Interactions outside local patches contribute to the compound topology of plant-pollinator networks in fragmented dune slacks

Plants and pollinators engage in ephemeral interactions that are essential for both plant reproduction and pollinator fitness. Most plant species interact with multiple pollinator species and, similarly, most pollinators visit multiple plant species, leading to complex networks of interactions. A better understanding of the factors that affect the structure of these networks is crucial for effective biodiversity conservation. While previous research has shown significant negative impacts of habitat fragmentation on plant and pollinator diversity, far less is known about how habitat fragmentation contributes to the overall network structure. In this study, we used DNA metabarcoding to construct pollen transport networks across nineteen dune slacks along a fragmentation gradient at the Belgian coast. For each network, we investigated the impact of patch area, connectivity, and floral diversity on network size, connectance, nestedness and modularity. We found a total of 3222 unique pairwis..., Data collection Pollinators were collected during the summer of 2021 in two sampling periods: 24 June – 9 July and 2 – 13 August. These periods were chosen to coincide with the two main flowering peaks in the study area. Each of the nineteen dune slacks (Fig. S1) was sampled once during each period. Sampling took place between 10:00 and 17:00 under sunny weather conditions, with air temperature above 16°C, wind speeds below 3 Bft, and cloud cover below 90%, using manual netting, with two persons actively walking through the entire dune slacks for two hours. Every insect species that was observed foraging on flowers was considered a pollinator. In total 3307 pollinators were collected. After capturing, pollinators were immediately placed in individual tubes, filled with 100% ethanol to kill and preserve them. Whenever possible, pollinators were identified to species level using sequential identification keys. If species identification was not possible, individuals were assigned to the hi..., , # Interactions outside local patches contribute to the compound topology of plant-pollinator networks in fragmented dune slacks [https://doi.org/10.5061/dryad.sj3tx96dp](https://doi.org/10.5061/dryad.sj3tx96dp) ## Description of the data and file structure **Interactions outside local patches preserve compound topology of plant-pollinator networks in fragmented dune slacks** In this study, we used DNA metabarcoding to construct pollen transport networks across nineteen dune slacks along a fragmentation gradient at the Belgian coast and  investigated the impact of patch area, connectivity, and floral diversity on network size, connectance, specialization, nestedness and modularity. Networks showed a low degree of specialization and none of them were significantly nested, while most were significantly modular with a hierarchical compound structure. Importantly, no significant relationships were found between network measures and patch area or connectivity, indicating that local patch ...,植物与传粉者之间存在短暂的互作关系，这种互作对植物繁殖与传粉者适合度均至关重要。多数植物物种会与多种传粉者物种产生互作，同理，多数传粉者也会造访多种植物物种，由此形成复杂的互作网络。深入理解影响此类网络结构的关键因素，对于开展有效的生物多样性保护工作具有重要意义。既往研究已证实栖息地破碎化对植物与传粉者多样性存在显著负面影响，但针对栖息地破碎化如何作用于传粉网络整体结构的认知仍十分有限。本研究借助DNA宏条形码（DNA metabarcoding）技术，构建了比利时海岸沿破碎化梯度分布的19处沙丘洼地的花粉传播网络。针对每一处网络，我们分别探究了斑块面积、连通性以及植物多样性对网络规模、连接度、嵌套性与模块化的影响。本研究共发现3222个独特的成对互作…… 数据采集 传粉者样本采集于2021年夏季的两个采样时段：6月24日至7月9日，以及8月2日至13日。选取这两个时段是为了匹配研究区域内的两个主要开花高峰。19处沙丘洼地（图S1）在每个采样时段均被采样一次。采样工作于每日10:00至17:00间开展，要求天气晴朗、气温高于16℃、风速低于3蒲福级、云量低于90%。采用手动网捕法，由两名研究人员耗时两小时遍历整片沙丘洼地进行采样。所有被观察到在花上觅食的昆虫物种均被视为传粉者。本次研究共采集到3307头传粉者个体。捕获后，传粉者立即被放入装有100%乙醇的独立试管中，以完成处死与保存。若条件允许，我们将通过分类检索表依次将传粉者鉴定至物种水平；若无法完成物种级鉴定，则将个体归类至…… , # 局地斑块外的互作贡献了破碎化沙丘洼地中植物-传粉者网络的复合拓扑结构 [https://doi.org/10.5061/dryad.sj3tx96dp](https://doi.org/10.5061/dryad.sj3tx96dp) ## 数据与文件结构说明 **局地斑块外的互作维持了破碎化沙丘洼地中植物-传粉者网络的复合拓扑结构** 本研究借助DNA宏条形码（DNA metabarcoding）技术，构建了比利时海岸沿破碎化梯度分布的19处沙丘洼地的花粉传播网络，并探究了斑块面积、连通性以及植物多样性对网络规模、连接度、特化程度、嵌套性与模块化的影响。研究结果显示，所有网络的特化程度均较低，且无一呈现显著嵌套性；但多数网络具有显著的模块化特征，呈现出层级式的复合结构。值得注意的是，未发现网络指标与斑块面积或连通性之间存在显著关联，这表明局地斑块……