垂叶榕榕小蜂群落及种间互作网络季节动态

Seasonal dynamics of fig wasp community and interaction networks in Ficus benjamina

群落中的物种相互作用构成了复杂的生态网络。有关物种的数量和组成的季节性动态变化已有较多的研究,但是对于生态网络的动态变化知之甚少。揭示生态网络的动态变化对于理解群落的稳定性以及群落的动态变化过程和机理具有重要意义。本研究以垂叶榕(Ficus benjamina)榕小蜂群落为研究对象,分别在西双版纳的干季和雨季采集了榕小蜂的种类和数量信息。比较了两个季节榕小蜂群落的动态变化以及共存网络的参数(例如网路直径、连接数、嵌套性和群落矩阵温度)变化。结果显示:雨季榕果内传粉榕小蜂Eupristinakoningsbergeri所占比例高于干季,传粉榕小蜂的种群数量也高于干季,而在干季非传粉榕小蜂的种类增加(干季15种小蜂,雨季14种)。从榕树–传粉榕小蜂互利共生系统的适合度来看,干季非传粉小蜂的增加对传粉榕小蜂和榕树的适合度是不利的。在干季,共存网络物种间的连接数(干季0.95,雨季0.47)多于雨季,群落矩阵温度(干季23.24,雨季2.64)也显著高于雨季。表明干季榕小蜂群落组成及种间关系较雨季更为复杂而多样,高的矩阵温度暗示群落受到的干扰更大。

Species form complex interactive networks within communities,which often experience seasonal species oscillations or species composition shifts.However,the variation that occurs within such networks is poorly understood.Studying seasonal changes of ecological networks may reveal the mechanisms that maintain the stability of a community.In this study,we collected fig wasps from Ficus benjamina during the dry and rainy seasons in Xishuangbanna to understand how fig wasp communities may shift seasonally.We compared fig wasp abundance,species composition,and metrics of coexistence networks(e.g.network diameter,connectance,nestedness,and community temperature)between the rainy season and the dry season.The pollinating wasp,Eupristina koningsbergeri was the most abundant species in both rainy season and dry season.There were more non-pollinating fig wasp species during the dry season(15 fig wasp species)than the rainy season(14 fig wasp species).A higher number of non-pollinating fig wasps can be detrimental to fig-pollinator wasp mutualisms because they reduce both fig seed production and pollinator abundance.Additionally,the dry season experiences higher species connectivity(0.95 in dry season,0.47 in rainy season),higher network temperature(23.24 in dry season,2.64 in rainy season)than the rainy season,which indicate more complex inter-specific interactions,and a higher level of disturbance of fig wasp community in the dry season.