Data from: High cover of hedgerows in the landscape supports multiple ecosystem services in Mediterranean cereal fields

Field-margin diversification through conservation and restoration of hedgerows is becoming a prominent intervention for promoting biodiversity and associated ecosystem services in intensive agricultural landscapes. However, how increasing cover of hedgerows in the landscape can affect ecosystem services has rarely been considered.
Here, we assessed the effect of increased field-margin complexity at the local scale and increasing cover of hedgerows in the landscape on the provision of pest control, weed control and potential pollination. Locally, three types of field margin were compared as follows: (i) standard grass margin, (ii) simple hedgerow and (iii) complex hedgerow, along two independent gradients of hedgerow cover and arable land cover in the landscape. We performed an exclusion experiment to measure biological control of cereal aphids and assessed natural enemy and pest abundance in the field. We sampled plant weed communities and performed a phytometer experiment to test the effects of pollinators on plant reproductive success.
At the local scale, planting a new hedgerow or improving its structural complexity and vegetation diversity did not enhance the delivery of ecosystem services in the neighbouring field.
However, high cover of hedgerows in the landscape enhanced aphid parasitism (from 12 to 18%) and potential pollination (visitation rate and seed set increased up to 70%) irrespective of local margin quality. The cover of arable land in the landscape reduced the abundance of plant-dwelling predators and weed diversity, but did not affect the delivery of the investigated ecosystem services.
Synthesis and applications. Our results highlight the key importance of the surrounding landscape context, rather than local factors, to the delivery of ecosystem services. This suggests a need for new policies that pay particular attention to the conservation of hedgerows at large scales for promoting multiple ecosystem services in agroecosystems. Specifically, hedgerows can serve to develop a network of ecological corridors that can facilitate the movement of beneficial organisms, such as pollinators and natural enemies in the agricultural matrix. Such interventions may be a ‘low cost–high benefit solution’, since farmers can create or conserve high-quality habitats taking little or no land from crop production and without the need to change their crop management.

通过保护与修复树篱（hedgerows）实现田边多样化，已成为集约化农业景观中推动生物多样性及其关联生态系统服务提升的重要干预举措。然而，此前鲜有研究探讨景观尺度下树篱覆盖度提升对生态系统服务的影响。
本研究评估了局部田边复杂度提升与景观树篱覆盖度提升对害虫防控、杂草防控及潜在授粉服务的调控效应。实验设置三类田边处理开展局部尺度对比：(i) 标准草本田边、(ii) 简易树篱田边与(iii) 复杂树篱田边，并同步设置景观尺度上树篱覆盖度与耕地覆盖度的两条独立梯度。我们通过排除实验测定了麦蚜的生物防控效果，同时评估了田间天敌与害虫的种群丰度；此外对杂草群落进行采样，并开展植物指示试验（phytometer）以检测传粉者对植物繁殖成功率的影响。
在局部尺度下，新建树篱或优化其结构复杂度与植被多样性，并未提升邻近农田的生态系统服务供给水平。
但景观尺度下树篱高覆盖度可显著提升麦蚜寄生率（从12%升至18%）与潜在授粉服务（访花率与结籽率最高提升70%），且该效应不受局部田边质量的影响。景观中耕地覆盖度会降低植物栖居型天敌的种群丰度与杂草多样性，但并未对本研究关注的生态系统服务供给产生显著影响。
综合与应用：本研究结果表明，农田周边的景观背景而非局部田边因素，对生态系统服务供给具有关键调控作用。这提示亟需制定全新政策，重点关注大尺度树篱保护工作，以推动农业生态系统中多种生态系统服务的供给。具体而言，树篱可构建生态廊道网络，助力传粉者与天敌等有益生物在农业基质中迁移扩散。此类干预手段堪称‘低成本高收益方案’：农户可在几乎不占用耕地、无需改变作物种植管理模式的前提下，创建或保护优质生境。