The Sulphur Content and pH of Rainfall and of Throughfalls Under Pine and Birch

Alcock, M. R.; Morton, A. J.

doi:10.2307/2402374

Cited by 13 publications

(1 citation statement)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…3) suggest that is not the case). Alcock and Morton (1981) reported no enhancement of sulphate deposition in throughfall compared to bulk precipitation under 30-year old Scots pines in a 2-year study near Ascot, only about 30 km distant from the present site, in the years 1975-77. However, this was a dense plantation of young trees with a density of about 1 tree per 4 m 2 .…”

Section: Figure 6 Near Herecontrasting

confidence: 57%

The effects of a changing pollution climate on throughfall deposition and cycling in a forested area in southern England

Skeffington

Hill

2012

Science of The Total Environment

View full text Add to dashboard Cite

This study compares two sets of measurements of the composition of bulk precipitation and throughfall at a site in southern England with a 20-year gap between them. During this time, SO(2) emissions from the UK fell by 82%, NO(x) emissions by 35% and NH(3) emissions by 7%. These reductions were partly reflected in bulk precipitation, with deposition reductions of 56% in SO(4)(2-), 38% in NO(3)(-), 32% in NH(4)(+), and 73% in H(+). In throughfall under Scots pine, the effects were more dramatic, with an 89% reduction in SO(4)(2-) deposition and a 98% reduction in H(+) deposition. The mean pH under these trees increased from 2.85 to 4.30. Nitrate and ammonium deposition in throughfall increased slightly, however. In the earlier period, the Scots pines were unable to neutralise the high flux of acidity associated with sulphur deposition, even though this was not a highly polluted part of the UK, and deciduous trees (oak and birch) were only able to neutralise it in summer when the leaves were present. In the later period, the sulphur flux had reduced to the point where the acidity could be neutralised by all species - the neutralisation mechanism is thus likely to be largely leaching of base cations and buffering substances from the foliage. The high fluxes are partly due to the fact that these are 60-80 year old trees growing in an open forest structure. The increase in NO(3)(-) and NH(4)(+) in throughfall in spite of decreased deposition seems likely due to a decrease in foliar uptake, perhaps due to the increasing nitrogen saturation of the catchment soils. These changes may increase the rate of soil microbial activity as nitrogen increases and acidity declines, with consequent effects on water quality of the catchment drainage stream.

show abstract

Section: Figure 6 Near Herecontrasting

confidence: 57%