Toräng Per, Ehrlén Johan, Agren Jon
Department of Ecology and Evolution, Evolutionary Biology Centre, Uppsala University, Villavägen 14, SE-752 36 Uppsala, Sweden.
Ecology. 2006 Aug;87(8):2113-7. doi: 10.1890/0012-9658(2006)87[2113:fiaihw]2.0.co;2.
Population context should influence pollination success and selection on floral display in animal-pollinated plants because attraction of pollinators depends not only on the characteristics of individual plants, but also on the attractiveness of co-occurring conspecifics. The insect-pollinated herb Primula farinosa is polymorphic for inflorescence height. Natural populations may include both long-scaped plants, which present their flowers well above the soil surface, and short-scaped plants, with their flowers positioned close to the ground. We experimentally tested whether seed production in short-scaped P. farinosa varied with local morph frequency and surrounding vegetation height. In tall vegetation, short-scaped plants in polymorphic populations produced more fruit and tended to produce more seeds than short-scaped plants did in monomorphic populations. In low vegetation, population composition did not significantly affect fruit and seed output of short-scaped plants. The results suggest that long-scaped plants facilitate short-scaped plants in terms of pollinator attraction and that the facilitation effect is contingent on the height of the surrounding vegetation. The documented facilitation should contribute to the maintenance of the scape length polymorphism in ungrazed areas where litter accumulates and vegetation grows tall.
种群环境应该会影响动物传粉植物的授粉成功率以及对花展示的选择，因为传粉者的吸引不仅取决于单个植物的特征，还取决于同时出现的同种植物的吸引力。虫媒传粉草本植物粉报春的花序高度具有多态性。自然种群可能包括长花茎植物（其花朵高出土壤表面）和短花茎植物（其花朵靠近地面）。我们通过实验测试了短花茎粉报春的种子产量是否随当地形态频率和周围植被高度而变化。在高大植被中，多态种群中的短花茎植物比单态种群中的短花茎植物结出更多果实，且往往产生更多种子。在低矮植被中，种群组成对短花茎植物的果实和种子产量没有显著影响。结果表明，长花茎植物在传粉者吸引方面对短花茎植物有促进作用，且这种促进作用取决于周围植被的高度。记录在案的这种促进作用应该有助于在未放牧地区（枯枝落叶堆积且植被高大）维持花茎长度多态性。
