Reintroducing native and rare species into former industrial waste sites in Syracuse, USA
Alkaline refuse from industrial processes can result in lime waste sites that lay unvegetated for decades. However, with careful analysis and plant selection, these sites can also support native rare species.
The Solvay Setting Basins in Syracuse, New York, is a 600-acre site historically used for the dewatering of soda ash process tailings. The sterile, alkaline waste at the site has inhibited vegetation from growing for more than 30 years, since deposition ceased.
Two goals in one
The project aimed to minimize leachate through site-wide evapotranspiration using willow plants, while the unique environmental conditions at the site enabled the restoration of rare native plant communities that would provide habitat and natural heritage.
Choosing native plant species
The Ramboll team worked with Donald J. Leopold from the State University of New York College of Environmental Science and Forestry on the study. For the restoration they selected native plant species from New York’s natural communities found on infertile, stressful and calcareous soils such as alvar grassland and fen, as well as stress-tolerant species from freshwater and inland salt marshes.
Introducing 55,000 plants
Approximately 55,000 plants were installed over a two-year period and 7.98 metric tons of pelletized 5-10-5 fertilizer was applied, and invasive species were managed.
Vast improvements in just five years
In the five years since the project began, 271 vascular plant species have been observed on site, which is as good or better than natural areas in the region, 10 of these are classified as threatened or endangered in New York, an astounding figure for a post-industrial site.
Total cover, absolute and relative cover of planted species and species richness per m2 have all been tracked improving over time. Relative cover of Phragmites australis is on a negative trajectory while that of Lythrum salicaria remains stable over time.
The project has supported significant botanical diversity and valuable evapotranspiration has been established, which has contributed to the leachate minimization goal of the site.
Making the most of post-industrial sites
This project demonstrates that Solvay waste provides the stresses enabling the restoration and persistence of rare plant communities, and creation of significant conservation value on a post-industrial site.
More generally, this study underscores that strategically using native plant species and communities in the remediation and restoration of post-industrial sites is highly cost effective and beneficial to regional conservation.