Biology 214 Exam 2

mx

average # of offspring multiply nx by mx

Mechanisms of competition

exploitative and interference Interference: Occurs directly between individuals via aggression when the individuals interfere with foraging, survival, reproduction of others, or by direct ly preventing their physical establishment. DIRECT COMPETITION THRU AGGRESIION. PHYSCIALLY PREVENTING RESOURCE IN HABITAT ex:: red ants making holes to avoid another ant going in Exploitattion competition: Occurs directly through a common limiting resource which acts as an intermediate ex: use of resource depletes the amount available for others Limting resource: a resource that contains population size. INDIRECT BY LIMITING OF RESOUCE

Logistic growth

dN/dt= rN(1-N/K) as N approaches K growth rate approaches 0 K is carrying capacity

Geometric growth model

discrete breading seasons; pulse breading ex: flowering plant that only grows in specific seasons Nt=N0R^t -non-overlapping generatic

intraspecific competition

example self thinking plants at low densities to a larger size at high densities they remain small -members of the same species compete for limited resources

Parasitism

example: Tape Worms Complex lifecycles -Timing of reproduction -transport host -Intermediate host -final host Example: ZOmbie snalls hijacked by Green-Banded Broodsac Flatworm Eyefluke in fish, bird and snail

gene flow

movement of alleles from one population to another offspring size and dispersal

Hutchinson's modern concept of the niche

n -dimensional hypervolume n is # of factor important to survival and reproduction a species

Its hard to study community and ecosystem stability

need long term data to understand background fluctuations but ecosystem turnover extent beyond our lifetime - hard to find tru replication

Symbiosis

A close relationship between two species that benefits at least one of the species.

population

A group of individuals that belong to the same species and live in the same area characterizes population: -distribution -abundance -density -birth/death rates, age distribution, immigrations and emmigration, rates of growth

Commensalism

A relationship between two organisms in which one organism benefits and the other is unaffected. ex: barnacle and rumor on shark -Artificial divisions by humans -Metabiosis (Hermit crab and Anemone) -Phoresy -inquilism

Mutualism

A relationship between two species in which both species benefit -caries both cost to each partner and benefits too -favored when benefits are greater than the cost so net benefit determine interactions -doenst have to be symmetric : one organism can be obligated to the mutualism, while the other can live without it's mutualistic partner

climax community

A stable, mature community that undergoes little or no change in species over time unless disrupted by environmental factor -not prone to invasion -renew themselves -composition is made by plant species and abiotic factor -biomes are climax communities

animal-animal symbiosis

Anemones & clownfish Hornbills & warthogs Crabs & sea Urchins Oxpecker & Zebra

what controls population size and Growth rate ?

Density-independent factors -disturbance, environmental conditions -hurricance, flood Density-dependent factor -Intraspecific competition (food and space etc) -contageious disease -waste product -interspecific interaction

Animal-Algal Symbiosis

Zooxanthella -dinoflagellate present in large # in the cytoplasm of many marine invertebrates. coral and algae depend on each other to survive. algae give coral food and color if stressed coral, algae leaves the coral tissue and becomes bleached then becomes more susceptible to disease. Then starves and gets a disease. then becomes skeleton and get covered with algae.

Asexual

Advantage: no need to find a mate, all genes are transmitted to all offspring, offspring phenotype already successful in that environment Disadvantage; all offspring vulnerable to same enemies, all offspring respond to the same fashion to change in environment

Assumption of logistic growth

- no migration (dispersal keeps a pop from going extinct) -constant K (same environment over time and space) -All individual have equal reosurces (same age)

Conditions for survival

-abiotic: pH, temp, salinity, forces of wind or waves resources: water, food, Co2, O2 and solar radiation

when should you reproduce?

-low adult survival, reproduce ealier -high adult survival reproduce later and invest in growth using smaller allocation of production energy

Mutualism can be observed in

-pollination -cleaning: Aquatic cleaning station -Defense: one gets food/shelter other gets protection Ex: ants-acacia system ---ants helps the acacia shoot grow much faster

Density Dependence

-populations with density dependence can be modeled using logistic growth equation -assumes that populations level off at carrying capacity

Ecological Niche

-range of physical AND biological conditions that organism can survive and reproduce - product of an organism rather than the environment "empty niche" is not valid !

community stability

1. has equilibrium state that is stable over time if the environment doesn't change 2. return to equilibrium state after a disturbance that alters community structure

Which of the following is NOT an exploitative interaction?

Competition

multi-dimensional hypervolume

Complete niche for all possible environmental variables with each axes for each variable making it impossible to visualize.

Realized niche

Conditions which the organism actually survives, grows and reproduces -forces organism to occupy a niche that's narrower than fundamental niche

Exponential growth

Countinous breading ex: humans -overlapping generation -instantanoes rates 0 interval Nt=N0(e)^rt r is intrinsic rate of increase (MOST IMPORTANT) important to population during : in which resources are not limiting -establishment of new environment -exploitation of transient (short lasting), favorable conditions -during the recovery after a major decline

Population Growth

Enables us to predict rates and patterns of population growth and what factors limit population sizes with unlimited resources population can either grow geometrically or exponentially

Semelparous

Individuals only have a single period of reproductive output. They devote most of their life to growth and storage of resources for reproduction, and die shortly after reproduction.

pioneer community

First integrated set of plants, animals, and decomposers found in an area undergoing primary ecological succession.

