1
Chapter 8:
Properties of Populations
1. Defnit Defnition ion o Popu Populat lation ions s a. De Den nit itio ion: n: A gr grou oup p of indiv individ idua uals ls of the same species occupying a given area. b. Pop opula ulati tion ons s ar are e al also so dene dened d as bo both th a genetic and spatial unit. i. Gen enet etic ic un unit it: Individuals of a popu po pula lati tion on di disp spla lay y a po pote tent ntia iall fo forr interbreeding (for seually reproducing organis!s". ii. Sp Spati atial al uni unitt: Pop opula ulati tion ons s re re#u #uir ire e a dened spatial boundary b oundary.. $. 3. Unit Unitary/M ary/Modul odular ar Orga Organism nisms s a. Unitary %or!& organisms: develop!ent devel op!ent&& gro't gro'th& h& and longev longevity ity are predictable. he seually for!ed )ygote gro's in t o a genetically distinct individual. b. Mo Modu dula larr orga or gani nism sms s: he )ygote develo dev elops ps int into o a !od !odule ule tha thatt pro produc duces es si!ilar !odules. i. Genet: *odules arising fro! a )ygote (through seual reproduction". ii. amet: *odul *odules es produc produced ed ase aseually& ually& usua us uall lly y by th the e ge gene net. t. +a! a!et ets s are genet gen etic ical ally ly id ident entic ical al an and d ar are e of ofte ten n called clonal colonies. ,. !. Po Popul pulati ation on Dis Distri tri"ut "ution ion a. Di Dis stribution describe bes s the spa pattial location 'here a population occurs and is based on the absence and presence of individuals. b. Geog Geograp#i rap#ic c rang range e: A dene ned d area 'her 'h ere e all ind ndiv iviidu dual als s of a sp spec eciies es-population occurs. c. Po Popula pulatio tion n distribu distributio tion n is inuence inuenced d by biotic bioti c and abiot abiotic ic fact factors& ors& li/e habita habitat& t& resources& and habitat suitability. d. U"i$uitous: 0pecies 'i 'ith a 'i 'ide geographical distribution. e. %ndemic: 0pecies restricted to a locali)ed habitat or specic locality. f. Pop opul ulat atio ions ns ca can n ha have ve su subp bpop opul ulat atio ions ns&& 'ith 'i th co coll llec ecti tive ve lo loca call su subpo bpopul pulat atio ions ns /no'n as metapopulations. .
&. '"undance e(ects Density and Distri"ution o Populations a. '"undance: Denes the si)e of a population2 a function of t'o factors: i. Po Popu pula lati tion on de dens nsit ity y ii.. 'r ii 'rea ea o Di Dist stri ri"u "uti tion on b. )rude density: nu!ber of individuals per unit area. c. Spatial distri"ution distri"utions s: ho' individuals are ar e dis distri tribut buted ed 'it 'ithin hin the popu populat lation ion&& and !ay be: i. andom 3 no pattern can be analy)ed2 indi in divi vidua duall-s s po posi siti tion on is ind indepe epend ndent ent fro! others. ii. Uniorm 3 individuals are !ore or less evenl ev enly y sp spac aced ed22 us usua uall lly y re resul sults ts fr fro! o! negative 'ith neighboring individuals2 co! o!!o !on n in te terrri rito tori rial al ani ni!a !alls or co!peting plant species. iii. )lumped 3 individuals occur in groups2 !ay !a y fo forr! du due e to so soc cia iall fa fact cto ors or distribution of resources in a landscape. d. %c %col olog ogic ical al dens de nsit ity y: nu!ber of indivi ind ividua duals ls per uni unitt of ava availa ilable ble liv living ing space 8. *. Sam Sampl pling ing Den Densi sity ty a. Mar+,recapture: te tec chn hni# i#ue ue us used ed fo forr ani!al population esti!ates 14. 11. Meas Measures ures o Popu Populatio lation n Struct Structure ure a. Pop opul ulat atio ions ns ca can n be di divi vide ded d in into to th thrree ecologically i!portant age classes: i. Pr Prer erep epro rodu duct ctiv ive e ii.. e ii epr prod oduc ucti tive ve iii. ii i. Po Post stre repr prod oduc ucti tive ve b. Ag Age e st stru ruc ctu turre of a po popu pula lati tio on can be represented by age pyramids. 1$. 13.. S# 13 S#it its s in SeSe- atio atios s it# it# 'ge 'ge a. 0eually reproducing organis!s theoretica theor etically lly have a 11 se- ratio& but !ay shift as individuals !ature. 1,. 1!. Movement o 0ndividuals it#in t#e Population a. *ove!ent of individuals directly inuences their local density.
$ b. Dispersal: *ove!ent of individuals in space. i. %migration: *ove!ent of individuals out of a subpopulation. ii. 0mmigration: *ove!ent of individuals fro! another location into a subpopulation. c. *any organis!s depend on passive processes for dispersal. d. Dispersal in !obile ani!als !ay involve any individual. e. Migration: +ound5trip !ove!ent of ani!als for various factors& and can be daily or seasonal. i. 0o!e !igrations have only one return trip (i.e. sal!on" 1. 1&. emporal and Spatial )#anges in Population Distri"ution and Density a. Dispersal can shift the spatial distribution of individuals and conse#uently locali)ed patterns of population distribution. 18. 1*. %2ects o umans in Dispersal o Species a. 0ntroduced species 6onnative species spread by unnatural factors& usually by hu!an !ove!ent. i. Invasive species usually succeed in their ne' habitat due to lac/ of li!iting factors and an abundance of resources. ii. 6ot all introduced species are invasive2 they only beco!e invasive 'hen they outco!pete a native species for habitat utili)ation. $4.
