1. The addition of floral resources is often recommended to improve entomophilous crop pollination. However, implanting new plots of mass-flowering resources in landscapes can have both positive and negative effects on pollinator visitation rates to crops.
2. We investigated the effects of plot characteristics (size and nesting quantities) on the best places to locate new co-flowering plots to optimise crop pollination. First, we parameterised and validated an existing pollination model with field data. We set up experiments to simulate the conversion of random plots into new sunflower fields versus wildflower plots (intended to provide more nesting sites than sunflower fields and co-flowering with sunflower) and quantified the change in pollinator visitation rates to existing target sunflower fields.
3. We predicted a decrease in visitation rates (competition) when floral plots were established next to target fields and an increase in visitation rates (facilitation) when floral plots were established farther away. We identified the competition-facilitation transition distance (CF distance) and the distance at which facilitation was maximal (Fmax distance). We interpreted competition effects as a dilution of pollinators among the floral resources and facilitation effects as an increase in habitat quality, thus supporting bigger pollinator populations. Implanting floral resources that provide more nesting sites, such as wildflower plots versus new sunflower fields, significantly increased facilitation and reduced CF distance (713 m vs. 1,241 m) and Fmax distance (1,138 m vs. 1,788 m). The size of the converted plot did not affect CF or Fmax distance.
4. We predicted a benefit in isolating rather than aggregating multiple sunflower fields in terms of global crop pollination.
5. Synthesis and applications. Our findings highlight the opportunity to optimise the spatial distribution of mass-flowering resources at the landscape scale to enhance crop pollination. We also suggest preserving or introducing nesting sites as a priority in areas with high-density mass-flowering resources to compensate for the negative consequences of pollinator dilution.

中文翻译：

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在景观尺度上优化大量开花斑块的空间分布以增加作物授粉

1. 通常建议添加花卉资源以改善虫媒作物授粉。然而，在景观中种植大量开花资源的新地块会对传粉媒介对作物的访问率产生积极和消极的影响。
2. 我们研究了地块特征（大小和筑巢数量）对寻找新的共同开花地块以优化作物授粉的最佳地点的影响。首先，我们使用现场数据参数化并验证了现有的授粉模型。我们设置了实验来模拟随机地块向新的向日葵田与野花地的转换（旨在提供比向日葵田更多的筑巢地点并与向日葵共同开花），并量化传粉媒介对现有目标向日葵田的访问率的变化。
3. 我们预测，当花地靠近目标田地时，访问率（竞争）会降低，而当花地距离更远时，访问率（促进）会增加。我们确定了竞争促进过渡距离（CF 距离）和促进最大的距离（Fmax 距离）。我们将竞争效应解释为花卉资源中传粉媒介的稀释，将促进效应解释为栖息地质量的提高，从而支持更大的传粉媒介种群。植入提供更多筑巢地点的花卉资源，例如野花地块与新的向日葵田地，显着增加了促进作用并减少了CF 距离（713 m 对 1,241 m）和Fmax 距离（1,138 m 与 1,788 m）。转换图的大小不影响CF或Fmax 距离。
4. 我们预测，在全球作物授粉方面，隔离而不是聚集多个向日葵田会带来好处。
5. 合成与应用。我们的研究结果强调了在景观尺度上优化大量开花资源的空间分布以增强作物授粉的机会。我们还建议在具有高密度大量开花资源的地区优先保留或引入筑巢地点，以补偿传粉媒介稀释的负面影响。