Liao Jinbao, Xi Xinqiang, Bearup Daniel, Sun Shucun
Ministry of Education's Key Laboratory of Poyang Lake Wetland and Watershed Research, School of Geography and Environment, Jiangxi Normal University, Ziyang Road 99, 330022, Nanchang, China.
Department of Ecology, School of Life Science, Nanjing University, 163 Xianlin Avenue, Nanjing, 210023, China.
Ecology. 2020 Aug;101(8):e03071. doi: 10.1002/ecy.3071. Epub 2020 May 8.
Recent observations have found plant-species-specific fly-host selection (i.e., specialization) of wasp parasitoids (wasps) in plant-fly-wasp (P-F-W) tripartite networks, yet no study has explored the dynamical implications of such high-order specialization for the persistence of this network. Here we develop a patch-dynamic framework for a unique P-F-W tripartite network with specialization observed in eastern Tibetan Plateau and explore its metacommunity robustness to habitat loss. We show that specialization in parasitoidism promotes fly species diversity, while the richness of both plant and wasp decreases. Compared to other two null models, real network structure favors plant species coexistence but increases the extinction risk for both flies and wasps. However, these effects of specialization and network structure would be weakened and ultimately disappear with increasing habitat loss. Interestingly, intermediate levels of habitat loss can maximize the diversity of flies and wasps, while increasing or decreasing habitat loss results in more species losses, supporting intermediate disturbance hypothesis. Finally, we observe that high levels of habitat loss initiate a bottom-up cascade of species extinction from plants to both flies and wasps, resulting in a rapid collapse of the whole tripartite networks. Overall, this theoretical framework is the first attempt to characterize the dynamics of whole tripartite metacommunities interacting in realistic high-order ways, offering new insights into complex multipartite networks.
最近的观察发现，在植物-苍蝇-黄蜂（P-F-W）三方网络中，黄蜂寄生蜂（黄蜂）存在针对植物物种的特定苍蝇宿主选择（即专业化），但尚无研究探讨这种高阶专业化对该网络持久性的动态影响。在此，我们针对青藏高原东部观察到的具有专业化特征的独特P-F-W三方网络，开发了一个斑块动态框架，并探讨其对栖息地丧失的集合群落稳健性。我们发现，寄生专业化促进了苍蝇物种的多样性，而植物和黄蜂的丰富度均有所下降。与其他两个零模型相比，真实的网络结构有利于植物物种共存，但增加了苍蝇和黄蜂的灭绝风险。然而，随着栖息地丧失的增加，专业化和网络结构的这些影响会被削弱并最终消失。有趣的是，中等程度的栖息地丧失可以使苍蝇和黄蜂的多样性最大化，而增加或减少栖息地丧失都会导致更多物种丧失，这支持了中度干扰假说。最后，我们观察到，高水平的栖息地丧失引发了从植物到苍蝇和黄蜂的自下而上的物种灭绝级联反应，导致整个三方网络迅速崩溃。总体而言，这个理论框架首次尝试刻画以现实的高阶方式相互作用的整个三方集合群落的动态，为复杂的多部分网络提供了新的见解。
