Presentation on theme: "03 June 2010Habitat.ppt1 Habitat & Niches. 03 June 2010Habitat.ppt2 Habitat Type of environment in which a population or species regularly lives. –Physical."— Presentation transcript:
03 June 2010Habitat.ppt2 Habitat Type of environment in which a population or species regularly lives. –Physical and biotic environment –Vegetation Forest, meadow, pasture, coniferous forest, etc.
03 June 2010Habitat.ppt3 Habitat Habitats may be subdivided into layers or zones –Microhabitats Forest canopy: leaves, branches Shrub layer: leaves, branches, trunks Herb layer: leaves, stems, mosses, ferns Litter: dead fallen leaves, logs, –Varies in depth, quality Soil: topsoil, subsoil
03 June 2010Habitat.ppt4 Niche Species’/population’s role in its community –Dimensions of a niche: Habitat & microhabitat (space occupied) Food “spectrum,” essential nutrients –Plants eaten &/or not eaten Reproductive requirements –Nutrition, nest/den sites Seasonality: When are resources required, used.
03 June 2010Habitat.ppt5 Niche Fundamental niche –All resources that could be used in absence of competition.
03 June 2010Habitat.ppt6 Niche Realized niche –Resources actually used in presence of competitor(s).
03 June 2010Habitat.ppt7 Niches Competitive exclusion –When forced to compete, one species eliminates other(s)
03 June 2010Habitat.ppt8 Niches Resource partitioning avoids competition; Realized niches divide resources (caterpillars) among several species of warblers.
03 June 2010Habitat.ppt9 Niches Resource partitioning avoids competition; Realized niches divide resources (insects) among several species –woodpeckers, nuthatches, & creepers. Each species evolved & adapted to specialized diet.
Keystone Species Species in a community with vital role (niche) in community organization. Analogy to arch 03 June 2010Habitat.ppt10
Keystone Species Species with vital role in community organization. Sea otter on North America’s Pacific Coast 03 June 2010Habitat.ppt11
Keystone Species More examples: –Sea stars on rocky shores –Dominant plant species Lupines in mountain meadows –“Top” carnivores Wolves in Yellowstone National park Sharks on coral reefs Invasive species may upset keystone –Removal of sea otters, wolves, sharks Removal of nutrients Out-compete keystone 03 June 2010Habitat.ppt12
03 June 2010Habitat.ppt13 Niches Invasive species competitively exclude native species –Imported fire ant –KudzuKudzu
03 June 2010Habitat.ppt14 Niches Invasive species competitively exclude native species –Purple loosestrifePurple loosestrife –Zebra musselZebra mussel
03 June 2010Habitat.ppt15 Niches Invasive species competitively exclude native species –Sea lampreySea lamprey
Invasive species –Kudzu –Fire ant –Zebra mussel –Purple loosestrife –Leafy spurge –Asian long-horned beetle –Emerald ash borer –Japanese beetle –African honeybee –Tiger mosquito –Brown tree snakeBrown tree snake Guam –European starling –House sparrow –More, & more, & … 03 June 201016Habitat.ppt