Abstract：
Agricultural intensification is a major driver of global biodiversity loss. In Europe, intensification progressed over the 20th century and was accelerated by instruments of the EU\'s Common Agricultural Policy. Central and Eastern European (CEE) countries standing outside the EU until the beginning of the 21st century employed less intensive farming and are considered one of the continent\'s farmland biodiversity strongholds. Their recent EU accession might be either viewed as a threat to farmland biodiversity due to the availability of funds to increase agricultural production or as an opportunity to implement conservation measures aimed to preserve biodiversity. Here we assessed these possibilities using long-term monitoring data on farmland bird populations in seven CEE countries. We tested whether mean relative abundance and population trends changed after countries\' EU accession, and whether such changes also occurred in agricultural management and conservation measures. Both agricultural intensity and spending for agri-environmental and climatic schemes increased when the CEE countries joined the EU. At the same time, farmland bird populations started to decline and their relative abundance was lower after than before EU accession. In addition, increases in fertilizer application were negatively associated with annual changes in relative farmland bird population sizes, indicating a negative impact of intensive agriculture. Taken together, these results indicate that despite the great power of the EU\'s environmental legislation to improve the population status of species at risk, this does not apply to farmland birds. In their case, the adverse impacts of agricultural intensification most likely overrode the possible benefits of conservation measures. To secure this region as one of the continent\'s farmland biodiversity strongholds, policy and management actions are urgently needed.
摘要：
农业集约化是全球生物多样性丧失的主要驱动力。在欧洲,集约化在20世纪取得了进展，并在欧盟共同农业政策的工具的推动下加速。中欧和东欧（CEE）国家站在欧盟之外，直到21世纪初，都采用了较低的集约化农业，被认为是非洲大陆的农田生物多样性据点之一。由于有增加农业生产的资金，他们最近加入欧盟可能被视为对农田生物多样性的威胁，也可能被视为实施旨在保护生物多样性的保护措施的机会。在这里，我们使用了七个中东欧国家农田鸟类种群的长期监测数据来评估这些可能性。我们测试了各国加入欧盟后平均相对丰度和人口趋势是否发生变化，以及农业管理和保护措施是否也发生了这种变化。当中东欧国家加入欧盟时，农业强度和农业环境和气候计划的支出都有所增加。同时,农田鸟类种群开始下降，其相对丰度低于加入欧盟之前。此外,施肥的增加与相对农田鸟类种群规模的年度变化呈负相关，表明集约化农业的负面影响。一起来看,这些结果表明，尽管欧盟的环境立法有很大的力量来改善处于危险中的物种的种群状况，这不适用于农田鸟类。在他们的情况下，农业集约化的不利影响很可能超过保护措施的可能好处。为了确保该地区成为非洲大陆农田生物多样性的据点之一，迫切需要采取政策和管理行动。
