Title Authors Year
Increases in soil acidity in north west Wales between 1957 and 1990

…

1991
Physiological effects of long term exposure to low concentrations of SO2 and NH3 on poplar leaves.

Hove, L.W.A…

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
Changes in species composition of semi-natural vegetation associated with the increase in atmospheric inputs of nitrogen

Pitcairn, C…

1991
Acid rain since 1985 - times are changing

Brydges, T.…

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
Conservation of freshwater fish in the British Isles: the current status and biology of threatened species. Aquatic Conservation

Maitland, P…

1991
Critical Load Maps for the United Kingdom I: Soil

UKCLAG,

 		1991