| Title | Authors | Year | 
|---|---|---|
| Seasonal variations in acidic pollutant inputs and their effects on the chemistry of stemflow, bark and epiphyte tissues in three oak woodlands in N.W. Britain | 
                               Farmer, A.M…  | 
                                                                                        1991 | 
| Proceedings of the 2nd workshop on sources of variation in ecotoxicological tests with Daphnia magna | 
                               Van der…  | 
                                                                                        1991 | 
| Air pollution and agriculture | 
                               Ashmore, M.…  | 
                                                                                        1991 | 
| A Field-Study of Fertilization and Embryonic Development in the Common Frog (Rana-Temporaria) with Particular Reference to Acidity and Temperature | 
                               Beattie, R.…  | 
                                                                                        1991 | 
| Decline of ectomycorrhizal fungi in Europe. | 
                               Arnolds, E…  | 
                                                                                        1991 | 
| Nitrate in soil water | 
                               Westling, O…  | 
                                                                                        1991 | 
| Acid rain since 1985 - times are changing | 
                               Brydges, T.…  | 
                                                                                        1991 | 
| Zeigerwerte von Pflanzen in Mitteleuropa | 
                               Ellenberg,…  | 
                                                                                        1991 | 
| Influence of HN3 and (HN4)2 SO4 on heathland vegetation | 
                               Van der…  | 
                                                                                        1991 | 
| Nitrogen Uptake and Allocation by Calluna-Vulgaris (L) Hull and Deschampsia-Flexuosa (L) Trin Exposed to 15NH3 | 
                               Dueck, T.A…  | 
                                                                                        1991 |