Assessing the Functional Level of a Constructed Intertidal Marsh in Mississippi.
Abstract
Detailed assessments of the major biotic components of a 25-acre (10.12-ha) constructed marsh were undertaken 7 years after it was constructed by grading down uplands. The marsh consisted of low-elevation (Spartina alterniflora), midelevation (Juncus roemerianus), and high-elevation (salt panne) zones with a centrally located creek included to facilitate water exchange across the site. The predominantly sandy texture of the sediments in the constructed marsh (sand >80 percent) was substantially different from that of nearby natural marshes (sand <10 percent), reflecting the grade-down nature of the site. The elevation of the low-marsh zone of the constructed marsh was also different (16.6 cm lower) from that of the natural reference site, resulting in greater flooding frequency and duration in this zone. Despite physical differences, the constructed marsh supported similar vegetative, benthic, and nektonic assemblages compared with the natural reference. Mammal and avifaunal use was also similar between sites. Nekton use of the constructed low-marsh Spartina zone was higher than that of the natural marsh, apparently in response to the associated higher flooding frequency and duration. Sedimentation appears to be occurring in the constructed marsh and will likely continue. The tidal creek appears to have facilitated the development of comparable plant and benthic assemblages across the constructed site and also allows for the use of the entire site by nekton. Sampling with flume weirs provided a more detailed description of the nekton community of the marsh compared with lift nets.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1996
- Accession Number
- ADA317569
Entities
People
- Mark W. Lasalle
Organizations
- Mississippi State University