Relationships of nitrogen loadings, residential development, and physical characteristics with plant structure in New England salt marshes

Wigand, Cathleen; McKinney, Richard A.; Charpentier, Michael A.; Chintala, Marnita M.; Thursby, Glen B.

doi:10.1007/bf02803658

Cited by 74 publications

(59 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…), and were conducted in different regions and under different environmental conditions. Species composition, baseline ambient nitrogen loading (19,20), salinity, flooding frequency, and the concentration of other nutrients also vary widely across the existing literature, and can significantly affect the outcome of nitrogen addition experiments (4,(21)(22)(23)(24)(25)(26)(27)(28)(29)(30)(31). Hence, to isolate the potential impacts of increased nitrogen concentrations, we use the minimum (55.2 g N·m −2 ·y −1 ) and maximum (892.8 g N·m −2 ·y −1 ) nitrogen addition levels and the corresponding biomass responses from one study that explored a wide range of nitrogen addition levels at a single site (6).…”

Section: Significancementioning

confidence: 99%

Spatial response of coastal marshes to increased atmospheric CO ₂

Ratliff

Braswell

Marani

2015

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

The elevation and extent of coastal marshes are dictated by the interplay between the rate of relative sea-level rise (RRSLR), surface accretion by inorganic sediment deposition, and organic soil production by plants. These accretion processes respond to changes in local and global forcings, such as sediment delivery to the coast, nutrient concentrations, and atmospheric CO 2 , but their relative importance for marsh resilience to increasing RRSLR remains unclear. In particular, marshes up-take atmospheric CO 2 at high rates, thereby playing a major role in the global carbon cycle, but the morphologic expression of increasing atmospheric CO 2 concentration, an imminent aspect of climate change, has not yet been isolated and quantified. Using the available observational literature and a spatially explicit ecomorphodynamic model, we explore marsh responses to increased atmospheric CO 2 , relative to changes in inorganic sediment availability and elevated nitrogen levels. We find that marsh vegetation response to foreseen elevated atmospheric CO 2 is similar in magnitude to the response induced by a varying inorganic sediment concentration, and that it increases the threshold RRSLR initiating marsh submergence by up to 60% in the range of forcings explored. Furthermore, we find that marsh responses are inherently spatially dependent, and cannot be adequately captured through 0-dimensional representations of marsh dynamics. Our results imply that coastal marshes, and the major carbon sink they represent, are significantly more resilient to foreseen climatic changes than previously thought.sea-level rise | coastal marshes | coastal dynamics | atmospheric CO 2 | CO 2 fertilization C oastal marsh extent and morphology are directly controlled by rate of relative sea-level rise (RRSLR) and the soil accretion rate, the latter associated with inorganic sediment deposition and organic soil production by plants. Previous studies observed that CO 2 fertilization increases marsh plant biomass productivity through increased water use efficiency and photosynthesis (1), and hypothesized that, as a consequence, marsh resilience should increase via increased organic accretion (2, 3). However, this hypothesis has not yet been tested, and the observed increased plant productivity in response to the CO 2 fertilization effect has not been translated into its actual geomorphic effects. In fact, direct CO 2 effects on vegetation and marsh accretion (as opposed to its indirect effects, e.g., via the increase in temperature) have not yet been incorporated into marsh models, and their importance relative to other leading forcings of marsh dynamics (e.g., inorganic deposition, RRSLR, nutrient levels) remains unknown. Here we use existing data and a 1D ecomorphodynamic model to assess the direct impacts of elevated CO 2 on marsh morphology, relative to ongoing [e.g., RRSLR, and suspended sediment concentration (SSC)] and emerging [nutrient levels (4-6)] environmental change. Vegetation Responses to Changing Environmental ConditionsWe use publ...

show abstract

Section: Significancementioning

confidence: 99%

Spatial response of coastal marshes to increased atmospheric CO ₂

Ratliff

Braswell

Marani

2015

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

show abstract

“…Some studies have concluded that the observed variability in growth forms among Spartina populations may be the result of genetic differentiation (Gallagher et al, 1988;Sanchez et al, 1997;Proffitt et al, 2003), identifying ecotypes with different canopy heights and biomass accumulation (Lessmann et al, 1997;Daehler, 1999;Otero et al, 2000;Seliskar et al, 2002;Proffitt et al, 2005). In contrast, other studies have attributed different growth forms to phenotypic plasticity in response to differences in environmental factors (Anderson & Treshow, 1980), such as the availability of nutrients (Dai & Wiegert, 1997;Wigand et al, 2003;Zhao et al, 2010), salinity (Phelger et al, 1971;Trnka & Zedler, 2000) or sediment anoxia (Castillo et al, 2005a). The consequence of this is that the different growth forms are ecophenes.…”