Fundamental niche

Full range of environmental conditions under which an organism can exist

survivorship curve

Graph showing the number of survivors in different age groups for a particular species. type 1: juvenile survivorship is high and most mortality occurs among older type 2: die at equal rate regardless of age type 3: die at high rate as juveniles and then much lower rate late run life

species interactions

Growth of one population and the effect on the size of the other a12- effect of population 2 on 1 a21- effect of population 1 on population 2

Hawaii island tectonic plate

Hawaiian islands have formed over hot spots on the pacific tectonic plate, forming an island chain varying greatly in age. It shows 4 million years of ecosystem. Different patter on nutrient distribution across the chronosequence. nitrogen is limited on early succession (bottom right) phosphorous is limited on later succession (top left)

Monoecious

Hermaphrodite : 2 genders simultaneous hemaphrodite are both at once ex; plants and flatworms sequential: first female then male ex wrasses

Crowding

Increased competition - reduces food and other resources promotes sread of disease attracts the attention of predators result: population declines slowly and eventually halts, decrease growth with increasing population size

Dioecious

Individual organisms are single sex --humans

K-selected species

Limited by carrying capacity density dependent relatively stable organisms are larger, long live, produce fewer offspring and provide greater care -iteropasity maximize efficiency type 1 and 2

R0 values

NET REPRODUCTIVE RATE. greater than one indicates growth R0 is lx times mx is for all ; lxmx is usually given just need to add up all of them to find total 1 is stable less than one is declining population. Also calculated as geometric rate of increase lambda= N t+1/N t λ = 1, r = 0 in stable generation R0 only accounts for reproduction, while r accounts for births and deaths

Interactions

Neutralism : 0.0 Ammensalism : -,0 Commensalism: +, 0 Competition : -,- Predation/Parasitism/Herbivory: -,+ Mutualism: +,+

Population Dynamics

Nfuture = Nnow + B - D + I - E. when B+I = D+E then the population size is constant. if B+I<D+E the pop. is declining

Which pattern of nutrient distribution has been found across the chronosequence on the Hawaiian islands?

Nitrogen is limiting early on in its succession while phosphorus is limiting later in succession

Phoresy (commensalism)

One organism uses another for transportation without being a parasite example : sloth and moths. "Hitch a ride"

Iniquilism

One organisms shelter WITHIN or on another organism ex: woodpeckers and squirrels that nest in trees or barnacles living above mussels insects living inside a leave

Metabiosis Commensalism

One organisms unintentionally creates or prepares the remains an environment or species for protection ex: hermit carb lives in shell from a dead gastropod for protection. A burrowing owl living in the abandoned burrow of a prairie dog is an example of. "Let me say here, you're not here anymore"

What best describes facilitation as a mechanism of succession?

Pioneer species modify the environment so that it becomes less suitable for themselves Pioneer species modify the environment so that it becomes more suitable for new species

loktra-Volterra model

Predicts species can Coexist when intraspecific competition stronger than interspecific assumptions: -these models assume logistic growth -species are near equilibrium (zero growth rate) - a is constant - Temporal or spatial heterogeneity can alter outcomes

What do the reciprocal oscillations in predator and prey populations in the Lotka-Volterra predation model suggest

Prey population growth is dependent of predator population size Predator population growth is dependent of prey population size

Loktra-Volterra predator Prey model

Produces reciprocal oscillations in predator and prey population -lower predation is more prey but higher predation is lower prey ---its a cycle Eliminating the time axis reveals an elliptical osculation in predator and prey numbers

Iteroparous

Repeated reproduction throughout lifetime

secondary succession

Succession following a disturbance that destroys a community without destroying the soil. - started by an even that reduces an ALREADY established ecosystem to a smaller population of species on existing soil ex: deforestation, hurricane, harvesting, forest fire. flood

calculate T and r?

T = estimated generation time; total xlxmx/r0 r= per capita rate of increase aka b-d *(ln)R0/T

why are life tables important

Tell us age that organism will die Fecundity schedule : tells us which age individuals make the greatest contribution to the next generation - age -fate -number of offspring number 2 factor of life table: survivorship & fecundity. forms a foundation of natural selection

what happens is the competition is removed?

The niche of competitively-ineferior species expanse in the absence of the competitively-superior species. Competitive release is when the niche of inferior species expands in the absence of the competitively superior species.

You create a life table for a population of annual flowering plants, Phlox drummondii, with R0 = 2.42. Given this R0 value, what is happening to the population?

The population in growing

What does K2/α21 = N1 represent in the Lotka-Volterra Models?

The population size of species 1 when species 1's use of species 2's resources equals the carrying capacity of species 2

Why is the variable p present in both the predator and prey population growth modeling equations?

