In order to qualify and quantify the acidifying and eutrophicating substances that contribute to atmospheric deposition in Dutch coniferous forests, open field precipitation and throughfall water have been sampled monthly at 14 locations in The Netherlands over an 18-month period. Spatial variation was studied by comparing the chemical composition of deposition in forests of four regions. Within the forests, throughfall fluxes of different tree species were compared. In this paper the deposition fluxes of sulphuric and nitrogenous compounds are emphasized. This study proves that most forested areas in The Netherlands receive high loads of nitrogenous (5-6 kmol N ha^1 y ~') and potentially acidifying (9-4 kmol H+ ha-1 y-1) compounds. Particularly, deposition of ammonium and sulphate is high, not only in areas with intensive agricultural activities, but throughout the country. Regional differences in deposition appear to be relatively small. With the exception of the two coastal locations, deposition shows little spatial variation. In the coastal region loads of nitrogenous and potentially acidifying compounds are lower than elsewhere in the country. Generally higher throughfall fluxes have been measured in Douglas fir stands than in pine stands. The larger surface area of firs probably accounts for an enhanced dry deposition. In the summer season throughfall fluxes are generally smaller than in the winter season.

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Acta botanica neerlandica

CC BY 3.0 NL ("Naamsvermelding")

Koninklijke Nederlandse Botanische Vereniging

A.L.F.M. Houdijk, & J.G.M. Roelofs. (1991). Deposition of acidifying and eutrophicating substances in Dutch forests. Acta botanica neerlandica, 40(4), 245–255.