Efforts to Support Biodiversity Best Focused on Less Intensive Systems

The authors of a new EU-funded study into the biodiversity of intensive and extensively managed farmland systems have recommended that efforts to conserve biodiversity be focused on less intensively managed systems.

Researchers compared the richness of plant species with levels of Nitrogen input on 130 grasslands and 141 arable fields across six European countries, including the UK. Intensively and extensively managed sites were assessed and the number of different plant species in each plot counted. 'Rare' species were defined as those with less than 1% cover in a study area.

The study found a link between increased Nitrogen inputs and a decrease in species richness, along with a link between the richness of plant species and the richness of invertebrates in the fields. The rare species of plant were shown to be the most vulnerable to increasing land-use intensity and were the most likely to disappear following fertilisation of the fields with Nitrogen.

The researchers found that the decline in species richness with an increase in Nitrogen application was sharper on the extensively managed plots, suggesting that species in these areas are more sensitive to land-use change. This suggests both that efforts to manage such areas sensitively can reap rewards for biodiversity, and also that restoration of biodiversity to intensively managed land will require an enhanced level of effort: lower sensitivity to change will mean that greater change will be needed to get the desired result.

The rate of extinction of species in intensively farmed land is 100 - 1000 times greater than the base rate, and is predicted to increase further in the future. The researchers suggest that the difficulty of restoring biodiversity on intensively managed land following such losses, along with the sensitivity of extensively managed land, means that efforts to preserve biodiversity could best be focused on extensively managed systems.

Original article: EU Science for Environment Policy, 15 January 2009
Research Source: Evaluating Current European Agri-environment Schemes to Quantify and Improve Nature Conservation Efforts in Agricultural Landscapes (EASY) (supported by the European Commission under the Fifth Framework Programme).