Summary

The collection of precipitation and throughfall (precipitation passing through the canopy) enables the calculation of fluxes for each site. Interception by the canopy is approximately 21% for broadleaved trees and 53% for coniferous species leading to a much higher water flux for the oak (66%) compared to the conifers (47%).

Evidence of changes in deposition chemistry

Significant declines in sulphur deposition and acidity have been detected at the sites.

Total Sulphur deposition flux across the Level 2 plots

Nitrogen deposition shows a decline of ammonium in some areas in the UK but no change in nitrate. A significant increase in dissolved organic nitrogen in rainfall, throughfall and soil solution has been detected across many sites.

Total Nitrogen deposition flux across the Level 2 plots