Brasschaat - De Inslag - Belgium

Basic Information

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Brasschaat - De Inslag

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General Site Description: 

The site under consideration is a 2 ha first generation plantation of Scots pine (Pinus sylvestris L.) stand on former heathland (planting age = 1929) which belongs to a mixed coniferous/deciduous forest located in the Campine plain of Flanders. The site is equipped with a measuring tower and a permanent intensive forest condition monitoring plot (ICP Forests level II). The landscape is flat, with a gentle (0.3%) slope at a mean elevation of 16 m. To the South and East, the forest extends over 2 km before turning into rural, partially forested terrain. The air pollution characteristics at this site are typical for a suburban forest exposed to vehicle emission (NOx), which is strongly affecting the NO-NO2-O3 chemistry. The site is, additionally, located in the waste plume derived from stack emissions (SO2, NOx, black carbon) generated by the petrochemical refinery in Antwerp port. Although no important agricultural emission sources are present in close proximity to the site, ammonia levels are elevated when winds blow from the eastern wind sector (due to remote agricultural activities > 5 km). Air pollution concentrations of SO2 and NOx show declining trends, whereas ozone levels tend to increase, especially during the spring time. Annual concentrations of NOx and NH3 still exceed long-term critical levels to protect vegetation from adverse effects. Also ozone indices, calculated to judge the risk for ozone damage, exceed the critical levels for ozone exposure. Empirical critical loads and critical loads based on simple mass balance calculations to protect the forest from vegetation changes or biodiversity loss are still exceeded. The monitoring of air pollutants will be continued by the INBO but more emphasis will be put on chemical and biological recovery of the forest ecosystem from historical elevated sulphur and nitrogen depositions. The study of combined effects of ozone, nitrogen and climate change on the forest ecosystem functioning will be given more attention. The site will also feature within the Belgian ICOS network which is operated by the University of Antwerp in collaboration with the Research Institute for Nature and Forest. The current database consists of 20 yr halfhourly records of meteorological variables along with the main air pollutants, measured by slow monitors and dry/wet denuders or passive samplers. The monitoring of air pollution effects in the adjacent ICP Forest monitoring plot took off in 1992 and will be continued in the future by INBO. A long-term dataset of CO2 fluxes is available (measurements conducted by the University of Antwerp, Carbo Europe).

General Characteristics, Purpose, History

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Purpose of Site : 

y The research infrastructure in Brasschaat is mainly used for intensive forest condition monitoring (ICP Forests), soil–vegetation-atmosphere transfer of nutrients (nitrogen, base cations, sulphur), dynamic soil chemistry modelling and observation of greenhouse gases (CO2, N2O, CH4, O3) in the atmosphere and soil compartment. Meteorological variables are measured using sensors mounted at the 40m high measuring tower or located within the 2 ha-scientific zone. Air concentration measurements are conducted at different heights along the measuring tower using slow response monitors (O3, NOx) for profile analysis or dry deposition calculations. Measurements of air pollutants (SO2, reactive nitrogen compounds,...) are also made at a single height using passive samplers. There is an eddy-covariance set up for flux measurements (heat, momentum, water vapour, CO2 and other GHG) to study the exchange of GHG between the forest and the atmosphere. The meteorological variables, which are collected on a half-hour basis, are used for dry deposition calculations and scrutinizing the environmental controls on the pollutant concentrations and the canopy uptake.

History of Site: 

The research infrastructure in Brasschaat is mainly used for study of air pollution and climate change effects on forest ecosystem functions (ICP Forests), biogeochemistry (cycling of base cations, nitrogen, sulphur), dynamic soil chemistry modelling and for study of the storage or emission of greenhouse gases (CO2, N2O, CH4, O3) in or from the vegetation and soil pools (ICOS). The self-supporting welded scaffolding tower was erected to 40 m in 1994. The tower has a 9 m² ground area and platforms at 9, 15, 18, 23, 31 and 39 m. The tower resides in a 2 ha Scots pine (Pinus sylvestris L.) stand of the forest (planting date: 1929) next to a level-II observation plot of the European ICP-Forests network (EC-UN/ECE, 1996). The measuring site was also part of the CARBOEUROPE and NITROEUROPE research networks. The site is currently participating in the ICOS labeling procedure and will feature within the ICOS network along with 5 other terrestrial monitoring sites in Belgium.

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Latitude: 51.307800000000
Longitude: 4.519720000000