Restoration efforts often focus on changing the composition and structure of invaded plant communities, with two implicit assumptions: (1) functional interactions with species of other trophic levels, such as pollinators, will reassemble automatically when native plant diversity is restored and (2) restored communities will be more resilient to future stressors. However, the impact of restoration activities on pollinator richness, plant–pollinator interaction network structure, and network robustness is incompletely understood. Leveraging a restoration chronosequence in Pacific Northwest prairies, we examined the effects of restoration-focused prescribed fire and native forb replanting on floral resources, pollinator visitation, and plant–pollinator network structure. We then simulated the effects of plant species loss/removal scenarios on secondary extinction cascades in the networks. Specifically, we explored three management-relevant plant loss scenarios (removal of an abundant exotic forb, removal of an abundant forb designated a noxious weed, and loss of the rarest native forb) and compared them to control scenarios. Pyrodiversity and proportion of area recently burned increased the abundance and diversity of floral resources, with concomitant increases in pollinator visitation and diversity. Pyrodiversity also decreased network connectance and nestedness, increased modularity, and buffered networks against secondary extinction cascades. Rare forbs contributed disproportionately to network robustness in less restored prairies, while removal of typical “problem” plants like exotic and noxious species had relatively small impacts on network robustness, particularly in prairies with a long history of restoration activities. Restoration actions aimed mainly at improving the diversity and abundance of pollinator-provisioning plants may also produce plant–pollinator networks with increased resilience to plant species losses.

中文翻译：

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规定的火灾增加了植物-传粉者网络对稀有本土草本植物损失的稳健性

恢复工作通常侧重于改变入侵植物群落的组成和结构，有两个隐含的假设：（1）当本地植物多样性恢复时，与其他营养级物种（例如传粉昆虫）的功能相互作用将自动重新聚集；（2）恢复社区将更有能力应对未来的压力。然而，恢复活动对传粉媒介丰富度、植物与传粉媒介相互作用网络结构和网络稳健性的影响尚不完全清楚。利用太平洋西北大草原的恢复时间序列，我们研究了以恢复为重点的规定火烧和本土杂草重新种植对花卉资源、传粉媒介访问和植物传粉媒介网络结构的影响。然后，我们模拟了植物物种丧失/移除情景对网络中二次灭绝级联的影响。具体来说，我们探索了三种与管理相关的植物损失情景（去除丰富的外来草本植物、去除丰富的指定为有毒杂草的草本植物以及最稀有的本地草本植物的损失），并将它们与对照情景进行比较。火的多样性和最近燃烧的面积比例增加了花卉资源的丰富性和多样性，伴随着传粉媒介的访问和多样性的增加。火多样性还减少了网络连接和嵌套，增加了模块化，并缓冲了网络以防止二次灭绝级联。在恢复程度较低的草原上，稀有杂草对网络稳健性的贡献不成比例，而去除外来和有毒物种等典型“问题”植物对网络稳健性的影响相对较小，特别是在恢复活动历史悠久的草原上。主要旨在提高传粉媒介植物的多样性和丰度的恢复行动也可能产生植物-传粉媒介网络，增强对植物物种损失的抵御能力。