| Urbanization can have important and sometimes irreversible effects on the natural world. Over 50% of the human population now lives in cities and understanding the impacts to the ecosystems on which cities are built is important for the sustainability of future cities. Many ecological studies focus on larger cities; however, of the people who live in cities, half live in medium-sized cities characterized by lower urbanization and closer interactions with nature. In this dissertation I studied the effects of urbanization on headwater stream ecosystems in Greater Binghamton, a medium-sized city in upstate New York. Headwater streams are highly sensitive to anthropogenic disturbances and urbanization can affect stream insect communities and ecological functions. Between 2014 and 2017 I studied the aquatic insect biodiversity, functional group abundance and biomass, riparian cover, allochthonous and autochthonous energy pools, and leaf litter breakdown in paired downstream urban and upstream rural reach sites in headwater streams. I found that, like in streams in larger cities, aquatic insect taxonomic richness was lower in the urban than in the rural sites. This also impacted insect functional feeding group richness and abundance and potentially leaf litter breakdown. However, I also found that among-site insect beta-diversity was more heterogeneous among urban sites than among rural sites and that riparian cover and allochthonous and autochthonous energy pools were not different between urban and rural sites. These findings demonstrate more biodiversity than what has been reported previously in larger cities, and show that medium-sized cities can retain some biodiversity and natural stream features, likely due to heterogeneity of urban land use intensity. |
