Variation in throughfall deposition across a deciduous beech (Fagus sylvatica L.) forest edge in Flanders.
Throughfall deposition and canopy exchange of acidifying and eutrophying compounds and major base cations were studied by means of throughfall analysis in a deciduous beech (Fagus sylvatica L.) forest edge in Belgium over a period of 1 year. Throughfall fluxes of Cl(-), NH(4)(+) and Na(+) were significantly elevated at the forest edge compared to the forest interior. As no edge effect on throughfall water volume could be detected, the observed edge enhancement effects were mainly due to dry deposition and canopy exchange patterns. Indeed, there was an elevated dry deposition of Cl(-), Na(+), K(+), Ca(2+) and Mg(2+) up to 50 m from the field/forest border. Within the forest, throughfall and dry deposition of SO(4)(2-) were highly variable and no significant differences were observed between the forest edge and the forest interior. Leaching of K(+) and Ca(2+) was reduced in the forest edge up to a distance of 30 m from the border. The measured nitrogen and acidic depositions far exceeded the current Flemish critical loads with respect to the protection of biodiversity in forests, especially at the forest edge. This points to an urgent need for controlling emissions as well as the need to consider the elevated deposition load in forest edges when calculating the critical loads in forests.
Devlaeminck
Rebecca
R
Laboratory for Forest, Nature and Landscape Research, University of Leuven, Vital Decosterstraat 102, 3000 Leuven, Belgium. rebecca.devlaeminck@agr.kuleuven.ac.be
De Schrijver
An
A
Hermy
Martin
M
D015258:Acid Rain / Q000032:analysis; D000393:Air Pollutants / Q000032:analysis / Q000592:standards*; D001530:Belgium; D002712:Chlorides / Q000032:analysis; D017753:Ecosystem; D004784:Environmental Monitoring / Q000592:standards*; D029964:Fagus; D008670:Metals / Q000032:analysis; D009566:Nitrates / Q000032:analysis; D009584:Nitrogen / Q000032:analysis; D000644:Quaternary Ammonium Compounds / Q000032:analysis; D011891:Rain; D013431:Sulfates / Q000032:analysis; D014197:Trees
D015258:Acid Rain; D000393:Air Pollutants; D002712:Chlorides; D008670:Metals; D009566:Nitrates; D000644:Quaternary Ammonium Compounds; D013431:Sulfates; D009584:Nitrogen