Marsh organ

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The marsh organ is a collection of plastic pipes attached to a wooden framework that is placed in marshes to measure the effects of inundation time and flood frequency on the productivity of marsh vegetation. [1] The information is used for scientific research purposes.

Contents

The marsh organ was developed by James Morris from the University of South Carolina with support from the National Science Foundation and NOAA's National Centers for Coastal Ocean Science. Their objective was to quantify short-term and long-term effects of sea level rise on coastal processes such as plant productivity, decomposition of organic matter in soil, sedimentation that contribute to the structuring of wetland stability. [2]

Climate change

The marsh organ is used to determine how well various coastal processes will respond to sea level rise. Climate change impacts such as accelerated sea level rise causes coastal marshes to experience higher water levels than normal, which leads to higher salinity inland, sediment and elevation loss, and change to the plant community structure.

These consequences will affect stress-gradients that are imposed on coastal vegetation, but the tolerances of these plant species and the trade-offs they may experience are unclear. This device is a way to directly manipulate what marsh vegetation may experience in the future and provide better insight into the restoration efforts needed to prevent detrimental consequences to coastal marshes.

Design

The marsh organ is a structure with rows of pipes at different vertical elevations. These pipes are filled with mud and marsh plant species are planted into each pipe. The various vertical levels represent varying water-level "elevation" that the marsh plants would experience. As the tides ebb and flow, the pipes are exposed to rising and falling water levels. Scientists can adjust various factors, such as the total elevation of the setup, flooding duration, added nutrients and much more.

Over time, scientists can gather information such as total plant biomass accumulation, total organic matter, peat formation, decomposition rates, and sedimentation. The data can be used to forecast the future health of the marsh being studied, and to infer how the marsh will respond to sea level rise in the future.

Species-specific effects

With many different marsh organ study designs and approaches, researchers have found that marsh plants may respond to future sea level rise differently, therefore it is entirely species-specific.

Researchers studying marsh plant responses in Northeast Pacific tidal marshes utilized a marsh organ and found that species typically found in the high marsh (flooded only during high tide or extreme weather events) like Salicornia pacifica and Juncus balticus were sensitive to increased flooding. Other species such as Bolboschoenus maritimus and Carex lyngbyei were abundant in marshes at or above the elevation corresponding with their maximum productivity. [3] Another group using the marsh organ also found that increased inundation reduced biomass for species commonly found at higher marsh elevations. The presence of neighbors reduced total biomass even more. [4]

A group of researchers used a marsh organ to evaluate the effects of an invasive grass to the native plant communities of an estuary in China. They found that the invasive grass survived well in optimal elevations, and not very well in extreme high and low elevations. When mixed with native species, the invasive grass suppressed the native biomass by 90% at intermediate elevation where biomass was typically the greatest. [5] Another group who used the marsh organ in the Pacific Northwest of North America to study its role in field testing seed recruitment niches found that species common to the area like S. tabernaemontani exhibited nearly significant higher germination rates around the average tidal height, while the species Carex lyngbyei survived significantly better around the highest tidal height. Both species also showed sensitivity to competitors, with S. tabernaemontani being the only species to germinate in the presence of competition. [6]

External stressors

Along with the stress of rising sea levels, marsh vegetation is also influenced by many outside sources such as storms, drought, nutrient enrichment, and elevation change with subsidence. The responses of marsh plants to these stressors have been tracked in various studies using the marsh organ.

A group using the marsh organ to study Spartina alterniflora, an abundant low marsh (typically flooded throughout the day) grass found that storm and drought stressors led to significantly less above-ground biomass and below-ground biomass than those planted in ambient rain conditions. Plants flooded at high inundations additionally had finer roots and shoots resulting in a plant that is structurally weaker. [7]

Nutrient addition has the potential to aid in the growth of many plant species, but excess nutrients can have the reverse affect and be detrimental to the success of many marsh plants. In one marsh organ study, researchers found a positive relationship where added nitrogen enhanced plant growth at sea levels where plants are most stressed by flooding, and the effects were larger in combination with elevated carbon dioxide. However, they noted that chronic nitrogen addition from pollution reduces the availability of propagules (a bud of a new plant) of flood-tolerant species which would shift species dominance making marshes more susceptible to collapse. [8] This trade-off has also been found in marsh organ studies where nutrient addition has to potential to increase primary productivity, but can adversely impact organic matter accumulation and peat formation. [9]

