The Tensas River basin covers approximately 718,000 acres of the Mississippi River's alluvial plain in northeastern Louisiana and was once about 90 percent forested. Today, more than 70 percent of it, much of which has been cleared and drained, is in agriculture. The basin still contains some 65,000 acres of forested bottomlands, most of which are protected within the federal Tensas River National Wildlife Refuge and the state Big Lake Wildlife Management Area.
About 1.5 million acres that includes the Tensas basin and additional habitat identified as critical to the recovery of the Louisiana black bear, a subspecies of the American black bear listed as threatened by the U.S. Fish and Wildlife Service, has been designated as a priority conservation site by The Nature Conservancy. Also located within the site are nine priority bird conservation areas.
Despite extensive alterations, the Tensas basin retains significant biodiversity, sheltering the largest known population of the Louisiana black bear among its more than 400 mammal, bird, reptile, amphibian and fish species. Aquatic species richness within the Tensas Basin is among the highest in the state and includes three globally rare freshwater mussels: fat pocketbook, pyramid pigtoe and ebony shell.
Land use changes within the Conservancy's designated Tensas basin site have resulted in considerable losses and fragmentation of wild habitat, while stream alterations have brought about declines in the populations of many aquatic species. Specifically, altered streams have contributed to lower water quality, including increased sedimentation. Past forestry practices have altered tree ages and species composition within the area's forests.
Between the early 1970s and early 1990s, 12 percent of the forests remaining in the Tensas basin disappeared, and the rapid change sparked a concentrated effort to restore the basin. Along with numerous local, state and federal partners, the Conservancy participated in the formulation of a comprehensive watershed restoration plan, including measures to improve water quality and restore bottomland habitat. The Conservancy is also a participant in the local Partners for Fish and Wildlife Program and the Black Bear Conservation Committee.
Results achieved by these and other programs have been substantial. More than 56,000 acres of agricultural land have been reforested and about 48,000 acres have been enrolled in the federal Wetlands Reserve Program. Almost 4,000 acres of bottomland habitat and some 15 miles of streamside vegetation zones have been restored. In addition, sustainable management practices are being implemented on agricultural and forest lands, erosion-control structures have been built to reduce sedimentation, water-quality monitoring has been improved and ongoing educational programs are aimed at increasing public participation in efforts to conserve the Tensas basin. The Conservancy is also working to expand the amount of publicly-held land within its Tensas basin conservation site.
In 2007, the Conservancy launched a new effort in Louisiana called the Tensas River Basin Project that will result in the reforestation and reconnection of additional acres of marginal farmland and help mitigate some of the impacts of climate change.
The Tensas River Basin Project is part of a larger Conservancy effort to create a big contiguous block of forest within the Lower Mississippi Valley that will restore critical habitat.
The Conservancy purchased a 524-acre tract (which contains 114 acres of existing forest and 410 acres of farm fields) in the Tensas River basin. The land is adjacent to a number of other parcels of land enrolled in the Conservation Reserve and Wetland Reserve programs or owned by Farmer's Home Administration and managed by the U.S. Fish and Wildlife Service.
With financial support from Northwest Airlines, the Conservancy is planting trees on the farm fields. Over time as the forest matures, these trees will store thousands of short tons of carbon dioxide. The Tensas project is the first offering in The Nature Conservancy's voluntary carbon offset program, designed to help reduce the effects of climate change caused by carbon emissions.