Response of ants to human-altered habitats with reference to seed dispersal of Corydalis giraldii Fedde (Papaveraceae)

10 April 2018

Zhu, Yan; Wang, Dong

Anthropogenic habitat disturbance has potential consequences for ant communities. However, there is limited information on the effects of ant responses on associated ecological processes such as seed dispersal. We investigated the effect of disturbance on the abundance, richness, and composition of ant communities and the resulting seed-dispersal services for a herbaceous myrmecochore, Corydalis giraldii (Papaveraceae), in an undisturbed habitat (forest understory), moderately disturbed habitat (abandoned farm field), and highly disturbed habitat (road verge) on Qinling Mountains, China. In total, we recorded 13 ant species, and five out of these were observed to transport seeds. The community composition of dispersers was significantly different amongst habitats. The richness of the dispersers did not differ among the habitats, but their total abundance significantly varied across habitats and was recorded to decrease in the road verge by 21%, in comparison to abandoned farm fields. The major seed-dispersing ant species in both the forest understory and abandoned farm field were large-bodied (Myrmica sp. and Formica fusca, respectively), whereas the major seed-dispersing ants found in the road verge were small-bodied (Lasius alienus). This difference resulted in lower seed removal rates and dispersal distances in the road verge than in the other two habitats. The different dispersal patterns were attributed primarily to differences in dispersing ant abundance and identity, most likely in response to habitats with different degree of anthropogenic disturbance. The possible influence of disturbance on the ecological specialization of ant-seed dispersal interaction was also discussed.