Data from: Landscape context and farm uptake constrain effects of bird conservation in the Swedish Volunteer & Farmer Alliance

1. In Europe, agri-environmental schemes (AES) have been unsuccessful in halting biodiversity declines to any great extent. Two particular 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. 2. 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. 3. Uptake was higher for unsubsidised (i.e. non-AES) measures than for AES options, and depended on farmers’ interest in nature, farm size (higher uptake on larger farms) and production type (higher on organic farms). 4. 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 conventional farms. 5. 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 other non-crop species and in field-nesting species 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. 6. Implications: 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, and especially so 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 AES) dependent on landscape context, as well as on ensuring high on-farm uptake of different interventions.

1. 在欧洲，农业环境计划（agri-environmental schemes, AES）在大幅遏制生物多样性下降方面收效甚微。该计划存在两项突出缺陷：一是农户参与率偏低，二是多数计划选项的实施效果欠佳。为部分弥补这些不足，鼓励农民积极参与生物多样性保护的各类举措逐渐受到关注，但目前几乎没有针对此类举措的评估研究。
2. 本研究采用实施前后评估框架，基于农户层面的调查数据，对瑞典志愿者与农民联盟（Swedish Volunteer & Farmer Alliance）这一由瑞典国际鸟盟（BirdLife Sweden）协调开展的农田鸟类保护项目中，农户对保护建议的采纳情况，以及农田鸟类对相关保护举措的响应进行了评估。
3. 未受补贴的保护措施（即非农业环境计划措施）的农户采纳率高于农业环境计划选项，且采纳率与农户对自然的兴趣、农场规模（大型农场的采纳率更高）以及生产类型（有机农场的采纳率更高）密切相关。
4. 总体而言，在两次调查年度（间隔中位数为3年）之间，非作物筑巢鸟类和农田筑巢鸟类的种群丰度均有所下降。农业边际区域的种群下降幅度高于以耕地为主的区域，且有机农场的种群下降幅度大于传统农场。
5. 农场实施的保护措施越多，非作物筑巢鸟类种群丰度的负向趋势便会得到缓解，但这一效应仅在以耕地为主的景观中存在。其他非作物筑巢鸟类以及农田筑巢鸟类的种群变化与实施的保护措施并无显著关联，但由于高采纳率农场的样本量较小，且农场间的变异性较高，检测此类效应的统计效力普遍偏低。
6. 研究启示：本研究结果表明，志愿者农民联盟以及新增未受补贴的保护措施，有望在农户层面改变农田中非作物筑巢鸟类的本地种群数量，在集约化管理的农业景观中这一效果尤为显著。因此，未受补贴的保护措施可作为农业环境工具库的有益补充，尽管其对繁殖鸟类种群数量的影响（与农业环境计划一样）取决于景观背景，同时也取决于能否确保农户对各类保护干预措施的高采纳率。