Past Symposia

USI is collaborative and interdisciplinary by design. Our international symposium on urban soils is an annual gathering welcoming colleagues working and living in cities on every continent. With equal rigor and enthusiasm we might discuss reduced microbial presence in urban forest soils; the Cantonese tradition of mud silk fabrics; the impact of increased rainfall on the hydrologic behavior of sealed and compacted soils, and; witness the performance eco-activism of the Next Epoch Seed Library, stocked with seeds gathered from vacant lots, street verges, superfund sites and abandoned infrastructure to provide a gene pool of tough, highly adaptable plants well-suited to live in close quarters with humans and their attendant landscape transformations.

At each symposium scientific and artful provocations abound and new collaborative projects begin.

We do all this over delicious, well-sourced food and drink, good music, humor and unexpected urban adventures.

See you this year, we hope.

USI 2019 | Building Better Biodiversity

Our 2019 theme explored the diversity and development of soils in the urban environment. How do soils hold the capacity to build and optimize biodiversity and ecological productivity in cities across our earth’s climate zones?

How does soil life respond to our urban environmental restoration, remediation, and rehabilitation efforts?  How do living organisms in the soil keep toxic elements from concentrating and forming inhospitable layers in a soil and contributing to the circulation of nutrients in the soil, as Illinois biologist James B. Nardi writes.

For several centuries, human urban development has caused soil sealing, alteration of soil properties and fragmented landscapes. Human land development has led to a loss of connectivity between habitats linked to air and water quality, biodiversity and well-being across multiple species.

What does it mean to develop sustainable cities? What is biodiversity? Do our cities have biodiversity? Is it in our capacity to implement nature-based solutions and green cities in order to fulfill what we call sustainability? How we value nature in the city? In how we engineer nature through structural systems and individual choices?

2018 Symposium | Soils and Remediation

Our cities are built on soils. They are the axis of our urban universe. They scrub our air, filter our water, manage floods, buffer our coasts, support vegetation, food, animals, infrastructure, and us.

But what happens when we degrade our soils and the systems they support? How do they function then?

How do contaminated urban soils behave? Urban soils, like people, are diverse and complex. During the 2018 symposium, participants presented lessons learned from working in urban soils and exchanged practices for how best to support contaminated soils, reverse the damage we’ve caused, and work with soil systems for a better future.​

nationwide cleanup. in 1980, congress created a superfund to pay for the cleanup of 1,700 of the country’s 47,000 most hazardous waste sites.

2017 Symposium | Soils: Our Resource & Our Future 

November 29-30, 2017 | New York Botanical Garden.

The simple truth about soils is that they are pivotal for all of life. The beauty of soils’ simplicity lies in their complexities: how they develop; how they function and fulfill their services; how we impact them and how they respond, and; how they can be built.

Our understanding of soils grows from interacting with them and learning from them, which requires both basic and applied research.

In cities, we have a unique opportunity and responsibility to understand and conserve urban soils, as they are our key to sustainable cities. Cities have a huge impact on local and regional ecological resources and it’s important for us understand how our interactions with soils in cities impact the soils outside of our city boundaries.

NEXT EPOCH SEED LIBRARY | INTERSECTING imaginaries in the bronx

2016 Symposium | Soils of Our City: Features and Applications

anthropogenic soils

The built environment and vibrant cultural life of cities can hide the vital biological processes occurring in soils and the critical roles they play in supporting our urban lifestyles.

Even in hyper-developed cities with excavation projects exposing soil layers on every other block, soils are seldom understood as a resource and therefore poorly understood. The inaugural USI symposium convened a diverse group of soil scientists, physicists, geochemists, environmentalists, students and curious residents to showcase the soils of New York City.

Headlining the 2016 symposium were scientists from Cornell University’s Agricultural Extension Service and USI co-founders — USDA-NRCS and NYC Soil and Water Conservation District — presenting the New York City Reconnaissance Soil Survey, a pilot project for both the NRCS and the Department of Agriculture Urban Initiatives.

The New York City Reconnaissance Soil Survey provides a general guide to soil patterns across the city and serves as the foundation for our more detailed, high intensity surveys. It is an important element in the assessment of a city’s environmental quality, and a source of useful information for making broad-based land use decisions. Even in an area this densely populated, site suitability for redevelopment, restoration, and remediation is still an everyday concern. An inventory of the soil properties of New York City’s open space can help identify wetlands and wildlife habitat, and assist in the management of the 28,000 acres of parks. Understanding the soils, drainage, runoff, and stream flow in the urban environment is necessary for long-term improvements in water quality.

Soils perform essential functions in the urban ecosystem. Along with providing the growth medium for landscape plants, community gardens, and urban forests, they support our buildings, roads, and athletic fields. Soils control water flow, remove and treat non-point source pollutants from runoff, cycle and store nutrients. Maintaining soil quality is a fundamental part of the health and well being of the urban environment. Understanding the effects of anthropogenic disturbance on the natural environment is a major new scientific frontier.