Standing in the dormant prairie grass on the golf course in Eisenhower Park, naturalist Carole Neidich-Ryder pondered how it must have looked four centuries ago when the first European settlers arrived.
"When the grasses come up in the spring, they're like a bluish-green, so when the first settlers got here they thought they were at the ocean, because it was about the height of a cow and it was waving," she said.
Centuries of grazing and mowing and human activity have taken their toll, and the grasses grow shorter in the present day, Neidich-Ryder said. But with the help of a computerized mapping technique she developed with a colleague, she hopes the grasses can be preserved -- and perhaps spread -- in the area of central Nassau County known as the Hempstead Plains.
The extent of the original plains area in Nassau has been put at 60,000 acres by some U.S. Geological Survey references and published reports. Neidich-Ryder said her research pegs the area to about 33,400 acres, stretching from western Nassau eastward to just past the Suffolk border, and between what now are Hempstead and Jericho turnpikes.
No longer in plain sight
The original plains has been lost to development or encroachment of invasive species, but "remnants" remain, she said, including 21 acres of rough on the Red Course at Eisenhower, 19 acres on the grounds of Nassau Community College, 15 acres in a county recharge basin on Salisbury Road, and 19 acres near the Nassau Coliseum that is known as the Hempstead Plains Preserve and the Francis T. Purcell Preserve.
"That is why it is considered a globally endangered habitat," she said. "So finding other remnants or areas that have prairie plants that can be utilized as seed banks for restoration projects is important."
"You can get seed from the prairie grass in the Midwest, but it's not our prairie grass," she said emphatically as she steered a golf cart along the course.
The prairie-grass mapping research grew, in part, from circumstance.
Neidich-Ryder, 63, of Garden City, retired from her job with the Nassau County park system in 2007 and began working for a private consulting firm, Bowne AE & T Group. That same year, 2007, she signed up for class at LIU Post on geographic information systems, then took an advanced GEIS class in 2008.
She and her instructor at the Brookville campus, Patrick Kennelly, 52, of Port Washington, found they had a common interest in earth sciences, and they teamed up. Both now are instructors with LIU's Department of Earth & Environmental Sciences.
They got maps from the New York State Geographic Information System, shelled out $100 for a software program and began the work of separating the colors in map images -- a process similar to filtering light through a prism.
Each computer pixel has three bands of color, and each color has up to 256 shades, for a potential of 16.7 million colors in all. She and Kennelly categorized each pixel by its color characteristics, and 1,000 pixels then were matched to what she observed on the ground. The computer program correctly identified 89 percent of the ground objects.
"There was very little prairie grass," she said. Of the 328 pixels identified as prairie grass, she confirmed that 307 of them really were by eyeballing them on the ground -- a positive identification rate of 82 percent.
The mapping project is important because Hempstead Plains is the only true prairie east of the Appalachian Mountains, she said. Later, she qualified that -- somewhat. The soil is the same as that under Midwest prairies, but it has a separate geological classification as "Hempstead loam."
There are plenty of grasses similar to the ones in Hempstead Plains, and they're often found in areas laid bare by forest fires, such as Harriman State Park upstate, she said. Prairies also are dotted with wildflowers, but the violets that grow in the Midwest are different from the ones in the Hempstead Plains.
While her own interests have been largely local, she said the mapping system is "a tool in the box" that land managers anywhere can use.
"It has the potential to locate specific vegetation and by using [aerial] photographs taken over different years or different seasons, it may be used to track progress in land restoration projects and changes in ecosystems," she said.