$1.
Chapter 14:
7ife istory
1. 4ie istory a. Denition: he lietime pattern o grot#5 development5 and reproduction of an organis!. b. Age5specic patterns are the result of evolution by natural selection. c. 'daptation involves constraints and trade5o9s& 'ith a benecial change in a
trait is associated 'ith a detri!ental in another. $$. 6. rade,o2s in 4ie istories a. ach individual has a li!ited a!ount of resources it can allocate to specic tas/s. b. ;rganis!s face trade5o9s in life history characteristics related to reproduction& Intrinsic factors relating to phylogeny& develop!ent patterns& genetics& and physiology i!pose constraints resulting in trade5o9s. $<. <. Se-ual and 'se-ual eproduction a. Se-ual reproduction: occurs bet'een t'o diploid individuals 'hen #aploid gametes co!bine to for! a diploid )ygote. Genetic recom"ination is an i!!ediate and !a=or source of genetic varia"ility a!ong o9spring. b. 'se-ual reproduction: ;9spring are produced 'ithout the involve!ent of ga!etes. he ne' individuals are genetically identical to their parents. i. Part#enogenesis 3 o9spring birth by fe!ales& lit . virgin "irt# $,. 7. 8orms o Se-ual eproduction a. Separate se-es: !ost co!!on for! of seual reproduction2 !ale and fe!ale individuals are separate. b. ermap#roditism: individuals possess both !ale and fe!ale organs& and can be: i. Simultaneous #ermap#rodites: !ale organ of one individual is !ated to the fe!ale organ of the other. ii. Se$uential #ermap#rodites: individuals of a species !ay be of one se during one part of their life cycle and be the other in another. his is usually stimulated "y a c#ange in se- ratio o t#e population. $>. !. 9enefts and )osts o eproduction to 0ndividual 8itness a. P#enotypic traits co!e 'ith benets and costs.
< b. A central tenet of lie #istory t#eory states that behavioral& physiological& and energetic activities involved in reproduction 'ill cost reduced survival?fecundity?gro'th in echange for uture reproductive success. c. +eproduction can also directly reduce an individual-s ability to produce o9spring. d. Allocation to reproduction has been sho'n to reduce gro'th. e. +eproduction at a given age has potential i!plications to both age, specifc patterns of mortality and ecundity. $. :. 'ge and Maturity a. he age and si)e at !aturity are !ai!i)ed 'hen the di2erence "eteen t#e costs and "enefts o maturation at di9erent ages and si)es is !ai!i)ed. b. eproductive stage represents the transition fro! =uvenile to adult& or the stage 'hich the rst reproduction event occurs. c. 6atural selection 'ill favor those individuals 'ho age at !aturity results in the greatest nu!ber of o9spring produced over the individual-s lifeti!e. d. he primary ftness o delaying maturity is the larger body si)e obtained 'hen they rst reproduce. he primary cost o delaying reproduction is increased !ortality before the rst reproduction. e. 6atural selection favors earlier !aturation in reduced adult survival& and delayed !aturation in cases of reduced =uvenile survival. f. Predator species alter age5specic survival due to their si;e,specifcity in prey selection. 6&. &. rade,o2s "eteen 8ecundity and Survival Govern eproductive %2ort a. 8ecundity: 6u!ber of o9spring produced per unit of ti!e.
b. %nergetic costs of reproduction include a 'ide variety of physiological and behavioral activities. c. 6atural selection functions to ma-imi;e ftness over the lifeti!e of the parent. 6<. <. rade,o2s "eteen Si;e and =um"er o O2spring a. he nu!ber of o9spring a9ects the parental investment each receives. b. 'ltricial ;9spring animals: born?hatched helpless and re#uire parental care. c. Precocial ;9spring animals: eperience longer incubation?gestation& and thus are born in an advanced state of develop!ent. d. he degree o parental care varies 'idely. Invest!ent allocations in reproduction& nu!ber of o9spring& and parental care all interact to deter!ine the return to individual in ter!s of increased tness. $@. *. iming o eproduction in Species a. 0telparous organisms: organis!s that produce o9spring !ore than once over their lifeti!e. i. arly reproduction early !aturity less gro'th less fecundity per repro. period reduced survivorship reduced potential for future reproduction ii. 7ater reproduction increased gro'th later !aturity increased survivorship less ti!e for reproduction b. Semelparous organisms: organis!s invest all energetic resources in gro'th& develop!ent& and energy storage& follo'ed by one !assive reproductive e9ort& and then die. i. ;rganis!s that invest in this strategy have sli! chances of survival& thus it 'ould be eBcient to epend all energy in one bout of reproduction. c. Optimal reproductive e2ort per unit time (per reproductive event" is
, the balance bet'een current and future reproduction that functions to !ai!i)e the parent individual-s tness. <4. 1>. Genotype 0nteraction it# t#e %nvironment is epresented "y t#e 0ndividual?s 4ie istory a. ;bserved phenotypic variations 'ithin populations can arise fro!: i. Genotypic variations a!ong individuals ii. 0nteractions bet'een the genotype and the environ!ent b. P#enotypic plasticity: the ability of a genotype to give rise to di9erent phenotypic epression under di9erent environ!ental conditions. c. =orm o reaction: set of phenotype epressed by the genotype across a range of environ!ental conditions. <1. 11. Mating Systems a. Mating systems: pattern of !ating bet'een !ales and fe!ales ". Structure o mating systems in animals i. Monogamy: %or!ation of a lasting pair bond bet'een a !ale and fe!ale. 1. Prevalent a!ong birds& rare in !a!!als $. ists !ostly a!ong species in 'hich parental cooperation is needed for successful raising of the o9spring. <. *onoga!ous birds !ay c#eat in etra5pair copulations 'hile !aintaining care for the pairing !ate and the young. his !ay increase the tness of the cheating individual. ii. Polygamy : Ac#uisition of t'o or !ore !ates. 1. A pair bond eists bet'een the individual and each !ate. $. Polyga!ous individuals are generally involved in o9spring care.
