ACCELERATING SALT MARSH FUNCTIONAL DEVELOPMENT THROUGH PLANT GENOTYPE SELECTION

uring the fall of 1989, a newly created 0.5 acre salt marsh in Lewes, Delaware was planted with five genotypes of Spartina alterniflora, four of Spartina patens, and six of Distichlis spicata, two of which were from tissue culture. The purpose of the project was to identify those genotypes of each species which most rapidly accelerate the various above- and belowground processes of marsh functional development toward equivalency with the natural marsh. Years later, the selections remain distinct and reflect characteristics of plants at their site of origin. Genotypes differ in canopy height, stem density, and in potential detritus production. Decomposition rates of aboveground material also vary among genotypes. The quantity and depth distribution of carbon allocated belowground is dependent upon genotype, as is the carbohydrate concentration and composition of the rhizomes. The persistent differences exhibited by the various genotypes can be exploited for use in accelerating the functional development of newly created salt marshes. For example, depending on the created marsh site, the amount of detritus produced may or may not be an important consideration, or perhaps the height of the canopy may be a concern relative to animal usage. The various genotypes provide a series of options to select from when designing a salt marsh.

Funding Source: NOAA Estuarine Habital Program

The created marsh in its first growing season.

The created marsh four years after planting.

Dr. Jack Gallagher and graduate student Laurie Mutz taking soil cores in the marsh.

Minnow traps are used for assessing fish usage in the new marsh.

Dr. Denise Seliskar

Halophyte Biotechnology Center

Dr. John Gallagher