Wednesday, August 06, 2008

Grasslands


The Francis Beidler Forest encompasses over 16,000 acres of Four Holes Swamp. Much of this protected land is beyond the old-growth forest and boardwalk at the Francis Beidler Forest Audubon Center.

As noted in a previous blog entry, we are restoring to grassland a loblolly plantation site that was logged prior to its aquisition by Audubon South Carolina. The grassland plots are located at the Spring Branch tract near the intersection of I-26 and U.S. Hwy 15 (N33 deg 17' 36.24" and W80 deg 30' 15.73" for Google Earth). In preparation for planting, the three 2-acre plots needed to be flagged for the heavy-equipment operator contracted to clear the logging debris still on the site. The images show that many of the sweet gum trees suffered only minor damage from the aerial herbicide application. Funding, paperwork, work schedules, and the weather conspired in the previous weeks to leave us little option but to sally forth today into the sunny, humid, 100+F "frying pan." What we lacked in shade, we made up in water supplies. We learned that our shirts and jeans can hold over one gallon of water, since we drank that quantity and sweat was the only route of exit from our bodies. Only the bramble thickets along our path and the raisin-size ticks made the day more enjoyable than we could have expected.

Before going out to the field and while in the cool, air-conditioned office, we drew our 2-acre plots on our computer using the ESRI ArcMap Geographic Information Systems (GIS) software. Initially, the polygons that we drew were slightly larger than two acres, so we downsized them on the computer. Using a Trimble Juno unit borrowed from the Geography Department at the University of South Carolina, we downloaded our polygons and the aerial image of the site (see map image from before logging). Once at the site, the Global Positioning System (GPS) capabilities of the Juno unit allowed us to see, on the Juno's display screen, our position as well as the aerial photograph and the grassland polygons. One person holding the Juno walked along the edge of the polygon while the others followed and flagged the line.

GIS/GPS technology certainly made the job of flagging the grassland plots more efficient. A GPS unit alone would not have allowed the navigator to remain on the polygon's boundary and using a compass alone would have been tedious due to the short sighting distances in the thick vegetation. Once restored, the birds won't need any of that fancy navigational technology to find their way to the desirable grassland habitat.

Images by Mark Musselman

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