-25- 



communities and, as distinctive communities, each type takes on 

 an ecological value based on abundance, diversity, productivity, 

 and other factors described later. 



What follows is a brief taxonomy of the region's key 

 ecosystems. The typical plants present in each ecosystem are 

 mentioned, along with associated animals. Appendix B gives a more 

 complete description of each ecosystem type, with more varieties 

 of plants and animals, including the scientific nomenclature. 



Salt Marsh or Brackish Tidal Marsh . This type of biotic 

 community is flooded periodically, the period depending on the 

 elevation of the marsh. The classic low marsh, flooded twice 

 daily, is characterized by the ecologically important salt-marsh 

 cordgrass, which serves as a base for many complex foodchains. 

 The frequency of low marsh increases from north south in the Bay, 

 particularly on the eastern shore. The flushing action of the 

 tides is essential to the low marsh community, bringing in both 

 fishes and nutrients and flushing out wastes. Tidal creeks 

 meander through the salt marsh, rich in silt and organic debris 

 from inland runoff, which provide additional nutrient supply. 



High salt marsh is flooded only irregularly, and is composed 

 of associations of grasses, rushes and sedges such as salt grass, 

 saltmeadow cordgrass, black needlerush, glasswort, etc. Typical 

 animals of both low and high salt marshes include: horseshoe, 

 fiddler and marsh crabs; several species of snails, mussels and 

 snakes; mallard, pintail and black ducks; sparrows, hawks and 



