Hegland Stein Joar, Totland Ørjan
Department of Ecology and Natural Resource Management, Norwegian University of Life Sciences, P.O. Box 5003 (UR), 1432 As, Norway.
Oecologia. 2005 Oct;145(4):586-94. doi: 10.1007/s00442-005-0165-6. Epub 2005 Oct 13.
Knowledge about plant-plant interactions for pollinator service at the plant community level is still scarce, although such interactions may be important to seed production and hence the population dynamics of individual plant species and the species compositions of communities. An important step towards a better understanding of pollination interactions at the community level is to assess if the variation in floral traits among plant species explain the variation in flower visitation frequency among those species. We investigated the relative importance of various floral traits for the visitation frequency of all insects, and bumblebees and flies separately, to plant species by measuring the visitation frequency to all insect-pollinated species in a community during an entire flowering season. Visitation frequency was identified to be strongly positive related to the visual display area and the date of peak flowering of plant species. Categorical variables, such as flower form and symmetry, were important to the visitation frequency of flies only. We constructed floral similarity measures based on the species' floral traits and found that the floral similarity for all species' traits combined and the continuous traits separately were positively related to individual visitation frequency. On the other hand, plant species with similar categorical floral traits did not have similar visitation frequencies. In conclusion, our results show that continuous traits, such as flower size and/or density, are more important for the variation in visitation frequency among plant species than thought earlier. Furthermore, differences in visitation frequency among pollinator groups give a poor support to the expectations derived from the classical pollination syndromes.
尽管植物间相互作用对种子生产以及单个植物物种的种群动态和群落物种组成可能很重要，但在植物群落层面上关于传粉者服务的植物间相互作用的知识仍然匮乏。朝着更好地理解群落层面传粉相互作用迈出的重要一步是评估植物物种间花部性状的差异是否能解释这些物种间访花频率的差异。我们通过测量整个开花季节一个群落中所有虫媒传粉物种的访花频率，分别研究了各种花部性状对所有昆虫、单独对熊蜂和苍蝇访花频率的相对重要性。访花频率被确定与植物物种的视觉展示面积和盛花期密切正相关。分类变量，如花型和对称性，仅对苍蝇的访花频率很重要。我们基于物种的花部性状构建了花部相似性度量，发现所有物种性状组合的花部相似性以及连续性状单独的花部相似性都与个体访花频率正相关。另一方面，具有相似分类花部性状的植物物种并没有相似的访花频率。总之，我们的结果表明，诸如花大小和/或密度等连续性状对植物物种间访花频率差异的影响比之前认为的更为重要。此外，传粉者群体间访花频率的差异对源自经典传粉综合征的预期支持不足。
