Trends from Level II forest health monitoring plots

 

Data sets reveal long-term trends as follows:

• A significant decline in soil solution SO₄ and S uptake which is consistent with the reduction in S deposition as a result of emissions control policies.
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• A significant decline in soil solution K⁺ in the majority of the Level II plots, possibly due to enhanced K leaching and/or uptake in response to management intervention.
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• Variable NO3 in soil solution, with a distinct increase in NO₃ observed in peat soils under Sitka spruce.
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• The first signs of recovery from soil acidification at previously polluted sites.
• Soil acidification at a site with high N deposition from local sources.