The UK Environmental Change Network: Emerging trends in the composition of plant and animal communities and the physical environment

This review identifies the major trends in physical, chemical and biological data between 1993 and 2007 at the 12 terrestrial sites in the United Kingdom Environmental Change Network (ECN) and assesses the effectiveness of the programme. Temperature and precipitation increased and sulphur (S) deposition decreased across the network. There were also significant local trends in nitrogen (N) deposition. The decreasing S deposition was associated with increasing pH of rainfall and soils and there was widespread evidence of soil pH showing recovery from acidification. Warm-adapted butterfly species tended to increase at northern, upland sites, consistent with an effect of increasing temperatures. In contrast, carabid beetle species associated with cooler northern and upland areas showed declining populations. The increasing trend in precipitation may account for a decline in ruderal plant species in the lowlands, reversing an increase associated with drought in the early part of the time series. There was no general shift in the composition of plant communities which might reflect rising soil pH. This may reflect the slow dynamics of plant community processes or a distinction between pH trends at the surface and lower soil horizons. The ECN is effective in detecting trends in a range of different variables at contrasting sites. Its strength is the ability to monitor causes and consequences of environmental change in the same programme, improving the ability to attribute causes of change, which is essential to developing conservation policy and management in the 21st century.