Research Article: Organic animal farms increase farmland bird abundance in the Boreal region

Date Published: May 15, 2019

Publisher: Public Library of Science

Author(s): Andrea Santangeli, Aleksi Lehikoinen, Tanja Lindholm, Irina Herzon, Willem F. de Boer.

http://doi.org/10.1371/journal.pone.0216009

Abstract

Agriculture is a primary driver of biodiversity loss worldwide, and several expensive schemes have been designed to make modern farming landscapes more hospitable for wildlife. One such market-based mechanisms is the agri-environment-climate schemes (AES) in the European Union (EU). AES compensate farmers for reducing land-use intensity and maintaining or introducing biodiversity-rich habitats. Despite their high costs, impacts of AES vary by measure, region and taxonomic group considered, and have rarely been studied over large areas covering an entire country. Here we assess the country-wide impact of several AES measures on bird abundance using citizen science data on birds and detailed information on AES take up from across Finland. We report a positive impact of organic animal farming on abundance of all farmland associated birds. This effect was particularly strong for insectivorous species, species that are associated to farmyards and long-distance species. None of the other AES measures considered for study did show any relationship with bird abundance. Overall, these findings highlight the potential positive impact that some compensatory measures, such as organic animal farming, may have on wildlife. Traditional animal husbandry is based on grazing of animals and restriction on external inputs, similarly to what is stipulated under organic production contract. As such, traditional animal husbandry may represent an effective landscape management tool for restoring or maintaining threatened species and ecosystems in rural areas of the EU. Ultimately, the apparent lack of a measurable effect of the other AES considered here supports the current move towards evidence-based regional targeting of compensatory measures, so as to concentrate scarce resources to where they can yield the highest ecological benefits.

Partial Text

Agriculture is one of the most important drivers of biodiversity loss globally [1]. While the expansion of agriculture causes loss of native ecosystems, the intensification of land-use within existing agricultural landscapes often causes declines of species adapted to traditional man-managed agro-pastoral systems [2, 3]. In Europe, agriculture represents a dominant land-use type and supports considerable levels of biodiversity [4]. Across the continent, farmland-associated taxa are showing severe declines owing to increasingly intensive production regimes heavily based on use of chemical inputs, as well as simplification of the landscape and growing mechanization [3–5].

Overall, bird abundance was positively correlated with three variables: the percentage cover of fields within 5 km from the transect line, the relative influence of non-field grassland (i.e., semi-natural pastures and meadows) and presence of organic animal farms (both already certified as organic or in transition; Table 2 and Fig 2). The above results were consistent at both the 300m and 1 km scale. Of the above, only organic animal farms are subsidised under the agri-environmental programme. None of the other AES variables considered had a significant effect on bird abundance at any of the two spatial scales.

Here we assessed the effect of several measures under agri-environment schemes (AES), including organic farming, on the abundance of farmland- associated birds across Finland. We show that, among all AES measures considered, organic animal farming was the only measure that had a measurable positive effect on bird abundance. Specifically, we found that the effect of organic animal farms was most positive on insectivorous, and to a lower extent, on omnivorous birds, as well as on farmyard or long-distance migrant species. With regard to land-use types, we found that non-field grassland (i.e. semi-natural pastures and meadows) had a measurable positive effect on bird abundance. The above results were consistent at both 300m and 1km spatial scales considered. None of the other AES measures, including organic crop farm contract, had any significant effect on bird abundance.

 

Source:

http://doi.org/10.1371/journal.pone.0216009

 

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