Chapter 25 - Evolutionary Analysis PDF

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Notes on the chapter, for the class Evolution and Ecology at UIC...

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Below the black zone lies the littoral or intertidal zone, which is covered and uncovered daily by the tides. The lowest part of the littoral zone, uncovered only at the spring tides and not even then if wave action is strong, is the infralittoral fringe. Below the infralittoral fringe is the infralittoral or subtidal zone. Life on sandy and muddy beaches consists of epifauna, which are organisms living on the sediment surface, and infauna, which are organisms living in the sediments Salt or tidal marshes occur in temperate latitudes where coast- lines are protected from the action of waves within estuaries, del- tas, and by barrier islands and dunes ( Replacing salt marshes on tidal flats in tropical regions are mangrove forests or mangals (Figure 25.9), which cover 60 to 75 percent of the coastline of the tropical regions. Hydrophytic plants are typically classified into one of three groups: (1) obligate wetland plants that require saturated soils, which include the submerged pondweeds, floating pond lily, emergent cattails and bul- rushes, and trees such as bald cypress (Taxodium distichum); (2) facultative wetland plants that can grow in either saturated or upland soil and rarely grow elsewhere, such as certain sedges and alders, and trees such as red maple (Acer rubrum) and cottonwoods (Populus spp.); and (3) occasional wetland plants that are usually found out of wetland environments but can tolerate wetlands. The third group of plants is critical in determining the upper limit of a wetland along a gradient of soil moisture. Wetlands dominated by emergent herbaceous vegetation are marshes Forested wetlands are commonly called swamps Along many large river systems are extensive tracts of bottomland or riparian woodlands (Figure 25.16), which are occasionally or seasonally flooded by river waters but are dry for most of the growing season. Wetlands that are characterized by an accumulation of partially decayed organic matter with time are called peat- lands or mires (Figure 25.17). hydroperiod, which involves duration, frequency, depth, and season of flooding....