The Elbe River is one of the major rivers in Central Europe. It springs at an altitude of about 1,400 meters in the Giant Mountains in the north of the Czech Republic. It flows through eastern, middle, and northern Bohemia, and its catchment area includes most of Bohemia. The Elbe traverses the northeastern part of Germany and flows into the North Sea. The total river length is 1,094 km. In the Czech Republic, the monitored river length is 371 km and the catchment area includes 49,933 km2. The average flow at the Czech-German borders is 311 m3 s-1. Many weirs dam the watercourse of Elbe River in the Czech Republic. This artificial intervention is crucial for the characteristics of the riverbed, its width, depth, and bottom substrate. The width of the riverbed in the monitored area ranges from approx. 10 m on the upper course to approx. 150 m on the lower course and river sections above the weirs. The depth of the river varies from 0.5 m in the upper parts and below the weirs to more than 5 m in the lower course and above the weirs. The bottom substrate varies from the stony, gravelly, and sandy fractions in shallow and fast-running sections to muddy/silty fractions in slow-running sections above the weirs. The main tributaries of the Elbe in Bohemia are Metuje, Orlice, Jizera, Ploučnice, Vltava, Ohře and Bílina rivers. The catchment area is densely populated. The river is exposed to various sources of pollution (organic, agricultural, and industrial) and hydromorphological pressures (straightening, shortening, regulation of meanders, and fragmentation of river continuity). There are seven permanent monitoring sites on the Elbe River in the Czech Republic: Děčín (river kilometer 747.9), Litoměřice (796.9), Obříství (842.1), Lysá nad Labem (878.8), Valy (954.7), Hradec Králové (994.4) and Vestřev (1051). The Elbe basin long term environmental research has been organised by the Ministry of Environment of the Czech Republic and cooperation institutions since 1993. More than 600 physicochemical parameters, including sensory properties of water, are regularly monitored in at least nine different types of matrices (water, sediment, periphyton, floats, sedimentable floats, benthos, fish tissues, fish fry, and Dreissena polymorpha tissue) and using passive samplers. Among the main monitored characteristics belong balances of macroelements (carbon, nitrogen, oxygen, phosphorus), concentrations of inorganic salts, heavy metals and various organic pollutants such as pesticides, personal care products (including drugs) and other anthropogenic substances in the environment. Characteristics such as abundance and species composition are regularly monitored in fish, macrophytes, macrozoobenthos, phytobenthos and plankton.

The LTSER Zone Atelier Bassin de la Moselle belongs to LTER-France network and is located in eastern France, Lorraine / Moselle. The ZAM acquires knowledge for better controls the impact of human activities on the quality of the water resources in Lorraine County (France), in the watershed of the Moselle River.

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.

Socio-ecological interactions in ecosystems of mid-altitude mountains The LTSER Zone Atelier Arc Jurassien belongs to LTER-France network and is located in eastern France.The LTSER site Jurassian Arc (ZAAJ stands for Zone atelier Arc jurassien, in French) is designed to promote long-term interdisciplinary research into the environment and ecosystems in relation to society issues. It federates a network of research partnerships around interactions between the environment, society and the dynamics of moutain socio-ecological systems.ZAAJ helps to capitalise on field data and to analyze and promote the results from long-term observation schemes at the interface between ecology, the environment and society. Benefiting of more than 25 years of experience on the issue, accredited by the CNRS Ecology and Environment Institute (INEE) in 2013, ZAAJ is a cluster of five research units totalling 40 researchers.

Lake Maggiore was studied since the beginning of last century although not systematically. Regular research started by the foundation in 1938 of the Italian Institute of Hydrobiology "Dr. Marco De Marchi" located in Verbania Pallanza. A limnographic (level and temperature profile) and weather station came into operation in 1952. Studies on plankton and on hydrochemistry of Lake Maggiore continued between the 1950s and the 1970s, showing the progressive eutrophication of the lake. Thanks also to the research of the institute, in the 1980s effective actions to control the eutrophication were undertaken, with the large-scale activation of waste water treatment plants. In the same period a program, still active, of systematic monitoring and research sponsored by the CIPAIS (International Commission for the Protection of the Italian Swiss Waters) started: it allowed collecting an uninterrupted and long-time series, with high sampling frequency, of data related to meteorology, hydrology, physic and chemistry of the lake, organic carbon and bacterial populations, phyto-and zooplankton. The analysis of these time series highlighted an oligotrophication process leading to the current state of oligotrophy of Lake Maggiore. Recent studies also showed the effects of global warming on Lake Maggiore, which went towards the gradual warming of deep hypolimnion as well as the raising of the average temperature of the surface layers.

Lake Orta is a deep subalpine lake, located in Northern Italy, at a mean altitude of 290 m a.s.l. Its perimeter is 33,8 km, surface area 18,14 km2, volume 1,29 km3. Lake Orta has a maximum depth of 143 m and a mean depth of 71 m. Lake Orta is well known for being polluted by industrial discharges (copper sulphate and ammonia) since the late 1920: as a consequence, the pH of the lake water dropped down till 4 and the food web was almost completely destroyed, except for some few, strongly adapted species. The pollution stopped around mid 1980s and a liming intervention was carried out in 1989-1990, to neutralize the acidic waters of the lake. The recovery was very fast, new species started to colonise the lake just after the liming. The lake, however, is still at risk, due to the large amount of heavy metals stored in the sediments.

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.

Small agricultural catchment (320 ha) with 30 years of data to study impact of climate change and agricultural practices on soil erosion, weathering rate and river fluxes. Continuous measurements with sensor: river discharge, Temperature, pH, conductivity, turbidity, dissolved oxygen, nitrate Weekly samples and high resolution sampling during storm runoff: major cations and anions, alkalinity, pH, dissolved silica, conductivity, total suspended solids, stable isotopes (13C of DIC, 2H and 18O of H2O, 15N of nitrates), heavy metals, some pesticide molecules Climatological station, rain collector for precipitation chemistry, soil solution station with lysimetric plate at different depths. Continuous measurement since 2004 of CO2, N2O, water vapor, energy exchange in the soil-vegetation-atmosphere continuum thanks to Eddycovariance and closed chamber methodologies (see OZCAR-RI Regional Spatial Observatory in the South West France contribution) Collaboration with the Aurade farmer association for fertilizer and pesticide inputs, cultivation, agricultural practices... Aurade experimental catchment and flux site are an international field site of the Critical Zone Exploration Network CZEN and of ICOS network, a field site of the French Research Infrastructure OZCAR and it is also a site of the French LTSER ZA PYGAR "Zone Atelier Pyrénées-Garonne". and a regional Platform of Research and Innovation-Midi Pyrénées.