In ecology,a biological interaction is the effect that a pair of organisms living together in a community have on each other. They can be either of the same species,or of different species. These effects may be short-term,or long-term,both often strongly influence the adaptation and evolution of the species involved. Biological interactions range from mutualism,beneficial to both partners,to competition,harmful to both partners. Interactions can be direct when physical contact is established or indirect,through intermediaries such as shared resources,territories,ecological services,metabolic waste,toxins or growth inhibitors. This type of relationship can be shown by net effect based on individual effects on both organisms arising out of relationship.
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.
Sporobolus alterniflorus,or synonymously known as Spartina alterniflora,the smooth cordgrass,saltmarsh cordgrass,or salt-water cordgrass,is a perennial deciduous grass which is found in intertidal wetlands,especially estuarine salt marshes. It has been reclassified as Sporobolus alterniflorus after a taxonomic revision in 2014,but it is still common to see Spartina alterniflora and in 2019 an interdisciplinary team of experts coauthored a report published in the journal Ecology supporting Spartina as a genus. It grows 1–1.5 m tall and has smooth,hollow stems that bear leaves up to 20–60 cm long and 1.5 cm wide at their base,which are sharply tapered and bend down at their tips. Like its relative saltmeadow cordgrass S. patens,it produces flowers and seeds on only one side of the stalk. The flowers are a yellowish-green,turning brown by the winter. It has rhizoidal roots,which,when broken off,can result in vegetative asexual growth. The roots are an important food resource for snow geese. It can grow in low marsh as well as high marsh,but it is usually restricted to low marsh because it is outcompeted by salt meadow cordgrass in the high marsh. It grows in a wide range of salinities,from about 5 psu to marine,and has been described as the "single most important marsh plant species in the estuary" of Chesapeake Bay. It is described as intolerant of shade.
Ecological facilitation or probiosis describes species interactions that benefit at least one of the participants and cause harm to neither. Facilitations can be categorized as mutualisms,in which both species benefit,or commensalisms,in which one species benefits and the other is unaffected. This article addresses both the mechanisms of facilitation and the increasing information available concerning the impacts of facilitation on community ecology.
Intertidal ecology is the study of intertidal ecosystems,where organisms live between the low and high tide lines. At low tide,the intertidal is exposed whereas at high tide,the intertidal is underwater. Intertidal ecologists therefore study the interactions between intertidal organisms and their environment,as well as between different species of intertidal organisms within a particular intertidal community. The most important environmental and species interactions may vary based on the type of intertidal community being studied,the broadest of classifications being based on substrates—rocky shore and soft bottom communities.
Joan Roughgarden is an American ecologist and evolutionary biologist. She has engaged in theory and observation of coevolution and competition in Anolis lizards of the Caribbean,and recruitment limitation in the rocky intertidal zones of California and Oregon. She has more recently become known for her rejection of sexual selection,her theistic evolutionism,and her work on holobiont evolution.
California's coastal salt marsh is a wetland plant community that occurs sporadically along the Pacific Coast from Humboldt Bay to San Diego. This salt marsh type is found in bays,harbors,inlets,and other protected areas subject to tidal flooding.
Sesarma reticulatum,the purple marsh crab or simply marsh crab,is a crab species native to the salt marshes of the eastern United States.
Judith Shulman Weis is an American marine biologist. Her research and writing focuses on estuarine ecology and ecotoxicology,including the responses of salt marsh and brackish marsh organisms,populations and communities to stresses,particularly heavy metal contaminants,invasive species and parasites. She is also working to reduce the spread of microplastics in the environment and find solutions to protecting coastal marshes from sea level rise.
The Coastal and Estuarine Research Federation (CERF) is a private,nonprofit organization created in 1971. At that time,the members of two regionally based organizations,the Atlantic Estuarine Research Society (AERS) and the New England Estuarine Research Society (NEERS) recognized the need for a third estuarine organization that would address national estuarine and coastal issues. Today,CERF is a multidisciplinary federation of members and seven regionally-based Affiliate Societies dedicated to the understanding and wise stewardship of estuaries and coasts worldwide.
Brackish marshes develop from salt marshes where a significant freshwater influx dilutes the seawater to brackish levels of salinity. This commonly happens upstream from salt marshes by estuaries of coastal rivers or near the mouths of coastal rivers with heavy freshwater discharges in the conditions of low tidal ranges.
Littoraria irrorata,also known by the common name the marsh periwinkle,is a species of sea snail,a marine gastropod mollusk in the family Littorinidae. The specific epithet irrorata means 'moistened' or 'dewy.'
In ecology,a priority effect refers to the impact that a particular species can have on community development as a result of its prior arrival at a site. There are two basic types of priority effects:inhibitory and facilitative. An inhibitory priority effect occurs when a species that arrives first at a site negatively affects a species that arrives later by reducing the availability of space or resources. In contrast,a facilitative priority effect occurs when a species that arrives first at a site alters abiotic or biotic conditions in ways that positively affect a species that arrives later. Inhibitory priority effects have been documented more frequently than facilitative priority effects. Studies indicate that both abiotic and biotic factors can affect the strength of priority effects.. Priority effects are a central and pervasive element of ecological community development that have significant implications for natural systems and ecological restoration efforts.
Geukensia demissa is a species of mussel,a marine bivalve mollusk in the family Mytilidae,the true mussels. This species is native to the Atlantic coast of North America. The common names for this species include ribbed mussel,Atlantic ribbed marsh mussel and ribbed horsemussel. However,the common name ribbed mussel is also used for the Southern Hemisphere mussel Aulacomya atra. The appearance of the shell is grooved and oval in shape. The interior of this mussel is tinted purple.
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.
A habitat cascade is a common type of a facilitation cascade. where “indirect positive effects on focal organisms are mediated by successive formation or modification of biogenic habitat”.
Armases cinereum,also known as the squareback marsh crab or wharf crab,is a species of crab in the family Sesarmidae. The wharf crab is a small crab that is dark brown to muddy in color,which allows it to blend in with its usual surroundings. It is found on the Atlantic southeastern coast,down into the Gulf of Mexico. It is an omnivore and is prevalent in marshy coastal environments along the Southwestern Atlantic.
A facilitation cascade is a sequence of ecological interactions that occur when a species benefits a second species that in turn has a positive effect on a third species. These facilitative interactions can take the form of amelioration of environmental stress and/or provision of refuge from predation. Autogenic ecosystem engineering species,structural species,habitat-forming species,and foundation species are associated with the most commonly recognized examples of facilitation cascades,sometimes referred to as a habitat cascades. Facilitation generally is a much broader concept that includes all forms of positive interactions including pollination,seed dispersal,and co-evolved commensalism and mutualistic relationships,such as between cnidarian hosts and symbiodinium in corals,and between algae and fungi in lichens. As such,facilitation cascades are widespread through all of the earth's major biomes with consistently positive effects on the abundance and biodiversity of associated organisms.
Carol Anne Blanchette is research biologist at the University of California,Santa Barbara who is known for her work on marine intertidal zones and the biomechanics of marine organisms.
David M. Post is a research scientist and academic administrator. He is currently a professor of Ecology and Evolutionary Biology at Yale University and the Vice President .,Dean of Faculty,and Visiting Wong Ngit Liong Professor at Yale-NUS College,the first liberal arts college in Singapore. Post is an aquatic ecologist who studies food webs,evolution,and stable isotopes in lakes and rivers in Connecticut and Kenya.
