| 书目名称 | Concepts and Controversies in Tidal Marsh Ecology | | 编辑 | Michael P. Weinstein,Daniel A. Kreeger | | 视频video | http://file.papertrans.cn/235/234894/234894.mp4 | | 图书封面 |  | | 描述 | In 1968 when I forsook horticulture and plant physiology to try, with the help of Sea Grant funds, wetland ecology, it didn’t take long to discover a slim volume published in 1959 by the University of Georgia and edited by R. A. Ragotzkie, L. R. Pomeroy, J. M. Teal, and D. C. Scott, entitled “Proceedings of the Salt Marsh Conference” held in 1958 at the Marine Institute, Sapelo Island, Ga. Now forty years later, the Sapelo Island conference has been the major intellectual impetus, and another Sea Grant Program the major backer, of another symposium, the “International Symposium: Concepts and Controversies in Tidal Marsh Ecology”. This one re-examines the ideas of that first conference, ideas that stimulated four decades of research and led to major legislation in the United States to conserve coastal wetlands. It is dedicated, appropriately, to two then young scientists – Eugene P. Odum and John M. Teal – whose inspiration has been the starting place for a generation of coastal wetland and estuarine research. I do not mean to suggest that wetland research started at Sapelo Island. In 1899 H. C. Cowles described successional processes in Lake Michigan freshwater marsh ponds. There i | | 出版日期 | Book 2000 | | 关键词 | Ecology; Fauna; Sediment; algae; benthic; biogeochemical cycles; ecosystem; ecosystems; environment; fisherie | | 版次 | 1 | | doi | https://doi.org/10.1007/0-306-47534-0 | | isbn_softcover | 978-94-017-4080-7 | | isbn_ebook | 978-0-306-47534-4 | | copyright | Springer Science+Business Media B.V. 2000 |
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Front Matter |
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Abstract
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Tidal Marshes as Outwelling/Pulsing Systems |
Eugene P. Odum |
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Abstract
Now that we are beginning to understand that the balance of nature is a pulsing one and not a steady-state as is the case at the organism level (i.e., homeorhesis rather than homeostasis) estuaries become important sites for research because they pulse so strongly. The external tidal pulses interface in a complex manner with internal biological and life history pulses. I review the concept that productivity of near shore ocean waters can be enhanced not only by upwelling of nutrients from deeper waters but also by outwelling of nutrients and organic matter from fertile estuaries. I conclude 1) that the extent of the latter depends on the level of production within the estuary, the tidal amplitude and the geomorphology of the estuarine landscape and 2) the outwelling from tidal marshes where it occurs is often intermittent and largest during rain storms and storm tides.
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Salt Marsh Values: Retrospection from the end of the Century |
John M. Teal,Brian L. Howes |
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Abstract
Two of the greatest problems in coastal waters are eutrophicaton and rapid decline in populations of important fish species. Salt marshes are important in combating both these problems. A paradigm for salt marsh function: marshes import inorganic nutrients and export organic nutrients and, as a result, grow fish. As ground and tidal water flow through salt-water wetlands, plants, bacteria and algae produce or transform the organic matter of the food chain that supports fish and shellfish populations. While salt marshes modify the principal plant nutrients, N and P, some of the pathways result in removal of nutrients from biologically active systems. Nitrogen is removed primarily either by being trapped in refractory organic matter that contributes to marsh maintenance through accretion or through loss to the atmosphere (as N.) by denitrification. Salt marshes along the Atlantic coast of the United States have changed during the past century; the number of hectares has declined and the nutrient loading per hectare has increased. We examine data on the correlation between fish catch and various marsh features from Long Island, New York in 1880. We review research on the ways salt mar
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Role of Salt Marshes as Part of Coastal Landscapes |
Ivan Valiela,Marci L. Cole,James Mcclelland,Jennifer Hauxwell,Just Cebrian,Samantha B. Joye |
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Abstract
Salt marshes are located between land and coastal water environments, and nutrient and production dynamics within salt marshes interact with those of adjoining ecosystems. Salt marshes tend to export materials to deeper waters, as shown by mass balance and stable isotopic studies. Salt marshes also intercept land-derived nutrients, and thus modify the potential response of phytoplankton, macroalgae, and seagrasses in the receiving estuarine waters. In particular, the maintenance of eelgrass meadows seems to depend on the ability of fringing salt marshes to intercept land-derived nitrogen. The bulk of the interception of land-derived nitrogen is likely to be the result of relatively high rates of denitrification characteristic of salt marshes. Thus, through exports of energy-rich materials, and interception of limiting nutrients, salt marsh parcels interact in quantitatively important ways with adjoining units of landscape. These interactions are of importance in understanding the basic functions of these mosaics of different coastal systems, as well as provide information needed to manage estuaries, as for example, in conservation of valuable eelgrass meadows.
