EE BIOL 109 Lecture Notes - Lecture 10: Poaceae, Salt Marsh, Osmotic Power
31 Dec 2017
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Document Summary
Soft bottom lacks macroalgae (need hard substrate) and macro herbivores but has lots of infauna. Detritus has important role in soft bottom. Estuary = partially enclosed body of water where freshwater mixes with salt water. Salt marsh, mud flats = soft sediments. Increases with depth: affects distribution of organisms, highest amounts of species found at freshwater/saltwater extremes since it is hard to be a specialist and live in middle where salinity will often change (challenges osmotic homeostasis) Tidal influenced coastal wetlands found on shorelines and edge of estuaries. Determined by salinity tolerance, submergence tolerance, tolerance of anoxic sediments. Always wet -> sometimes wet: low to mid-low to mid-high to high tide areas. Decomposition and limited mixing results in anoxic sediments since decomposers remove oxygen. Spartina adaptation for anoxia/submergence: aerenchymal tissue allows for gas exchange despite being surrounded by anoxic soil. Disturbance of sediment layers by biological activity (of burrowers, deposit feeders, predators)
