Upload
jaylene-giberson
View
214
Download
0
Embed Size (px)
Citation preview
Creative Creative Community Community EcologyEcologyCh 54 notesCh 54 notes
I. Introductory I. Introductory VocabularyVocabulary
Community Community group of populations in an area or group of populations in an area or
habitathabitat
II. Interspecific II. Interspecific Interactions Interactions
Relationships between the species Relationships between the species of a community of a community
Types include:Types include:
CompetitionCompetition -/--/-
PredationPredation +/-+/-
MutualismMutualism +/++/+
CommensalismCommensalism +/0+/0
A. Competition A. Competition
Detrimental to both species Detrimental to both species Organisms compete for available Organisms compete for available
resources such as food, water, shelter, resources such as food, water, shelter, sunlightsunlight
1. Competitive exclusion 1. Competitive exclusion principle principle
Two species so similar that they Two species so similar that they compete for the same limiting compete for the same limiting resource cannot coexist in the same resource cannot coexist in the same placeplace
QuickTime™ and a decompressor
are needed to see this picture.
2. Ecological niche 2. Ecological niche
sum total of a species’ use of biotic and sum total of a species’ use of biotic and abiotic resources – how an organism fits abiotic resources – how an organism fits into it’s ecosystems (it’s role)into it’s ecosystems (it’s role)
two species cannot coexist in a two species cannot coexist in a community if they community if they occupy the same occupy the same nicheniche
3. Resource partitioning 3. Resource partitioning
if two species have the same niche, the if two species have the same niche, the less competitive one will either be driven less competitive one will either be driven from the area, or will evolve through from the area, or will evolve through natural selection to use a different set of natural selection to use a different set of resourcesresources
4. Character 4. Character displacement displacement
The tendency for characteristics The tendency for characteristics to be more divergent in to be more divergent in sympatric (geographically sympatric (geographically overlapping) populations of two overlapping) populations of two species than in allopatric species than in allopatric (geographically separate) (geographically separate) populations of the same two populations of the same two speciesspecies
B. Predation B. Predation
beneficial to one organism but not the beneficial to one organism but not the otherother
one organism eats another one organism eats another includes herbivory (eating part of a plant), includes herbivory (eating part of a plant),
parasitism (parasite living on host) parasitism (parasite living on host)
1. Predator adaptations 1. Predator adaptations
acute senses to locate preyacute senses to locate prey many have claws, teeth, fangs, stingers, many have claws, teeth, fangs, stingers,
poisonpoison generally fast and agile if they have to generally fast and agile if they have to
pursue preypursue prey
2. Animal defenses 2. Animal defenses against predators against predators
Passive defenses: hiding, chemical Passive defenses: hiding, chemical toxinstoxins
Active defenses: escaping, defending Active defenses: escaping, defending themselves, warning callsthemselves, warning calls
Animal defenses against Animal defenses against predatorspredators
Adaptive colorationAdaptive coloration camoflauge – cryptic coloration to blend with camoflauge – cryptic coloration to blend with
environmentenvironment aposematic coloration – bright coloration of aposematic coloration – bright coloration of
animals that have animals that have chemical toxins chemical toxins dangerous to predatorsdangerous to predators
Can you see me?
Animal defenses against Animal defenses against predatorspredators Mimicry – “copycat” adaptationMimicry – “copycat” adaptation
Batesian mimicry – harmless species mimics Batesian mimicry – harmless species mimics a harmful model (ex. larvae puffs up and a harmful model (ex. larvae puffs up and resembles cobra)resembles cobra)
I’m Harmless!!!
Animal defenses against Animal defenses against predatorspredators
Mullerian mimicryMullerian mimicry two unpalatable two unpalatable species resemble species resemble each other each other
predators learn predators learn more quickly more quickly about danger of about danger of the appearancethe appearance
3. Parasites and 3. Parasites and Pathogens as predators Pathogens as predators
host harmed in the processhost harmed in the process endoparasites – live within their endoparasites – live within their
host (tapeworm)host (tapeworm) ectoparasites – feed on external ectoparasites – feed on external
surface of host (mosquito)surface of host (mosquito) parasitoidism – insects lay eggsparasitoidism – insects lay eggs
on living hoston living host
4. Herbivory4. Herbivory
Organism eats part of a plant or algaOrganism eats part of a plant or alga ex. Cattle, many invertebrates, manateeex. Cattle, many invertebrates, manatee Herbivores may have adaptations such Herbivores may have adaptations such
as chemical sensors to detect toxins, as chemical sensors to detect toxins, specialized teethspecialized teeth
QuickTime™ and a decompressor
are needed to see this picture.
5. Plant defenses 5. Plant defenses against herbivores against herbivores
Chemical toxinsChemical toxins SpinesSpines ThornsThorns Used since plants cannot Used since plants cannot
run from predatorrun from predator
C. Mutualism C. Mutualism
interspecific interaction that is beneficial interspecific interaction that is beneficial to both species to both species
often requires coevolution of adaptations often requires coevolution of adaptations in both species in both species
if one is harmed, the other is usually if one is harmed, the other is usually harmed as well harmed as well
Examples of MutualismExamples of Mutualism
microorganisms in digestive system of microorganisms in digestive system of termites and ruminants (help digest termites and ruminants (help digest cellulose) cellulose)
Photosynthesis by algae in tissue of coralPhotosynthesis by algae in tissue of coral
There’s bacteria in my bellyWho knew!!!
