An inland salt marsh is a saltwater marsh located away from the coast. It is formed and maintained in areas when

evapotranspiration Evapotranspiration (ET) is the combined processes by which water moves from the earth’s surface into the atmosphere. It covers both water evaporation (movement of water to the air directly from soil, canopies, and water bodies) and transpir ...

exceeds

precipitation In meteorology, precipitation is any product of the condensation of atmospheric water vapor that falls under gravitational pull from clouds. The main forms of precipitation include drizzle, rain, sleet, snow, ice pellets, graupel and hai ...

and/or when

sodium Sodium is a chemical element with the symbol Na (from Latin ''natrium'') and atomic number 11. It is a soft, silvery-white, highly reactive metal. Sodium is an alkali metal, being in group 1 of the periodic table. Its only stable ...

- and

chloride The chloride ion is the anion (negatively charged ion) Cl−. It is formed when the element chlorine (a halogen) gains an electron or when a compound such as hydrogen chloride is dissolved in water or other polar solvents. Chloride s ...

-laden

groundwater Groundwater is the water present beneath Earth's surface in rock and soil pore spaces and in the fractures of rock formations. About 30 percent of all readily available freshwater in the world is groundwater. A unit of rock or an unconsolidat ...

is released from natural

brine Brine is a high-concentration Solution (chemistry), solution of salt (NaCl) in water (H2O). In diverse contexts, ''brine'' may refer to the salt solutions ranging from about 3.5% (a typical concentration of seawater, on the lower end of that of ...

aquifers An aquifer is an underground layer of water-bearing, permeable rock, rock fractures, or unconsolidated materials (gravel, sand, or silt). Groundwater from aquifers can be extracted using a water well. Aquifers vary greatly in their characterist ...

. Its vegetation is dominated by

halophytic A halophyte is a salt-tolerant plant that grows in soil or waters of high salinity, coming into contact with saline water through its roots or by salt spray, such as in saline semi-deserts, mangrove swamps, marshes and sloughs and seashores. ...

plant communities. Salt flats in an inland salt marsh

Overview

Inland salt marshes (ISMs) are rare, non-tidal

wetlands A wetland is a distinct ecosystem that is flooded or saturated by water, either permanently (for years or decades) or seasonally (for weeks or months). Flooding results in oxygen-free ( anoxic) processes prevailing, especially in the soils. The ...

which form either due to the influence of saline groundwater and proximate springs and seeps or from

exceeding

. Primarily located in the

Great Lakes region The Great Lakes region of North America is a binational Canada, Canadian–United States, American region that includes portions of the eight U.S. states of Illinois, Indiana, Michigan, Minnesota, New York (state), New York, Ohio, Pennsylvania ...

of the US, they are dominantly composed of salt-tolerant,

plant communities including the invasive ''

Phragmites australis ''Phragmites australis'', known as the common reed, is a species of plant. It is a broadly distributed wetland grass that can grow up to tall. Description ''Phragmites australis'' commonly forms extensive stands (known as reed beds), which may ...

'' (common reed). Anthropogenic impacts on brine springs have decreased their already low global coverage and have led to their classification as G1 critically imperiled ecosystems. Of note, inland salt marshes are globally occurring, though this article primarily discusses ISMs from the US and Europe.

Flora and fauna

If vegetation is at all present, ISMs are typically dominated by

vegetative communities, though species-specific composition may vary among marshes. In a study quantifying spatial variability of ISM vegetation, New York ISMs were found to be composed of ''

Phalaris arundinacea ''Phalaris arundinacea'', or reed canary grass, is a tall, perennial bunchgrass that commonly forms extensive single-species stands along the margins of lakes and streams and in wet open areas, with a wide distribution in Europe, Asia, northern ...

'' (reed canary grass), ''Typha'' × ''glauca'''', Lythrum salicaria'' (purple loostrife)'','' and invasive ''

'' (common reed). Rapidly invading US ISMs, ''Phragmites australis'' has been shown to associate with highly saline areas with short hydroperiods, suggesting high water levels dilute salinity and decrease photosynthetic activity of this halophytic species. Michigan ISMs were found to be mainly composed of ''E. parvula'' and ''S. americanus,'' with little commonality with New York ISMs. Vegetation of inland salt marshes have also been shown to reflect environmental conditions. A recently accepted European study provides detailed analyses on species associations with

salinity Salinity () is the saltiness or amount of salt dissolved in a body of water, called saline water (see also soil salinity). It is usually measured in g/L or g/kg (grams of salt per liter/kilogram of water; the latter is dimensionless and equal ...

moisture Moisture is the presence of a liquid, especially water, often in trace amounts. Small amounts of water may be found, for example, in the air (humidity), in foods, and in some commercial products. Moisture also refers to the amount of water vapo ...