<. he nu!ber of !ates an individual can !onopoli)e depends on the degree of synchrony in seual receptivity. ,. nviron!ental and behavioral conditions can produce either polygyny (1 !ale: $ or !ore fe!ales" or polyandry (1 fe!ale: $ or !ore !ales& !ostly an eception". iii. Promiscuity: *ales and fe!ales !ate 'ith one or !any of the opposite se and no pair bonds are for!ed. c. Mating systems in plants i. Outcrossing: cross5fertili)ation ii. 'utogamy: self5fertili)ation <$. 16. Se-ual Seleection a. he t#eory o se-ual selection by Dar'in eplains the seual di!orphis! of a species through t'o processes: i. 0ntrase-ual selection: !ale5to5 !ale?fe!ale5to5fe!ale co!petition for opportunity to !ate. 0econdary seual characteristics are eaggerated. ii. 0nterse-ual selection: di9erential attractiveness of one se to another. It is a for! of assortative !ating 'here fe!ales select a !ale based on specic phenotypic characteristics. <<. 13. 4ie istory )#aracteristics e(ect %-ternal Selective 8orces a. r,strategists: typically short5lived species 'ith high reproductive rate 'ith lo' population densities& rapid develop!ent& s!all body si)e& large nu!ber of lo'5survival o9spring& and !ini!al parental care. hey use te!porary habitats& and eploit nonco!petitive situation. b. @,strategists: co!petitive species 'ith long5lived individuals 'ith slo'er gro'th rate at lo' populations& but !aintain that gro'th rate at high densities. hey
> can also cope 'ith physical and biotic pressures. c. he t'o contrasting strategies are classied by the para!eters of the logistic !odel of population gro'th: r and . d. r: per capita population gro'th e. @ : !ai!u! sustainable population si)e <,.
<>. Chapter 11: Intraspecic Population +egulation 1. 8unction o %nvironment in 4imiting Population Grot# a. %-ponential model o population grot#: essential resources (space& food& etc." are unli!ited and environ!ent is constant& but reality sho's that resources are li!ited and the environ!ent is changing. b. As the density of population increases& the de!and for resources increases. c. Changes in birthrates and death rates 'ith increased population can be represented by a linear unction Astraig#t lineB d. )arrying capacity AK B: !ai!u! sustainable population si)e for the prevailing environ!ent. K is a function of supply of resources. e. 4ogistical model o population grot#: rates of birth ( b" and death (d " vary 'ith population si)e using K. <. 6. Density Dependence and Population egulation a. Density,dependent actors: factors that inuence a population in proportion to its si)e. i. Density,dependent mortality: slo's rate of population gro'th and density by increasing !ortality rates. ii. Density,dependent ecundity: decreases fecundity rates.
b. Increase in population density decrease in per capita availability of resources c. Population density can also inuence patterns o predation and spread o parasites and disease. d. Density5independent factors: Inuences that a9ect a population regardless of nu!ber of individuals.
3. 4imited esources esult in )ompetition a. )ompetition: occurs 'hen individuals use the sa!e resource that is in short supply relative of n using it. i. 0ntraspecifc: a!ong individuals of the same species. b. +esponses of populations to li!ited resources: i. Scram"le competition: e#ual depression of gro'th and reproduction across individuals 'ith increasing intensity of co!petition. ii. )ontest competition: so!e individual clai! enough a!ounts of a resource 'hile depriving others. c. %-ploitation: individuals gather a lot of a resource to deprive others. d. 0ntererence: individuals prevent others fro! occupying a habitat or utili)ing a resource. <. 7. Grot# and Development are a2ected "y 0ntraspecifc )ompetition a. Intraspecic co!petition can a9ect individual survival and reproduction. b. he density5dependent gro'th is an indirect relationship bet'een population density and individual gro'th. c. Eehavioral and develop!ental responses can adapt to co!petition. <8. !. 0ntraspecifc )ompetition and Mortality ates
a. Co!petition for resources at high pop. densities can function to reduce survival. b. Mortality functions to increase per capita resource availability& 'hich leads to increased gro'th of survivors. c. ;rganis!s 'ith indeter!inate gro'th rates sensitive to changes in resource availability can be observed. d. Sel,t#inning: progressive decline in density and bio!ass increase?gro'th of survivors caused by both density, dependent mortality and grot#. <@. :. 0ntraspecifc )ompetition and eproduction a. Co!petition 'ithin a population can reduce ecundity. b. Ani!als 'ith indeter!inate rates of gro'th and develop!ent are !ostly a9ected by density5dependent gro'th& as fecundity is related to body si)e. c. Density5dependent controls on fecundity are co!!on in plant populations ,4. &. %2ect o ig# Density on 0ndividuals a. Individual living space beco!es restricted in high5density populations& 'ith increasing aggressive contacts a!ong individuals. b. Increased cro'ding and social contact causes stress that triggers hor!onal changes that can suppress gro'th& reproductive& and seual activity. c. P#eromones: perfu!e5li/e che!ical substances released by an ani!al into the environ!ent that a9ect the behavior?physiology of other !e!bers of the species. ,1. <. Dispersal can "e Density,Dependent a. 0o!e ani!als disperse instead of coping 'ith stress& 'hich can occur all the ti!e. 4ac+ o resources and
overpopulation are so!e of the driving forces behind dispersal. b. Dispersal 'hen pop. density is lo'?increasing is i!portant in population regulation before the local population overeploits the resources. c. Dispersal !ay not function as a regulatory !echanis! but contributes to population epansion and aids in persistence of local populations. 76. @. Social 9e#avior in 4imiting Population a. Intraspecic co!petition can epress itself in social "e#avior& 'hich appears to be a !echanis! that li!its the nu!ber of ani!als living in a particular habitat. b. *any ani!al species live in groups 'ith so!e social organi)ation& 'ith group structure so!eti!es crucial to ac#uiring resources. c. Social dominance plays a role in population regulation 'hen it a9ects reproduction and survival in a density5dependent !anner. ,<. 1>. erritoriality a. ome range: area that an ani!ally nor!ally uses during a year& and it varies 'ith available food resources. b. In !a!!als& ho!e range si)e is related to body si)e. c. Aggressive individuals !ay defend any part of its ho!e range. Fell5 dened behavioral patterns describe the regular patterns of distribution by these individuals. d. erritory : defended area of the ho!e range. e. he area divided by the average si)e of territory deter!ines the nu!ber of territorial ani!als it can support. f. %loaters can replace the occupants in a range. g. erritoriality functions to li!it access to the defended area by other individuals in the population.
