EAGER: Microbial Populations as Biosignatures for Evaluating Long Term Effects of Urbanization

Montana State University, Bozeman MT

Investigators

Abstract

This unique, high-risk, multidisciplinary study will bridge microbial ecology, environmental genomics, archaeology and urban ecology. The investigators posit that studies of soil microbial communities will reveal new insights into the activities of past civilizations, particularly at sites that have undergone repeated urbanization. Samples will be collected from soil profiles at an archaeological site in Turkey (Tel Ta'yinat) and Israel (Tel Gezer). DNA sequences will be recovered from soils and used to profile the microbial communities, and correlate them with other geological measurements. A model will be formulated using the multiple lines of evidence generated from this experimental regime, and informed by previous excavations and interpretations of the cultural history of the two sites. The research involves international collaborative work with colleagues in Australia and Canada, and at sample sites in Turkey and Israel. The project will also involve hands-on, process-oriented, guided inquiry learning field trips for undergraduate and high school students to archaeological sites in Montana and Wyoming. The project will broaden participation in science by supporting the involvement of an a faculty member at a Hispanic American-serving institution. Soil microorganisms provide a potentially tractable system to investigate repeated urbanization events. These communities, or "microbiomes" could provide new insight into the processes that shape and modify urban landscapes across time scales. This team hypothesizes that natural and anthropogenic processes localized at tells (archaeological mounds created by human occupation and abandonment) have produced measurable signatures from microbiomes, and that these microbiosignatures can be correlated to human impacts as reflected in urbanization and land use dynamics. Two Middle Eastern tells representing a gradient of duration of abandonment (4000 to 40 years) will be studied with two objectives in mind: i) characterization of each tell using compound-specific isotopic, biogeochemical, stoichiometric, and archaeological approaches in combination with novel biosignature/-omics approaches providing a description of the legacy of human occupation and use and ii) parameterization of a process-based model capable of defining the complex evolution of microbiosignatures to help predict human disturbance effects. The novel approach of this project addresses these questions: i) What secondary metabolite inventory is resident in tell soils that is not found in non-urbanized soils? ii) How does this inventory reflect the complex urbanization history of tells? iii) How can Hardin's Law of Human Ecology help frame the mass and energy balance dimensions of urban tells? Hardin's law states that total human impact on the ecosphere (here, each tell) is the product of the population and per capita impacts. The outcome will be the ability to define human carrying capacity (in terms of the occupation of each tell) which include the ecological footprint and boundary extent of each tell to that area of land provisioning ecological goods and services. The cross disciplinary team includes biologists, archaeologists, microbial ecologists, and a soil scientist and relies upon the integration of expertise across a broad range of disciplines to frame the question of urbanization impact in a novel historical, biological, and environmental context. The resulting product will be a microbiome-based protocol for understanding historical human impact in urbanization settings. This will transform our capabilities of predicting current and future environmental consequences of urbanization. The team will naturally impact a broad range of research communities as well as K-12 education through a summer workshop utilizing process-oriented guided inquiry learning (POGIL) techniques and archaeological sites in the Greater Yellowstone Area.