TERENO Eifel-Rur Observatory. TERENO (TERrestrial ENvironmental Observatories) spans an Earth observation network across Germany that extends from the North German lowlands to the Bavarian Alps. This unique large-scale project aims to catalogue the longterm ecological, social and economic impact of global change at regional level.The central monitoring site of the TERENO Eifel/Lower Rhine Valley Observatory is the catchment area of the River Rur. It covers a total area of 2354 km² and exhibits a distinct land use gradient: The lowland region in the northern part is characterised by urbanisation and intensive agriculture whereas the low mountain range in the southern part is sparsely populated and includes several drinking water reservoirs. Furthermore, the Eifel National Park is situated in the southern part of the Rur catchment serving as a reference site. Intensive test sites are placed along a transect across the Rur catchments in representative land cover, soil, and geologic settings.The Rollesbroich site is located in the low mountain range “Eifel” near the German-Belgium border and covers the area of the small Kieselbach catchment (40 ha) with altitudes ranging from 474 to 518 m.a.s.l.. The climate is temperate maritime with a mean annual air temperature and precipitation of 7.7 °C and 1033 mm, respectively, for the period from 1981 to 2001. Soils are dominated by (stagnic) Cambisols and Stagnosols on Devonian shales with occasional sandstone inclusions that are covered by a periglacial solifluction clay–silt layer. The mountainous grassland vegetation is dominated by perennial ryegrass (Lolium perenne) and smooth meadow grass (Poa pratensis).The study site is highly instrumented. All components of the water balance (e.g. precipitation, evapotranspiration, runoff, soil water content) are continuously monitored using state-of-the-art instrumentation, including weighable lysimeters, runoff gauges, cosmic-ray soil moisture sensors, a wireless sensor network that monitors soil temperature, and soil moisture at 189 locations in different depths (5, 20 and 50 cm) throughout the study site. Periodically also different chamber measurements were made to access soil or plant gas exchange.This data set contains weekly updated flux-, meteorological and soil measurements of the permanent operating EC/Climate station Rollesbroich 1 (50.621° N, 6.304° E, 515 m a.s.l.), which was installed in spring 2011 at the border of two fields of grassland (5.8 and 7.8 ha) within the study site. Management of both fields is typical for the low mountain range of the Eifel region with one fertilizer application and three cuts per year. The area within the fetch of the eddy covariance tower is relatively flat with slopes ranging between 0.35° and 3.12°. The station is equipped with a CSAT3 sonic anemometer and LI7500 gas analyser. Besides flux measurements and typical climate parameters (radiation, air temperature, air humidity, soil moisture, soil temperature etc.) also the plant height and farming activities are recorded.Meteorological and soil data was at least controlled by visual inspection by using common plausibility ranges and cross checks with nearby stations. Afterwards the data was flagged according to it's quality (O.K., suspect, moderate, bad etc.). Flux data was processed and checked according to the TERENO QC scheme (Mauder,et al., 2013, doi:10.1016/j.agrformet.2012.09.006).