h. erritoriality acts as a density, dependent mec#anism in the ecess of !ales and fe!ales in reproductive stage unable to establish breeding territories. ,,. 11. Plants a. Plants are not territorial in the sa!e sense as ani!als& but can capture and hold onto space. b. Plants can occupy a certain a!ount of space and eclude other individuals. c. hese can also establish ;ones o resources depletion associated 'ith the canopy and root syste!s. d. he presence of a unifor! distribution often indicates than there is co!petition in plant populations. e. Plants successful in capturing space increase their tness at the epense of others. 16. 0nverse Density Dependence can occur in Small Populations a. Density5dependent !echanis!s have been identied that function to reduce rates of birth and survival at lo' population densities. b. 'llee e2ect: population regulation !echanis! in lo' population densities. c. 0!all population can be susceptible to a variety of factors that directly inuence the survival and birth rates. d. Fhen population densities drop& birthrates decline or !ortality rates increase at lo' pop. si)es e. 0!all pop. si)e !ay result in the "rea+don o social structures in species. If the population is too s!all to sustain an e9ective herd?pac/& population !ay decline fro! increased !ortality. ,>. 13. Density,0ndependent 8actors can 0n(uence Population Grot# a. Density,independent actors can inuence population that do not relate to the density of the population.
b. %nvironmental conditions eceeding the li!it of tolerance of an organis! can a9ect gro'th& !aturation& reproduction& !ove!ent& and survival. c. Pronounced changes in population gro'th often correlate directly 'ith variations in !oisture and te!perature. ,.
,. Chapter 1$: 0pecies Interactions& Population Dyna!ics& G 6atural 0election 1. )lassifcation o Species 0nteractions "ased on eciprocal %2ects a. =eutral A>>B neither of the populations a9ect the other. b. Mutualism populations ACCB !utually benet. c. )ommensalism A>CB a species provides suitable living conditions for the other but is not a9ected. d. )ompetition A,,B: detri!ental relationship to both species e. 'mensalism A,>B: a species adversely a9ects the other but the a9ected does not inuence the a9ecting species. f. Predation AC,B: process of feeding on a prey& usually /illing it. g. Parasitism AC,B: organis! feeds on the host but does not /ill it i!!ediately2 host lives 'ith reduced tness. h. Parasitoidism AC,B parasitoid /ills the host eventually& usually observed in species that lay their eggs inside the host and the larva eat the host. ,8. 6. Species 0nteractions in(uence Population Dynamics a. Interactions inuence the collective properties of birth and death at the population level.
8 b. As predator population increases& prey populations decline directly due to increased prey !ortality. c. Fhen individuals of t'o di9erent species share a co!!on li!iting resource that denes the carrying capacity& there is potential for co!petition bet'een individuals of the t'o species Ainterspecifc competitionB. d. In all cases of species interaction& the nature can be classied #ualitatively as neutral?positive?negative& 'ith the inuence evaluated on i!pacts on survival.
3. Species 0nteractions can unction as =atural Selection 'gents a. Interaction bet'een t'o species 'ill not inuence all individuals 'ithin the respective populations e#ually. b. Interspecic interactions involve a diverse array of physiological processes and behavioral activities inuenced by phenotypic characteristics (physiological& !orphological& and behavioral characteristics of the individual". hese characteristics vary a!ong individuals 'ithin the population& thus the degree and nature of interaction 'ill be di9erent. c. )oevolution: process 'here t'o species undergo reciprocal evolutionary change through natural selection. i. a!ple: Eird bill shapes 'ill change to crac/ seeds& but seeds 'ill tend be larger due to the tness of the predator li!ited by seed si)e. he predator 'ill adapt to this by shifting the phenotype distribution to'ards larger bills. d. Speciali;ation is a conse#uence of coevolution& 'here changes in phenotypic characteristics of the species involved function to li!it the ability of the species to carry the
sa!e or si!ilar interactions 'ith another species. e. *utually negative interactions can lead to divergence in phenotypic characteristics that function to reduce the intensity of the interaction.
