Ecosystem Functions of Tidal Fresh, Brackish, and Salt Marshes on the Georgia Coast

Więski, Kazimierz; Guo, Hongyu; Craft, Christopher; Pennings, Steven C.

doi:10.1007/s12237-009-9230-4

Cited by 99 publications

(65 citation statements)

References 31 publications

(31 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Despite the ecological importance of wetlands and the magnitude of the salinization threat, there is no up-to-date assessment of wetland salinization on a global scale. Recent research indicates that many wetlands undergoing salinization display unique, non-linear behavior indicative of rapid, and perhaps irreversible, environmental change (Davis et al 2003, Strehlow et al 2005, Sim et al 2006, Davis et al 2010, Larsen et al 2010, Runyan and D'Odorico 2010, suggesting that comparisons between freshwater and saline wetlands (Redeke 1922, Remane 1934, Remane and Schlieper 1971, Odum 1988, Hopkinson et al 1999, Craft 2007, Wieski et al 2010 may not be the best model for understanding wetland salinization. On a global scale, the extent of wetland salinization is poorly quantified.…”

Section: Introductionmentioning

confidence: 99%

A global perspective on wetland salinization: ecological consequences of a growing threat to freshwater wetlands

et al. 2015

View full text Add to dashboard Cite

Abstract. Salinization, a widespread threat to the structure and ecological functioning of inland and coastal wetlands, is currently occurring at an unprecedented rate and geographic scale. The causes of salinization are diverse and include alterations to freshwater flows, land-clearance, irrigation, disposal of wastewater effluent, sea level rise, storm surges, and applications of de-icing salts. Climate change and anthropogenic modifications to the hydrologic cycle are expected to further increase the extent and severity of wetland salinization. Salinization alters the fundamental physicochemical nature of the soil-water environment, increasing ionic concentrations and altering chemical equilibria and mineral solubility. Increased concentrations of solutes, especially sulfate, alter the biogeochemical cycling of major elements including carbon, nitrogen, phosphorus, sulfur, iron, and silica. The effects of salinization on wetland biogeochemistry typically include decreased inorganic nitrogen removal (with implications for water quality and climate regulation), decreased carbon storage (with implications for climate regulation and wetland accretion), and increased generation of toxic sulfides (with implications for nutrient cycling and the health/functioning of wetland biota). Indeed, increased salt and sulfide concentrations induce physiological stress in wetland biota and ultimately can result in large shifts in wetland communities and their associated ecosystem functions. The productivity and composition of freshwater species assemblages will be highly altered, and there is a high potential for the disruption of existing interspecific interactions. Although there is a wealth of information on how salinization impacts individual ecosystem components, relatively few studies have addressed the complex and often non-linear feedbacks that determine ecosystem-scale responses or considered how wetland salinization will affect landscape-level processes. Although the salinization of wetlands may be unavoidable in many cases, these systems may also prove to be a fertile testing ground for broader ecological theories including (but not limited to): investigations into alternative stable states and tipping points, trophic cascades, disturbance-recovery processes, and the role of historical events and landscape context in driving community response to disturbance.

show abstract

Section: Introductionmentioning

confidence: 99%

A global perspective on wetland salinization: ecological consequences of a growing threat to freshwater wetlands

et al. 2015

View full text Add to dashboard Cite

show abstract

“…Salt marshes provide diverse ecosystem services that have been evaluated as being some of the most valuable services for humanity (Costanza et al 1997, Wieski et al 2010. These services and human benefits include disturbance regulation (e.g.…”

Section: Introductionmentioning

confidence: 99%

“…bird watching), and productivity (e.g. primary and secondary production, including plant biomass production as a source of organic matter and nutrients, and fish production through fishing activities and aquaculture) (Boorman 2003, Gedan et al 2009, Wieski et al 2010.…”

Section: Introductionmentioning

confidence: 99%

Denitrification: an ecosystem service provided by salt marshes

Sousa¹,

Lillebø²,

Risgaard-Petersen³

et al. 2012

Mar. Ecol. Prog. Ser.

