VEGETATIVE MARSH MANAGEMENT IN LOUISIANA: 

 LONG-RANGE RECOMMENDATIONS 



Bill Good 



Coastal Vegetation and Wetland Restoration Program 



Louisiana Geological Survey 



Louisiana State University 



Baton Rouge, LA 70803 



ABSTRACT 



The major objectives of vegetative marsh management are to prevent the conversion of marsh 

 to open water and to control the erosion at marsh-water interfaces. Two key strategies for 

 combatting the erosion of marshland, soil stabilization, and succession acceleration can be used to 

 accomplish this. In many cases soil stabilization can be accomplished more cost-effectively with 

 vegetative marsh management than with other methods. Succession acceleration can reduce erosion 

 if an environment changes faster than natural plant succession can recolonize the area. A proposed 

 procedure for selecting an optimal project design incorporates site evaluation data, the likelihood 

 of project success, potential benefits, and project costs. The techniques, materials, designs, and 

 goals of vegetative restoration in Louisiana are discussed. Also, a state-wide prioritization scheme 

 is suggested that would locate vegetation projects in those areas with the highest rates of wetland 

 loss. 



INTRODUCTION 



Although it is not applicable in all marsh loss situations, vegetative marsh management has been 

 demonstrated to be effective in combatting interface erosion and the loss of marsh lands that 

 result from environmental changes such as rising salinity levels. Vegetative marsh management 

 often can be used where other management techniques are not feasible. The initial investment and 

 maintenance are usually much less costly. Vegetative techniques are not complicated, but designing 

 effective projects and setting priorities for their implementation requires that site conditions be 

 scientifically evaluated and that costs, risks, and benefits be carefully weighed. 



A critical step in the development of an effective vegetative marsh management program is to 

 determine where such techniques are cost-effective. We must have guidelines by which appropriate 

 vegetative techniques can be selected for a given situation. In addition, we must use a decision- 

 making process that will maximize benefits. This report discusses two proposed strategies for off- 

 setting marsh loss-soil stabilization and succession acceleration; it describes some techniques and 

 materials available; and it proposes a method for project design and prioritization of vegetative 

 marsh management in Louisiana. 



STRATEGIES 



Soil Stabilization 



Erosion is used here to mean the removal of marsh by the physical influence of water. This 

 process is a significant contributor to marsh loss along canals and bayous (Turner et al. 1982), the 

 shores of lakes and bays (Adams et al. 1978), and the Gulf of Mexico (van Beek and Meyer- 

 Arendt 1982). Marsh vegetation helps reduce erosion by absorbing wave energy and by providing 



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