habitat habitats, niches, and community interactions

7/27/2019 Habitat Habitats, Niches, and Community Interactions

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03 June 2010 Habitat.ppt 1

Habitat & Niches


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Habitat

Type of environment in which a population

or species regularly lives.

Physical and biotic environment

Vegetation

Forest, meadow, pasture, coniferous forest, etc.


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Habitat

Habitats may be subdivided into layers orzones

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


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Niche

Species/populations 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.


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Niche

Fundamental niche

All resources that could be used in absence of

competition.


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Niche

Realized niche

Resources actually used in presence of competitor(s).


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Niches

Competitive exclusion

When forced to

compete, one specieseliminates other(s)


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Niches

Resource partitioning

avoids competition;

Realized niches divideresources (caterpillars)

among several species

of warblers.


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Niches

Resource partitioning

avoids competition;

Realized niches divide

resources (insects)among several species

woodpeckers, nuthatches,

& creepers.

Each species evolved &

adapted to specialized

diet.


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Keystone Species

Species in a community with vital role (niche)

in community organization.

Analogy to arch



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Keystone Species

Species with vital role

in community

organization.

Sea otter on NorthAmericas Pacific

Coast



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Keystone Species

More examples:

Sea stars on rocky

shores

Dominant plant species Lupines in mountain

meadows

Top carnivores

Wolves in YellowstoneNational park

Sharks on coral reefs

Invasive species may

upset keystone

Removal of sea otters,

wolves, sharks

Removal of nutrients

Out-compete keystone



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Niches

Invasive species

competitively

exclude native

species

Imported fire ant

Kudzu
http://www.nps.gov/plants/alien/fact/pumo1.htmhttp://upload.wikimedia.org/wikipedia/commons/4/4c/Kudzu_on_trees_in_Atlanta%2C_Georgia.jpghttp://www.nps.gov/plants/alien/fact/pumo1.htm


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Niches

Invasive species

competitively exclude

native species

Purple loosestrife

Zebra mussel
http://www.nps.gov/plants/alien/fact/lysa1.htmhttp://www.glsc.usgs.gov/main.php?content=research_invasive_zebramussel&title=Invasive%20Invertebrates0&menu=research_invasive_invertebrateshttp://www.glsc.usgs.gov/main.php?content=research_invasive_zebramussel&title=Invasive%20Invertebrates0&menu=research_invasive_invertebrateshttp://www.nps.gov/plants/alien/fact/lysa1.htm


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Niches

Invasive species

competitively

exclude native

species

Sea lamprey
http://www.glsc.usgs.gov/main.php?content=research_lamprey&title=Invasive%20Fish0&menu=research_invasive_fishhttp://www.glsc.usgs.gov/main.php?content=research_lamprey&title=Invasive%20Fish0&menu=research_invasive_fish


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Invasive species

Kudzu

Fire ant

Zebra mussel

Purple loosestrife

Leafy spurge

Asian long-horned

beetleEmerald ash borer

Japanese beetle

African honeybee

Tiger mosquito

Brown tree snake

Guam

European starling

House sparrow

More, & more, &

03 June 2010 16Habitat.ppt
http://www.fort.usgs.gov/Resources/Education/BTS/http://www.fort.usgs.gov/Resources/Education/BTS/

habitat habitats, niches, and community interactions

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