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Community Community RelationshipsRelationships

Unit 2 NotesUnit 2 Notes

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Niche isthe species’ occupation

and its

Habitat location of species

(its address)

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NicheNicheA species’ functional role in its ecosystem; includes anything affecting species survival and reproduction

1. Range of tolerance for various physical and chemical conditions

2. Types of resources used

3. Interactions with living and nonliving components of ecosystems

4. Role played in flow of energy and matter cycling

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NicheNiche

Realized niche:Realized niche: more restricted more restricted set of conditions under which set of conditions under which the species actually exists due to the species actually exists due to interactions with other speciesinteractions with other species

Fundamental niche:Fundamental niche: set of set of conditions under which a conditions under which a species might exist in the species might exist in the absence of interactions with absence of interactions with other speciesother species

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Types of SpeciesTypes of Species•Generalist

–large niches–tolerate wide range of environmental variations–do better during changing environmental

conditions

•Specialist–narrow niches– more likely to become endangered– do better under consistent environmental

conditions

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• Depending upon the characteristics of the organism, organisms will follow a biotic potential or carrying capacity type reproductive strategy

The r-strategists1. High biotic potential – reproduce very fast2. Are adapted to live in a variable climate3. Produce many small, quickly maturing offspring = early

reproductive maturity4. “Opportunistic” organismsThe K-strategists1. Adaptations allow them to maintain population values around the

carrying capacity2. They live long lives3. Reproduce late4. Produce few, large, offspring

r and k strategistsr and k strategists

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Types of SpeciesTypes of Species• Native speciesNative species normally live and thrive in a

particular ecosystem• Nonnative speciesNonnative species are introduced - can be

called exotic or alien• Indicator speciesIndicator species serve as early warnings of

danger to ecosystem- birds & amphibians• Keystone speciesKeystone species are considered of most

importance in maintaining their ecosystem

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Nonnative Nonnative SpeciesSpecies• Nonnative plant species are invading the Nonnative plant species are invading the

nation's parks at an alarming rate, nation's parks at an alarming rate, displacing native vegetation and displacing native vegetation and threatening the wildlife that depend on threatening the wildlife that depend on themthem

• At some, such as Sleeping Bear Dunes At some, such as Sleeping Bear Dunes National Lakeshore in Michigan, as much National Lakeshore in Michigan, as much as 23 percent of the ground is covered with as 23 percent of the ground is covered with alien species, and the rate of expansion is alien species, and the rate of expansion is increasing dramatically.increasing dramatically.

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Indicator Indicator SpeciesSpecies

• a species whose status provides information on the overall condition of the ecosystem and of other species in that ecosystem

• reflect the quality and changes in environmental conditions as well as aspects of community composition

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Keystone SpeciesKeystone Species• A keystone is the stone at the top of an arch that supports the

other stones and keeps the whole arch from falling– a species on which the persistence of a large number of other species in

the ecosystem depends.

• If a keystone species is removed from a system– the species it supported will also disappear

– other dependent species will also disappear

• Examples– top carnivores that keep prey in check

– large herbivores that shape the habitat in which other species live

– important plants that support particular insect species that are prey for birds

– bats that disperse the seeds of plants

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Species Species InteractionInteraction

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CompetitionCompetitionAny interaction between two or more

species for a resource that causes a decrease in the population growth or

distribution of one of the species

1. Resource competition

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CompetitionCompetition

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Resource CompetitionResource Competition

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CompetitionCompetitionAny interaction between two or more

species for a resource that causes a decrease in the population growth or

distribution of one of the species

1. Resource competition

2. Preemptive competition

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CompetitionCompetitionAny interaction between two or more

species for a resource that causes a decrease in the population growth or

distribution of one of the species

1. Resource competition

2. Preemptive competition

3. Competitive exclusion

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Competitive ExclusionCompetitive Exclusion

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CompetitionCompetitionAny interaction between two or more

species for a resource that causes a decrease in the population growth or

distribution of one of the species1. Resource competition2. Preemptive competition3. Competition exploitation 4. Interference competition

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CompetitionCompetition

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PREDATION

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Predator AdaptationsPredator Adaptations• Prey detection and recognition

–sensory adaptations

–distinguish prey from non-prey

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Predator AdaptationsPredator Adaptations• Prey detection and recognition

–sensory adaptations

–distinguish prey from non-prey

• Prey capture–passive vs. active

–individuals vs. cooperative

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Predator AdaptationsPredator Adaptations• Prey detection and recognition

–sensory adaptations–distinguish prey from non-prey

• Prey capture–passive vs. active–individuals vs. cooperative

• Eating prey–teeth, claws etc.

