Ecology 4 NotesEcology 4 Notes

Interactions Interactions between Speciesbetween Species

Different ecosystems around Different ecosystems around the world…the world…

Although we haven’t discussed Although we haven’t discussed biomes in detail yet, which ones do biomes in detail yet, which ones do you think are most “productive”?you think are most “productive”?

Which ones are “least productive”?Which ones are “least productive”?

Very productive ecosystems…Very productive ecosystems…

Tropical rainforestsTropical rainforests Temperate evergreen and deciduous Temperate evergreen and deciduous

forestsforests Savanna is pretty good…Savanna is pretty good…

THE MOST productive is actually THE MOST productive is actually the estuaries, swamps, and the estuaries, swamps, and marshlands!!!marshlands!!!

Why would these be more Why would these be more productive than tropical productive than tropical

rainforests?rainforests?

It has to do with the availability and It has to do with the availability and

variety of variety of nichesniches…along with …along with pretty ideal conditions for organism pretty ideal conditions for organism growth and prosperity…growth and prosperity…

More niches reduces More niches reduces

competitioncompetition

What is a What is a NICHE?NICHE? An organism’s An organism’s rolerole within the within the

structure and function of an ecosystemstructure and function of an ecosystem

How does it get How does it get nourishmentnourishment?? What is it’s What is it’s habitathabitat?? Is it part of a Is it part of a predator/prey predator/prey

relationship? Or some sort of relationship? Or some sort of symbioticsymbiotic relationship? relationship?

Who does this it Who does this it competecompete with? with? How does it How does it interact interact with abiotic with abiotic

components of the environment? components of the environment? ((tolerancetolerance))

NICHENICHE

NOT just the habitatNOT just the habitat

Sum total of an organism’s Sum total of an organism’s use of its biotic and abiotic use of its biotic and abiotic resources.resources.

CompetitionCompetition Interactions within or between Interactions within or between

populations for a limited populations for a limited resource. resource. The closer the The closer the niches, the more intense the niches, the more intense the competition.competition.

Intraspecific more intense than Intraspecific more intense than interspecific.interspecific.

Gauses’ Gauses’ Competitive Competitive

Exclusion Exclusion PrinciplePrinciple One species eliminates the other One species eliminates the other

one entirely when two species one entirely when two species niches overlap and the system is niches overlap and the system is allowed to go to saturation allowed to go to saturation ((intense competitionintense competition).).

Paramecium caudatumParamecium caudatum Paramecium aureliaParamecium aurelia (pg 78 (pg 78

text)text)

Paramecia – Kingdom ProtistaParamecia – Kingdom Protista(ciliate)(ciliate)

How similar can two How similar can two species niches be and still species niches be and still

coexist?coexist? If two species have overlapping If two species have overlapping

niches, it is to the advantage of niches, it is to the advantage of both to REDUCE COMPETITION.both to REDUCE COMPETITION.

RESOURCE RESOURCE PARTITIONINGPARTITIONING

Stable CoexistenceStable Coexistence MacArthur’s MacArthur’s

WarblersWarblers 5 North American Warblers 5 North American Warblers

appear to have the same niche. appear to have the same niche. How do they coexist?How do they coexist? Resource partitioningResource partitioning

Differences in portions of trees Differences in portions of trees where they feed, nest, timing of where they feed, nest, timing of feeding, etc.feeding, etc.

Types of Types of Community Community InteractionInteraction

Commensalism (+ o)Commensalism (+ o) Mutualism (+ +)Mutualism (+ +) Predation / Parasitism (+ -)Predation / Parasitism (+ -) Competition (- -)Competition (- -)

Parasitism, commensalism and Parasitism, commensalism and mutualism = all examples of mutualism = all examples of symbiosissymbiosis

Examples of Types of Examples of Types of Community InteractionCommunity Interaction

Deer and rabbits both feed on Deer and rabbits both feed on the grass in a meadow.the grass in a meadow.

Competition!

Examples of Types of Examples of Types of Community InteractionCommunity Interaction

Remora fish use suction cup like Remora fish use suction cup like structures to attach to sharks. structures to attach to sharks. They get a free ride to lunch…They get a free ride to lunch…

But they don’t hurt the sharks…But they don’t hurt the sharks… Sometimes they eat parasites… Sometimes they eat parasites…

They also eat small bits of food They also eat small bits of food missed by the shark or other host. missed by the shark or other host.

