Fire Effects on Coastal Marsh Vegetation
Currently fire effects on marsh habitat structure and function are poorly documented. In a community profile for salt marshes of the northeastern Gulf of Mexico, Stout (1984) suggested that repeated marsh burns would result in community succession but also stated that the details of succession and impacts on marsh functioning are not known. Almost two decades later, the necessary research still has not been done. A few studies have shown that, following dormant-season burns, plant species composition is rarely modified and live biomass rapidly recovers to pre-burn levels, often within a year (reviewed in Mendelssohn et al. 1996). However, other details about the removal of marsh biomass are lacking. Although reduction of invasive shrubs (both natives and exotics) is often listed as a reason for marsh burns, prescribed fire’s effectiveness for producing this result is rarely quantified nor are measurements usually made of fuel (biomass) reduction. This is especially true for marshes dominated by Juncus roemerianus.
Some studies have described the relationship between fire and changes in plant production (cf. Hackney and de la Cruz, 1981). In general, past studies have indicated that burning increases plant production, but these results were based only on dormant-season burns. It is not known how growing-season burns affect plant production. Vertical accretion (formation of new marsh soil) has been deemed an important process, especially in areas where rising sea level threatens to drown marshes. This concern may be more significant in
Encyclopedia ID: p216