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Spatial Variation in Process and Pattern in Salt Marsh Plant Communities in Eastern North America |
Mark D. Bertness,Steven C. Pennings |
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Abstract
While we have learned a great deal about the structure and organization of salt marsh plant communities in the past two decades, this understanding is based on experimental studies conducted at just a handful of study sites. How general are these results and how far can we extrapolate from them to understand other marsh systems? In this paper, we argue that the zonation of eastern North American marsh plant communities may be strongly influenced by both eutrophication and climate, and that spatial variation in these factors may limit our ability to uncritically generalize between marshes. The striking zonation of marsh plant communities has been explained to be the product of competitively superior plants dominating physically mild habitats and displacing competitively subordinate plants to physically harsh habitats. At higher latitudes, this typically results in competitively dominant plants monopolizing high marsh elevations while competitively subordinate plants are limited to lower elevations. Recent studies, however, have suggested that both nutrient supply and thermal stress can influence this simple scenario. Increased nutrient availability, a typical consequence of eutrophi
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Eco-Physiological Controls on the Productivity of , Loisel |
Irving A. Mendelssohn,James T. Morris |
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Abstract
The intertidal salt marshes of the Atlantic and Gulf coasts of the United States are dominated by the perennial grass, . Loisel. The ecology of salt marshes in which this species dominates has been extensively investigated because of the documented biogeochemical functions that these ecosystems perform and the resulting societal values they provide. Since many of the salt marsh-derived values originate, either directly or indirectly, from the presence of a vegetated marsh and its primary productivity, it has long been a major goal of salt marsh ecology to elucidate the determinants of the growth of .. This paper reviews the interaction of the abiotic environment with key eco-physiological processes controlling the growth of this important plant species. The productivity of . can vary on both spatial and temporal scales. Spatial differences in productivity on a local scale are primarily determined by abiotic factors, particularly the interaction of soil anoxia, soluble sulfide, and salinity, with plant nitrogen uptake and assimilation. Also, . induce a positive feedback on productivity by enhancing substrate aeration. The growth enhancing effects of marsh infauna, e.g., fiddler crab
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Community Structure and Functional Dynamics of Benthic Microalgae in Salt Marshes |
Michael J. Sullivan,Carolyn A. Currin |
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Abstract
Benthic microalgae are a ubiquitous feature in sediments directly exposed to full sunlight or shaded by a vascular plant canopy in coastal salt marshes. Diatoms, cyanobacteria, and green algae are the dominant groups. Of these, diatoms are universally present and abundant, exhibit migratory rhythms driven mainly by light, and are by far the taxonomically most diverse group. Dense mats of cyanobacteria and secondarily green algae frequently develop where light levels are high. The more abundant species of all three algal groups are widely distributed within and among salt marshes of the United States and Europe. Standing crops of benthic microalgae beneath various vascular plant canopies exhibit mean annual values of 60 to 160 mg chl a m.. Annual benthic microalgal production (BMP) has been shown to range from 28 g C m. y. beneath . to 314 g C m. y. beneath .. In general, BMP increases in a southerly direction in Atlantic coast marshes but is lowest in Gulf Coast marshes. In Atlantic and southern California marshes a significant portion of benthic microalgal production occurs when the overstory vascular plants are dormant. Experimental manipulations have shown that BMP and biomass b
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Structure and Productivity of Microtidal Mediterranean Coastal Marshes |
Carles Ibñez,Antoni Curco,John W. Day Jr.,Narcis Prat |
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Abstract
This paper reviews the literature on structure and production of Mediterranean microtidal marshes. Literature on structure and zonation is relatively abundant but there are relatively few studies of coastal wetland primary productivity in the Mediterranean. These tidal marshes are poorly flushed because of the low tidal range and freshwater tidal marshes are rare. Most marshes are found in deltas and fringing coastal lagoons. Recent studies carried out in the Ebre, Po and Rhone deltas show that net primary production (NPP) of marshes is strongly influenced by soil salinity and flooding. The productivity of these marshes is generally low, but there are significant exceptions. Minimum values of NPP of emergent vegetation (below-plus above-ground) were obtained in salt marshes dominated by . 237 g m. y.), characterized by low flooding frequency and high salt stress. Maximum values (up to 9685 g m. y.) were obtained in fresh marshes dominated by ., with high flooding frequency. In general terms, Mediterranean microtidal marsheshave low production due to salt stress and weak tidal flushing. This suggests that there is low export of marsh production to coastal lagoons, bays and open coas