Marsh plants can be sensitive to elevation change accompanying sea level rise due to the altering of their desired habitats. Using the marsh organ setup, researchers discovered that for marsh elevations higher than optimum expected at low sea level rise rates, acceleration in the rate of sea level rise will enhance root growth, organic accretion and wetland stability altogether. But, for sub-optimum marsh elevations expected at rapid sea level rise rates with low sediment supply, increases in water level will lead to reduced root growth and a decrease in the rate of elevation gain. This could lead to a rapidly deteriorating marsh. [10] [11] Coinciding with elevation, a group of researchers utilizing the marsh organ found that soil subsided less in planted treatments than unplanted control treatments suggested that plants potentially help alleviate the loss of marsh elevation due to sea level rise [12]

Researchers have also found that water level variability in a specified time period affects the growth of coastal marshes, with emphasis on anomalies in sea level. These consist of slow changes that do not affect sediment transport, but do affect marsh flooding and vegetation growth. [13]

Related Research Articles

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An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime environments and are an example of an ecotone. Estuaries are subject both to marine influences such as tides, waves, and the influx of saline water, and to fluvial influences such as flows of freshwater and sediment. The mixing of seawater and freshwater provides high levels of nutrients both in the water column and in sediment, making estuaries among the most productive natural habitats in the world.

<span class="mw-page-title-main">Wetland</span> Land area that is permanently, or seasonally saturated with water

A wetland is a distinct ecosystem that is flooded or saturated by water, either permanently for years or decades or seasonally for a shorter periods. Flooding results in oxygen-poor (anoxic) processes taking place, especially in the soils. Wetlands are different from other land forms or water bodies due to their aquatic plants adapted to oxygen-poor waterlogged soils. Wetlands are considered among the most biologically diverse of all ecosystems, serving as home to a wide range of plant and animal species. Methods exist for assessing wetland functions and wetland ecological health. These methods have contributed to wetland conservation by raising public awareness of the functions that wetlands can provide. Constructed wetlands are a type of wetland that can treat wastewater and stormwater runoff. They may also play a role in water-sensitive urban design. Environmental degradation threatens wetlands more than any other ecosystem on Earth, according to the Millennium Ecosystem Assessment from 2005.

<span class="mw-page-title-main">Marsh</span> Low-lying and seasonally waterlogged land

In ecology, a marsh is a wetland that is dominated by herbaceous plants rather than by woody plants. More in general, the word can be used for any low-lying and seasonally waterlogged terrain. In Europe and in agricultural literature low-lying meadows that require draining and embanked polderlands are also referred to as marshes or marshland.

<span class="mw-page-title-main">Salt marsh</span> Coastal ecosystem between land and open saltwater that is regularly flooded

A salt marsh, saltmarsh or salting, also known as a coastal salt marsh or a tidal marsh, is a coastal ecosystem in the upper coastal intertidal zone between land and open saltwater or brackish water that is regularly flooded by the tides. It is dominated by dense stands of salt-tolerant plants such as herbs, grasses, or low shrubs. These plants are terrestrial in origin and are essential to the stability of the salt marsh in trapping and binding sediments. Salt marshes play a large role in the aquatic food web and the delivery of nutrients to coastal waters. They also support terrestrial animals and provide coastal protection.

<span class="mw-page-title-main">Coos Bay</span> Estuary in Oregon, United States

Coos Bay is an estuary where the Coos River enters the Pacific Ocean, the estuary is approximately 12 miles long and up to two miles wide. It is the largest estuary completely within Oregon state lines. The Coos Bay watershed covers an area of about 600 square miles and is located in northern Coos County, Oregon, in the United States. The Coos River, which begins in the Oregon Coast Range, enters the bay from the east. From Coos River, the bay forms a sharp loop northward before arching back to the south and out to the Pacific Ocean. Haynes Inlet enters the top of this loop. South Slough branches off from the bay directly before its entrance into the Pacific Ocean. The bay was formed when sea levels rose over 20,000 years ago at the end of the Last Glacial Maximum, flooding the mouth of the Coos River. Coos Bay is Oregon's most important coastal industrial center and international shipping port, with close ties to San Francisco, the Columbia River, Puget Sound and other major ports of the Pacific rim.

<span class="mw-page-title-main">Tidal creek</span> Inlet or estuary that is affected by ebb and flow of ocean tides

A tidal creek or tidal channel is a narrow inlet or estuary that is affected by the ebb and flow of ocean tides. Thus, it has variable salinity and electrical conductivity over the tidal cycle, and flushes salts from inland soils. Tidal creeks are characterized by slow water velocity, resulting in buildup of fine, organic sediment in wetlands. Creeks may often be a dry to muddy channel with little or no flow at low tide, but with significant depth of water at high tide. Due to the temporal variability of water quality parameters within the tidally influenced zone, there are unique biota associated with tidal creeks which are often specialised to such zones. Nutrients and organic matter are delivered downstream to habitats normally lacking these, while the creeks also provide access to inland habitat for salt-water organisms.