7. ariations o t#e =ature o Species 0nteractions across Geograp#ic 4andscapes a. 0pecies 'ith ide geograp#ical distri"ution tend to encounter broader ranges of physical environ!ental conditions in contrast to those 'ith restricted locales. b. he #ualitative nature of so!e species can be altered 'hen the bac/ground environ!ent is changed. ,@. !. Species 0nteractions a. *ost interactions are not eclusive. hese involve species that for! di9use associations. b. Di2use coevolution: net'or/ of species undergoing a reciprocal evolutionary change through natural selection. >4. :. 0n(uence o Species 0nteraction on t#e Species? =ic#e a. %cological nic#e: description of a species in ter!s of physicoche!ical condition in 'hich it survives and reproduces& and the array of essential resources it uses. b. ypervolume A"y G. utc#insonB: each ais is dened by a variable relating to the specic resource need or environ!ental factor necessary for the species- survival and successful reproduction. his is /no'n as the undamental nic#e. c. eali;ed nic#e: portion of the funda!ental niche that a species actually eploits as a result of interaction 'ith other species. >1. &. 'daptive adiation and Species 0nteractions
@ a. 'daptive radiation: process by 'hich one species gives rise to !ultiple species that eploit di9erent features of the environ!ent. b. P#enotypic the divergence: shifting of the population in various directions phenotypically if it results in reproductive isolation. c. Hariations a!ong local populations in biotic interactions can result in phenotypic divergence and can function as !echanis!s of adaptive radiation. >$.
><. Chapter 1<: Interspecic Co!petition 1. 0nterspecifc )ompetition a. 0nterspecifc competition: adverse relationships bet'een t'o or !ore species. b. %or!s of interspecic co!petition: i. %-ploitation ii. 0ntererence c. Alternative types: i. )onsumption: inhibition of another species by consu!ing a shared resource. ii. Preemption: pri!arily in sessile organis!s& settle!ent preclude establish!ent of others. iii. Overgrot#: overgro'ing and inhibiting access to an essential resource (in plants". iv. )#emical 0nteraction: che!ical gro'th inhibitors or toins released inhibit or /ill other species (i.e. Allelopathy". v. erritorial: behavioral eclusion of others fro! a defended territory. vi. %ncounter: occurs 'hen nonterritorial !eetings bet'een individuals 'ill negatively a9ect one?both species. >,. >>. >. >.
6. #e 4ot+a,olterra Model a. 4ot+a,olterra Model: eplains the relationship bet'een t'o species using the sa!e resource. b. E: co!petition coeBcient #uantifying the per capita e9ect of species $ on species 1 c. : per capita co!petition coefficient #uantifying the per capita e9ect of species 1 on sp. $ d. Fero,grot# isocline: represents the co!bined value of pop. si)e for sp. 1 and $ at 'hich the population gro'th rate of the respective species is )ero (d N?dt 4". >8. 3. 8our Outcomes o 0nterspecifc )ompetition a. 8irst outcome: the isocline of sp1 is parallel to& and lies co!pletely above the isocline of sp$& sp$ driven to etinction. b. Second: sp$ isocline lies above sp1& sp1 is driven to etinction. c. #ird isoclines cross2 each sp inhbits the gro'th of its o'n population2 species coeist. d. 8ourt#: isoclines cross2 each sp inhibits the gro'th of the other population2 the !ost abundant species 'ins. >@. 7. )ompetitive %-clusion Principle a. )ompetitive e-clusion principle: complete competitors (t'o species that live in the sa!e and have the sa!e ecological re#uire!ents" cannot eist. It involves assu!ptions that: i. he co!petitors have the eact sa!e resource re#uire!ents. ii. nviron!ental conditions re!ain constant. 4. !. )ompetition is in(uenced "y =onresource 8actors a. nviron!ent features other than resources directly inuence species gro'th and reproduction. hese are
14 not being co!peted over& but a9ect physiological processes. 1. :. )ompetition is in(uenced "y emporal ariations in t#e %nvironment a. A species !ore eBcient at eploiting a shared li!iting resource !ay eclude other species& but these co!petitive advantages !ay change& given the changing environ!ent. b. ariation in climate can function as a density5independent li!itation on population gro'th. $. &. )ompetition occurs or Multiple esources a. Co!petition for one resource often inuences the organis!-s abilities to access other resources. <. <. elative )ompetitive '"ilities in %nvironmental Gradients a. As environ!ental conditions change& so do relative co!petitive abilities of species. b. S#its in competitive a"ilities can result fro! changes in the K of species related to changing resource base or changes in the physical environ!ent that interact 'ith resource availability. ,. *. 0nterspecifc )ompetition in(uences t#e Species? =ic#e a. 0pecies do not al'ays occupy the part of their funda!ental niche 'here conditions yield the highest gro'th rate& reproductive rate& or tness. >. 1>. esource Partitioning in Species )oe-istence a. )oe-istence bet'een co!petitors is associated 'ith so!e degree of nic#e di2erentiation (di9erences in ranges of resources used or environ!ental tolerances". b. ach species eploits a portion of the resource unavailable to others&
resulting in di9erences a!ong co5 occurring species. c. Patterns of resource partitioning are a direct result of di9erences a!ong co5occurring species in specic physiological& !orphological& or behavioral adaptations. d. )#aracter displacement: a shift involving features of the speciesphysiology?!orphology?behavior. . 11. )ompetition is a )omple0nteraction involving 9iotic and '"iotic 8actors a. )ompetition is a co!ple interaction that seldo! involves the interaction bet'een t'o species for a single li!iting resource. It involves a variety of environ!ental factors that directly inuence survival& gro'th& and reproduction& and can vary in both ti!e and space.
