Suserup Skov (19.2 ha) is an old growth temperate forest dominated by beech Fagus sylvatica, pedunculate oak Quercus robur, ash Fraxinus excelsior, wych elm Ulmus glabra, and black alder Alnus glutinosa, admixed with lime Tilia platyphyllos and sycamore maple Acer pseudoplatanus. KU/IGN-SNB, is a 19,2 ha old-growth beech-dominated mixed deciduous forests on western Zealand owned by Sorø Academy. The forest use dates back to 4200 BC. A conservation act was placed on the forest in 1925 for biological and recreational purposes but allowing a minimum odd felling until the act was updated in 1961 to a non-intervention forest. The forest is unique at European level in terms of nonintervention, and the long-term status as non-intervention forest has led to a unique steady state in biomass and accumulation of dead wood, thus serving as an important reference site for unmanaged temperate deciduous forest development. There are long-term data records of e.g. biomass, dead organic matter, soil, forest structure, flora and fungi starting from 1992. The platform is included in a series of paired managed and non-intervention forests for studies of forest structure, biodiversity and biogeochemistry in mature and old beech-dominated forests. Suserup Forest includes an ICP Forests level II plot (2001-). Upgrades: eLTER master sites: soil moisture content (TDR), remote sensing of growth and forest structure, LAI, NDVI (Lidar, camera), continuous plant phenology (web cam),and insect monitoring (optical sensors) as biodiversity measures, ambient air quality and air pollution.

Vestskoven is a 15 km2 ongoing afforestation area located 15 km west of central Copenhagen. Since 1967 arable land has successively been bought up for afforestation in order to establish a large forest area for outdoor activities and wood production. In 1998, afforestation chronosequences in oak (Quercus robur) and Norway spruce (Picea abies) were established as a research platform to quantify soil carbon dynamics, water recharge, nitrogen budgets and ground vegetation species diversity. The soil and grund vegetation species composition were resampled in the chronosequences after 13 years in 2011. Since 2003, an ICP-Forests Level II/Core plot with integrated monitoring under the UN Convention on Long-Range Transboundary Air Pollution (CLRTAP) is placed in an oak stand. Monitoring has developed over time. There is no time limit on the monitoring financed by the Ministry of Environment and Food in Denmark.

The Hyytiälä SMEAR II site (Station for Measuring Ecosystem-Atmosphere Relations) is situated in the Hyytiälä Forestry Field Station of the University of Helsinki. The site consists is a managed, 60-yr old Scots pine forest stand. The main idea of SMEAR type infrastructures is continuous, comprehensive measurements of fluxes, storages and concentrations in the land ecosystem–atmosphere continuum. The forest measurements are operated continuously since 1996, and include e.g. leaf, stand and ecosystem scale measurements of greenhouse gases, volatile organic compounds, pollutants (e.g. O3, SO2, NOx) and aerosols, in addition to full suite of meteorological measurements. The biogeochemical cycles and vegetation–soil–atmosphere interactions are studied both experimentally and with long-term observations. The site has full carbon, water and nitrogen budgets made over 10 years, and it is a full ICOS ecosystem and atmospheric station. Ecosystem and atmosphere measurements also exist nearby in two open oligotrophic fen sites and a humic lake with forested catchment. Most of the measured data can be retrieved from: https://smear.avaa.csc.fi/