EFFECTS OF FARMLAND AND FOREST PRACTICES ON BIODIVERSITY CONSERVATION IN NORTH-WEST SPAIN

Abstract

anic farming in the area. This change has been mainly produced due to economical constraints in conventional farming, and most local farmers thought of it as the only way to continue living from farming. Many studies have documented how organic farming can counteract farmland intensification regarding the conservation of biodiversity, but few studies have considered how the effect of organic farming works in a heterogeneous landscape and how it varies between seasons. North-West Spain is an important wintering and breeding ground for many bird species, therefore, it is important to understand whether organic farming can enhance agricultural biodiversity conservation, as its effect in this area can affect biodiversity not only locally, but in a bigger scale. We analysed the effect of both farming and forest practices on biodiversity during an entire year by means of transects in paired organic and conventional farms and native and Eucalyptus patches. Bird, flying insect and plant species richness and abundance were compared. Bird species richness was higher in winter in organic than conventional farms. Bird abundance increased in organic squares with increasing surrounding native forest. Both species richness and abundance of plants and flying insects were higher in organic than conventional farms. Regarding forest and Eucalyptus patches, all species richness and abundance of birds, plants and flying insects were higher in native forests. Therefore, our results suggest that both organic agriculture and native forests have a key role in biodiversity conservation in the area, and that policies enhancing these two approaches will have positive effects on biodiversity conservation. Conserving traditional forest uses, such as chestnut production, or oak and chestnut wood use, at the same time as promoting an organic agriculture, will have a positive effect on biodiversity. Biodiversity conservation in the area cannot be separated from conservation of traditional land uses.