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Prey AdaptationsPrey Adaptations• Avoid detection

– camouflage, mimics,

– diurnal/nocturnal

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Prey AdaptationsPrey Adaptations• Avoid detection

– camouflage, mimics,

– diurnal/nocturnal

• Avoid capture– flee

– resist

– escape

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Prey AdaptationsPrey Adaptations• Avoid detection

– camouflage, mimics, – diurnal/nocturnal

• Avoid capture– flee– resist– escape

• Disrupt handling (prevent being eaten)– struggle?– protection, toxins

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HerbivoryHerbivoryHerbivore needs to find most

nutritious–circumvent plant defenses

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HerbivoryHerbivoryHerbivore needs to find most

nutritious–circumvent plant defenses

Herbivory strong selective pressure on plants–structural adaptations for defense–chemical adaptations for defense

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HerbivoryHerbivory

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HerbivoryHerbivory

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HerbivoryHerbivory

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Symbiosis: Symbiosis: Mutualists, Mutualists,

Commensalists Commensalists and Parasitesand Parasites

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• Symbiosis and symbiotic relationship are two commonly misused terms

• Translation of symbiosis from the Greek literally means “living together”

• Both positive and negative interactions

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MutualismMutualismDEFINITION:

An interaction between two individuals of different species that benefits both partners in this interaction

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MutualismMutualism

• Increase birth rates

• Decrease death rates

• Increase equilibrium population densities,

Raise the carrying capacity

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PollinationPollination

• Animals visit flowers to collect nectar and incidentally carry pollen from one flower to another

• Animals get food and the plant get a pollination service

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• Yucca’s only pollinator is the yucca moth. Hence entirely dependent on it for dispersal.

• Yucca moth caterpillar’s only food is yucca seeds.

• Yucca moth lives in yucca and receives shelter from plant.

Yucca and Yucca Moth Yucca and Yucca Moth

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Lichen (Fungi-Algae)Lichen (Fungi-Algae)• Symbiotic relationship of algae and

fungae…results in very different growth formas with and without symbiont.

• What are the benefits to the fungus?

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Nitrogen FixationNitrogen Fixation

Darkest areas are nuclei, the mid-tone areas are millions of bacteria Gram -, ciliate

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CommensalistsCommensalists• Benefit from the

host at almost no cost to the host

• Eyelash mite and humans

• Us and starlings or house sparrows

• Sharks and remora

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Parasites and ParasitoidsParasites and Parasitoids• Parasites: draw resources from

host without killing the host (at least in the short term).

• Parasitoids: draw resources from the host and kill them swiftly (though not necessarily consuming them).

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Parasitic waspsParasitic wasps

• Important parasites of larvae.

• In terms of biological control, how would this differ from predation?

ovipositor

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Ecological Ecological ProcessesProcesses

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Ecological SuccessionEcological Succession

Primary and Secondary SuccessionPrimary and Secondary Succession

gradual & fairly predictable change in species composition with time

•some species colonize & become more abundant;

•other species decline or even disappear.

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Ecological SuccessionEcological SuccessionGradual changing environment in

favor of new / different species / communities

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Primary Primary SuccessionSuccession

Glacier Glacier RetreatRetreat

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DisturbanceDisturbanceEvent that disrupts an ecosystem or community;

• Natural disturbance

•tree falls, fires, hurricanes, tornadoes, droughts, & floods

• Human–caused disturbance

•deforestation, erosion, overgrazing, plowing, pollution,mining

• Disturbance can initiate primary and/or secondary succession

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Ecological StabilityEcological StabilityCarrying Capacity – maximum number of

individuals the environment can support

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Ecological Stability - StressEcological Stability - Stress1. Drop in Primary Productivity2. Increased Nutrient Losses3. Decline or extinction of indicator

species4. Increased populations of insect

pests or disease organisms5. Decline in Species diversity6. Presence of Contaminants

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Which law directed the Secretary of the Which law directed the Secretary of the Interior to review every roadless area of Interior to review every roadless area of 5,000 or more acres and every roadless 5,000 or more acres and every roadless island within National Wildlife Refuge and island within National Wildlife Refuge and National Park Systems?National Park Systems?

A. Endangered Species ActA. Endangered Species ActB. Wilderness Act B. Wilderness Act C. Lacey ActC. Lacey ActD. National Park ActD. National Park ActE. Wild and Scenic Rivers ActE. Wild and Scenic Rivers Act

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What are keystone species?What are keystone species?

