传粉网络的研究进展:网络的结构和动态

植物与传粉者之间相互作用,构成了复杂的传粉网络。近年来,社会网络分析技术的发展使得复杂生态网络的研究成为可能。从群落水平上研究植物与传粉者之间的互惠关系,为理解群落的结构和动态以及花部特征的演化提供了全新的视角。传粉网络的嵌套结构说明自然界的传粉服务存在冗余,而且是相对泛化的物种主导了传粉。在多年或者多季度的传粉网络中,虽然有很高的物种替换率,但是其网络结构仍然保持相对稳定,说明传粉网络对干扰有很强的抗性。尽管有关网络结构和动态的研究逐渐增多,但传粉网络维持的机制仍不清楚。网络结构可以部分由花部特征与传粉者的匹配来解释,也受到系统发生的制约,影响因素还包括群落构建的时间和物种多样性,以及物种在群落中的位置。开展大尺度群落动态的研究,为探索不同时间尺度、不同物种多样性水平上的传粉网络的生态学意义提供了条件。但已有的研究仍存在不足,比如基于访问观察的网络无法准确衡量传粉者的访问效率和植物间的花粉流动,以及结果受到调查精度区域研究不平衡的制约等。目前的研究只深入到传粉者携带花粉构成成分的水平,传粉者访问植物的网络不能代表植物的整个传粉过程。因此,研究应当更多地深入到物种之间关系对有性生殖的切实影响上。

Progress in pollination networks: network structure and dynamics

The interactions between plants and pollinators represent complex pollination networks.Recent improvements in social network analysis provide suitable tools for plant-pollinator interactions within an ecological context.Studies devoted to mutualism in the pollination network at community level have shed important insights into the structure and dynamic of these interactions and also floral evolution.The nested structure of pollination networks suggests that pollination service is redundant,and that relatively generalized species dominate these networks.Although these networks have high species composition turnover,they remain stable in terms of structure and species position,suggesting high interference resistant of pollination networks among seasons or years.Relatively little is known about the mechanisms behind these patterns.It has been suggested that network structure is largely controlled by morphology match between flowers,pollinator traits,and phylogenetic relationships.Meanwhile,community history and biodiversity have been used to link structure and species position of network.Ecologists and evolutionary biologists have become increasingly interested in these networks and recent studies of large-scale dynamics to facilitate the detection of mechanisms between different spatial and biodiverse scales in natural communities.However,there are many challenges of testing these networks.For example,previous visit-centered approaches provide insufficient information about pollen transfer among species,which is essential for plant reproductive success.Also,sample efforts have not been standardized and few studies have focused on zones of high biodiversity.Although debates will continue on the mechanisms behind these patterns,we suggest that factors relating to re-productive success should be considered in future studies,such as the impacts of pollen composition on pollinator condition or pollination efficiency.