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Chapter 1,: Predation
1. 8orms o Predation a. Predators: species that /ill their prey !ore?less i!!ediately after capture. b. Predators function as agents o mortality on prey populations. c. ypes: i. er"ivores: consu!e only part of a plant2 does not result in !ortality of the plant. ii. Seed predators iii. a#uatic Plan+tivores: herbivores feeding on phytoplan/ton iv. Parasites: feed on host 'hile the host is still alive2 feeding activity generally not lethal in the short ter! v. Parasitoids : eggs laid on the host and the larva use the host as food source. 8. 6. Mat#ematical Model o Predator and Prey Population 0nteraction
11 a. Per consu!ption rate by predators is assu!ed to increase linearly 'ith prey population si)e. b. otal rate o predation: product of the per capita rate of consu!ption and the nu!ber of predators2 this is subtracted fro! the rate of pop. gro'th (eponential !odel". c. Prey population functions as a source of density,dependent regulation on the birthrate of the predator population. d. he gro'th rate of predator populations is )ero 'hen the si)e of the prey population e#uals the per capita rate !ortality rate of the predator divided by the product of predation eBciency and the ability to convert consu!ed prey into o9spring. @. 3. Population )ycles esult rom Predator,Prey 0nteraction a. A cyclical pattern o predator, prey relations#ips can be observed using a graphical analysis of the co!bined dyna!ics of the predator and prey populations using ;ero, grot# isoclines. b. he prey is never #uite destroyed2 the predator never co!pletely dies out. 4. 7. Mutual Population egulation a. 8unctional response: relationship bet'een per capita rate of consu!ption and nu!ber of prey. b. =umerical response: increased prey consu!ption results to increased predator reproduction. c. he 7ot/a5Holterra !odel of predator5 prey interaction assu!es a mutual regulation o predator and prey populations. 1. !. 8unctional esponses relate )onsumed Prey to Prey Density a. ype 0 unctional response: nu!ber of prey captured per unit ti!e increases linearly 'ith
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increasing nu!ber of prey. his is characteristics of passive predators. b. ype 00 unctional response: per capita rate of predation increases in a decelerating fashion& thus reac#ing an asymptote related to predator-s ti!e budget. c. ype 000 unctional response: at high prey density& the response is si!ilar to ype II& but a sigmoid as#ion is observed as predation rate approaches !a value. d. Searc# image: the ne' species in an area has a lo' ris/ of being predated upon at rst& but a predator !ay identify it as desirable prey. e. Prey sitc#ing: predation shifts to !ore abundant alternative prey $. =umerical esponse o Predators to )#anging Prey Density a. As prey density increases& the predator population gro'th is epected to respond positively. b. 'ggregative response: i!!igration of predators into area of high prey density. his is i!portant as predator populations gro' slo'er co!pared to prey. <. ime and %nergy Decisions in 8oraging a. Optimal oraging t#eory: natural selection favors eBcient foragers that !ai!i)e energy?nutrient inta/e per unit e9ort. b. Prey types are often pic/ed due to protability. c. ;pti!al prey choice and patterns of prey selection generally follo' the rules of ecient oraging. ,. Predation is+ can in(uence 8oraging 9e#avior a. *ost predators are preyed upon by other predatory species. b. he forager !ust balance its potential energy gains against the ris/ of being eaten. >. Predator and Prey )oevolution
1$ a. 6atural selection functions to produce s!arter& !ore evasive prey& as 'ell as s!arter& !ore s/illed predators. b. o a void e-tinction via predation& prey !ust evolve !eans of avoiding capture. . 1>. 'nimal Deense Mec#anisms against Predators a. Defenses can be categori)ed as: i. Permanent/constitutive: ed features in an organis! ii. 0nduced: defenses brought about by presence or action of predators b. Predator deenses: characteristics used to avoid capture i. )#emical release of secreted substance to alar! or repel (phero!ones"& or poisons (toin?veno!". ii. )ryptic coloration: coloration and patterns that allo' prey to blend in the environ!ent. iii. O"Hect resem"lance: distracts the predator a'ay fro! the ani!al or deluding the! into attac/ing a less vulnerable part of the body. iv. 8las#ing coloration: sudden colorations that distract and disoriented predators2 often used in group cohesion. v. Iarning coloration/'posematism: bold colors 'ith patterns that 'arn predators not to eat the!. vi. 9atesian edible mimicry: species (!i!ic" rese!bles the inedible species(!odel". vii. MJllerian !any mimicry: unpalatable?veno!ous species share a si!ilar color pattern. viii. Protective armor i. 9e#avioral deenses: 'ide range of prey behavior ai!ed at avoiding detectiong& eeing& and 'arning others. -. 4iving in #erds or groups
i. Predator satiation: nu!erous production of o9spring so that the predator can only ta/e a fraction of the o9spring population. . 11. Predation unting actics a. 'm"us# #unting: lying in 'ait of prey. b. Stal+ing: deliberate hunting 'ith sudden attac/. c. Pursuit #unting: the predator usually /no's the location of prey but 'ith increased pursuit ti!e. d. Predators !ay use cryptic coloration& deception& che!ical poisons& and group for!ations to attac/ prey. 8. 16. Predation o er"ivores on 'utotrop#s a. er"ivores: organis!s that prey on autotrophs (plants and algae". b. 'utotrop#,#er"ivore interactions represent a /ey feature of all co!!unities. c. Plants respond to defoliation 'ith a ush of ne' gro'th. @. 13. er"ivore,Deterring )#aracteristics o Plants a. Plants have evolved adaptations that discourage selection by herbivores. b. Secondary compounds: che!icals not involved in !etabolis! but act as deterrents fro! feeding or digestion& and can be: i. Kuantitative: produced in large #uantities. ii. Kualitative: present in s!all #uantities but are toic& usually cyanogenic c. 0o!e plants attract the predators of their predators by e!itting che!ical signals. 84. 17. 0nteraction o Plants5 er"ivores5 and )arnivores a. Plants& herbivores& and carnivores are interrelated in their interactions and regulation !echanis!s of each other-s population.
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1!. 4et#al and =onlet#al %2ects o Predator 0n(uence on Prey Dynamics a. Predators can suppress prey populations through consu!ption and cause changes in prey characteristics. b. Predator5induced defensive responses can help prey fro! not being consu!ed& but these co!e at a cost.
