Research Division Agroecology and Environment, Agroscope, Zürich, Switzerland.
Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zürich, Switzerland.
Ecol Lett. 2022 Nov;25(11):2422-2434. doi: 10.1111/ele.14104. Epub 2022 Sep 22.
To stop the ongoing decline of farmland biodiversity there are increasing claims for a paradigm shift in agriculture, namely from conserving and restoring farmland biodiversity at field scale (α-diversity) to doing it at landscape scale (γ-diversity). However, knowledge on factors driving farmland γ-diversity is currently limited. Here, we quantified farmland γ-diversity in 123 landscapes and analysed direct and indirect effects of abiotic and land-use factors shaping it using structural equation models. The direction and strength of effects of factors shaping γ-diversity were only partially consistent with what is known about factors shaping α-diversity, and indirect effects were often stronger than direct effects or even opposite. Thus, relationships between factors shaping α-diversity cannot simply be up-scaled to γ-diversity, and also indirect effects should no longer be neglected. Finally, we show that local mitigation measures benefit farmland γ-diversity at landscape scale and are therefore a useful tool for designing biodiversity-friendly landscapes.
为了阻止农田生物多样性的持续减少，人们越来越多地呼吁农业范式的转变，即从保护和恢复农田生物多样性的田间尺度（α多样性）转变为景观尺度（γ多样性）。然而，目前关于驱动农田γ多样性的因素的知识有限。在这里，我们在 123 个景观中量化了农田γ多样性，并使用结构方程模型分析了塑造它的生物和土地利用因素的直接和间接影响。塑造γ多样性的因素的作用方向和强度与已知的塑造α多样性的因素不完全一致，间接效应通常比直接效应更强，甚至相反。因此，塑造α多样性的因素之间的关系不能简单地扩展到γ多样性，间接效应也不应再被忽视。最后，我们表明，当地的缓解措施有利于景观尺度的农田γ多样性，因此是设计生物多样性友好型景观的有用工具。
