ecological communities notes

7/26/2019 Ecological Communities Notes

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Ecological Communities

Tuesday, September 1, 2015

9:58 A

Defnition - groups o species that are related to each other in that theyinteract with each other

They are living in the same habitat

E.G. - or new guinea orest we might be interested in all the species or asubset such as the

Tree community

Bird community

Stream insect community

haracteristics o a species - recogni!e characteristics o species

"abitat -

#here a species lives$ its address

%iche

#hat a species does or a living &its occupation&

'hysical environment tolerances - cold tolerance( how much drought

E)ample* bu+alo

"abitat - grassland ,prairie - not in desert( not in swampy areas

%iche - gra!es on grasseso ble to survive in water

Species relationships

'ossible relationships between species


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ompetition sp/ - sp0 - !negati"e, t#e species on eac# ot#er is negati"e, meansyou #a"e t$o species trying to get same resource, any time one gets it t#e ot#er isnegati"ely a%ected&

ommensalism sp/ 1 sp0 2 !species 1 bene'ts (rom it but species 2 doesn)t geta%ected&

'redation and parasitism sp/ 1 sp0* !species 1 bene'ts (rom interaction!predator or parasite& and species 2 is negati"ely a%ected&

3utualism sp/ 1 sp0 1!t$o species mutually bene't eac# ot#er * polination&

oevolution -

#hen 0 species a+ect each other ,all relationships e)cept commensalismthere is coevolution - adapts in one species leads to or a+ects adapttationin the other species

4 there is adaptation in one species it could lead to an adaption in anotherspcies

'rey evolves to get aster - predators get aster to 5eep up with prey -coevolve( evolve together

Di+erent than evolving to deal with physical environment - thisenvironment doesn6t change when you adapt

ompetition - both species negatively a+ected by interaction

7nly 7ccurs when there is overlap in the niche o two organisms - i nicheis same

%iche - indication o what you do or living - i what you do and some otherdoes is the same - you are competing with each other


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4 they don6t overlap - not tapping into same resources and not competing

Two 5inds o competition

4ntraspecifc competition ,within a species

8ery intense because niches overlap completely - individual bu+alo -competition between other bu+alo - eating same thing you are eating -niche is e)actly the same

4nterspecifc communication ,between species

9ess intense( partial niche overlap - other species aren6t doing e)act samething you are doing - only partial niche overlap

Types o( competition * t$o general +inds

E)ploitative* e%ect (ell t#roug# t#edepletion o shared resources !2 stra$s ina glass& e%ect o( competition is indirect * (elt t#roug# depletion o( s#ared resource

4ntererence - fght or resources

#ysical acti"ity-'g#ting (or resources

ggression

Territoriality ,intraspecifc - minimi!ed - seen in birds and mammals

- home territories - rather than have all individuals o speciescompeting head to head - each individual carves out terrirtory that ise)clusively his or her own - protect territory against other individuals

Conse.uences o( competition

Competiti"e e/clusion principle gause

Two species with same niche cannot coe)!ist


9oss o one specieso eg e/periment $it# paramecium specieso gg $#en non nati"e species are introduced * suc# as #oneybees and

#ouse sparro$s * nati"e spcies may disappear


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ne outcome * competiti"e e/clusion principal by cause * t$o species (rom samenic#e cannot e/it * t$o species doing same t#ing (or li"ing cannot e/ist, one $illdri"e t#e ot#er out o( business * grap#s * t$o di%erent paramcium species * gro$t#in red and ot#er in blue * gro$ paramesium * single celled species (ound in pond *gro$ t#em in lab * one species * start out $it# a (e$ and $e let t#em go (or periodo( time * population gro$s and reac#es steady state point * carrying capacity *second species * start out a culture ust $it# t#at species * population also ta+es o%and reac#es steady point * carrying capacity * put t$o species toget#er * "ery

similar in $#at t#ey eat, inest small particles

ut t$o o( t#em toget#er * t#ird grap# * small amounts o( species * initiallye"eryt#ing is going o+ay * bot# populations are gro$ing * blue population declinesand is out competed by species in red line * gauses principal * "ery similar * one $illoutcompete t#e ot#er

Conse.uences o( competition *


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ne species dissapears in t#at particular #abitat

3on nati"e species introduced

4oneybes, #ouse sparro$s at (eeders * introduced species, not nati"e to t#e unitedstates

ne t#ings t#at #appened * nati"e bees and nati"e birds * numbers go $ay do$n ordissapear * typically $it#out predators to +eep t#eirn umbers do$n


:esource partitioning

Two species that are competing with each other - one thing that can

happen - adaptations can occur that competition is reduced - two species -niche changes because o evolution and chances su;ciantly so there ispartial overlap andspecies can coe/it

eg +angaroo rats


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Sout# $eset desert and not#ern destert

