Some Algona residents are up in arms about plans to restore a local nature preserve to an even older “natural” condition. The Union Slough Refuge in rural Kossuth County is about to lose thousands of old trees, and some nearby residents are outraged. The federal government is starting to cut down all the trees in the national wildlife refuge, in line with a comprehensive management plan written up five years ago to return the slough to its original habitat, of tallgrass prairie. A couple weeks ago when the trees started coming down, area residents started to worry. But slough managers say the tallgrass prairie is the most endangered ecosystem in the lower 48 states, and the birds are dependent upon it.