Western part of the Gulf of Riga (the Baltic Sea) littoral and sublitoral zone. The marine site is located on the west coast of the Gulf, in the Engure Nature protected area. The monitoring activities are based on three transects which represent an open area of very similar substrate type. These transects are located on the tip of Mersrags, 2.5 km northwards from the port of Mersrags. Long-term studies of the Gulf of Riga coastal zone communities and macrophytes as the key component of littoral zone under natural and anthropogenic impact and possible threats to the littoral zone biological resources. The SCUBA diving is used in marine site assessment.

The site consists of high elevation vegetation in central Mediterranean basin, along the Apennines mountain range: xerophitic primary grassland (Pediculari elegantis-Seslerietum tenuifoliae) and mesophitic primary grassland (Luzulo italiacae-Festucetum macratherae), with important resident and migratory bird communities. Six plots, each one 100 m2 large, grouped in two cluster-plots including each one three plots, representative of a larger area of 0,5 km2 ca., ranging from 2100 to 2300 m a.s.l. (alpic and Mediterranean high-mountain belts.

The Hölstein site is located in in the eastern part of the Swiss Jura mountains (47°26’16.4’’, 7°46’31.1’’; 540 m a.s.l.), in a mixed, temperate forest with an exceptionally high biodiversity and a vigorous tree regeneration. The research plot has a size of 1.6 ha and comprises 540 mature trees. The main tree species are Fagus sylvatica and Picea abies with an admixture of Abies alba, Quercus petraea, Pinus sylvestris, Acer pseudoplatanus, Carpinus betulus, Fraxinus excelsior and Sorbus torminalis. A canopy crane is installed in the center of the research area to access the tree canopies for in situ measurements and for sampling of leaf material. Rainout shelters will be installed in 2019 for conducting a long-term throughfall exclusion experiment.

The Sani Environmental Observatory (S.E.O.) is located within a mature, near-coastal Aleppo pine (Pinus halepensis L.) ecosystem at the peninsula of Kassandra, in Chalkidiki, Greece. It is part of the Stavronikita forest, which comprises approximately 300 ha of land covered mainly by forests and to a lesser extend by shrubs and pastures. The Observatory aims primarily at the assessment of the carbon and water balance of this typical low-elevation forest ecosystem to the ongoing climatic shift. Such ecosystems may be prone to the intensified heat and drought events, as well as to the associated insects’ and pathogens’ outbreaks, which are increasingly occurring at the Mediterranean region and particularly at its eastern part. Although Aleppo pines, as well as other Mediterranean pines, are generally adapted to the region’s xerothermic conditions, the in-depth understanding of their ecophysiological and growth responses will allow us to predict the potential of such ecosystems to adapt to climate change. SEO also serves to assess the carbon stocks and fluxes and the contribution of these natural, old-growth ecosystems to carbon sequestration and, thus, to climate change mitigation. S.E.O. is developed by the Forest Research Institute (Lab of Forest Ecophysiology) of the Hellenic Agricultural Organization Dimitra with the support of Sani Resort SA, the owner of the studied forest ecosystem, presenting a nice example of collaboration between the research community and the private sector. Given that SEO is located at a region of high touristic and aesthetic value, close to a wetland and the sea, the Observatory also plans actions to familiarize people with environmental monitoring and the multiple functions and services of the studied Mediterranean ecosystem.

'Tyrolean Mountain Grassland and -Forest' currently consits of 'Stubai - combination of Neustift meadows and Kaserstattalm' (DEIMS.iD: https://deims.org/324f92a3-5940-4790-9738-5aa21992511c). Additional forested research locations may be added in the future.

As the largest contiguous pine forest in Switzerland, the Pfyn forest in Canton Valais (46° 18' N, 7° 36' E, 615 m ASL) offers the best conditions for such measurements. In light of this, a WSL research team installed a long-term experiment of 20 years duration in the Pfyn forest. The average temperature here is 9.2°C, the yearly accumulated precipitation is 657 mm (average 1961-1990). The pines in the middle of the forest are about 100 years old and 10.8 m high. The test area has 876 trees covering 1.2 ha divided into 8 plots of 1'000 m2 each (Image 4). Between the months of April and October four of these plots are irrigated by a sprinkler system providing an additional 700 mm of water, annually. In the other four plots, the trees grow under natural, hence relatively dry conditions.

