Interaction engineering: non-trophic effects modify interactions in an insect galler community

1. Theory suggests that non-trophic interactions can be a major mechanism behind community stability and persistence, but community-level empirical data are scarce, particularly for effects on species interactions mediated through changes in the physical environment. 2. Here we explored how ecosystem engineering effects can feed back to the engineer, not only modulating the engineer’s population density (node modulation) but also affecting it’s interactions with other species (link modulation). 3. Gall induction can be viewed as ecosystem engineering since galls serve as habitat for other species. In a community-level field experiment, we generated treatments with reduced or elevated ecosystem engineering by removing or adding post-emergence galls to different plots of their host plant in the Brazilian Cerrado. We tested the effect of post-emergence galls on the galler, as well as on the galler-parasitoid and galler-aphid interactions. 4. The manipulation of post-emergence galls had lit...

1. 理论研究表明，非营养相互作用（non-trophic interactions）可能是群落稳定性与持久性的核心驱动机制之一，但当前群落水平的实证数据仍较为匮乏，尤其是针对由物理环境变化介导的物种相互作用效应相关的数据。
2. 本研究探讨了生态系统工程效应（ecosystem engineering effects）如何对工程物种产生反馈调控：其不仅可调节工程物种的种群密度（节点调控，node modulation），还能影响其与其他物种的相互作用（链路调控，link modulation）。
3. 虫瘿诱导（gall induction）可被视为一种生态系统工程行为，因为虫瘿可为其他物种提供栖息生境。本研究依托巴西塞拉多（Brazilian Cerrado）地区的宿主植物样地，通过移除或添加羽化后的虫瘿，构建了生态系统工程强度降低或升高的实验处理组，开展了群落水平的野外操控实验。我们检验了羽化后虫瘿对造瘿昆虫（galler）、造瘿昆虫-寄生蜂（galler-parasitoid）以及造瘿昆虫-蚜虫（galler-aphid）相互作用的影响。
4. 对羽化后虫瘿的操控实验对...