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Development and Structure of Salt Marshes: Community Patterns in Time and Space |
A.J. Davy |
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Abstract
The relatively species-rich tidal marshes of western Europe show strong spatial zonation in plant species, communities and ecosystem function that is correlated with elevational and environmental gradients from sea to land. Such spatial zonation has traditionally been interpreted as representing a chronosequence, a classic example of succession, mainly because of the demonstrable dependence of marsh formation and vertical development on sedimentary processes. First I seek to separate zonation from succession. Since the earliest days of salt-marsh ecology, physico-chemical factors related to submergence (elevation) have been invoked to explain patterns of distribution. The dominant halophytes are essentially land plants that occupy physiologically adverse environments by virtue of adaptations to salinity, submergence, hypoxia and tidal scouring. Thus their lower limits on the marsh are likely to be determined directly by physico-chemical tolerances. Generally reduced competitive ability is a trade-off in the evolution of tolerance and so upper limits of species may depend substantially on interactions with other, less tolerant, species. Such interactions may also represent to varyin
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Microbial Secondary Production from Salt Marsh-Grass Shoots, and Its Known and Potential Fates |
Steven Y. Newell,David Porter |
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Abstract
Several lines of evidence (direct microscopy, index biochemicals) point to predominance of eukaryotic decomposers in natural decay of dead shoots of smooth cordgrass (.). Recent research shows that this is also true for black needlerush (.). Ascomycetous fungi are the major initial secondary producers based on the dead shoots. There is no overlap between the species of the cordgrass (e.g., .) and needlerush (e.g., .) fungal-decay communities. Even when conditions in the marsh are manipulated in directions that would be expected to favor prokaryotes (extra water and nitrogen), the ascomycetes accumulate maximum organic masses in standing-decaying shoots hundreds of times larger than prokaryotic masses. Rates of fungal production are not increased by raising duration of high water availability, probably due to fine-tuned fungal adaptation to periodic dryness, but nitrogen does limit fungal productivity in decaying cordgrass. Content of living-fungal mass can be 10 to 20% of totalsystem (= microbes + remaining plant) mass, depending on nitrogen availability, rates of invertebrate mycophagy, and probably several further factors yet to be determined. Standing crops of living fungi in co
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Trophic Complexity Between Producers and Invertebrate Consumers in Salt Marshes |
Daniel A. Kreeger,Roger I.E. Newell |
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Abstract
Salt marshes on the Atlantic coast of North America are characterized by having a high biomass of smooth cordgrass, .. Because of the refractory nature of the lignocellulosic structure of this angiosperm, invertebrates utilize C from these plants with very low efficiency, if at all. This is true for both living cordgrass and post-senescent plant detritus. To balance their C demands, invertebrate consumers living in salt marshes must utilize a wide variety of other resources, including microheterotrophs (bacteria and bacterivorous flagellates) either associated with detritus or free in the water column, fungi colonizing decaying vascular plants, surface-associated algae (e.g., microphytobenthic diatoms and cyanobacteria, epiphytes, surface film algae) and phytoplankton. This high degree of trophic complexity is likely to be an important source of community stability. As an example, we estimate that ribbed mussels, ., in a Delaware marsh must rely on a variety of different food resources since no single food type can meet their nutritional demands for either C or N. To balance their C demands, mussels appear to rely mainly on microheterotrophs, followed by phytoplankton > microphytob
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Trophic Linkages in Marshes: Ontogenetic Changes in Diet for Young-of-the-Year Mummichog, Fundulus H |
KellY J. Smith,Gary L. Taghon,Kenneth W. Able |
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Abstract
Transfer of salt marsh production in the form of detritus to surrounding coastal and estuarine areas has been an area of interest for a number of years. The common mummichog, . has been proposed as an important link in trophic transfer, however little is known about the role of small young-of-the-year (YOY) in this process. To address this lack of information, YOY were collected from the flooded salt marsh surfaces at a lower Delaware Bay site over 2 summers in order to determine ontogenetic shifts in food habits. Young-of-the-year . were abundant on the marsh surface, and during peak larval recruitment to the marsh, fish densities reached 15 to 30 fish M. Multiple cohorts were visible in 1997, indicating up to 4 separate spawning events. Stomach contents for YOY were dominated by detrital-sediment aggregates, harpacticoid copepods, and annelid worms. The food habits changed with size, with the stomach contents of the smallest individuals (6.6 mm<20.4 mm SL) composed primarily of benthic fauna such as harpacticoid copepods and annelid worms. The stomach contents of larger YOY (20.5–30.4 mm SL) shifted to mostly . detritus and sediment aggregate. Thus, YOY . consume detritus both di
