7 May 2006 Learning the lessons of the world's oldest ecological experiment

Ecologists are getting ready to celebrate the 150th anniversary of the world's oldest ecological experiment. The Park Grass Experiment was set up at Rothamsted Research in Hertfordshire in 1856 – three years before Darwin published Origin of Species – to answer crucial agricultural questions of the day but has since proved an invaluable resource for studying natural selection and biodiversity.

To mark the occasion, a major review of Park Grass is published today in the British Ecological Society's Journal of Ecology, and on 22nd-24th May 2006 Rothamsted Research is hosting an international symposium exploring the unique value of long-term ecological research.

Park Grass was originally designed to test the effect of fertilisers and manures on hay yields. However, it soon became apparent that the treatments were also affecting the botanical make-up of the plots and the ecology of this 2.8 ha field has been studied ever since. In spring, the field is a colourful tapestry of flowers and grasses, some plots still having the wide range of plants that most meadows probably contained hundreds of years ago.

According to the authors of the paper, Professor Jonathan Silvertown of The Open University and colleagues from Rothamsted Research, the Centre for Ecology and Hydrology and Lincoln University in New Zealand: “Park Grass illustrates how long-term experiments grow in value with time and how they may be used to investigate scientific questions that were inconceivable at their inception. This is as likely to be true of the future of Park Grass as it has proved to be of its past.”

Over its 150 year history, Park Grass has:

• demonstrated that conventional field trials probably underestimate threats to plant biodiversity from long term changes, such as soil acidification
• shown how plant species richness, biomass and pH are related, has demonstrated that competition between plants can make the effects of climatic variation on communities more extreme
• provided one of the first demonstrations of local evolutionary change under different selection pressures 
• endowed us with an archive of soil and hay samples that have been used to track the history of atmospheric pollution, including nuclear fallout.

“Today, Park Grass has acquired new relevance for the study of fundamental ecological processes and for nature conservation. It has inspired new ecological theory and has helped ecologists to recognise the value of long-term experiments in ecological studies,” the authors say.