Section: Aerial Biomass Of Cordgrassesmentioning

confidence: 99%

Cordgrass Biomass in Salt Marshes

Castillo¹,

Rubio-Casal²,

Figueroa³

2010

Biomass

View full text Add to dashboard Cite

“…Nitrogen load to one salt marsh in Narragansett Bay, Rhode Island, was calculated to be 10,253 kg N ha -1 yr -1 (Wigand et al 2003) ) is a small proportion of the total N budget (Morris 1991). However, atmospheric deposition can be the primary N source in some regions.…”

Section: Intertidal Wetlandsmentioning

confidence: 99%

“…Regardless of its source, N enrichment is shown to alter the structure and function of intertidal wetland ecosystems (Table 17.3) by causing increased primary production (Darby and Turner 2008a, Mendelssohn 1979, Tyler et al 2007, Wigand et al 2003; invasion of nonnative species (Tyler et al 2007); altered competition between native species (Crain 2007, Mendelssohn 1979, Wigand et al 2003; loss of , the density of saltmeadow cordgrass and short smooth cordgrass rapidly decreased and the density of tall smooth cordgrass increased.…”

Section: Intertidal Wetlandsmentioning

confidence: 99%

“…Only two studies (Table 17.3) have addition levels below 100 kg N ha -1 yr -1 . Based on the results of Wigand et al (2003), a critical load to protect the community structure of salt marshes is likely to be 63 to 400 kg and biogeochemistry. Latimer and Rego (2010) found that eelgrass coverage started to decrease rapidly at N loading higher than 50 kg N ha -1 yr -1 , with no eelgrass at loading levels higher than 100 kg N ha -1 yr -1 .…”

Section: Intertidal Wetlandsmentioning

confidence: 99%

See 1 more Smart Citation

Assessment of Nitrogen deposition effects and empirical critical loads of Nitrogen for ecoregions of the United States

Pardo¹,

Robin-Abbott²,

Driscoll³

2011

View full text Add to dashboard Cite

Human activity in the last century has led to a substantial increase in nitrogen (N) emissions and deposition. This N deposition has reached a level that has caused or is likely to cause alterations to the structure and function of many ecosystems across the United States. One approach for quantifying the level of pollution that would be harmful to ecosystems is the critical loads approach. The critical load is defi ned as the level of a pollutant below which no detrimental ecological effect occurs over the long term according to present knowledge.The objective of this project was to synthesize current research relating atmospheric N deposition to effects on terrestrial and aquatic ecosystems in the United States and to identify empirical critical loads for atmospheric N deposition. The receptors that we evaluated included freshwater diatoms, mycorrhizal fungi and other soil microbes, lichens, herbaceous plants, shrubs, and trees. The main responses reported fell into two categories: (1) biogeochemical, and (2) individual species, population, and community responses.The range of critical loads for nutrient N reported for U.S. ecoregions, inland surface waters, and freshwater wetlands is 1 to 39 kg N ha -1 y -1. This broad range spans the range of N deposition observed over most of the country. The empirical critical loads for N tend to increase in the following sequence for different life forms: diatoms, lichens and bryophytes, mycorrhizal fungi, herbaceous plants and shrubs, trees.The critical loads approach is an ecosystem assessment tool with great potential to simplify complex scientifi c information and effectively communicate with the policy community and the public. This synthesis represents the fi rst comprehensive assessment of empirical critical loads of N for ecoregions across the United States.

show abstract

Relationships of nitrogen loadings, residential development, and physical characteristics with plant structure in New England salt marshes

Cited by 74 publications

References 37 publications

Spatial response of coastal marshes to increased atmospheric CO ₂

Spatial response of coastal marshes to increased atmospheric CO ₂

Cordgrass Biomass in Salt Marshes

Assessment of Nitrogen deposition effects and empirical critical loads of Nitrogen for ecoregions of the United States

Contact Info

Product

Resources

About

Relationships of nitrogen loadings, residential development, and physical characteristics with plant structure in New England salt marshes

Cited by 74 publications

References 37 publications

Spatial response of coastal marshes to increased atmospheric CO 2

Spatial response of coastal marshes to increased atmospheric CO 2

Cordgrass Biomass in Salt Marshes

Assessment of Nitrogen deposition effects and empirical critical loads of Nitrogen for ecoregions of the United States

Contact Info

Product

Resources

About

Spatial response of coastal marshes to increased atmospheric CO ₂

Spatial response of coastal marshes to increased atmospheric CO ₂