View full text Add to dashboard Cite

We hypothesized that denitrification rates, as an N removal process, would be enhanced in salt marsh rhizosediments as compared to sediments without vegetation (bare mudflats). Denitrification rates (measured by the 15 N-isotope pairing technique), potential nitrification, and nutrient fluxes were seasonally quantified in a Spartina maritima salt marsh and in adjacent bare mudflats. Potential nitrification rates were significantly higher in autumn and winter, but there were no significant differences between the bare mudflats and S. maritima vegetated sediment. Seasonally, denitrification rates in vegetated sediments under dark conditions were significantly higher in winter (676 ± 497 µmol N 2 m −2 h −1 , mean ± SD), whereas bare mudflats showed a maximum rate of 151 ± 24 µmol N 2 m −2 h −1 in summer. The high denitrification rates recorded in winter may be due to many abiotic and biotic factors, namely higher potential nitrification and nitrate availability in the water column, lower competition for nitrogen within the sediment, and less competition between plants, microphytobenthos, and nitrifiers, especially in dark conditions. Hence, during winter, there was a higher contribution of S. maritima marshes to N removal through denitrification, highlighting the role of the marshes in this ecosystem service. As a whole, considering the seasonal variations of the studied processes, it cannot be concluded whether or not annual denitrification was significantly different between the vegetated sediment and the bare mudflats.

show abstract

“…Taken at a larger spatial scale, a general gradient of lower salinities within the upper coast stations to higher salinities on the lower coast stations was evident, yet within a regional scale of an individual studies (WQS Study along the middle Texas coast) to a limited to local scale (TCEQ studies centered around Galveston Bay), this salinity trend is interrupted by the high degree of variability within different tidal segments (see Table 2). This overarching role of salinity (and secondarily, turbidity; see [4,33]) in structuring the available habitats within estuaries has been commonly reported [11,21,34], and salinity was one of the most important factors identified by one of the largest-scale assessments of tidally influenced waters ever undertaken (European Union's Marine Strategy Directive; see [10]). The other physical parameters of temperature, dissolved oxygen concentrations, and pH readings were each far less influential in configuring the streams amongst the studies, although this could be attributed to the limiting temporal scale of the present study (only the common summer sampling season being the time period under consideration due to the nonuniformity of collections across studies).…”

Section: Water Quality Assessmentsmentioning

confidence: 93%

“…Tidal streams also serve as important nursery areas for many fish and shellfish species, and a number of species have been shown to actively recruit to these important habitats [1][2][3][4]. Routine monitoring of several tidally influenced segments throughout the state of Texas has revealed that water quality standards are not currently being met (Texas Commission on Environmental Quality (TCEQ), 2010 [5]).…”

Section: Introductionmentioning

confidence: 99%

Spatial Assessment of a Biocriteria Applied to Texas Tidal Streams

Tolan

Nelson

2013

Journal of Ecosystems

View full text Add to dashboard Cite

This study reports on a derived multivariate method for assessing ecosystem health within tidally influenced portions of river basins and coastal basins. These tidally influenced areas are highly productive transitional areas which serve as important nursery areas for many fish and shellfish species. Numerous Texas tidal streams under varying degrees of anthropogenic stressors were analyzed jointly with this new, standardized methodology. Physical and chemical constituents of the tidal systems, as well as their resident nekton communities, were compared with nonparametric ordination techniques in order to uncover a biocriteria that might have general applicability over large spatial scales. All of the tidal stream communities were dominated by only a few taxa that each displays tremendous euryhaline/physiological tolerances, and these abilities allow taxa utilizing tidal streams to adapt to a wide variety of environmental stressors. The absence of any clear connections between degraded water-bodies and any impaired nektonic communities should not automatically be viewed as a constraint inherent to the techniques of the methodology presented, but rather a verification that impaired tidal streams are not that common of an occurrence along the Texas coast, at least not when using nekton communities as the degradation indicator.

show abstract

Ecosystem Functions of Tidal Fresh, Brackish, and Salt Marshes on the Georgia Coast

Cited by 99 publications

References 31 publications

A global perspective on wetland salinization: ecological consequences of a growing threat to freshwater wetlands

A global perspective on wetland salinization: ecological consequences of a growing threat to freshwater wetlands

Denitrification: an ecosystem service provided by salt marshes

Spatial Assessment of a Biocriteria Applied to Texas Tidal Streams

Contact Info

Product

Resources

About