Göte Bertilsson

On biodiversity in Agriculture.

Some references from 2007-2008.

Summary and comments.

Uniform areas with large-scale management and large fields are negative for biodiversity, naturally enough. But there seems to be hope for improvement by mitigating measures which can be combined with efficient management.

Organic or conventional production is not decisive. It is not use of fertilizers or pesticides in normal agriculture that is critical, but the size of the fields, the crops grown and the variation in the landscape. Even trees and bushes at field edges favour biodiversity.

Some references.

Herzon et al 2008. Intensity of agricultural land-use and farmland birds in the Baltic States. Agriculture, Ecosystems and Environment 125, 93-100.

An inventory shows that there are 20% fewer birds in intensive agricultural areas than in less intensive. And the development is further intensification. Especially birds dependent on edge structures are negatively influenced by increasing field size.

Reference is made to a decision in Gothenburg that EU countries should introduce measures to stop the biodiversity reduction before 2010. It is not enough to focus on natural grazing lands. There is a need for programs for the croplands.

Kragten et al 2008. Field-breeding birds on organic and conventional farms in the Netherlands. Agriculture, Ecosystems and Environment 126, 270-274.

There was no general difference between the systems. Lark and lapwing were more abundant in organic farms studied, which was explained by differing crops.

Fox et al 2008. What regional features of Danish agriculture favour the corn bunting in the contemporary farming landscape. Agriculture, Ecosystems and Environment 126, 261-269.

The corn bunting is fairly stationary. It was more common a few decades ago, it is more common today in the mixed agriculture in Jylland than in the crop production areas on the islands. There is optimism about its future, but more should be learnt about the needs. It seems clear that the bird is disfavoured by large scale and uniform crop production. Spring cereals, leaving stubble over the winter and grassland is positive.

Haslem et al 2008. Countyside elements and the conservation om birds in agricultural environments. Agriculture, Ecosystems and Environment 125, 191-203.

This is work from Australia, but principles should be universal.

Highest priority is to conserve natural lands. But in addition to this a large inventory shows that landscape elements as scattered trees, edge vegetation and small patches are important.

Ekroos et al 2008. Role of organic and conventional field boundaries on boreal bumblebees and butterflies. Agriculture, Ecosystems and Environment 124, 155-159.

Last lines in Conclusions, somewhat abridged:

.. field edges have a key role in promoting pollinating insects in crop systems. Measures there are very important (for instance to promote flowering plants). Type of agricultural system had no influence.