Landscape context and farm uptake limit effects of bird conservation in the Swedish Volunteer & Farmer Alliance.
Abstract
In Europe, agri-environmental schemes (AES) have been unsuccessful in halting biodiversity declines to any great extent. Two shortcomings of AES include the low farm uptake and the modest efficacy of many AES options. Partly in response to these shortcomings, initiatives encouraging farmers to take an active role in biodiversity conservation have gained in popularity. However, almost no evaluations of such initiatives exist. We evaluated uptake of conservation advice on farms in the Swedish Volunteer & Farmer Alliance, a BirdLife Sweden-coordinated project aimed at farmland bird conservation, and the response of farmland birds to those actions using farm-level survey data, in a before-after implementation assessment. Uptake was higher for unsubsidised (i.e. non-AES) measures than for AES options, and depended mainly on farmers' interest in nature, with farm size and production type having less importance. In general, abundances of non-crop nesting and field-nesting bird species declined between inventory years (median interval 3 years). Decreases were more marked in agriculturally marginal regions than in more arable-dominated regions, and declines were stronger on organic than on conventional farms. Negative abundance trends among non-crop nesting species were reduced by an increasing number of conservation measures at the farm, but only in the more arable-dominated landscapes. Changes in field-nesting species, or at species level, did not significantly relate to implemented measures, but the power to detect such effects was generally small due to the small sample size of high-uptake farms as well as high inter-farm variability. Synthesis and applications. Our results suggest that volunteer farmer alliances and the addition of unsubsidised measures may be successful in changing the local number of non-crop nesting farmland birds, at the farm level, particularly in intensively managed agricultural landscapes. Thus, unsubsidised measures can be a useful addition to the set of agri-environment tools, although their effects on breeding bird numbers are (as with agri-environmental schemes) dependent on landscape context, as well as on ensuring high on-farm uptake of different interventions.