Open Collections

Sandoval Acuna, Pablo

University of British Columbia

Ecological communities can be shaped by urbanization – the movement of people from rural to urban areas – and the accompanying creation of dense, human-built environments and city neighbourhoods with distinct socioeconomic characteristics. Water-filled treeholes and ground containers are excellent systems for studying ecological communities in small environments. We installed artificial treeholes and ground containers in 125 locations across the Lower Mainland of British Columbia, Canada. After three months, we analyzed the direct and indirect effects of urban land use (e.g. proportion of imperviousness surface, building density) and socioeconomic factors (e.g. neighbourhood-wide income level, age of residents) on the aquatic invertebrates that colonize these microcosms. We hypothesized that aquatic communities of invertebrates in containers are determined by the pool of potential adult colonists and aquatic larval survival. We predicted that: (1) urban land use and neighbourhood socioeconomics would determine which species are available to colonize the new ecosystems; (2) the local environment within and around these ecosystems would indirectly mediate the effects of urban land use and socioeconomics on larval survival; and (3) these effects would differ between the two microcosms. Piecewise structural equation models revealed that urban land use variables strongly affected the invertebrate community, largely mediated by local factors such as water chemistry, water quantity, temperature, and microorganism density and activity. Urban land use metrics were also associated with socioeconomic factors, which particularly affected invertebrate richness in ground containers. We found differences in species composition between the microcosm types, with treeholes having more diverse communities that also included taxa typical of forested habitats. Disentangling these effects reveals how cities affect ecological communities and can help us better understand how we can positively impact biodiversity.

Text

2024-05-16

Attribution-NonCommercial-ShareAlike 4.0 International

http://hdl.handle.net/2429/88327

Zoology

University of British Columbia

UBCV

http://creativecommons.org/licenses/by-nc-sa/4.0/