Interconnected Ecological Focus Areas Are Particularly Valuable for Species Richness

Agroscope studied various categories of ecological focus areas and showed that the presence of these in connectivity projects makes a major contribution to large-scale species richness in the agricultural landscape.

Biodiversity is decreasing worldwide, in many places due inter alia to intensive agricultural use, which limits the habitat for animals and plants. In order to reduce the strong pressure on biodiversity, agricultural environmental programmes have been introduced whose core element consists of ecological focus areas (EFAs). If a number of indicator plants or small ecological structures are identified in addition to the minimum management requirements constituting Quality Level 1 (QI), EFAs are considered to be Quality Level 2 (QII). Regardless of whether they earn the QII rating, EFAs can be incorporated into connectivity projects. Several farmers and other experts are developing projects of this type involving the selection of advantageously located land and its appropriate management so that resources and expansion opportunities are available to selected species. These selected species are so-called ‘Agriculture-related Environmental Objectives’ species (AEO species), which are to be prioritised for conservation and promotion in the agricultural area according to the jointly formulated AEOs of the Federal Office for the Environment FOEN and the Federal Office for Agriculture FOAG.

Study on the impact of EFA categories on biodiversity

In its ‘Agricultural Species and Habitats’ Monitoring Programme ‘ALL-EMA’, Agroscope investigated the impact of the three EFA categories (EFA QI, EFA QII and EFA in Connectivity Projects) on small-scale biodiversity (plant species richness over an area of 10m²) and large-scale biodiversity (species richness of plants, butterflies and breeding birds on the agriculturally utilised area within 1km²), taking topography and climate into account. In terms of biodiversity, both AEO species richness and total species richness were investigated.

Biodiversity-friendly management and interconnectedness increase species richness

Small-scale plant species richness was higher in all three EFA categories than in comparablle areas outside the EFAs, i.e. the minimal biodiversity-friendly management requirements of the EFA QIs had an impact. There were major differences between the individual EFA categories, however: in EFA QII the AEO plant species richness was over twice as high as outside of the EFA areas, and AEO plant species richness in EFA QI was actually increased by two-thirds when the EFAs were incorporated into connectivity projects. The EFA ‘QII’ and ‘Connectivity’ categories have thus contributed to a marked increase in or preservation of plant-species richness.

Butterflies and breeding birds are reliant on interconnected EFAs

For plants, this effect was also seen on the 1km² scale: The greater the area managed as an EFA, the higher the plant diversity in the area. By contrast, large-scale butterfly and breeding-bird species richness only increased along with total EFA area if the EFAs were also incorporated in a connectivity project. Clearly, the targeted supplementation and management of EFAs for selected species by means of connectivity projects contributes to the greater availability of resources for butterflies and birds in general, and the careful placement of the EFAs allows mobile species requiring several habitats for their continued existence (e.g. for breeding, feeding and procreating) to obtain and exploit these resources.