Millions of native orchids have been found growing on a former mining site in New York’s Adirondacks mountain region, strengthening the restoration value of land thought to be blighted.
State University of New York (SUNY) College of Environmental Science and Forestry (ESF) graduate Grete Bader finished her master’s thesis on the site and said the flowers are growing on iron mine “tailings” (waste).
She said that apart from the six types of native orchids found at the site, it also contains New York state’s largest population of the threatened pink shinleaf (or pink wintergreen) species.
“The fact that this site restored itself from bare mine tailings to a diverse wetland plant community over the past 60 years is incredible, and the populations of orchids and pink shinleaf notably enhance its conservation value,” she said.
The wetland, at approximately 40 hectares in the north western Adirondacks, developed where the previous Benson Mine held iron ore extraction remains. The mining operation was most active from 1941 until its closure in 1978. At its peak, it was the world’s largest open pit magnetite mine, generating around one million metric tonnes of iron per annum.
Dr. Donald Leopold, Bader’s major professor, said that the large number of orchids at the site was “extraordinary” and has never seen something like this in his 40 years of research.
“Until Grete did her research I had thought that there were hundreds of thousands individuals of these orchid species here but Grete’s more careful assessment suggests that there are actually a million or more of some species,” he said.
Bader’s research suggests that the growth of unique plant species is contributed by a variety of factors including water and soil pH, and the range of mycorrhizal fungi. These fungi have a symbiotic relationship with plants; attaching to the plants roots to increase its ability to absorb nutrients and water and in turn, benefit from the effects of photosynthesis.
Orchids and pink shinleaf are some of the species that rely on the fungi for germination.
Associate professor at ESF and expert on mycorrhizal, Dr. Thomas Horton said the industrial site’s past might also have contributed to the number of flowers.
“All the orchids and the wintergreen are dependent on mycorrhizal fungi for seed germination. Without the fungi, there would be no plants. Yet after deposit of the mine tailings, the belowground system had to develop from scratch and now we see that all elements have returned have returned for incredible floral displays,” he said.