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Factors Influencing Habitat Selection in Fishes with a Review of Marsh Ecosystems |
J. Kevin Craig,Larry B. Crowder |
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Abstract
We review the general theory regarding habitat selection in fishes and integrate this theory with recent data to evaluate habitat selection by marsh fishes. Models of habitat selection in fishes have evolved rapidly. The earliest models predicted habitat selection based on simple variables like temperature or salinity. Optimal foraging models project habitat selection of individuals based on food availability. Environmental factors and food can be integrated using bioenergetic models to predict the distribution of individuals based on bioenergetic optimization. Habitat selection can be modified by the presence of other individuals including competitors (theory based on ideal free distributions) and predators (theory based on trade-offs of growth vs. predation risk). The most current models use game theory to project the dynamics of habitat selection for both prey species and their mobile predators. In a review of marsh ecosystems, we found that little information is currently available with which to evaluate potential mechanisms underlying patterns of habitat use in these systems. Though marshes are widely considered important for foraging and predator refuge, this function has rar
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Salt Marsh Ecoscapes and Production Transfers by Estuarine Nekton in the Southeastern United States |
R. T. Kneib |
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Abstract
Understanding the role of tidal marshes in supporting estuarine nekton populations requires consideration of how different species and life stages use, and depend on, a variety of habitats. The problem might best be viewed from the perspective of a tidal marsh ecoscape, which relates variation in ecological interactions or processes to spatial patterns that emerge when associated marsh habitats are viewed together as a functional unit. Vegetated intertidal habitats, which define the salt marsh and account for most of its areal extent and productivity, are not used directly by most species of estuarine nekton in the southeastern U.S. If they function in the trophic support of these populations, marshes might supply dissolved nutrients to drive primary production in adjacent open waters or they could be a source of passively transported particles (i.e. drift) gathered by nekton from the water column or epibenthos. Alternatively, the few groups of nekton (mostly small marsh resident species) that feed within the marsh vegetation may actively translocate intertidal production horizontally across boundaries within the marsh ecoscape in a type of “trophic relay”. Transfers to open estuar
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Salt Marsh Linkages to Productivity of Penaeid Shrimps and Blue Crabs in the Northern Gulf of Mexico |
Roger J. Zimmerman,Thomas J. Minello,Lawrence P. Rozas |
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Abstract
Secondary production derived from coastal marshes of the northern Gulf of Mexico exceeds that of other regions in the United States and is exemplified by large fishery catches of penaeid shrimps (., and . – 66% of U.S.) and blue crabs (. −25% of U.S.). We believe that this production arises from coastal wetlands, and is driven by wetland geomorphology and hydrology resulting from the delta building and wetland loss cycles of the Mississippi River. Quantitative surveys document that high densities of shrimps and blue crabs directly use northern Gulf marsh surfaces. Manipulative experiments demonstrate that such marshes provide these fishery species with increased resources for growth and with protective cover to reduce predator-related mortality. Thus, access to the marsh surface is an important component in controlling the link between secondary productivity and coastal wetlands. Marsh access is influenced by tidal flooding patterns, amount of marsh/water edge, and extent of connections between marsh systems and the Gulf. Low-elevation Gulf marshes are flooded nearly continually during some seasons and are extensively fragmented; such characteristics provide maximum access. By cont
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Ecophysiological Determinants of Secondary Production in Salt Marshes: A Simulation Study |
J. M. Miller,W. H. Neill,K. A. Duchon,S. W. Ross |
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Abstract
Variation in the abiotic environment is generally presumed to stress fish in estuarine marshes despite abundant food resources and refuge from predation. Chief among the important variables are dissolved oxygen, temperature, pH and salinity. With new technology for collecting high-resolution abiotic data and with mechanistic models for interpreting these data, it is possible to revisit and refine the conventional paradigm(s) of abiotic stresses and secondary production in salt marshes. With data from National Estuarine Research Reserves (NERR) and our ecophysiological model for juvenile fish, we ask “what is the relative impact of abiotic factors on growth in different marsh types?” Based on data from four NERR sites representing a spectrum of marsh hydrotypes and latitudes, we conclude that abiotically-forced variation in growth could explain much of the variation in secondary production in marshes.
