SMEAR II: Station for Measuring Ecosystem-Atmosphere Relations (1995-) includes a 128 m measurement mast and measurement towers within and above tree canopy. The station continuously monitors forest ecophysiology and productivity, soil and water balance, meteorology, solar and terrestrial radiation, fluxes, ambient concentrations, atmospheric aerosols and deposition. Similar processes are being monitored also in a nearby lake and peatland area. Data is available online.
Some 50 to 100 researchers work at the station, publishing roughly 50 refereed articles every year. The station has contributed to more than 10 EU projects.
The SMEAR station network extends across Finland and, among other countries, to Estonia and China. The SMEAR II station at Hyytiälä is the largest and most versatile station in the network. In addition, the Finnish network includes SMEAR I in the Värriö Strict Nature Reserve in north-eastern Lapland, SMEAR III in urban conditions in Kumpula, Helsinki, SMEAR IV in the Puijo Tower in Kuopio, SMEAR-agri in the fields of Viikki and Haltiala in Helsinki, as well as the latest addition, the measurements carried out at the Tvärminne Zoological Station in Hanko.