East Tennessee State University Johnson City, Tennessee, United States
Abstract: Urbanization is one of the most drastic forms of anthropogenic habitat alteration and is associated with a decrease in both plant and animal diversity. Changes in biodiversity can affect the interactions between the remaining species within an ecosystem, which can lead to changes in the provision of essential ecosystem services such as seed dispersal and pollination. Despite the wealth of studies examining the effects of urbanization on biodiversity, however, relatively few studies have investigated the effects of urbanization on species interactions and the ecosystem services provided by them. Seed dispersal provides an ideal study system for investigating these effects. The goal of this study was to assess the impact of urbanization on plant-frugivore interaction networks in southern Appalachia – specifically the impact on species richness, interaction richness, and several network metrics related to ecosystem function (H2, interaction evenness, and weighted nestedness).
The study was conducted across two fall – winter observation periods to coincide with the period of peak fruit production, from September – January in 2021-2022 and 2022-2023. Data was collected from 9 study sites during multiple visits via direct observation of bird-fruit interactions, with a total of 635 interactions recorded. Although more data analysis remains to be done before conclusions can be drawn, initial results indicate that there is no significant difference in species richness or interaction richness between natural and urban sites. This has interesting implications, as it suggests that plant-frugivore networks are relatively robust to disturbance caused by urbanization, which is promising for the continued provision of ecosystem services in disturbed and urbanized areas.
