Dynamics of Ecosystem Services from Linked Urban Forests and Streams: Towards Next-Generation Landscape Indicators

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A full accounting of the ways forests produce ecosystem services in urban areas requires understanding their links to aquatic systems. Fragmentation of urban forests, alongside expanding impervious surfaces, impacts streams and aquatic habitats in numerous ways, with long-lasting impacts. To address this challenge, my Discovery Grant research program will develop new ways to synthetically monitor both terrestrial and aquatic systems in urban settings. The proposed research synthesizes nearly two decades of approaches I helped pioneer using landscape indicators to assess aquatic systems. Here, I expand to urban-rural gradients and leverage new open source data working with a tightly-integrated team. Working together, HQP contribute to tackling - and in some cases span across - multiple transdisciplinary objectives. OBJECTIVE 1: Create "next generation" landscape indicators of ecosystem services in urban systems that incorporate: (a) long-term change and (b) temporal lags. To achieve this, we use collaboratively developed geospatial information to assess historical dynamics in urban forests and streams. First, we use long-term satellite imagery spanning three decades to map the ebb and flow of greenspace. Then, we use these same greenspace maps to evaluate empirical relationships between landscape indicators and long-term trends in water chemistry of urban and rural streams in Vancouver. OBJECTIVE 2: Integrate spatial heterogeneity into landscape indicators. The inherent spatial heterogeneity of urban ecosystems makes them challenging to map. Thus, we evaluate and compare satellite imagery at multiple scales with ground verification information (derived from aerial photography and field work) to assess the spatially variable features of urban forests and wetlands. Our aim is to capture the range of heterogeneity across the entire spectrum of "green-infrastructure" from green-to-blue-to-grey infrastructure, which includes forests, riparian zones, wetlands, and engineered wetlands. We use our strengthened representation of spatial heterogeneity in urban ecosystems to better evaluate urban greenspace and build "next-generation" landscape indicators of urban stream status. OBJECTIVE 3: Extrapolate and evaluate indicators across continents. Upon ascertaining the role of spatial heterogeneity in Vancouver, we adapt our methods for extrapolation and expansion. To achieve this, we develop novel ways to track land use with social media, adapt our remote sensing analysis methods to rapidly urbanizing locations in India and China, and then test our key findings along urban-rural gradients in tropical landscapes. In training inter-disciplinary scientists, my research program will provide science with better ways to track and understand landscape change and improve the evidence base regarding the role of forests and wetlands in rapidly urbanizing landscapes.