Seasonal dynamics and functional diversity of frugivorous bird-plant interaction network in the karst habitat.

Introduction: The karst region of southwest China is characterized by fragmented habitats with high plant diversity but low resource availability, and its strong topographic and edaphic heterogeneity drives spatial variation in resource distribution, ultimately structuring frugivorous bird-plant interaction networks. Methods: We established six 2-3 km transects in a nature reserve in southern China. We conducted year-round observations of interactions between plants and frugivorous birds, subsequently using metrics to examine network structure and the functional trait of plants and birds shaping their network roles. Results: We recorded 196 unique links and 3,327 interactions events involving 19 frugivorous bird and 23 fruiting plant species. Compared with the null-model network (N=1000), the observed network exhibited lower connectance (C Discussion: These findings highlight the seasonal variation in frugivorous bird-plant networks in the karst habitats and species traits affecting network functional roles, providing new insights into the mechanisms sustaining interaction networks in heterogeneous, resource-limited ecosystems.