Remora attached to a tiger Remora attached to a tiger sharkshark

                                               

    

Commensalism / Mutualism

Examples of Types of Examples of Types of Community InteractionCommunity Interaction

Protozoans live in and digest Protozoans live in and digest cellulose for termites.cellulose for termites.

And they get a “free” place to And they get a “free” place to live…live…

TrichonymphaTrichonympha Mutualistic Mutualistic

flagellated flagellated protozoan protozoan found in the found in the gut of gut of termites. termites. They digest They digest cellulose for cellulose for the termite.the termite.

Termites and Termites and Trichonympha = Trichonympha =

MutualismMutualism

Examples of Types of Examples of Types of Community InteractionCommunity Interaction

Fish-cleaning shrimp set up Fish-cleaning shrimp set up stations to remove parasites stations to remove parasites from fish.from fish.

The shrimp get food….The shrimp get food….

Shrimp that cleans fish Shrimp that cleans fish

                                        

Mutualism!!

Examples of Types of Examples of Types of Community InteractionCommunity Interaction

Egrets (birds) feed off of Egrets (birds) feed off of invertebrates that cattle kick up invertebrates that cattle kick up when they walk around the when they walk around the pasture.pasture.

Cattle Egrets Cattle Egrets in Englandin England

CommensalisCommensalism!m!

Examples of Types of Examples of Types of Community InteractionCommunity Interaction

Ants feed off of sugary Ants feed off of sugary secretion from Acacia tree secretion from Acacia tree and protect the tree from and protect the tree from herbivores.herbivores.

Ant sipping Ant sipping on sugar on sugar from from AcaciaAcacia

MutualisMutualismm!!

A tick on a horse…A tick on a horse…As the tick is sucking the blood of the horse, it is benefiting while the horse is not…

Parasitism!

LICHENSLICHENS Algae Algae

provide provide sugar and sugar and possibly possibly nitrogen for nitrogen for the fungus.the fungus.

The fungus The fungus helps to helps to maintain maintain water and water and minerals for minerals for the algae.the algae.

This is a This is a really goodreally good example example of…of…

Mutualism!!!Mutualism!!!

PredationPredation

Not really a symbiotic Not really a symbiotic relationship, but it is relationship, but it is certainly an important certainly an important interactioninteraction

Permits energy flow from Permits energy flow from one trophic (feeding) level to one trophic (feeding) level to another.another.

Predation Predation

Regulates the population Regulates the population growth of the next lower trophic growth of the next lower trophic levellevel

Lynx and HareLynx and Hare

LynxLynx

Hare in Hare in winterwinter

Hare in summerHare in summer

Would this be positive or Would this be positive or negative feedback?negative feedback?

NEGATIVE!!!!NEGATIVE!!!!

Prey Techniques Prey Techniques

Constant interaction between predator Constant interaction between predator and prey populations selects for and prey populations selects for increased efficiency of both. increased efficiency of both.

Any characteristic that increases the Any characteristic that increases the predator’s efficiency at detecting, predator’s efficiency at detecting, capturing or eating prey would be capturing or eating prey would be selected for. Conversely, any prey selected for. Conversely, any prey characteristics that would enhance its characteristics that would enhance its ability to avoid detection, capture or ability to avoid detection, capture or being eaten would also be selected for being eaten would also be selected for (an advantage)(an advantage)

It is an ARMS RACE!It is an ARMS RACE!

(coevolution)(coevolution)

Escape utilizing behavior.Escape utilizing behavior.Starling and peregrine falcon.Starling and peregrine falcon.Starlings tighten flying formation Starlings tighten flying formation when peregrines are nearby.when peregrines are nearby.

Falcon has vision 5 times better Falcon has vision 5 times better than humans. than humans.

Stoops, closes wings and dives at Stoops, closes wings and dives at speeds greater than 200 miles speeds greater than 200 miles per hourper hour

Prey killed instantly by the talons.Prey killed instantly by the talons.

Peregrine Peregrine FalconFalcon

Starling

See Chapter 4 for See Chapter 4 for more details…more details…

((pg 73-74 for defenses; also see pg 73-74 for defenses; also see symbiotic relationship symbiotic relationship

examplesexamples ) )