A. A. existing in such small numbers that it is in existing in such small numbers that it is in danger of becoming extinctdanger of becoming extinct

B. introduced to an environment where it is not B. introduced to an environment where it is not native, and that has since become a nuisance native, and that has since become a nuisance

C. likely to become an endangered species within C. likely to become an endangered species within the foreseeable future throughout all or a the foreseeable future throughout all or a significant portion of its rangesignificant portion of its range

D. serve as early warnings of damage to a D. serve as early warnings of damage to a communitycommunity

E. presence and role within an ecosystem has a E. presence and role within an ecosystem has a disproportionate effect on other organisms within disproportionate effect on other organisms within the system the system

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Who did Roosevelt appoint to head Who did Roosevelt appoint to head the newly created US Forest the newly created US Forest Service to protect and manage the Service to protect and manage the worldworld’’s forests?s forests?A. E.O. Wilson A. E.O. Wilson B. Aldo LeopoldB. Aldo LeopoldC. Robert MacArthurC. Robert MacArthurD. Stephen MatherD. Stephen MatherE. Gifford PinchotE. Gifford Pinchot

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Mutualism benefits:Mutualism benefits:

A) one of the organisms & hurts A) one of the organisms & hurts the otherthe other

B) neither of the organismsB) neither of the organismsC) both of the organismsC) both of the organismsD) benefits one & doesnD) benefits one & doesn’’t hurt the t hurt the

otherotherE) only one of the organismsE) only one of the organisms

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CommensalismCommensalism::

A) benefits only one of the organismsA) benefits only one of the organisms

B) benefits both organismsB) benefits both organisms

C) benefits one, doesnC) benefits one, doesn’’t harm the othert harm the other

D) benefits neither of the organismsD) benefits neither of the organisms

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Biodiversity:Biodiversity:

A) decreases with speciation and A) decreases with speciation and extinction extinction

B) decreases with speciation and B) decreases with speciation and increases with extinctionincreases with extinction

C) increases with speciation and C) increases with speciation and extinctionextinction

D) increases with speciation and D) increases with speciation and decreases with extinctiondecreases with extinction

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What is not a pre-zygotic barriers?What is not a pre-zygotic barriers?

A) behavioral isolationA) behavioral isolation

B) habitat isolationB) habitat isolation

C) mechanical isolationC) mechanical isolation

D) hybrid isolationD) hybrid isolation

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Which of the following does Which of the following does species richness not depend on?species richness not depend on?

A) rate of immigrationA) rate of immigration

B) island sizeB) island size

C) distance from mainlandC) distance from mainland

D) types of speciesD) types of species

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Which is a species on which the Which is a species on which the persistence of a large number of other persistence of a large number of other species in the ecosystem depends?species in the ecosystem depends?

A) r-strategistsA) r-strategists

B) k-strategistsB) k-strategists

C) nonnative C) nonnative

D) keystoneD) keystone

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What is not characteristic of a What is not characteristic of a k-strategists?k-strategists?

A) long lifeA) long life

B) bigger bodiesB) bigger bodies

C) produce a lot of offspringC) produce a lot of offspring

D) produce late in lifeD) produce late in life

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What is not a predator What is not a predator adaptation?adaptation?

A) prey detectionA) prey detection

B) prey captureB) prey capture

C) eating preyC) eating prey

D) avoid detectionD) avoid detection

E) mass numbersE) mass numbers

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BibliographyBibliography1. Miller 11th Edition2. http://abandoncorporel.ca/medias/evolution.jpg3. http://www.ne.jp/asahi/clinic/yfc/fetus.html4. rob.ossifrage.net/images/ 5. http://www.mun.ca/biology/scarr/Five_Kingdoms_Three_Domains.htm6. http://www.gpc.peachnet.edu/~ccarter/Millerlec5/Millerlec5.PPT7. http://www.dnr.state.md.us/education/horseshoecrab/lifecycle.html8. http://www.falcons.co.uk/mefrg/Falco/13/Species.htm9. http://www.sms.si.edu/irlspec/NamSpecies.htm10. http://www.falcons.co.uk/mefrg/Falco/13/Species.htm11. http://www.globalchange.umich.edu/globalchange1/current/lectures/complex_life/complex_life.html12. http://nsm1.nsm.iup.edu/rwinstea/oparin.shtm13. http://www.angelfire.com/on2/daviddarling/MillerUreyexp.htm14. http://exobiology.nasa.gov/ssx/biomod/origin_of_life_slideshow/origin_of_life_slideshow.html15. http://www.geo.cornell.edu/geology/classes/Geo104/HistoryofEarth.html16. http://astrobiology.arc.nasa.gov/roadmap/objectives/o2_cellular_components.html17. http://pubs.usgs.gov/gip/fossils/18. http://hyperphysics.phy-astr.gsu.edu/hbase/nuclear/halfli.html19. http://www.accessexcellence.org/AE/AEPC/WWC/1995/teach_rad.html20. http://biology.usgs.gov/s+t/SNT/noframe/pi179.htm21. http://www.npca.org/magazine/2001/march_april/nonnative_species.asp22. http://www.bagheera.com/inthewild/spot_spkey.htm23. Biology, 2003, Prentice Hall24. http://www.nearctica.com/ecology/habitats/island.htm25. http://www.valdosta.edu/~grissino/geog4900/lect_1.htm