U.S. Department of Agriculture: Animal and Plant Health Inspection Service


Date of this Version



Published (pages 49-89) in D. C. Abreu and S. L. De Borbon, editors. Marshes : Ecology, Management and Conservation. Nova Science Publishers, Inc., 2012.


Marshes, both tidal and non-tidal, are productive and complex ecosystems. The water in these systems ranges from fresh, to brackish, to saline as one moves from inland to coastal areas. Marshes are an interface between upland and aquatic habitats, and many biotic and abiotic processes lead to increased species richness and diversity (Gedan et al., 2009). Marshes provide many ecological services, including recharge and discharge of ground water; water quality control; retention, removal, and transformation of nutrients; habitats for many floral and faunal species; biomass production and exports; flood control and storm buffering; and stabilization of sediments and slowing of erosion (Southwick Associates, 2004; Woodward et al., 200 1). Marshes also provide for human activities such as hiking, wildlife viewing, hunting, trapping, fishing, etc. (Bounds and Carowan, 2000; Southwick Associates, 2004).

Marshes in North America, and elsewhere in many parts of the world, have been greatly affected by human activities, including dredging, filling, water diversions, flood control structures, contamination by pollutants, conversion to agricultural cropland and urban centers, introduction of invasive species, salinization, habitat fragmentation, and other factors (Bounds and Carowan, 2000; Takekawa et al. , 2006; Pathikonda et al, 2008; McFalls et al. , 20 10). Sea level rise and hurricanes also affect marshes and species interactions (Pathikonda et al., 2008; Pyke et al., 2008). Additionally, many marshes have been invaded by exotic species, upsetting normal physical and ecological functions, species richness, and species interactions. Much has been studied and published about invasive plants invading marshes (e.g., Guntenspergen and Nordby, 2006; Pathikonda et al., 2008), but much less has been reported about invasive herbivore impacts in marshes.