| Title | Authors | Year | 
|---|---|---|
| Nitrate in soil water | Westling, O… | 1991 | 
| Atmospheric Transport of Iron and Its Deposition in the Ocean | Duce, R. A… | 1991 | 
| Zeigerwerte von Pflanzen in Mitteleuropa | Ellenberg,… | 1991 | 
| Effects of nitrogen loading on wetland ecosystems, with particular reference to atmospheric deposition | Morris, J.T… | 1991 | 
| Physiological-effects of long-term exposure to low concentrations of SO2 and NH3 on poplar leaves | Hove, L.W.A… | 1991 | 
| Nitrogen Uptake and Allocation by Calluna-Vulgaris (L) Hull and Deschampsia-Flexuosa (L) Trin Exposed to 15NH3 | Dueck, T.A… | 1991 | 
| Air pollution and agriculture | Ashmore, M.… | 1991 | 
| Comparisons of 3 Woodland Sites in NW Britain Differing in Richness of the Epiphytic Lobarion-Pulmonariae Community and Levels of Wet Acidic Deposition | Farmer, A.M… | 1991 | 
| Acid rain since 1985 - times are changing | Brydges, T.… | 1991 | 
| Critical Load Maps for the United Kingdom I: Soil | UKCLAG, | 1991 |