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Salt Marsh Ecosystem Support of Marine Transient Species |
Linda A. Deegan,Jeffrey E. Hughes,Rodney A. Rountree |
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Abstract
One of the most important reasons stated in legislation for protecting salt marshes is their support of commercially and recreationally important nekton (fish and crustaceans). Yet, there is a surprising level of uncertainty among scientists regarding the role of salt marshes in supporting secondary production. The emphasis has been on “marine transient” species (in earlier literature often referred to as “estuarine dependent”) because they have life histories that seem designed to place young-of-the-year or juveniles in marsh habitats and because these species are often of commercial or recreational value. Salt marshes are believed to provide: 1) trophic support resulting in high growth rates, 2) increased survivorship due to lowered mortality, and 3) a suitable physico-chemical environment for development of young fishes. In this paper, we consider the evidence for each of these, with an emphasis on the trophic and survivorship aspects. The seasonally warmer temperatures of estuaries and salt marsh creeks apparently provide a metabolic advantage that supports high growth rates. The influence of marsh-derived organic matter in estuarine food webs is apparent, and its importance to
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Benthic-Pelagic Coupling in Marsh-Estuarine Ecosystems |
Richard F. Dame,Eric Koepfler,Leah Gregory |
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Abstract
Active and passive mechanisms utilized by many organisms in marsh-estuarine ecosystems couple the water column to the bottom. These linkages are often engineered by dense populations of plants (marshes) or animals (beds and reefs) that use their organismic structure, i.e., bodies or shells, and functional processes, i.e., water pumping, suspension feeding, etc., to enhance the movement of materials between the two habitats. These adaptations to the benthic boundary layer result in organismically mediated fluxes of materials between the water and the bottom that may dramatically alter either or both habitats. Dense stiff blades of grass dominate the salt marsh component of marsh-estuarine ecosystems. This structure ensures low water flow, low shear velocities, high drag and high roughness at the benthic boundary. These physical factors allow molecular diffusion and sedimentation to dominate exchange mechanisms. Marsh mussels magnify benthic-pelagic coupling by their active pumping and filtration of water. The shells of bivalve beds form a rough benthic surface that enhances turbulent mixing and increases the width of the benthic boundary layer. These beds can remove, via sedimentati
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Twenty More Years of Marsh and Estuarine Flux Studies: Revisiting Nixon (1980) |
Daniel L. Childers,John W. Day Jr.,Henry N. Mckellar Jr. |
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Abstract
In 1980, Scott Nixon reviewed the role of salt marshes in estuarine and coastal productivity. His review was effectively a progress report on the testing of “The Outwelling Hypothesis” (Odum, 1980). Nixon (1980) signaled a crucial turning point in the direction of estuarine flux studies conducted since then. In this review we revisit Nixon (1980), focusing on research and thinking that has been guided by The Outwelling Concept in the last two decades. Since 1980, estuarine flux studies have been conducted at 41 different sites and presented in over 42 publications. More than a third of these were conducted in Europe, Africa, Australia, or Mexico. Our review of these studies highlighted several important advances. The first was evolution of a conceptual approach that decomposes the estuary-coastal ocean landscape into interacting subsystems (i.e., the coastal ocean, estuarine basins, and marsh). Most post-1980 flux studies have addressed interactions between these individual subsystems, often in an hierarchical sense. Over half of these quantified exchanges between marsh-dominated basins and the greater estuary-generally through a single, well-defined tidal channel. From these data,
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The Role of Oligohaline Marshes in Estuarine Nutrient Cycling |
Jennifer Z. Merrill,Jeffrey C. Cornwell |
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Abstract
Oligohaline marshes, poised at the land-sea margin, often occur where the estuary is most enriched in inorganic particles and nutrients. Although light can limit the production of planktonic communities, high nutrient concentrations and regular tidal inundation results in highly productive macrophyte and algal communities. Despite potentially important water quality values, relatively few detailed studies of N and P cycling in oligohaline marshes are evident in the literature. Because of the temporal variability in marsh flux studies, the net annual retention of N and P is best assessed by measurement of N and P burial in the sediment. In the Chesapeake Bay and other estuaries and subestuaries, high rates of tidal marsh N and P burial indicate an important water quality function. A recent study shows the marshes of a Chesapeake Bay tributary retain a large portion of nitrogen and phosphorus entering the river from above the fall line. The marshes trap 35% of the nitrogen and 81% of the phosphorus which would otherwise be recycled, exported, or buried in the subtidal sediments of the estuary. Although there are few studies, high nitrate supply rates, potentially high nitrification r
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