Interspecific pollen transport between non-native fennel and an island endemic buckwheat: assessment of the magnet effect
Interspecific pollen transport between non-native fennel and an island endemic buckwheat: assessment of the magnet effect
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DOI：
10.1007/s10530-021-02626-0
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发表时间：
2021-09-23
影响因子：
2.9
通讯作者：
Holway, D. A.
中科院分区：
文献类型：
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作者：
Etter, K. J.;Junquera, G.;Holway, D. A.
非本地植物可以通过改变传粉者的觅食行为来破坏植物与传粉者的相互作用，从而影响本地和非本地植物物种之间的种间花粉传递水平。当引入的植物物种作为磁铁类群，增加传粉者对其他植物物种的访问时，这些过程可能会被放大。我们调查了在Santa Cruz Island （Santa Barbara Co., California）上分布广泛且数量众多的外来茴香（Foeniculum vulgare）与当地特有的Santa Cruz Island荞麦（Eriogonum arborescens）之间的相互作用，后者在当地分布和开花物候上与茴香有很大的重叠。一项茴香花去除实验表明，这种入侵者通过增加昆虫对邻近荞麦花的访问而起到磁铁物种的作用。对传粉昆虫携带花粉量（即花粉运输）的分析表明，96%的访花者携带荞麦花粉，72%的访花者携带荞麦花粉。花粉运输分析和访问率数据进一步表明，三种蜂属成员（主要是小球藻）可能负责大部分茴香花粉沉积在荞麦花柱头上（即花粉传递），反之亦然。最后，与茴香植物对邻近荞麦植物的访花者施加的磁铁效应相比，茴香花粉运输似乎发生在更大的空间尺度上。茴香作为一种磁铁物种的能力，加上它是一种广泛存在的入侵者，具有已知的化感能力，这表明未来的研究可以评估茴香花粉的转移是否会对引入茴香的地区的本地植物繁殖产生不利影响。
Non-native plant species can disrupt plant-pollinator interactions by altering pollinator foraging behavior, which can in turn affect levels of interspecific pollen transfer between native and non-native plant species. These processes may be amplified in cases where introduced plant species act as magnet taxa that enhance pollinator visitation to other plant species. We investigated these interactions on Santa Cruz Island (Santa Barbara Co., California) between non-native fennel (Foeniculum vulgare), a widespread and abundant invader, and the endemic Santa Cruz Island buckwheat (Eriogonum arborescens), which broadly overlaps fennel in its local distribution and blooming phenology. A fennel flower removal experiment revealed that this invader acts as a magnet species by increasing insect visitation to adjacent buckwheat flowers. Analysis of the amount of pollen carried on the bodies of insect pollinators (i.e., pollen transport) revealed that 96% of visitors to buckwheat flowers carried fennel pollen and 72% of visitors to fennel flowers carried buckwheat pollen. Pollen transport analyses and visitation rate data further suggest that members of three bee genera (primarily Augochlorella) may be responsible for the majority of fennel pollen deposited on the stigmas of buckwheat flowers (i.e., pollen transfer) and vice versa. Lastly, fennel pollen transport appeared to occur at a larger spatial scale than the magnet effect that fennel plants exert on floral visitors to neighboring buckwheat plants. The ability of fennel to act as a magnet species, coupled with the fact that it is widespread invader with known allelopathic capacities, suggests that future studies could evaluate if the transfer of fennel pollen adversely affects native plant reproduction in areas where fennel is introduced.