizes and volumes)
  • Portable gas analyzer-fluorescence analyzer
  • Thermal camera
  • Osmometer

Electricity available on site.

Distance from Laboratory facilities


Years measured: Minimum 23 years, for many meteorological variables 30 years or longer


Mean Temperature: 3.5 °C

February Mean Temperature: -7.7 °C

July Mean Temperature: 16 °C


Mean Annual Speed: 2 m/s

Max. Annual Speed: m/s

Dominant Direction: SW


Precipitation type: Both;

Total annual precipitation: 711 mm

Mean snow cover duration: days

Soil Types

State Variables

Continuously Measured

  • (aquatic) Conductivity
  • (aquatic) Current speed
  • (aquatic) Oxygen content
  • (aquatic) pH
  • (aquatic) Water temperature
  • Air humidity
  • Air temperature
  • Atmospheric pressure
  • Canopy temperature
  • Fluorescence
  • Incident PAR
  • Incident shortwave radiation
  • Soil temperature
  • Phenology
  • Soil water content

Spot Measured

  • (aquatic) Chlorophyl
  • (aquatic) Nutrient levels
  • (aquatic) Turbidity
  • Population densities
  • Species richness

Environmental Pressures

Variable Ecosystem Status
Management - rotation practice Forest Active
Management - other Forest Active
Airpoll Forest Planned
Habitatfrag Forest Planned
Pests Forest Planned
Precip Wetland Planned
Hydro Wetland Active

On site Staff and Accomodation

Peak season staff

Up to 25 people

Off season staff

Up to 20 people

Visiting personnel

Up to 150 visitors

Bedrooms available

Up to 100 beds

Showers on site

Showers on site

Laundry on site

Laundry on site