Rate of Sedimentation and Its Role in Nutrient Cycling in a Louisiana Salt Marsh

DeLaune, Ronald D.; PatrickJr., W. H.

doi:10.1007/978-1-4757-5177-2_17

Cited by 6 publications

(2 citation statements)

References 7 publications

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“…Sediments consisting of clay-sized particles (containing Fe, Al, Ca) may directly deposit particulate P in the wetland as well as provide new sorption sites for water soluble P (Cooper and Gilliam, 1987 , 1981). DeLaune and Patrick (1980) reported that sedimentation contributed 2.3 g p/m2/yr to a rapidly accreting (1.1 cm/yr) salt marsh. Likewise, Johnston et al (1984) reported high rates of P deposition (2.6 g/m2/yr) in a rapidly accreting (2.4 cm/yr) freshwater marsh.…”

Section: Sedimentationmentioning

confidence: 99%

Dynamics of nitrogen and phosphorus retention during wetland ecosystem succession

Craft

1996

Wetlands Ecol Manage

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We compared the mechanisms of nitrogen (N) and phosphorus (P) removal in four young (<15 years old) constructed estuarine marshes with paired mature natural marshes to determine how nutrient retention changes during wetland ecosystem succession. In constructed wetlands, N retention begins as soon as emergent vegetation becomes established and soil organic matter starts to accumulate, which is usually within the first I-3 years. Accumulation of organic carbon in the soil sets the stage for denitrification which, after 5-10 years, removes approximately the same amount of N as accumulating organic matter, 5-10 g/m2/yr each, under conditions of low N loadings, Under high N loadings, the amount of N stored in accumulating organic matter doubles while N removal from denitrification may increase by an order of magnitude or more. Both organic N accumulation and denitrification provide for long-term reliable N removal regardless of N loading rates. Phosphorus removal, on the other hand, is greatest during the first I-3 years of succession when sediment deposition and sorption/ precipitation of P are greatest. During this time, constructed marshes may retain from 3 g P/m2/yr under low P loadings to as much as 30 g P/m2/yr under high loadings. However, as sedimentation decreases and sorption sites become saturated, P retention decreases to levels supported by organic P accumulation (1-2 g P/m2/yr) and sorption/precipitation with incoming aqueous and particulate Fe, AI and Ca. Phosphorus cycling in wetlands differs from forest and other terrestrial ecosystems in that conservation of P is greatest during the early years of succession, not during the middle or late stages. Conservation of P by wetlands is largely regulated by geochemical processes (sorption, precipitation) which operate independently of succession. In contrast, the conservation of N is controlled by biological processes (organic matter accumulation, denitrification) that change as succession proceeds.

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Section: Sedimentationmentioning

confidence: 99%

Dynamics of nitrogen and phosphorus retention during wetland ecosystem succession

Craft

1996

Wetlands Ecol Manage

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“…If bulk densities above 0.20 gcm ~ are essential for growth of S. alterniflora, as suggested by DeLaune and Patrick (1980), then only the reference marsh provides the soil density conditions necessary to support salt marsh plant growth (0.27 _ 0.01 gcm vs. 0.17 + 0.01 g cm ~ in the managed marsh). Soils with a higher mineral content (i,e., bulk density) not only have a greater ability to sorb plant nutrients (Mitsch and Gosselink 1993), but also have been shown to provide more nutrients on a per volume basis relative to more organic salt marsh soils (DeLaune et al 1979).…”

Section: Discussionmentioning

confidence: 99%

Altered hydrology effects on Louisiana salt marsh function

1999

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A marsh subject to "structural marsh management," which changes natural wetland hydrology, was found to be functionally impaired when compared to an adjacent unimpounded reference marsh. The "managed" marsh had much lower sedimentation rates and tidal amplitude. Also, net annual primary production was lower in the managed marsh relative to the reference marsh. In light of the great importance of sedimentation, as well as primary production, to vertical accretion and maintenance of the salt marsh surface, our findings support the contention that structural marsh management (SMM) inhibits marsh surface accretion. Even so, much of the Louisiana coast has been proposed for this form of management in an effort to protect it from loss. However, our results show such management activities in the salt marsh could likely increase sediment aggradation deficits and wetland loss, especially in areas subject to high rates of subsidence or sea-level rise, such as Louisiana. Further research is needed to evaluate whether the results shown here are typical for saline SMM sites. In the absence of such research, the u~e of SMM in salt marshes is not presently recommended.

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Cesium-137, metals and organic carbon in the sediments of the James River estuary, Virginia

Wong¹,

Moy²

1984

Estuarine, Coastal and Shelf Science

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Rate of Sedimentation and Its Role in Nutrient Cycling in a Louisiana Salt Marsh

Cited by 6 publications

References 7 publications

Dynamics of nitrogen and phosphorus retention during wetland ecosystem succession

Dynamics of nitrogen and phosphorus retention during wetland ecosystem succession

Altered hydrology effects on Louisiana salt marsh function

Cesium-137, metals and organic carbon in the sediments of the James River estuary, Virginia

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