Abstract

Thimonier A (1998) Variabilité spatio-temporelle des dépôts atmosphériques d éléments minéraux sous hêtraie. Schweizerische Zeitschrift für Forstwesen, 149 (8): 585-614.

Keywords

CC/DB-WSI: atmospheric deposition, wet deposition, throughfall, spatial variability, temporal variability, precipitation chemistry, Fagus sylvatica, Swiss Plateau (CH), LWF plot Othmarsingen, LWF (Long-Term Forest Ecosystem Research),

Abstract

Precipitation chemistry has been monitored since 1994 in a beech stand and in an open area at Othmarsingen (AG). Spatial variability under the forest canopy was investigated using 16 throughfall collectors. In order to cover the high spatial and temporal variability, sufficient numbers of collectors, operated over a sufficiently long period, are needed to obtain representative estimates of atmospheric deposition in the form of throughfall. The exact number of collectors required depends on the desired precision of the estimates, the chemical elements of interest and the temporal resolution to be achieved. Sulphur deposition was rather low: 5.7 kg.ha 1.yr 1 in the open area and 10.9 kg.ha 1.yr 1 under forest canopy (average deposition over two years). Our estimates of total sulphur deposition are consistent with modelled deposition. Average nitrogen deposition amounted to 11 kg.ha 1.yr 1 in the open area and 17.4 kg.ha 1.yr 1 under forest canopy. Total nitrogen deposition can be only roughly estimated because a part of the total volume of atmospheric nitrogen compounds is taken up directly by the canopy. Modelled estimates are slightly higher than the upper value of the range we estimated. Even with these uncertainties it is very likely that total nitrogen deposition exceeds the critical loads for nitrogen for the investigated stand.

LWF Classification

Network: LWF, Sites: Othmarsingen, Category: peer-reviewed,