COS 46-3 - CANCELLED - Landscape and habitat contributions to observed plant diversity and composition in Chicago, IL

Abstract: Urban expansion has been associated with habitat loss and fragmentation, yet cities are also becoming increasingly instrumental in supporting regional conservation goals. Remnant habitats and other green spaces can represent biodiversity hotspots in the urban matrix, while providing steppingstones supporting animal migration. Increasing green space extent and biodiversity is also pivotal to promoting environmental justice and human well-being. To best target conservation needs and meet human needs, it is important to assess how this heterogeneous network of habitats can contribute to maintaining regional biodiversity and connectivity, but this requires extensive monitoring across habitats and landscapes. To address this need, we compiled plant observations conducted in Chicago, IL through community science programs (e.g., iNaturalist, Budburst), surveys conducted by local institutions, and peer-reviewed publications. Through these three data sources, we collected >70,000 observations together identifying more than 1,400 plant species in the last five years. We then identified the habitat type (e.g., open space, vacant lot) in which each observation was conducted and generated landscape metrics (e.g., green space coverage, habitat diversity, percent impervious cover) to describe the landscape context in which those observations had been made. To estimate the overall species richness of the city from this extensive yet incomplete dataset, we used the Chao richness estimator. Then, we used a jackknife approach to assess how removing particular habitat types and landscape contexts (e.g., industrial, commercial) might impact the overall richness of the city. Our results indicate that community science complements expert-led surveys well; while experts conduct more thorough surveys and identify more conservative species, community scientists substantially increase the spatial and taxonomic scope of plant observations in Chicago. Our preliminary analyses also show that forests preserves and conservations areas are critical to sustaining local diversity, but that other non-conservation spaces including transportation corridors, city parks, and residential areas also shelter several unique species thereby increasing regional diversity. Finally, we observe that green roofs and vacant lots can substantially increase connectivity and diversity in otherwise unhospitable landscapes such as the international airport and other industrial areas. The results of this study highlight how habitat and landscape complexity in cities is critical to supporting biodiversity while meeting human needs.