<span class="mw-page-title-main">Tidal marsh</span> Marsh subject to tidal change in water

A tidal marsh is a marsh found along rivers, coasts and estuaries which floods and drains by the tidal movement of the adjacent estuary, sea or ocean. Tidal marshes experience many overlapping persistent cycles, including diurnal and semi-diurnal tides, day-night temperature fluctuations, spring-neap tides, seasonal vegetation growth and decay, upland runoff, decadal climate variations, and centennial to millennial trends in sea level and climate.

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Barren vegetation describes an area of land where plant growth may be sparse, stunted, and/or contain limited biodiversity. Environmental conditions such as toxic or infertile soil, high winds, coastal salt-spray, and climatic conditions are often key factors in poor plant growth and development. Barren vegetation can be categorized depending on the climate, geology, and geographic location of a specific area.

<span class="mw-page-title-main">Brackish marsh</span> Marsh with brackish level of salinity

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<span class="mw-page-title-main">High marsh</span>

High marsh is a tidal marsh zone located above the Mean Highwater Mark (MHW) which, in contrast to the low marsh zone, is inundated infrequently during periods of extreme high tide and storm surge associated with coastal storms. This zone is impacted by spring tides, which is a bi-monthly lunar occurrence where the high marsh experiences higher inundation levels. The high marsh is the intermittent zone between the low marsh and the uplands, an entirely terrestrial area rarely flooded during events of extreme tidal action caused by severe coastal storms. The high marsh is distinguished from the low marsh by its sandy soil and higher elevation. The elevation of the high marsh allows this zone to be covered by the high tide for no more than an hour a day. With the soil exposed to air for long periods of time, evaporation occurs, leading to high salinity levels, up to four times that of sea water. Areas of extremely high salinity prohibit plant growth altogether. These barren sandy areas are known as "salt pans". Some cordgrass plants do survive here, but are stunted and do not reach their full size.

Low marsh is a tidal marsh zone located below the Mean Highwater Mark (MHM). Based on elevation, frequency of submersion, soil characteristics, vegetation, microbial community, and other metrics, salt marshes can be divided to into three distinct areas: low marsh, middle marsh/high marsh, and the upland zone. Low marsh is characterized as being flooded daily with each high tide, while remaining exposed during low tides.

<span class="mw-page-title-main">Ecological values of mangroves</span>

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<span class="mw-page-title-main">Salt pannes and pools</span> Water retaining depressions located within salt and brackish marshes

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<span class="mw-page-title-main">Marine habitat</span> Habitat that supports marine life

A marine habitat is a habitat that supports marine life. Marine life depends in some way on the saltwater that is in the sea. A habitat is an ecological or environmental area inhabited by one or more living species. The marine environment supports many kinds of these habitats.

<i>Sporobolus pumilus</i> Species of plant

Sporobolus pumilus, the saltmeadow cordgrass, also known as salt hay, is a species of cordgrass native to the Atlantic coast of the Americas, from Newfoundland south along the eastern United States to the Caribbean and north-eastern Mexico. It was reclassified after a taxonomic revision in 2014, but the older name, Spartina patens, may still be found in use. It can be found in marshlands in other areas of the world as an introduced species and often a harmful noxious weed or invasive species.

<span class="mw-page-title-main">Blue carbon</span> Carbon stored in coastal and marine ecosystems

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Estuary freshwater inflow is the freshwater that flows into an estuary. Other types of environmental flows include instream flow, the freshwater water flowing in rivers or streams, and estuary outflow, the outflow from an estuary to the ocean.

<span class="mw-page-title-main">Salt marsh die-off</span> Ecological disaster in low-elevation salt marshes

Salt marsh die-off is a term that has been used in the US and UK to describe the death of salt marsh cordgrass leading to subsequent degradation of habitat, specifically in the low marsh zones of salt marshes on the coasts of the Western Atlantic. Cordgrass normally anchors sediment in salt marshes; its loss leads to decreased substrate hardness, increased erosion, and collapse of creek banks into the water, ultimately resulting in decreased marsh health and productivity.

<i>Bolboschoenus planiculmis</i> Species of flowering plant in the sedge family Cyperaceae

Bolboschoenus planiculmis is a species of flowering plant in the sedge family Cyperaceae. It sprouts from tubers or seeds from April to May and flowers between May and July, with the aboveground biomass dying back in October. It is distributed in estuaries across and throughout East Asia, Central Asia, and Central Europe with small populations reported in Western European countries such as the Netherlands. B. planiculmis can be identified by its bifid styles as opposed to the trifid styles which are found on all other Bolboschoenus species in Europe.

