World-building ecology: Unraveling relationships between land-water bird species interactions, functional diversity, and ecological landscapes across scales in natural and anthropogenic systems.

Candidate: Adisa Julien
Supervisor: Dr. Stephanie Melles

Across the landscape, terrestrial and aquatic systems are deeply interconnected, each shaping the structure, function, and biodiversity of the other. Freshwater networks influence ecological patterns across land, while land use and cover reshape hydrological flows and connectivity. These interdependencies are increasingly transformed by urban expansion and rapid environmental change. In response to these complex dynamics, my research develops ecological models through a process I term world-building. This approach emphasizes describing what is occurring across the landscape by integrating species distribution, functional trait data, hydrological networks, and remotely sensed land cover. The dissertation begins by examining how watershed location affects species accumulation rates. Through analysis of spatial patterns, hydrological connections, and ecological relationships, the study reveals how positioning along freshwater systems influences terrestrial biodiversity and identifies significant variation in the rate of species accumulation across watershed positions, shaped by differences in land cover types and ecoregions.
Moving beyond species presence, the second chapter uses a multi-scale approach to train random forest models to predict avian preferences for land cover based on functional traits. By incorporating traits such as primary lifestyle, range size, and morphology the models distinguish between natural and human-modified environments with high accuracy and minimal sensitivity to scale. Zooming into heavily urbanized areas, the third chapter explores the concept of city traits using publicly available data from the City of Toronto. This includes building height, vertical vegetation structure, and 2D land cover metrics to explore how urban form influences avian diversity and functional dynamics. The analysis centers birds within their habitat choices and potential interactions, offering a holistic view of biodiversity in human-dominated landscapes. In conclusion, this research integrates terrestrial, freshwater, and urban ecological insights into a unified framework. Through comprehensive, multi-scale analysis, it offers practical tools for conservation, urban planning, and biodiversity management. This exercise in world-building lays the groundwork for accessible, place-based ecological modeling in an increasingly complex and dynamic world.