The soil sampling was part of a study by graduate student Lillian Magidow from Cornell University. She's working to increase our knowledge of the distribution of the invasive swallowworts (Vincetoxicum nigrum and V. rossicum) and the characteristics of the sites the occupy.
I was not familiar with the plant until many years ago when I attended an invasive plants class at the Conway School of Landscape Design in Massachusetts. They covered the plant since it is found to be invasive in New England and north. In Canada they called it "the dog-swallowing vine" since it could grow so thickly that if your dog entered a patch you might never see him again. I was relieved that we didn't have the plant at home—until I got home and, now knowing what it looked like, found some on the preserve. We've been trying to control it ever since, trying to prevent this plant in the milkweed family from blowing its pods of seeds all over.
This meadow is an old sheep pasture that we mow once per year and have burned twice (to keep it an open savanna). We have cut out chainsaw-thick stems of autumn olive to prevent that invasive species from taking over. It is now mostly a beautiful meadow of Indian grass, goldenrod, gentians, and milkweed.
I provided Lillian with random soil cores from the meadow, a description of the site, a list of other species growing there, a map and coordinates of the site, a brief history of the land management there and photographs.
If you know of sites that have this plant Lillian is able to accept soil samples until the end of October. Please call me for more information (610-286-7955).