References

  1. ↑ Morris, J.T. 2007. Estimating net primary production of salt-marsh macrophytes, pp. 106-119. In Fahey, T.J. and Knapp, A.K (eds). Principles and Standards for Measuring Primary Production. Oxford University Press
  2. ↑ NOAA. "What is a marsh organ?". National Ocean Science website. Retrieved May 3, 2021.
  3. ↑ Janousek, Christopher; Buffington, Kevin; Thorne, Karen; Guntenspergen, Glenn; Takekawa, John; Dugger, Bruce (2016). "Potential effects of sea-level rise on plant productivity: species-specific responses in northeast Pacific tidal marshes". Marine Ecology Progress Series. 548: 111–125. Bibcode:2016MEPS..548..111J. doi: 10.3354/meps11683 .
  4. ↑ Schile, Lisa; Callaway, John; Suding, Katharine; Kelly, N. Maggi (2017). "Can community structure track sea-level rise? Stress and competitive controls in tidal wetlands". Ecology and Evolution. 7 (4): 1276–1285. doi:10.1002/ece3.2758. PMC   5305999 . PMID   28303196.
  5. ↑ Peng, Dan; Chen, Luzhen; Pennings, Steven; Zhang, Yihui (2018). "Using a marsh organ to predict future plant communities in a Chinese estuary invaded by an exotic grass and mangrove". Limnology and Oceanography. 63 (6): 2595–2605. Bibcode:2018LimOc..63.2595P. doi: 10.1002/lno.10962 . S2CID   92141817.
  6. ↑ Lane, Stefanie (2022). "Using marsh organs to test seed recruitment in tidal freshwater marshes". Advances, Applications, and Prospects in Aquatic Botany. 10 (4): 20–30. doi:10.1002/aps3.11474. PMC   9400397 . PMID   36034188.
  7. ↑ Hanson, Alana; Johnson, Roxanne; Wigand, Cathleen; Oczkowski, Autumn; Davey, Earl; Markham, Erin (2016). "Responses of Spartina alterniflora to Multiple Stressors: Changing Precipitation Patterns, Accelerated Sea Level Rise, and Nutrient Enrichment". Estuaries and Coasts. 39 (5): 1376–1385. doi:10.1007/s12237-016-0090-4. S2CID   87682865.
  8. ↑ Langley, Adam; Mozdzer, Thomas; Shepard, Katherine; Hagerty, Shannon; Megonigal, Patrick (2013). "Tidal marsh plant responses to elevated CO2, nitrogen fertilization, and sea level rise" (PDF). Global Change Biology. 19 (5): 1495–1503. Bibcode:2013GCBio..19.1495A. doi:10.1111/gcb.12147. PMID   23504873. S2CID   9001921.
  9. ↑ Watson, E. B; Oczkowski, A. J; Wigand, C.; Hanson, A. R; Davey, E. W; Crosby, S. C; Johnson, R. I; Andrews, H. M (2014). "Nutrient enrichment and precipitation changes do not enhance resiliency of salt marshes to sea level rise in the Northeastern U.S.". Climatic Change. 125 (3–4): 501–509. Bibcode:2014ClCh..125..501W. doi:10.1007/s10584-014-1189-x. S2CID   154123639.
  10. ↑ Kirwan, Matthew; Guntenspergen, Glenn (2012). "Feedbacks between inundation, root production, and shoot growth in a rapidly submerging brackish marsh". Journal of Ecology. 100 (3): 764–770. doi: 10.1111/j.1365-2745.2012.01957.x .
  11. ↑ Kirwan, Matthew; Guntenspergen, Glenn (2015). "Response of Plant Productivity to Experimental Flooding in a Stable and a Submerging Marsh". Ecosystems. 18 (5): 903–913. doi:10.1007/s10021-015-9870-0. S2CID   18355559.
  12. ↑ Payne, Andrew; Burdick, David; Moore, Gregg (2019). "Potential Effects of Sea-Level Rise on Salt Marsh Elevation Dynamics in a New Hampshire Estuary". Estuaries and Coasts. 42 (6): 1405–1418. doi:10.1007/s12237-019-00589-z. S2CID   198262227.
  13. ↑ Mariotti, Giulio; Zapp, Samuel M. (2022). "A Framework to Simplify Astro‐Meteorological Water Level and Wind Inputs for Modeling Coastal Marsh Ecomorphodynamics". Journal of Geophysical Research: Earth Surface. 127 (11). doi:10.1029/2022JF006665. ISSN   2169-9003. S2CID   253620399.
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