1. Mutualistic networks are highly dynamic, characterized by high temporal turnover of species and interactions. Yet, we have a limited understanding of how the internal structure of these networks and the roles species play in them vary through time. 2. We used six years of observation data and a novel statistical method (dynamic stochastic block models) to assess how network structure and species' structural position within the network change throughout subseasons of the flowering season and across years in a quantitative plant-pollinator network from a dryland ecosystem in Argentina. 3. Our analyses revealed a core-periphery structure persistent through subseasons and years. Yet, species structural position as core or peripheral was highly dynamic: virtually all species that were at the core in some subseasons were also peripheral in other subseasons, while many other species remained always peripheral. 4. Our results illuminate our understanding of the dynamics of mutualistic networks and have important implications for ecosystem management and conservation.

中文翻译：

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植物传粉网络中的核心外围动态

1. 互惠网络是高度动态的，其特征是物种和相互作用的高时间周转。然而，我们对这些网络的内部结构以及物种在其中扮演的角色如何随时间变化的了解有限。2. 我们使用了六年的观测数据和一种新的统计方法（动态随机块模型）来评估网络结构和物种在网络中的结构位置在整个开花季节的子季和跨年的定量植物传粉网络中的变化来自阿根廷的旱地生态系统。3. 我们的分析揭示了一个贯穿次季和年的核心-外围结构。然而，作为核心或外围的物种结构位置是高度动态的：几乎所有在某些亚季处于核心的物种在其他亚季也处于外围，而许多其他物种始终处于外围。4. 我们的结果阐明了我们对互惠网络动态的理解，并对生态系统管理和保护具有重要意义。