Abstract The impact of agriculture on biodiversity depends on the extent and types of agriculture and the degree to which agricultural land contrasts with the natural ecosystem. Most research on the latter comes from studies on the influence of different agricultural types within a single ecosystem with far less study on how the natural ecosystem context shapes the response of biodiversity to agricultural production. We used citizen science data from agricultural areas in Canada’s Eastern Hardwood-Boreal (forest ecosystem, n=108 landscapes) and Prairie Pothole (prairie ecosystem, n=99) regions to examine how ecosystem context shapes the response of avian species diversity, functional diversity and abundance to the amount of arable crop and pastoral agriculture at landscape scales. Avian surveys were conducted along 8km transects of Breeding Bird Survey routes with land cover assembled within a 20km2 landscape around each transect. The amount of agriculture at which species diversity peaked differed between the forest (15%) and prairie (51%) ecosystems, indicating that fewer species tolerated the expansion of agriculture in the former. In both ecosystems, functional diversity initially increased with agriculture and peaked at higher amounts (forest: 42%, prairie: 77%) than species diversity suggesting that functional redundancy was lost first as agriculture increased. Species turnover with increasing agriculture was primarily among functional groups in forest where a shift from a low to a high agriculture landscape led to a decline in the percent of the community represented by Neotropical migrants, insectivores, upper foliage gleaners and bark foragers, and an increase in the percent of the community represented by short-distance migrants, granivores, omnivores and ground gleaners. There were few distinct shifts in the percent of the community represented by different functional groups in the prairie ecosystem. Total abundance was the least sensitive measure examined in both ecosystems and indicated that species losses with agriculture are likely followed by numerical compensation from agriculture tolerant species. Our results highlight the importance of ecosystem context for understanding how biodiversity is affected by agricultural production with declines in diversity occurring at lower agricultural extents in ecosystems with lower similarity between natural and agricultural land covers. These findings allow for more specific conservation recommendations including managing for species intolerant to agriculture in prairie ecosystems and limiting the expansion of high contrast agriculture and the loss of semi-natural habitat, such as hedge rows, in historically forested ecosystems.

中文翻译：

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农业和自然土地覆盖率之间的相似性决定了生物多样性如何对景观尺度的农业扩张做出反应

摘要 农业对生物多样性的影响取决于农业的范围和类型以及农业用地与自然生态系统的对比程度。对后者的研究大多来自对单一生态系统内不同农业类型影响的研究，而对自然生态系统环境如何塑造生物多样性对农业生产的反应的研究则少得多。我们使用加拿大东部硬木-北方（森林生态系统，n=108 景观）和草原坑洞（草原生态系统，n=99）地区农业区的公民科学数据来研究生态系统环境如何影响鸟类物种多样性、功能多样性的反应以及景观尺度上可耕作物和牧区农业的数量。鸟类调查是沿着 8 公里长的种鸟调查路线进行的，土地覆盖被组装在每个样带周围 20 平方公里的景观中。森林 (15%) 和草原 (51%) 生态系统之间物种多样性达到顶峰的农业数量有所不同，这表明前者能够容忍农业扩张的物种较少。在这两个生态系统中，功能多样性最初随着农业而增加，并且达到峰值（森林：42%，草原：77%）高于物种多样性，这表明随着农业的增加，功能冗余首先消失。随着农业的增加，物种周转主要是在森林中的功能群体中，从低农业景观到高农业景观的转变导致新热带移民、食虫动物、上部树叶采集者和树皮采集者，以及以短距离迁徙者、食谷动物、杂食动物和地面采集者为代表的社区百分比的增加。草原生态系统中不同功能群体所代表的群落百分比几乎没有明显变化。总丰度是在两个生态系统中检查的最不敏感的衡量标准，并表明农业物种损失可能紧随其后的是农业耐受物种的数量补偿。我们的研究结果强调了生态系统背景对于理解农业生产如何影响生物多样性的重要性，在自然和农业土地覆盖之间的相似性较低的生态系统中，多样性下降发生在较低的农业范围内。