8$. Chapter 1>: Parasitis! and *utualis! 1. Parasitism a. Sym"iosis: inti!ate and protracted association bet'een t'o or !ore organis!s of di9erent species. b. Parasitism : the parasite benets fro! the host (that is har!ed". c. )leptoparasitism: one ani!al appropriates food gathered by another& lit. parasitis! by theft d. 0nection: heavy load of parasites& leads to diseases. e. 0i)e distinction of parasites: i. Microparasites: s!all si)e (viruses& bacteria& protists"& 'ith short generation ti!e& 'ith direct host trans!ission. ii. Macroparasites: large& 'ith long generation ti!e and do not co!plete the entire life cycle in one organis!. f. Parasitic plants can be (photosynthetic2 #emiparasites derive 'ater 'ith associated nutrients fro! host"& or #oloparasites (nonphotosynthetic2 derive 'ater J nutrients co!pletely fro! host". g. Parasites are i!portant in interspecic relations. 8<. 6. osts provide Diverse a"itats or Parasites
a. %ctoparasites: parasites that live on the s/in& feathers& or hair of the organis!. b. %ndoparasites: parasites that live inside the host. c. Parasites !ust transfer fro! one host to another. 3. Direct ransmission "eteen ost Organisms a. Direct transmission: transfer of parasites fro! one host to another 'ithout the involve!ent of an inter!ediate vector. b. 0o!e parasitic plants are trans!itted directly. 7. Use o 0ntermediate ectors in ost ransmission a. Inter!ediate vectors are often invertebrates that trans!it the parasite to the denitive host or another inter!ediate organis!. 8,. !. Multiple osts and Stages a. Defnitive #ost: host 'here the parasite !atures and reaches adulthood. b. *any parasites have !ultiple hosts and stages and therefore can develop if the parasite is trans!itted to the appropriate host. c. he dyna!ics of parasite populations are tied closely to population dyna!ics& !ove!ent patterns& and interactions of the host species. 8>. :. ost esponse to Parasitic 0nvasion a. osts ehibit a range of adaptations that !ini!i)e parasite i!pacts. b. 0o!e defensive !echanis!s are "e#avioral. c. 0n(ammatory responses are the rst line of defense against parasitic infections. 0mmune responses are the second line of defense& 'ith antibody production usually /illing o9 the parasite. Fhen these are breached& the i!!une syste! of the ani!al is co!pro!ised and can prove to be fatal.
1, d. Plants respond to bacterial and fungal infection by for!ing cysts. 8. &. %2ects o Parasites on ost Survival and eproduction a. osts allocate resources to parasite defense !echanis!s. b. Parasites function to reduce both gro'th and reproduction. c. Parasitic infection can reduce !ale reproductive success by a9ecting their ability to attract !ates. d. Increased rates of !ortality can result fro! a variety of indirect conse#uences of infection. 8. <. egulation o ost Population t#roug# Parasites a. irulence is selected against& so that parasites beco!e less har!ful to their host and thus persist. b. A parasite should balance the trade5 o9 bet'een virulence and other co!ponents of tness such as trans!issibility. c. ertical transmission: parasite trans!ission fro! parent to o9spring. d. he host condition is i!portant to a parasite if it relates to the parasite-s reproduction and trans!ission. 88. *. Parasitism can evolve into Mutualistic elations#ips a. )ommensalism: adaptations have countered the negative i!pacts. It is a relationship bet'een t'o species 'here one species benets 'ithout signicantly a9ecting the other. b. Mutualism: the tolerant host eploits the relationship. It is a relationship 'here the survival& gro'th& and reproduction of both individuals are enhanced& a reciprocal eploitation rather than a cooperative e9ort. 1>. Mutualisms and Diverse Species 0nteractions a. Mutualistic interactions benet both parties involved& and can
vary in ho' !uch the species involved depend on one another. b. Degrees of !utualis! specicity: i. Specialists: species5 specic interactions ii. Generalists: 'ide diversity of !utualistic partners. c. Sym"iotic mutualisms: individuals coeist and the relationship is obligatory (see corals and lichens". d. =onsym"iotic mutualisms: t'o organis!s do not physically coeist but depend on each other for so!e essential function (see seed dispersers and pollinators". 8@. 11. Mutualism in =utrient ranser a. +u!inants and the !icrobiota in their digestive syste! are a fa!ous ea!ple of !utualis!s that are involved in nutrient transfer. b. Eacteria in plant roots help in nitrogen ation. @4. 16. Deensive Mutualisms a. *utualistic associations involve defense of the host or cleaning !utualis!& 'hich re!oves har!ful and un'anted !aterials b. Plants attract certain species by color& odor& and fragrances& and dust pollen over the! as they etract nectar& pollinating other o'ers as pollinators =u!p fro! o'er to o'er. @1. 13. Seed Dispersal in Mutualism a. Plants 'ith heavy seeds !ay have it dispersed by seed5eating ani!als to a favorable distance for ger!ination and establish!ent of the seedling. b. Mymec#ores: plants 'ith ant5 attracting food body on the seed coat (elaiosomes". c. 8rugivores organis!s that eat only the tissue surrounding the
1> seed& but do not depend eclusively on fruits. 17. 0n(uence o Mutualism on Population Dynamics a. *utualis! eists at the population level if the gro'th of sp1 increases 'ith the increasing density of sp$& and vice versa. b. 6onsy!biotic relationships are diBcult to deter!ine if it involves a nu!ber of species. c. *utualistic species inuence each other-s ftness o pop. grot# rate indirectly through a third species or altering the local environ!ent.
