传粉网络非对称特化的地理模式

植物与传粉者间相互作用,构成了复杂的传粉网络。非对称特化是共生互作网络中的有趣现象和基本特点,也被认为是植物-传粉者互作网络的结构特征之一。根据文献总结分析了植物-传粉者互作网络非对称特化的重要名词术语,并采用线性回归法深入分析了植物-传粉者互作网络的地理变异模式,以及植物生活型和网络大小等传粉网络特征对非对称程度的影响。结果表明:传粉网络大小与网络的交互作用间呈线性正相关关系,并随总物种丰度呈指数增长。25个传粉网络的线性回归斜率(Lβ)变异范围在0.002至0.031间,且斜率值随植物丰度(P)、传粉者丰度(A)、总物种丰度(R)、交互作用(I)及网络大小(M)上升而降低。海拔高度对传粉网络非对称性有一定影响效果,而纬度的变化并不显著影响传粉网络非对称性。草本植物、灌木及乔木植物与其传粉者之间的相关系数分别为-0.197,-0.026和0.200,表明草本物种比乔木物种非对称性更强。

Geographic pattern of asymmetric specialization in plant-pollinator interaction network

Pollination network results from the interactions between plants and their pollinators. Asymmetric specialization characterizes symbiotic interaction, and it is regarded among the structural characters of the network. To date, important progress has been made in recognizing asymmetry of the networks, but there was hardly any progress about the geographic variation and asymmetric specialization of the network as well as about the effects of plant life-form on the asymmetric specialization. Here, we summarized a number of concepts used for asymmetric specialization according to available literature and analyzed the geographic variation pattern of the networks as well as the relation of asymmetric specialization of the network to plant life-form and network size using linear regression based on data collected from published papers. We found that the network size is positively linearly correlated with network interaction and that it expressed an exponential increase with total richness of plant species. For all 25 networks investigated, the slope of linear regression (L_b) of the network ranged from 0.002 to 0.031 and it was negatively significantly correlated with plant richness (P), pollinator richness (A), species richness (R), interactions (I), and network size (M). L_b slightly decreased with altitude (P=0.053 for the partial effect of altitude), whereas no effect of latitude (P=0.618) was observed. The correlation coefficients between pollinators and herbs, trees, and shrubs were -0.197, -0.026, and 0.200, respectively, indicating that asymmetric degree was higher in herbs than in trees. This paper provides a novel method to investigate the asymmetry of plant-pollinator interaction network as well as an insight into the relationship between asymmetric degree and network size, latitude, and plant life-form.