4. Commensalism 4. Commensalism
interaction between species that interaction between species that benefits only one of the species but no benefits only one of the species but no harm to the otherharm to the other
ex. algae growing on shell, birds eating ex. algae growing on shell, birds eating insects flushed up by cowsinsects flushed up by cows
MOOOOYummy Bugs
III. Biodiversity III. Biodiversity
Species diversity in a community Species diversity in a community
Species DiversitySpecies Diversity
The variety of different kinds of The variety of different kinds of organisms that make up the communityorganisms that make up the community
QuickTime™ and a decompressor
are needed to see this picture.
QuickTime™ and a decompressor
are needed to see this picture.
QuickTime™ and a decompressor
are needed to see this picture.
QuickTime™ and a decompressor
are needed to see this picture.
Species Diversity Species Diversity
Species RichnessSpecies Richness number of species that a community can number of species that a community can
containcontain
Relative AbundanceRelative Abundance The proportion of each species represents of The proportion of each species represents of
all individuals in the communityall individuals in the community
Which community is more Which community is more diverse???diverse???
Community 1
Species A Species B
Species C Species D
Community 2Species A Species B
Species C Species D
Community 1 and 2 are equal in their species Community 1 and 2 are equal in their species richness (both have 4 different species)richness (both have 4 different species)
Community 1 is more diverse because there is Community 1 is more diverse because there is equal representation of all 4 equal representation of all 4
Community 2 has a large amount of Species ACommunity 2 has a large amount of Species A Community 1 has greatest heterogeneity (looks Community 1 has greatest heterogeneity (looks
at species number and relative abundanceat species number and relative abundance
IV. Trophic structures IV. Trophic structures
feeding feeding relationships relationships between between organismsorganisms
Quaternary Consumer(Carnivore)
Tertiary Consumer(Carnivore)
Secondary Consumer(Carnivore)
Primary Consumers(Herbivores/Zooplankton)
Primary Producers(plant/phytoplankton)
A. Food Chain A. Food Chain
Transfer of food energy from it’s source in Transfer of food energy from it’s source in plants through herbivores to carnivores and plants through herbivores to carnivores and eventually to decomposers eventually to decomposers
Each link makes a trophic levelEach link makes a trophic level Each food chain has only four or five links due Each food chain has only four or five links due
to inefficient energy transfer as you move up to inefficient energy transfer as you move up the chain the chain
Longer food chains may not be able to recover Longer food chains may not be able to recover as as quickly from environmental changequickly from environmental change
B. Food Web B. Food Web
more than one more than one food chain food chain hooked togetherhooked together
Dominant species Dominant species
have the highest abundance or the have the highest abundance or the highest biomasshighest biomass
exert control over occurrence and exert control over occurrence and distribution of other speciesdistribution of other species
Keystone species Keystone species
exert control on community structure by their exert control on community structure by their ecological role (niche)ecological role (niche)
may help to maintain diversity and balance in may help to maintain diversity and balance in communitycommunity
ex. sea otter eats sea urchin eats algaeex. sea otter eats sea urchin eats algae remove sea otter (keystone) and algae remove sea otter (keystone) and algae
population goes downpopulation goes down add sea otter – algae population increasesadd sea otter – algae population increases
Example of Keystone Example of Keystone SpeciesSpecies
Removal experimentRemoval experiment Robert Paine and Sea Star – Robert Paine and Sea Star – Pisaster Pisaster is is
a keystone predator of musselsa keystone predator of mussels With With PisasterPisaster – many species able to – many species able to
coexistcoexist Without Without PisasterPisaster – mussels able to – mussels able to
overtake area eliminating many other overtake area eliminating many other speciesspecies
Testing a Keystone Predator Hypothesis
0
10
20
30
1960 1965 1970 1975
Year
Numb
er o
f sp
ecie
s pr
esen
t
With Pisaster
Without Pisaster
Foundation SpeciesFoundation Species
Exert influence on a community by Exert influence on a community by causing physical changes in the causing physical changes in the environmentenvironment
ex. Beaver building a dam can transform ex. Beaver building a dam can transform the landscape on both sidesthe landscape on both sides
Can be positive or negative on other Can be positive or negative on other speciesspecies
QuickTime™ and a decompressor
are needed to see this picture.
V. Disturbances V. Disturbances
storms, fires, floods, drought, storms, fires, floods, drought, overgrazing, human activities overgrazing, human activities
may upset balance or equilibrium in may upset balance or equilibrium in communitycommunity
Ecological succession Ecological succession
transition in the biological species transition in the biological species composition of a community usually composition of a community usually following a disturbancefollowing a disturbance
Primary succession Primary succession
succession that begins in a virtually succession that begins in a virtually lifeless area where soil lifeless area where soil has not yet has not yet formed (like Hawaii)formed (like Hawaii)
Autotropic bacteria Autotropic bacteria lichens/mosses lichens/mosses soilsoilother plantsother plants animals animals
Secondary succession Secondary succession
existing community has been cleared by existing community has been cleared by a disturbance that leaves soil intacta disturbance that leaves soil intact
Often these areas return to something Often these areas return to something like the original statelike the original state