Historically, the role of the Galapagos Islands has been considered critical due to the evolutionary diversification induced by natural and historical isolation. The Galapagos National Park was established in 1959, based on its historical importance associated with Charles Darwin's voyage and its rare and endemic biodiversity, composed of unique vertebrate and plant communities (Rozzi et al. 2010). In 1978, the Galapagos Islands were declared a UNESCO World Heritage Site, a critical factor associated with this national park (Rozzi et al. 2010). The Galapagos Islands are a pristine area with local and regional climates influenced by the interaction of ocean currents and winds driven by the Inter-Tropical Convergence Zone; ITCZ (Conroy et al. 2008, Trueman and d'Ozouville 2010). The long-term programme includes forty natural aquatic ecosystems (lakes, ponds, lagoons and swamps) that will be sampled on the islands of San Cristobal, Santa Cruz, Isabela and Floreana, where possible along a lowland-highland gradient. The number of sampling points will vary according to environmental heterogeneity and the presence of a littoral region, among other factors.

Monitoring stations in Aukštaitija NP started functioning in 1993. Aukstaitija station (LT01) was founded in strict reserve zone of Aukstaitija national park in Ažvinčių old forest, Versminis river closed basin. The area of the basin is 101.5 ha. The lowest place is at 159.5 m, the highest - 188.6 m above sea level. Geographical co-ordinates of the basin are: longitude - 26*03*20* - 26*04*50*, latitude - 55*26*00* - 55*26*53*. The climate is characterised as average cold with high humidity and abundant precipitation. The average air temperature is 5.8 C, average precipitation - 682 mm. Length of vegetation period - 189 days. Side glavioacvalic accumulation forms with sand, gravel and stones are typical for river basin and in the western part of the basin, with the decrease of surface altitude transfers into fliuvioglacial terrace delta plain with fine sand, and at the source- into marsh accumulation forms with organic sediments. At the eastern side of the basin, which has higher altitudes, the typical for this basin glavioacvalic accumulation forms transfer into gravel sand. Carbonates start foaming at 45 cm depth (Gulbinas et al., 1996). The saturation of the river water with the oxygen is very weak. The average yearly oxygen concentration equals to 2.9 mg/l (minimal allowable concentration – 6 mg/l). The pH value of the water fluctuates from 7.10-7.75 mg/l, which indicates the alkalisation of the water. Concentration of hydro-carbonate ions varies in the intervals of 148-224 mg/l. Concentrations of sulphates and chlorides are very small. Calcium and magnesium ions are dominating in the media of cations. Concentration of natrium ions is insignificant – 2 mg/l 9DLK=120 mg/l), concentration of kalium ions reaches only tenths of mg/l (DLK=50 mg/l). According to the size of mineralisation the river water could be described as having average mineralisation levels. Concentrations of nitrogen materials (ammonium nitrogen, nitrates) are small, compared to maximum allowable concentrations (DLK) set for surface waters. Concentrations of phosphates are small. Silicium concentrations fluctuate from 2 mg/l to 9 mg/l (Čeponienė, 1997). Main ecosystems Coniferous multi-layered forest stands are prevailing in the basin, which are mainly pine trees with a mixture of spruce. Those stands usually have a second and third tree layer with abundant under layer vegetation. Spruce stands are also of complicated structure. The second and third spruce layer with abundant under layer vegetation are common. Remarkable amounts of territory are occupied by mixed conifer-deciduous or mixed conifer forests. Pure birch stands in more wet habitats in the vicinity of Versminis river source can also be found. According to the forest stand age they are old pure overmature or with accompanying forest stands of several age classes. It is mainly multi-aged and multi-layered over mature pine and spruce stands. In addition The study was based on monitoring data on crown defoliation of more than 3000 Scots pine (Pinus sylvestris L.) trees from 20 permanent observation stands (POS) annually obtained between 1994 and 2009 in Aukstaitija national park (ANP), located in the eastern part of Lithuania (Fig. 1). Over 16yr period mean values of crown defoliation of every sample pine stand were computed annually. Therefore the total number of treatments made N=320. These stands were classified according to stand maturity: 4 sapling stands (45 to 50 years – Table 1, section “Stand maturity”, group 1), 5 middle aged stands (61 – 80 years – group 2), 4 premature stands (81-100 years – group 3), 3 mature stands (101-120 years – group 4) and 4 over mature stands (> 121 years – group 5). Main characteristics of the considered stands are compiled in table 1. All stands represent the prevailing in Lithuania Pinetum vaccinio-myrtilosum forest type.

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/