@$. Chapter $$: Eiogeoche!ical Cycles 1. o MaHor ypes o 9iogeoc#emical )ycles a. 9iogeoc#emical cycle: cyclical o' of nutrients fro! nonliving and living and bac/. b. 'o basic types: i. Gaseous: at!osphere and the ocenans serve as the !ain pool of nutrients. hese are distinctly global. ii. 0edi!entary: the !ain pool of resources are the soil& roc/s& and !inerals. c. Cycles can be a hybrid of the t'o types. d. Cycles involve biological and non5 biological processes& driven by the energy (o through the ecosyste!. e. Iater is often the !ediu! that !oves ele!ents and nutrients through the ecosyste!s. f. hree basic co!ponents: inputs5 internal cycling5 and outputs. @<. 6. =utrient %ntry via 0nputs a. he input of nutrients depends on the type of biogeoche!ical cycle. 6utrients in gaseous cycles enter through the at!osphere& 'hile nutrient in sedimentary cycles
co!e fro! 'eathering of roc+s and minerals. b. Ietall: appreciable nutrient #uantities fro! precipitation. c. Dryall: nutrients co!ing fro! airborne particles and aerosols. d. 6utrient inputs for a#uatic ecosyste!s co!e fro! surrounding land& including drainage ater5 detritus5 sediment5 and precipitation. @,. 3. 4oss o =utrients via Outputs a. ;utput of nutrients !ust be o9set by inputs to avoid a net decline. b. Carbon is eported to the at!osphere in for! of car"on dio-ide. c. Organic matter can also transport nutrients fro! the ecosyste! and can also recycle nutrients& preventing rapid losses. @>. @. 7. #e )ar"on )ycle a. Carbon is ated by p#otosynt#esis& and is tied closely to energy (o. b. 0ource: carbon dioide in the at!osphere and the 'ater. c. P#otosynt#esis dra's carbon fro! the air and 'ater and introduces it into the living co!ponent of the ecosyste!. d. Carbon passes fro! herbivores to carnivores& and both die and beco!e a reservoir of dead organic matter. hey also release carbon bac/ to the at!osphere through respiration. e. =et ecosystem productivity: rate of carbon loss as a result of autotrophic and heterotrophic respiration. f. +ates of pri!ary productivity and deco!position deter!ine the rate of carbon cycling. g. Carbon can also be present as car"onates in the shells of !ollus/s and fora!inifers& and in coral reefs as aragonite. @.
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!. Daily and Seasonal ariations in )ar"on )ycling a. Carbon cycling is lo'est during the day& and highest at night. b. Seasonal (uctuations relating to te!perature and ti!ing of gro'ing is undergone by the production and use of carbon dioide. @8. :. Glo"al )ar"on )ycle a. he carbon budget of the earth is closely lin/ed to the atmosp#ere5 land5 oceans5 and movements o air around the planet. b. Surace ater in the oceans acts as the !ain site for carbon echange bet'een the at!osphere and the ocean. c. Kpta/e of carbon dioide fro! the at!osphere by terrestrial ecosyste!s is governed by gross production. @@. 144. &. #e =itrogen )ycle a. =itrogen is an essential constituent of protein 'hich is a building bloc/ of all tissues of organis!s. b. 6itrogen is generally available to plants as ammonium and nitrate. c. 'tmosp#eric decomposition brings nitrogen to the ecosyste! through etall and/or dryall. d. =itrogen f-ation can either be #ig#,energy (through cos!ic radiation& lightning& !eteorite trails"or (through "iological sy!biotic bacteria in plants& in cyanobacteria& and by free5living aerobic bacteria" e. 'mmonifcation: conversion of a!!onia to a!!oniu! as a 'aste product of !icrobial activity. f. =itrifcation: oidation of nitrite to nitrate by Nitrobacter . g. Denitrifcation: occurs in anaerobic conditions 'hen bacteria reduces nitrate to nitric oide and nitrogen gas. 141. <. #e P#osp#orus )ycle
a. P#osp#orus occurs in !inute a!ounts in the at!osphere and can only be transferred through the hydrological cycle fro! land to sea. b. oc+s and natural p#osp#ate deposits are the !ain reservoirs of phosphorus released through erosion& 'eathering& and leaching. c. Phosphorus !oves through three states: i. Particulate organic P ii. Dissolved organic p#osp#ates iii. 0norganic p#osp#ates d. he global phosphorus cycle has no signicant at!ospheric co!ponent. e. Upliting and su"se$uent eat#ering returns phosphorus deposits to the active cycle. 14$. *. #e Sulur )ycle a. he sulfur cycle has both sedimentary and gaseous co!ponents. It enters fro! co!bustion of ossil uels5 volcanic eruption5 surace e-c#ange in oceans5 and decomposition. b. %-cretion and deat# carry sulfur fro! living !aterial bac/ to the nonliving part of the ecosyste!. c. he global sulfur cycle is poorly understood& but the gaseous state o sulur enables global circulation& 'ith volcanic activity contributing to the global biogeoche!ical cycle of sulfur. d. uman activity such as !ining plays a role in the sulfur cycle. 14<. 1>. #e O-ygen )ycle a. 0ource: through atmosp#ere& dissociation o ater molecules or p#otosynt#esis. b. Kndeco!posed organic !atter as fossil fuels and carbon represent a net positive u of oygen to the at!osphere. c. ;ygen has a co!ple cycling in the ecosyste! due to its reactivity.
1 d. O;one is !aintained by a cycling reaction re#uiring sunlight& protecting organis!s for! har!ful KH radiation. 14,. 11.he Harious Eiogeoche!ical Cycles are 7in/ed
a. he lin/age of !a=or biogeoche!ical cycles are due to the! being components o living organisms that constituent organic !atter. 14>.
