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 Římov Reservoir was constructed in 1971–1978 at 21.85 km of the Malše River (tributary of the Vltava River), downstream its confluence with the Černá stream. The reservoir serves as an important drinking water supply for South Bohemia and helps to maintain a minimum flow downstream. The dam is 47 m high and 290 m long. Reservoir volume is 34.3×106 m3, the catchment area is 489 km2.Mean annual flow is 4,3 m3 s-1 and mean theoretical water retention time 92 days. The Římov Reservoir is a canyon-shaped impoundment with steep banks, the „tower“ for drinking water input is at 5 m distance from the dam. Being a drinking water source, Římov Reservoir is protected and no other uses are allowed. Regular investigations of the Římov reservoir in its lacustrine part started in 1979 and have continued at three-week intrevals up to now. Since 1997, the Římov reservoir has been a part of the Czech LTER network. The parameters studied include physical, chemical and biological data on pelagic organisms like bacteria, protists, phytoplankton and zooplankton. Once per year, the abundance and species composition of fish is investigated. Besides regular monitoring, a lot of extensive studies were done of pelagic organisms, their diversity, interactions and functions as well as chemical processes in water and sediment, both in the lacustrine part and in the canyon-shaped riverine part near the inflow. Such intense studies were possible due to the vicinity of well equipped labs in České Budějovice and the construction of a field station at the dam (in 1994).

'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.

The coastal marine observatory site Gulf of Trieste lies within the Marine Protected Area (MPA) of Miramare and includes the biological time-series station “C1”, part of the Italian Long-Term Ecological Research (LTER) network, and the in situ continuous MAMBO meteo-oceanographic buoy. Marine Protected Areas represent one of the most effective systems for marine biodiversity preservation and management. Since 1986, the time-series station “C1” in the Gulf of Trieste (GoTTs, Gulf of Trieste Time series) represents a crucial site for marine ecological research, as it is subject to the interaction among several natural forcing (river, groundwater discharge, tides, general circulation, intense meteorological) and numerous anthropogenic activities (maritime transport, harbours of Trieste and Monfalcone, urban waste discharge, mussel- and fish-farming, fishing and recreational activities). In 1999, the ecological research site has been equipped with a meteo oceanographic buoy (MAMBO) in order to acquire continuous data on meteorological conditions at sea and on seawater physical and biogeochemical properties. Due to the high temporal dynamics of ecological processes in coastal ecosystems, continuous and real-time data of the main meteorological, physical and biogeochemical properties are fundamental for a better understanding of marine ecosystem functioning.

The site is located in Clocaenog Forest in North East Wales (53o 03’ 19’’N -03o 27’ 55’’ W). It is a typical upland west-atlantic moorland, dominated by the evergreen shrub Calluna vulgaris (heather). Heather makes up >60% of the plant biomass at the site, but Vaccinium myrtillus and Empetrum nigrum are also present.

The Seine estuary is a megatidal estuary located in northern France. It is the third largest estuarine ecosystem in the country after the Gironde and Loire along the French Atlantic coast; its waters flow into the English Channel. The geographical zone of influence of the Seine estuary runs from just upstream of the Poses dam, at the limit of the tidal penetration into the estuary — 160 km upstream of Le Havre —to the eastern part of the Bay of Seine. It can be divided into three sections: the fresh water upstream section (125 km), the mixing zone characterized by varying salinity levels (35 km), and the marine downstream section under the influence of the Seine River. The megatidal regime generates a turbidity maximum in the mixing zone (middle estuary) between the marine and fluvial sections of the estuary. The Seine estuary is a typical estuarine ecosystem: highly stressed by natural fluctuations and anthropogenic pressures, and hosting a rich ecological system. The Seine valley and its estuary are of major economic importance for France, with the presence of two maritime ports. It’s watershed (79,000 km2) is the home to 17 million people, and accounts for 50 % of the river traffic in France, 40 % of the country's economic activity, and 30 % of its agricultural activities. In addition to the Greater Paris area (> 11 million inhabitants), which contributes heavily to the Seine estuary's upstream inputs, two other major river settlements — Rouen (500,000 inhabitants) and Le Havre (300,000 inhabitants) — are maritime ports of international importance. Due to economic development, the Seine estuary has been subjected to major hydrodynamic, ecological, biogeomorphological and biogeochemical changes. The importance of studying the effects of anthropogenic impacts on estuarine ecosystems has increased in the last decade, especially under the Water Framework Directive, which aims to achieve “good environmental status” of all European water bodies.

The Kinneret Limnological Laboratory (KLL) is situated at the ‘Sapir’ Site (Tabha) on the shores of Lake Kinneret (Sea of Galilee). The Lake Kinneret monitoring program conducted by KLL has been operating since Jan. 1969. The program has provided a unique database and information, due to the sampling resolution, accuracy of the measurements, and their continuity, it is used to make operational decisions and environmental policy. The monitoring program includes several stations around the lake and from numerous depths and includes fixed on-lake, high-resolution, and manual sampling of water samples analyzed in the laboratory. The Kinneret monitoring program has expanded in recent years and currently has four fixed on-lake and online sampling platforms, strategically placed, each with thermistor chains and multi-probe sensor systems including one that is a profiling system. Also, the program includes collaboration with the Ministry of Agriculture to carry out monitoring of fish and fisheries in the lake. As the lake suffers typically from two seasonal cyanobacteria blooms, (i.e., a winter Microcystis bloom and a summer N-fixing cyanobacteria bloom) routing monitoring of cyanobacteria biomass and toxins is conducted and adaptive to the extent of the bloom. This is carried out simultaneously with satellite imaging over the lake.

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.