Data from: Organic management in apple orchards: higher impacts on biological control than on pollination

1. Intensive agricultural management negatively affects both natural enemies of pests and pollinators. Such management also has the potential to adversely affect the ecosystem services that these communities confer. Organic management has been proposed as an alternative method to mitigate such problems by restoring the services provided by arthropod communities.
2. We evaluated the effect of organic management on two ecosystem services provided by arthropods in apple orchards: pollination and biological control. We used relative decrease in colonies to assess biological control of the major apple aphid pest, and measured pollination through fruit set, number of seeds per apple and pollinator visitation. Additionally, we monitored the organisms responsible for pollination and biological control services and established the impact of pollination on apple quality.
3. Our results show a strong effect of organic management on biological control and on the temporal dynamic of natural enemy-pest interactions. Parameters such as aphid colony suppression, first and repeated occurrence of natural enemies, natural enemy species evenness and natural enemy abundance were significantly higher in organic compared to conventional orchards. Predatory bugs were the natural enemies best-affected by organic management and played a key role in early predation of aphids preventing colony growth.
4. In this instance, pollination was not influenced by organic management. It is likely due to the temporal scale at which this service is delivered, a scale that differs greatly from biological control, combined with differences in the dispersal capacity of the organisms involved. Fruit weight, calcium, potassium and magnesium content were positively affected by pollination success.
5. Synthesis and applications. We found that organic management in apple orchards preserves the local natural enemy community, and specifically predatory bug populations, essential for early aphid colony suppression. Our results suggest that, in conventional orchards, local management options that decrease or even eliminate pesticide use early in the season would increase the biological control of aphids. This would lead to reduction in apple damage at harvest. Our results on pollination success indicate that the implementation of organic management at orchard scale does not enhance pollination services for apple growers.

1. 集约化农业管理（intensive agricultural management）会对害虫天敌（natural enemies of pests）与传粉者（pollinators）均产生负面影响。此类管理模式还可能损害这些节肢动物群落（arthropod communities）所提供的生态系统服务（ecosystem services）。有机管理（organic management）已被提议作为缓解此类问题的替代方案，通过恢复节肢动物群落提供的服务来解决相关问题。
2. 本研究评估了有机管理对苹果园（apple orchards）节肢动物所提供的两项生态系统服务的影响：传粉服务与生物防治（biological control）。我们通过菌落相对减少量来评估主要苹果蚜虫害虫（apple aphid pest）的生物防治效果，并通过坐果率（fruit set）、单果种子数（number of seeds per apple）及传粉者访花率（pollinator visitation）来衡量传粉服务。此外，我们还对负责传粉与生物防治服务的生物类群进行了监测，并明确了传粉对苹果品质（apple quality）的影响。
3. 研究结果表明，有机管理对生物防治及害虫-天敌互作的时间动态（temporal dynamic）均具有显著影响。相较于常规果园，有机管理果园的蚜虫菌落抑制率、天敌首次及重复出现频次、天敌物种均匀度（species evenness）及天敌丰度（abundance）等参数均显著更高。捕食性蝽类（predatory bugs）是受有机管理影响最为显著的天敌类群，其在蚜虫的早期捕食中发挥关键作用，可抑制蚜虫菌落的增殖。
4. 本研究中，有机管理并未对传粉服务产生显著影响。该现象可能源于传粉服务的发挥尺度与生物防治存在显著差异，加之参与两类服务的生物类群的扩散能力各不相同。传粉成功可显著提升果实重量以及钙、钾、镁元素的含量。
5. 总结与应用启示：本研究发现，苹果园的有机管理可维持本地天敌群落，尤其是捕食性蝽类种群，而此类群落在早期蚜虫菌落抑制中发挥关键作用。研究结果表明，在常规果园中，于生长季早期减少甚至停用农药（pesticide use）的本地化管理措施，可增强对蚜虫的生物防治效果，进而降低收获期（harvest）的苹果受损程度。此外，关于传粉成功的研究结果显示，在果园尺度推行有机管理，并不会为苹果种植者提升传粉服务效益。