Small mammals t#at eat seeds and come out at nig#t $ere (e$er predators

Sonoran desert * put out traps $it# peanut butter and capture

Sonoran desert * di%erent species

Aren6t +angaroo rats competing $it# eac# ot#er7

i%erent species come in di%erent sies * big one and "ery small one * loo+ at $#att#ey are eating * can tell by as t#ey eat t#ey 'll up c#ee+ pouc#es $it# (ood and gobac+ to burro$ * t#ey all eat seeds but big +angaroo rat is eating big seeds and little

+angaroo rat is eating little seeds and in bet$een are eating in bet$een seeds * oneo( t#e $ays is t#at t#is competition is resol"ed * resource partitioning * e"olutionaryc#anges in sie o( species * no$ nic#es is partially o"erlapped and don6t o"erlap tocause e/tinction o( species

5 di%erent species in great basin desert t#at di%er in sie and eat di%erent t#ings


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eg c#ipmun+s

iets are all reliti"ely similar

ne o( t#e $ays is t#at t#ey li"e and (eed in some$#at di%erent areas

3ame o( c#ipmun+s $#ere you can 'nd t#em

Alpine * #ig#est ele"ations

east * lo$est ele"ations

i"ing at di%erent ele"ations a"oid o"erlapping $it# eac# ot#er and coe/ist

Some inter(erence competition to some e/tent * some species +eep ot#erc#ipmun+s a$ay aggressi"e interactions

%ich o species - compressed to some e)tent because o presence ocompetitor

undamental niche - what a species could be doing


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:eali!ed niche - what a species is restricted to doing because ocompetetors

T$o barnacle species * 'nd t#em in intertidal area along coast line * line comes inand tides come out

;arnacles under$ater some o( time and some o( time e/posed to open air

Tolerances o( t#ese species (or being submerged or e/posed to open air "aries *component o( nic#e

ines * (undamental nic#es o( species * $#at a species could be doing * $#at it couldbe occupying i( t#e ot#er species $asn6t t#ere

;ro$n species could be t#roug#out $#ole area * but cannot because o( t#e ot#erspecies

Can 'nd by remo"ing ot#er speices

oo+ at realied nic#es o( ot#er species * bro$n one is only close to top part andblue one is to$ards t#e bottom

Situation $#ere precense o( competitor #as reduced t#e nice area t#at it canactually occupy and cannot go lo$ do$n as potentially capable o( doing


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ommensalism -

Benefts one species - no e+ect on the other

e.g. cattle egrets - cattle

E)ample - cattle gra!ing - tall white bird - cattle egrets -


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'ig - parasitic round worms

'rey and predator strategies -

7ten time - a lot o adeptations to avoid being eaten - strategies - preyhave - come in variety o guises

"ow organisms avoid being eaten

amou


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%umber o 5inds o mimicry

7ne case - mimic something that is inedible -

Sidewal5s under trees - bird droppings - white portion and dar5er portion

3oth - loo5s li5e bird dropping - during day inactive - sitting on lealoo5ing li5e bird dropping and most birds - are not very interested ineating bird dropping and pass over it

3imicry -

:esembling something to)ic

Batesian

3odel is distasteul and has warning coloration

3imic is tasty

3ullerian

%on related poinsounous species resembling one another

e.g. viceroy and monarch butter


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>iceroy and monarc# butter=y * "ery similar * orange and blac+ and spec+led $#ite *di%erent species * one point in time * t#oug#t it $as batesian mimicry * t#oug#tmonarc#s $ere poisonous and "iceroy * edible to birds

>iceroy * bad tasting to birds as $ell

Are similar in coloration patterns

Easy (or predators to a"oid

'redator strategies

amouacultative - two organisms can survive without each other but beneftwith each other

'lants and polinators because plants are stationary

'ollination( seed dispersal( plant protection

3ychorrhi!ae( ungus that lives on plant roots

lants * don6t #a"e a lot o( seeds to mo"e around in en"ironment * (ruit * ta+e (ruita$ay and consume it, disperse seeds


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lants use insects (or protection against #erba"ors * bac+ o( sun=o$er li+e plant *#as ants on it * attracted * necteries * e/tra=oral necteries t#at produce sugar (orants * and ants "ery protecti"e o( in=orecents * seed predator =ies * $ant to layeggs in seeds o( o"eries and ants +eep t#em a$ay

yc#orrie* (ungae t#at li"e on plant roots * almost all plants #a"e t#is * (ungi *

e/tract some minerals (rom soil t#at plants $ouldn6t be good at and plant rootspro"ide nutrients and carbo#ydrates due to p#otosynt#asie

7bligate - 0 organisms cannot survive without each other - yucca andyucca moth - lichen ,algae and ungus

ic#en * roc+y sur(aces and old dead trees * not a single species but t$o species *

Algae and (ungus !or bacteria&

T$o organisms * algae and (ungus * pro"ide di%erent t#ings (or eac# ot#er

Algae p#otosynt#esis * carbo#ydrate

?ungus * good (or minerals and mostiure in sur(ace *

@ro$ing intert$ined $it# eac# ot#er and pro"iding nutrience (or eac# ot#er

ease apart cells * cannot li"e on o$n

ucca plant and yucca mot#

ucca mot# * tra"els bet$een yucca plants * "isits =o$er and ta+es plant and puts iton stigma o( anot#er one