, light availability, and

nitrogen Nitrogen is the chemical element with the symbol N and atomic number 7. Nitrogen is a nonmetal and the lightest member of group 15 of the periodic table, often called the pnictogens. It is a common element in the universe, estimated at seve ...

content. Analyses suggest that certain ISM species have specific environmental requirements, and knowledge of which can better inform salt marsh conservation efforts accordingly.

Soil chemistry

Inland salt marshes can have extremely dynamic and harsh soil chemistry conditions. Much of the marsh is saturated with a layer of

sodium chloride Sodium chloride , commonly known as salt (although sea salt also contains other chemical salts), is an ionic compound with the chemical formula NaCl, representing a 1:1 ratio of sodium and chloride ions. With molar masses of 22.99 and 35 ...

, failing to sustain much plant life that can not tolerate such high

environments. For

plants which can colonize this harsh soil, nitrogen content is also a

limiting factor A limiting factor is a variable of a system that causes a noticeable change in output or another measure of a type of system. The limiting factor is in a pyramid shape of organisms going up from the producers to consumers and so on. A factor not l ...

. This limitation is increased when plants are inundated with water, as higher levels can

dilute Dilution may refer to: * Reducing the concentration of a chemical * Serial dilution, a common way of going about this reduction of concentration * Homeopathic dilution * Dilution (equation), an equation to calculate the rate a gas dilutes * Trad ...

the soil and reduce availability of

nitrate Nitrate is a polyatomic ion with the chemical formula . Salts containing this ion are called nitrates. Nitrates are common components of fertilizers and explosives. Almost all inorganic nitrates are soluble in water. An example of an insoluble ...

and

ammonium The ammonium cation is a positively-charged polyatomic ion with the chemical formula or . It is formed by the protonation of ammonia (). Ammonium is also a general name for positively charged or protonated substituted amines and quaternar ...

sources of nitrogen. Many studies have also investigated the role of

soil chemistry Soil chemistry is the study of the chemical characteristics of soil. Soil chemistry is affected by mineral composition, organic matter and environmental factors. In the early 1850s a consulting chemist to the Royal Agricultural Society in England ...

in the productivity and community structures of ISMs. For instance, a study on an Ohio salt marsh found ''

Salicornia europea ''Salicornia'' is a genus of succulent, halophytic (salt tolerant) flowering plants in the family Amaranthaceae that grow in salt marshes, on beaches, and among mangroves. ''Salicornia'' species are native to North America, Europe, Central Asia ...

'' (common glasswort) increased production when fertilized with nitrogen, and its different growth forms may be induced by varying soil nitrogen concentrations. Conversely, '' Hordeum jubatum'' (foxtail barley) and '' Atriplex triangularis'' (orache) were found to be limited by another factor other than nitrogen availability. In other words, different species are limited by different factors within an inland salt marsh ecosystem, providing competitive advantages and allowing for the occupation of different niches. There have also been efforts to apply GIS and

remote sensing Remote sensing is the acquisition of information about an object or phenomenon without making physical contact with the object, in contrast to in situ or on-site observation. The term is applied especially to acquiring information about Ear ...

methods to characterize the

of inland salt marshes.

Conservation and management

Inland salt marshes are quite rare and have unique conservation needs, yet there is a severe lack of research on these ecosystems. Protected by the European

Natura 2000 Natura 2000 is a network of nature protection areas in the territory of the European Union. It is made up of Special Areas of Conservation and Special Protection Areas designated under the Habitats Directive and the Birds Directive, respectiv ...

network and classified as a G1 category endangered ecosystem, there is a strong need to protect these rare, decreasing ecosystems, yet a lack of available research supports these conservation initiatives. One study aimed to address this gap with a case study in Central Europe; interdisciplinary analysis of various salt marsh conditions suggested that regular flooding of the inland salt marsh with nearby

, in this case from a nearby health center, could be used to restore endangered inland salt marshes.{{Cite journal , last1=Lubińska-Mielińska , first1=Sandra , last2=Kamiński , first2=Dariusz , last3=Hulisz , first3=Piotr , last4=Krawiec , first4=Arkadiusz , last5=Walczak , first5=Maciej , last6=Lis , first6=Marta , last7=Piernik , first7=Agnieszka , date=2022-04-01 , title=Inland salt marsh habitat restoration can be based on artificial flooding , journal=Global Ecology and Conservation , language=en , volume=34 , pages=e02028 , doi=10.1016/j.gecco.2022.e02028 , s2cid=246190293 , issn=2351-9894, doi-access=free

References

Soil Salt marshes

Overview

Flora and fauna

Soil chemistry

Conservation and management

See also

References