Abstract:

Aim: The ex situ conservation botanical garden, as a relatively homogenized artificial environment, offers an ideal model for exploring environmental adaptation mechanisms in plant–pollinator interactions. This study aims to investigate how the translocation of fig trees (Ficus auriculata Lour.) to ex situ conservation botanical gardens influences the composition of fig volatiles, the structure of fig wasp communities, and the stability of their obligate mutualistic interactions relative to natural habitats. 

Method: We analyzed volatile compounds emitted during the female flowering phase of male fig trees using dynamic headspace sampling combined with gas chromatography–mass spectrometry (GC–MS). Concurrently, we collected fig wasp communities from male flowering phase figs in male trees to compare community structure and interaction networks between natural habitats and ex situ conservation botanical garden. 

Results: (1) Volatile compositions differed significantly between the two habitats. Natural habitat figs emitted more defense–related fatty acid derivatives, while ex situ conservation botanical garden figs predominantly released terpene compounds that attract pollinating wasps. (2) Fig wasp communities also exhibited marked differences. Natural habitats had higher wasp diversity and a greater proportion of non–pollinating wasps, whereas pollinators accounted for 99.07% of individuals in ex situ conservation botanical garden, compared to 76.55% in natural habitats. (3) The fig–fig wasp interaction network in natural habitats showed higher connectivity, modularity, and robustness, suggesting greater complexity and adaptability. In contrast, ex situ conservation botanical garden network exhibited stronger specialization and nestedness, with the homogenized environment increasing the sensitivity of fig wasp communities to environmental change. 

Conclusion: This study is the first to systematically demonstrate how the fig–fig wasp interaction network adapts to artificial environments through changes in chemical signaling and community structure. The results confirm that habitat simplification can reshape obligate mutualisms by altering volatile profiles and niche partitioning. These findings enhance our understanding of the environmental adaptability of specialized mutualistic systems and offer important insights for the ex situ conservation of fig trees and biodiversity management strategies.

Key words: natural habitat, ex situ conservation, obligate mutualistic system, volatiles, fig wasp community, interaction network