Human disturbance reduces the network connectivity in female fig wasps more than in males

Abstract

In ecological communities, the relationships between interacting species are very complex, resulting in nonlinear or even chaotic oscillations. Human activities, such as habitat destruction and fragmentation, overexploitation of natural resources, and noise and light pollution, have been shown to influence species interactions. However, the pattern of impact of these activities on fig wasps remains unclear. In this study, we analyzed the network relationships associated with fig wasps at six different sites, including both human-disturbed habitats and primary rainforests in Xishuangbanna, tropical China. Our analysis revealed that the pollinator Ceratosolen fusciceps had complex non-linear relationships with five species of non-pollinator wasps in the primary rainforests. The connectivity and complexity of species networks were reduced in human-disturbed habitats, particularly regarding the number and strength of associations of the key pollinator, Ceratosolen fusciceps, with other non-pollinator wasps. Additionally, we separately analyzed the association networks of male and female fig wasps and found that human disturbance had a greater impact on female wasps, as evidenced by a more pronounced decrease in edges in the female network compared to the male network. The positive correlation between females and males was weakened in different populations under the influence of human interference, while it was strengthened in different sexes of the same species. Overall, human disturbances altered fig wasp numerical relationships, reducing connectivity and complexity in species networks. This impacted fig-fig wasp mutualism, especially involving Ceratosolen fusciceps and non-pollinator wasps. These findings may contribute to our understanding of the coevolution between fig-fig wasp mutualism.

Keywords

• Species interaction
• Sex structure
• Fig wasp
• Tropical rainforest
• Network analysis
• Anthropogenic disturbance