神农架地区典型草本群落中的昆虫访花行为比较

对神农架地区不同海拔高度(1,000–2,600 m)的典型草本群落中的昆虫访花行为进行了初步的监测和统计。在9个样地中共观察到鳞翅目、膜翅目、双翅目11科昆虫访花, 访花者的类群在不同海拔高度的群落中有所不同, 但明显与植物群落的物种组成有关。对昆虫访花频率的监测发现, 不同物种组成的草本群落中, 所有昆虫访花的总频率和不同类群的昆虫访花频率都有差异, 正在开花的物种较多的群落中通常能吸引相对较多的访花者。同一种植物在不同的群落背景中受访频率差异显著, 如花被不甚显著的酸模(Rumex acetosa)在某些群落中未观察到访花者, 在另一些群落中却有昆虫频繁访问。而花被显著的血见愁老鹳草(Geranium henryi)在各群落中都有频繁的昆虫访问。一些植物(如广布野豌豆Vicia cracca)虽然在不同群落中都有昆虫访问, 但访花者类群却有较大差异。作者认为, 在植物群落中, 不同植物的花在吸引昆虫传粉方面存在着一定的相互作用, 在研究特定植物的虫媒传粉时应重视该植物种群所处的群落背景所起的作用。

Insect visitors and their behaviors in the typical herbaceous plant communities of the Shennongjia Mountains

Insect visitation was preliminarily monitored in some typical herbaceous plant communities at different altitudes (1,000–2,600 m) in the Shennongjia Mountains, Hubei Province, China. In the nine quadrats studied, insects in eleven families of Hymenoptera, Lepidoptera and Diptera were observed to be floral visitors. The taxa of insect visitors were visibly associated with the community composition. Observing the behavior of floral visitors, we found that the total visitation frequency and the frequency of visits of each kind of insect both differed in communities with different plant species, and that more insect species ap-peared in communities with more plant species in bloom. Visitation frequencies to some plant species were significantly different when they occurred in different communities. For example, no insects were observed to visit Rumex acetosa flowers, with an indistinctive perianth, in some communities, but high visitation fre-quencies were observed in others. Geranium henryi, featuring an obvious perianth, was visited by insects in every community. On the other hand, some plants, such as Vicia cracca, were always visited by insects, but the taxa of visitors were different in each community. Our results suggest that different plants contributed to various roles in attracting pollinators within communities, and one should consider the community back-ground of the plant populations in studies of plant–pollinator interactions.