Urban Lake Biogeochemistry

Lakes within urban landscapes are often important ecosystems for a significant number of people. Not only are they important within the context that GLEON is traditionally focused on (sites of significant carbon and nutrient processing), but also from a recreational standpoint and even offering provisioning services, especially for those in underserved communities. The role of urban lakes in the human experience is multiplied due to the fact that these ecosystems exist within dense human development, and so are accessed by a significant number of people compared to many pristine or rural lakes. Despite their potential disproportionate importance, we still know very little about how these ecosystems function. As such, there exists an excellent opportunity for GLEON to leverage its large network of lakes and scientists to begin to better understand urban lakes more comprehensively. As many urban lakes are impacted systems facing eutrophication issues, we are interested broadly in biogeochemical cycling of N and P. The sources of high nutrient loads to urban lakes can be numerous, and so quantifying the magnitude of loads is an important first step in identifying ways to improve water quality. For the first project as a part of this group, we are interested in the variability in internal loading rates from urban ecosystems across the globe.  In order to best assess the variability in internal loading across different lake size, land use, and geographic contexts, we are coordinating a field sampling campaign to collect internal N and/or P rates in as many urban lakes as possible (defined as more than a quarter of the catchment area as urban land use). Our objective is to collect sediment cores from urban lakes around the globe. We will coordinate field sampling efforts as well as core incubations in the lab, and provide technical support when necessary. Water samples taken for chemical analyses will be sent to nearest coordinating lab responsible for analysis of N and P. This effort will lead to an assessment of internal N and P loading rates, while investigating for relationships with lake morphometry or lake and catchment physical characteristics. There also may be some opportunity to explore experimentation with variable land use, climate, or management scenarios. The ultimate goal of this project is a manuscript exploring these patterns across space and/or scenarios.