The SMEAR (Station for Measuring Ecosystem–Atmosphere Relations) station network consist of several sites nowadays and is expanding. The first station, SMEAR I, was built on the top of Kotovaara hill, in the vicinity of Värriö Research Station, in 1991. In the beginning, the measurement focus was on the airborne pollution from the mining industry in the Kola Peninsula, Northwestern Russia. Later, the focus broadened and includes nowadays a wide range of gas, particle, weather, radiation, photosynthesis and soil measurements.
In summer 2017, the original SMEAR I measurement building was extended and a new measurement building was built in the Yli-Nuortti river valley. The new facilities enable the inclusion of new measurement instruments and expands the activities to a new ecosystem. The old building stands in the middle of a natural Scots pine forest, whereas the new one enables the monitoring of a subarctic river ecosystem.