Weed infestation affects economically relevant orchard properties, including tree performance, yield, and fruit quality negatively, and weeds are therefore often controlled by herbicide application in conventional farming. The addition of organic mulch below tree canopies has been proposed as an alternative reliable practice to suppress weeds and preserve soil moisture in organic farming. Mulching, however, may also affect arthropod pest and natural enemy populations, which highlights the need for simultaneously assessing weed, natural enemy, and animal pest communities in mulch experiments. This study addresses the limited knowledge about nonchemical ground cover management strategies for the control of plant and animal pests in orchards as a major constraint for organic growers. Here, we hypothesize that decisions about ground cover management practices in organic temperate fruit orchards affect the composition of web‐building spider communities and their functional role as natural enemies of pest arthropods through effects on weed and insect pest communities. We studied weed, prey, and spider communities, as well as spider diet composition, in four temperate fruit types (apricot, peach, plum, and quince) on a single farm in the Western Cape, South Africa. We established experimental plots with and without addition of dead organic mulch under fruit tree canopies. Addition of organic mulch did not significantly affect weed cover under trees or the taxonomic composition of weed or spider communities over the eight‐month study period. However, independent of mulching, the taxonomic composition of weed communities was significantly related to the composition of potential prey and spider communities. These relationships indirectly affected the prey composition of web‐building spiders. These results suggest that the identity of weed species in the study orchards had a pronounced effect on the diet composition and functional role of web‐building spiders. Future research should focus on the value of individual plant species for the promotion of pest control services provided by spiders across larger spatial scales and with higher levels of replication to allow for wider generalizations. The expected results would not only be relevant for weed control but could also be considered during the development of future flower strips in orchards.

中文翻译：

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杂草物种而不是地膜覆盖物会影响南非有机果园中的蜘蛛网及其猎物

杂草的侵害会对经济相关的果园特性产生负面影响，包括果树性能，产量和果实品质，因此杂草通常通过常规耕种中的除草剂控制。有人提议在树冠下添加有机覆盖物，作为在有机耕作中抑制杂草和保持土壤水分的另一种可靠方法。但是，地膜覆盖也可能会影响节肢动物的害虫和天敌种群，这突出了在覆盖实验中需要同时评估杂草，天敌和动物害虫群落的需求。这项研究解决了关于非化学地面覆盖管理策略的有限知识，该策略用于控制果园中的动植物有害生物，这是有机种植者的主要制约因素。这里，我们假设有关有机温带果园地面覆盖管理措施的决策会影响杂草和害虫社区，从而影响网状蜘蛛群落的组成及其作为害虫节肢动物天敌的功能。我们在南非西开普的一个农场研究了四种温带水果类型（杏，桃，李子和木瓜）的杂草，猎物和蜘蛛群落以及蜘蛛的饮食组成。我们建立了在果树冠层下添加或不添加死有机覆盖物的试验区。在八个月的研究期内，添加有机覆盖物不会显着影响树木下的杂草覆盖率或杂草或蜘蛛群落的分类学组成。但是，与覆盖无关 杂草群落的分类学组成与潜在猎物和蜘蛛群落的组成显着相关。这些关系间接影响了网络构建蜘蛛的猎物组成。这些结果表明，在研究果园中杂草物种的身份对建网蜘蛛的饮食组成和功能作用具有显着影响。未来的研究应侧重于单个植物物种在更大范围的空间尺度上和以更高水平的复制来促进蜘蛛提供的有害生物控制服务的价值，以便进行更广泛的概括。预期的结果不仅与杂草控制有关，而且还可以在果园将来开发花条时考虑。这些关系间接影响了网络构建蜘蛛的猎物组成。这些结果表明，在研究果园中杂草物种的身份对建网蜘蛛的饮食组成和功能作用具有显着影响。未来的研究应集中在单个植物物种在促进蜘蛛在更大的空间规模和更高的复制水平上提供有害生物控制服务的价值方面，以实现更广泛的概括。预期的结果不仅与防除杂草有关，而且还可以在果园将来开发花条时考虑。这些关系间接影响了网络构建蜘蛛的猎物组成。这些结果表明，在研究果园中杂草物种的身份对建网蜘蛛的饮食组成和功能作用具有显着影响。未来的研究应侧重于单个植物物种在更大范围的空间尺度上和以更高水平的复制来促进蜘蛛提供的有害生物控制服务的价值，以便进行更广泛的概括。预期的结果不仅与杂草控制有关，而且还可以在果园将来开发花条时考虑。这些结果表明，在研究果园中杂草物种的身份对建网蜘蛛的饮食组成和功能作用具有显着影响。未来的研究应侧重于单个植物物种在更大范围的空间尺度上和以更高水平的复制来促进蜘蛛提供的有害生物控制服务的价值，以便进行更广泛的概括。预期的结果不仅与杂草控制有关，而且还可以在果园将来开发花条时考虑。这些结果表明，在研究果园中杂草物种的身份对建网蜘蛛的饮食组成和功能作用具有显着影响。未来的研究应侧重于单个植物物种在更大范围的空间尺度上和以更高水平的复制来促进蜘蛛提供的有害生物控制服务的价值，以便进行更广泛的概括。预期的结果不仅与杂草控制有关，而且还可以在果园将来开发花条时考虑。