#ysically in"ol"ed in polonation

ucca plant relys on t#is mot# (or polination

ucca plant cannot seed

ot# * relies e/clusi"ley on yucca plant (or (ood * (emale lays eggs in o"ary * s$ellsand lar"ae eat seeds (rom t#at =o$er

ore =o$ers t#at are polinated t#an are consumed by lar"ae * plus (or bot# mot#and plant to produce more species


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3utualism and aggressive mimicry -

leanier fsh and imposter - aggressive mimicry and mutualism

4mposter - many coral reis - fsh called cleaner fsh

9arge fsh - orange strip - come to these certain places called cleaningstation - cleaner fsh with blac5 stripe - big fsh are predators and go intotrance and little fsh cleans o+ little parasites on s5in and sometimes inthe mouth

leaner fsh gets to eed and big fsh gets to have parasites removed thatcould cause trouble

3imic species - that?s a predator - two species with blac5 stripe - one is

good guy and one is bad guy

'redator fsh - aggressive mimicry - loo5s li5e its going to be a cleaner fsh- but predator fsh - ta5e a bite out o fn or some other part while thelarger fsh is in its trance or cleaning fsh

ommunity change - succession - composition may change - loo5 atdi+erent species - and come bac5 later - in /22 years * composition o(community #as c#anged * di%erent tree species, plant species, and di%erentanimals

rocess called succession * relati"ley orderly process #o$ community c#anges

?ollo$ing distrubance * * 're, (orest cutting do$n

?ollo$ing t#e disturbance

Coloniation by species resulting in c#anges in species composition until a stableset o( species is reac#ed !clima/ community& c#anges a little bit

Situations * (ollo$ing disturbance and a(ter succession process * stable set o(

species * replaces itsel( (rom one species * remains set (or a long period o( time *clima/ community

Two 5inds o succession

'rimary succession


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Begin with barren habitat - roc5slide( lava


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Sand dune succession

Bn"ol"es establis#ing stable en"ironment (or plants * some grass type species cangain a (oot in t#ere * soil stablied * small s#rubs come in and trees come in

rocess occurs because o( di%erences in dispersal and s#ades tolerances

lima) community - stable community - no changes in species tolerant oown shade - beach maple orest

lima) - sel sustaining species community - composition doesn6t changemuch 2 disturbances can come in but continualsuccession process #appening* roots being e/posed creates an opening in (orest canopy * some cannopy * a lot o(species cannot li"e in s#ade e/cept species in clima/ * in s#ade o( itsel( in(act

;eac# maple (orest can continue

Tree (allen do$n * opening in canopy and some species #a"e #ig#er lig#tre.uirements can colonie temporarily

ommunity change - succession -

Disturbances can be bad things( but is a act o lie

Some species addapted that there is periodic disturbances

>ire - common in many types o communities - grassland( orests - burnevery ew years

Species living adapted to disturbances

'ine trees - ma5e cones - glued together by resin so that seeds are 5eptinside -

ones only release seeds when a fre comes through( melts resin and frecomes out

Seeds on (orest =oor * cleared o( "egetation

@rasslands * i( 're gro$s t#roug# * resprout t#roug# roots

Trees * typically negati"ley a%ected by 're * grasslands maintained as grasslandsand not (orests


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Some cumminities do not reco"er (rom some disturbances

lo$ed prairie * no $ay (or community to rec"er (rom plo$ing a prairie

3ot plo$ 'eld * no prairie plants le(t or no seeds le(t * c#ances are nearest prairie *10s or 20 more miles a$ay

et 'eld go * $on6t go bac+ no seed sources

Community organiation

"ow many species

#hat 5inds o species


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B( you tra"el around $orld * tropics and temperate ones, desert areas * di%erentcommunities t#ere

Tropic * many species and can "ary (rom place to place

Determining actors

%umber o actors

1 "ow many resources are availablea 'attern ound - 3ore species in tropical than temperate latitudes

- breeding birds - number o birds - temperate northern areas - @2degrees north latitude - wor5ing your way south - number o birdsincreases as you go south - more resources in tropics or birds(environment which is capable o supporting lie all year round - intemperate - winter=downtime or species

2 ompetition

a 9imits the number o species that can be present - can6t have toomany species competing or same resource - resource partitioningcan occur i a lot o species occuring( but limits by resourcesavailable

2 'redators - interesting a+ecta E+ect on competition - reduce nuimber o species - and others

where number o species in increasedb e.g. periwin5le predators and algae species diversity

2 Disturbancea "ighest species diversity with moderate disturbance

most communities have disturbance - low or moderate - lead tohigher species diversity - environment mosiac o disturbed and

non disturbed areas and di+erent species can live in distrubed vsnon distrubed areas - clima) in some areas - i distrubance isgreat - species diversity is reduced


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'redation - a+ects number o species living in area

Bntertidle area * snails on algae *

redators are t#ere * species di"ersity could be reduced * predators eating algae *but in (act


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ecological communities notes

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