Teillard Félix, Jiguet Frédéric, Tichit Muriel
INRA-AgroParisTech, UMR 1048 SAD APT, Paris, France.
MNHN-CNRS-UPMC, UMR 7204 CRBPO, Paris, France.
PLoS One. 2015 Mar 23;10(3):e0119674. doi: 10.1371/journal.pone.0119674. eCollection 2015.
The shape of the relationship between biodiversity and agricultural intensity determines the range of intensities that should be targeted by conservation policies to obtain the greatest environmental benefits. Although preliminary evidence of this relationship exists, the influence of the spatial arrangement of intensity on biodiversity remains untested. We conducted a nationwide study linking agricultural intensity and its spatial arrangement to a farmland bird community of 22 species. Intensity was described with a continuous indicator based on Input Cost per hectare, which was relevant for both livestock and crop production. We used the French Breeding Bird Survey to compute several descriptors of the farmland bird community along the intensity gradient and tested for the significance of an interaction effect between intensity and its spatial aggregation on these descriptors. We found that the bird community was comprised of both winner and loser species with regard to intensity. The community composition descriptors (trophic level, specialisation, and specialisation for grassland indices) displayed non-linear relationships to intensity, with steeper slopes in the lower intensity range. We found a significant interaction effect between intensity and its spatial aggregation on the grassland specialisation index of the bird community; the effect of agricultural intensity was strengthened by its spatial aggregation. We suggest that an opportunity to improve the effectiveness of conservation policies exists by targeting measures in areas where intensity is moderate to low and aggregated. The effect of the aggregation of agricultural intensity on biodiversity should be considered in other scales and taxa when developing optimal policy targeting and intensity allocation strategies.
生物多样性与农业集约化之间关系的形态决定了保护政策应针对的集约化范围，以获取最大的环境效益。尽管这种关系已有初步证据，但集约化的空间布局对生物多样性的影响仍未得到验证。我们开展了一项全国性研究，将农业集约化及其空间布局与一个包含22个物种的农田鸟类群落联系起来。集约化用基于每公顷投入成本的连续指标来描述，这对畜牧和作物生产均适用。我们利用法国繁殖鸟类调查来计算沿集约化梯度的农田鸟类群落的几个描述指标，并检验集约化及其空间聚集对这些指标的交互作用效应的显著性。我们发现，就集约化而言，鸟类群落既包含受益物种也包含受损物种。群落组成描述指标（营养级、专业化程度以及草地专业化指数）与集约化呈现非线性关系，在较低集约化范围内斜率更陡。我们发现集约化及其空间聚集对鸟类群落的草地专业化指数存在显著的交互作用效应；农业集约化的效应因空间聚集而增强。我们建议，通过在集约化程度为中度至低度且呈聚集状态的地区实施针对性措施，存在提高保护政策有效性的机会。在制定最优政策目标和集约化分配策略时，应在其他尺度和分类群中考虑农业集约化聚集对生物多样性的影响。
