Salt marshes of Atlantic Canada: their ecology and distribution

Abstract

This paper reviews the status of research on the Atlantic salt marshes of eastern Canada. The floristics, habitats, and biophysical aspects of the Atlantic salt marshes are described and aspects relating to anthropogenic influences on the Atlantic marshes are discussed in the context of contemporary rural settlement and vulnerability to offshore oil development. Guidelines for environment management, protection, and rehabilitation research are proposed. Such guidelines are deemed important since more than half the 33 000 ha of salt marshes in Nova Scotia have been dyked for agriculture. Most of the salt-marsh habitats in Newfoundland have a high degree of domestic grazing, even though the marshes are small in size and rare in occurrence. The least disturbed in terms of domestic use are the Labrador salt marshes which, although grazed by migratory ducks and geese, have not yet been influenced by man's activities. In addition, the Labrador salt marshes are discussed and compared with the northern marshes of arctic Canada in terms of their ecology and formation.

The forests and woodlands of Labrador, Canada: ecology, distribution and future management

“…The Labrador salt marshes are grazed by migratory waterfowl and are important feeding, mating and staging areas for some 75 migratory bird species, even though their total area is probably <200 km 2 . Birds and ice scouring are factors in the salt marsh structure in Panne and Sward communities, as well as intertidal mud flats and shorelines (Roberts and Robertson 1986;Adam 1993).…”

The intergeneric hybrid grass “Poa labradorica”

“…21). In x Du- (Dutilly et al 1954(Dutilly et al , 1958Dignard et al 1991) to Labrador (Roberts & Robertson 1986), D. fisheri ssp. psilosantha is known to occur in the wettest parts of salt marshes and brackish to gravelly shores.…”

“…Depressions may also be man-made (where mud is taken to build decoys for goose hunting) (Dionne 1976(Dionne , 1978 or result from trampling and feeding (on rhizomes) by geese (Jefferies et al 1979). Feeding activities of large numbers of geese at pool margins increase pool size through abrasion and digging creates small depressions that may evolve to larger pools (Roberts & Robertson 1986). …”

“…The icefoot freezes pools and pans to the ground and also all of the tidal marsh. During spring thaw the icefoot may completely uplift parts of the tidal marsh along with boulders and create or enlarge existing pans, pools or any other kind of depression (Dionne 1976(Dionne , 1978Riley & McKay 1980;Martini 198 1, 1982;Roberts & Robertson 1986). The icefoot may also cause erosion of plant communities on rocky and sandy shore habitats.…”

Effects of dimethylsulfoniopropionate (DMSP) produced by the cordgrass Spartina alterniflora on its epiphytic algal community

“…Otte et al (2004) suggested that it acts as an herbivore deterrent, as Morris et al (2002) showed that S. alterniflora fertilized with nitrogen, and therefore containing lower levels of DMSP (Otte and Morris, 1994;Mulholland and Otte, 2000) were consumed more by rice rats than plants located in unfertilized areas. Those authors also suggested that DMSP may act as a cryoprotectant in S. alterniflora, as its geographical distribution ranges from the U.S. warm southeastern salt marshes to the eastern Canadian coast of Labrador, where temperatures in the winter are below freezing (Hitchcock, 1971;Roberts and Robertson, 1986).…”