The predation rate can increase predator population and decrease the prey population The predation rate can decrease predator population and increase the prey population

life history

The series of events from birth through reproduction and death -interested in what affects the life history -discussed in context of adaptive response

intertidal zone

Tidal fluctuations produces gradient of environmental conditions within the intertidal zone -chthamalus survive in the upper intertidal zone -balanus survive to adulthood in the middle to lower zone, survives more with warm weather and calm sea when we remove baluns barnacle there is competitive release and Chthamalus expands to its fundamental niche

Population density decreases as organism size increase T/F

True

isocline

a line on a diagram or map connecting points of equal gradient or inclination. zero population growth -if they dont cross, top species wins -if they cross intraspecific is more powerful (Stable Equilibrium) or can e Unsatble

Chronosequence

a series of communities or ecosystems representing a range of ages or times since disturbance. similar attributes but represent different ages -used to study change in plants

Resistance

ability to maintain structure and function in face of potential disturbance

Resilience

ability to recover from disturbance

stability

absence of change -lack of distrubance -community resistance or resilience -depends on resolution an area is investigated and individual can change substantially

Population growth dynamics

an age structure among countries infers population growth from age structure growth varies among countries predict future sizes

Life tables

can generate a survivorship curve shows the patterns of survival in a population show how death rates vary with age 3 types - cohort: follows a group of small-aged individuals from birth to death, assumes they all have the same pattern -static: data collected from all ages at particular time wrong bc it assumes each age class dont change and the population is the same or stationary -static life based on mortality records like skulls or fossils

faculative

can grow either with or without the presence of other organism ex: Mycorrihzae mutualism - help extract water from soil -very common and important -help supply inorganic nutrients . -Protect pathogens -Fungi get photosynthate Like all alder species, red alder can release nitrogen into soil through nodules on its roots where the plant has a symbiotic relationship with nitrogen-fixing bacteria. The bacteria have an enzyme that converts atmospheric nitrogen into ammonia, which promotes plant growth. These plants are important in ecological succession. Which model of succession is red alder most likely to play a role in?

interspecific competition

competition between members of different species

Mechanism of succession

first species establish a new environment then... -facilitation; only a certain species can colonies, which modifies environment. new environment is less suitable to pioneers and more suitable for NEW species. pioneers die :( doesn't favor environment bc is resident species favored. - tolerance: less suitable for early pioneers but also not favorable for later succession species. only resident species survive. Only residents -Inhibition: less suitable for establishment by all species, resident species inhibit establishment for all specifies. later species dominate if they can resist dominance.

Characteristics of succession

increased diversity & composition - increase in biomass, primary production , respiration, nutrient retention -physical and biological systems are inseparable

lx

is proportion of cohort surving to stage. divide the current number serving(nx) by original (starting surving population)

r-selcted species

limited by reproductive rate (r) density independent relatives unstable smaller, short-lived, produce many offrspinf, provide no care for offspring -semlparity -below k maximizes high productivity type 3 survivorship

Park Grass Experiment

oldest experiment on grass in the world -investigated ecosystem stability - showed hw richness, biomass and pH are related -repsond to climatic perturbation & fertilization - biomas has a negative effect on species richness w/o fertilizing grass predominated -fertiliizing with phosphorus, potassium, sodium and magnesium increased the proportions of legumes and other speicies - fertilizing with n,k,na,mg GREATLY increased the proportions of other species and produced moderate increases n legumes -individual plant species change alot during the experiment while still maintaining stability in the community

Allocation

organism use energy for one function such as growth, the amount of energy available for other functions is reduced -tradeoff ex size and shape

succession

process of directional change in communities over time OR change in the species structure of an ecological community over time - regular change in community composition - 1 set of species succeeds a previous set could also be after a distrucbance and each stage is called SERE

Limits population growth

regulated by biotic and abiotic factors : - limited food supply or space -the buildup of toxic waste -increased disease -predation -weather conditions -competion

Ammensalism

relationship when one organism is harmed, the other is unaffected -humans and other organisms Human actions, such pollution of water by factories or other ecological accidents

obligatory

required or demanded cannot survive in the absence of the other partner ex: Lichens (algae and fungi)

Distribution

size, shape and location of area it occupies and the spacing individuals within the area 1. the boundary 2. patterns of boundary - affected by both biotic and abiotic factors -can examine ay multiple scales patterns: random. uniform/regular (fight for resource/compete), aggregated (clumped) clumped: most likely result from attraction between individuals or attraction to a common resource?

primary succession

succession that occurs on surfaces where no soil exists, on newly exposed geological substrates not yet modified by organisms - has no vegetation, new substrates, no animals. ex: glacier forms a lake, lava flow glacier bay moss will colonize fireweed are carried by winds dryas is good for enriching the soil with nitrogen alder fixes nitrogen in soil spruce tree grow under alder thicket --hemlock trees are an important member of the mature forest community

What is represented by rhNh in the equation:

the exponential rate of increase by the prey population

sexual reproduction

zygote formation from fusion of 2 gametes advantage are offspring is genetically diverse disadvantage : we need to find mate, risk of predation while mating, only provides 50% to offspring genes