Quamash EcoResearch, Olympia, Washington, USA.
School of Natural Resources and the Environment, University of Arizona, Tucson, Arizona, USA.
Ecol Appl. 2024 Mar;34(2):e2928. doi: 10.1002/eap.2928. Epub 2023 Nov 20.
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.
恢复工作通常侧重于改变入侵植物群落的组成和结构，这有两个隐含的假设：（1）当恢复本地植物多样性时，与其他营养级物种的功能相互作用，如传粉者，将自动重新组合；（2）恢复的群落将对未来的胁迫更具弹性。然而，恢复活动对传粉者丰富度、植物-传粉者相互作用网络结构和网络鲁棒性的影响尚不完全清楚。利用太平洋西北地区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地草本植物重新种植对花卉资源、传粉者访问和植物-传粉者网络结构的影响。然后，我们模拟了植物物种损失/去除情景对网络中次级灭绝级联的影响。具体来说，我们探索了三种与管理相关的植物损失情景（去除一种丰富的外来草本植物、去除一种被指定为有害杂草的丰富草本植物和失去最稀有的本地草本植物），并将其与对照情景进行了比较。火多样性和最近燃烧面积的比例增加了花卉资源的丰度和多样性，同时传粉者的访问量和多样性也增加了。火多样性还降低了网络连接度和嵌套性，增加了模块性，并缓冲了网络对次级灭绝级联的影响。在恢复程度较低的草原中，稀有草本植物对网络鲁棒性的贡献不成比例，而去除外来和有害物种等典型“问题”植物对网络鲁棒性的影响相对较小，尤其是在恢复活动历史悠久的草原中。主要旨在提高传粉者供应植物多样性和丰度的恢复行动，也可能产生对植物物种损失具有更高弹性的植物-传粉者网络。
