Sphaeroma terebrans (Bate 1866) is an economically and ecologically important cosmopolitan species because this isopod is found burrowed in wood and marine structures of fresh to saline water. Existing literature on S. terebrans focuses on the destruction of red mangrove (Rhizophora mangle) in India, Pakistan, and Florida. This study concentrates on S. terebrans habitat and boring preferences in bald cypress (Taxodium distichum) in Lake Pontchartrain near the Bonnet Carre Spillway, Louisiana. In addition laboratory experiments for water column distribution and substrate preferences were conducted using cypress, Styrofoam, and balsa. Results indicate that this population may be parthenogenic and that wood or material hardness determines whether S. terebrans burrow when given a choice of substrates. The lake shoreline near the Bonnet Carre Spillway is retreating and the presence of S. terebrans contributes to shoreline erosion by weakening and destroying cypress. This has implications for restoration projects in coastal Louisiana.

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The purpose of this study was to determine the effects of amendments (control, (1x) compost, (2x) compost, (TS) topsoil, and 1x+TS) and microtopography (level, pit and mound) on three parameters (plant species composition, above-ground characteristics of Taxodium distichum, and plant root characteristics) of vegetation growing at a created tidal freshwater swamp in Virginia. None of the soil treatments met the traditional vegetation criteria for federal wetland jurisdictional determination, which only considers dominant species. When the same criteria were used for all of the species, the control, 1x, and 2x treatments met jurisdictional criteria. Considering these findings, vegetative criteria should be re-evaluated for young created wetlands. Compost addition produced the highest proportion of obligate wetland species (30%) while topsoil additions created the lowest proportion of wetland obligates (11%) and the highest proportion of upland plants. The 1x treatment generated the greatest species evenness and lowest weighted average (2.57). Topsoil treatments had the lowest diversity and evenness. Therefore, compost amendment is recommended to increase hydrophytes without compromising evenness and diversity. Bald cypress in pits were taller, had larger trunk diameter and basal trunk swelling than trees growing at higher elevations. Roots growing in mounds were more numerous with greater length than roots at lower elevations. Root length and count were highest for the control soil treatment. Amended treatments may have had lower rooting values because nutrient supply was adequate. Overall, incorporating microtopography and compost during wetland creation had a positive effect on vegetative function in this system. / Master of Science

Ecological restoration of a converted wetland was characterized within a recently drained impoundment along the James River in Charles City County, Virginia. Colonizing vegetation was assessed over three growing seasons in both tidal and non-tidal environments. Study objectives were to (1) examine geospatial relations of recruitment patterns among colonizing species over three growing seasons, (2) quantify species composition and potential differences between extant species cover and soil seed banks across restored and natural wetland habitats and (3) assess geospatial patterns to develop a GIS model of bald cypress (Taxodium distichum L.) recruitment. The two most common native colonizing species during 2009, 2010 and 2011 growing seasons were narrow-leaf cattail (Typha angustifolia L.) and rice cutgrass (Leersia oryzoides L.). Vegetative communities dominated by these two species covered 72% of the basin in each growing season. Differences were observed between extant species cover in the field and seed bank species across habitats. Two hundred and eighty T. distichum individuals have been located in wetland habitats at the VCU Rice Center. Using a GIS weighted suitability model we identified potential areas within the restored wetland for natural and facilitated bald cypress recruitment. At the VCU Rice Center ~9.7 ha have potential for natural regeneration and ~48.5 ha have potential for facilitated restoration of T. distichum.

No description available.