Book summary

Proximate explanation

an explanation in terms of what is going on “here and now”

ultimate explanation

explanation in evolutionary terms, of the present distribution and abundance of this animal lies in the ecological experiences of its ancestors

populations

Functioning groups of individual organisms of the same species in a defined location

communities

consist of all species populations present in a defined location

ecosystems

include both the community of organisms and the physical environment in which they exist

bioosphere

Totality of all of life interacting with the physical environment at the scale of the entire planet

at level of organism

ecology deals primarily with how individuals are affected by their environment and with their physiological and behavioural reponses to the environement

poulation ecology

Stresses the trends and fluctuations in the number of individual of a particular species at a particular time and place, as determined by the interactions of birth and death rates and the interactions between the populations themselves

community ecology

what controls the diversity of species in a given area

ecosystem ecology

strives to understand the functioning of entire lakes, forests, wetlands or other portions of the earth in terms of energy and material inputs and outputs

three generalities

1. The properties observed at a particular level arise out of the functioning of parts at the level below → how an ecosystem fucntions is the result of the functioning of the communities within it interacting with the physical environment

2. To understand the dysfunction in an individual organism, we must look at the the functioning of the organs in that organism. To understand the controls on birth rate in a population, we must look at reproduction in individual organisms

3. Properties at a given level of organization may be predicted without fully understanding the functioning at lower levels. - predict patterns in ecosystems without understanding all of the details of the dynamics of constituent populations and can predict patterns in populations without understanding all of the details of the responses of individual organism

ecological succesion

the successive and continuous colonization of a site by certain species populations, accompanied by the local extinction of others

ecological evidence

\- Observations: often of changes in abundance or system functioning over either time or space, and often involving comparisons across and between different areas or systems - Experiments, lab and field - Mathematical models; capture some compnent of ecological interactions, function and structure

manipulative field experiment

monitor changes

comparative field observations

explicitly compare same sort of data from many different sites

p

results are statistically significant

p>0.05

1) There really is no effect of ecological importance 2) The data are simply not good enough, or there are not enough of them, to support the effect even though it exists, possibly because the effect itself is real but weak

sampling: aim

1) obtain an estimate that is accurate and unbiased; that is, neither systematically too high nor too low as a result of some flaw in the program 2) obtain data that have as little variation as possible 3) use the time, money and human effort invested in the program as effectively as possible, because these are always unlimited

natural expirment

Not planned beforehand, but rather ecologists take advantage of a situation where either natural events or human-contralled events set the stage to learn something about ecological processes.

annual species

complete a whole generation from seed to adult thourgh to seeds againi within a year  good at increasing in abundance rapidly in relatively empty habitats

perennial

live for several or many years and may not reproduce in their early years  slower to establish byt more persistent once the do

eutrophication

Excess growth of algae and cyanobacteria as a result of excessive inputs of nutrients

mathematical models

1) Can be valuable for exploring scenarios and situations for which we do not have, and perhaps cannot expect to obtain, real data 2) Can be valuable for summarizing our current state of knowledge and generating predictions in which the connection between current knowledge, assumptions and predictions is explicit and clear 3) In order to be valuable in these ways, a model does not have to be a full and perfect description of the real world it seeks to mimic, all models incorporate approximations1 4) caution is therefore always necessary – all conclusions and predictions are provisional and can be no better than the knowledge and assumptions on which they are based – but applied cautiously they can be useful 5) a model is inevitably applied with much more confidence once it has received support from real sets of data

experiments

Natural experiments - Small scale experiments - Whole ecosystem experiments

evolution of natural selection

1) Individuals that form a population of a species are not identical 2) Some of the variation btween individuals is heritable _it has genetic basis-  able tob e passed down to descendants 3) All populations could grow at a rate that would overwhelm the envrionment, but in fact most individuals die before reproducing 4) different ancestors leave different numbers of descendants

hybridization

the production of offspring sharing the characteristics of two parents

reciprocal transplant experiments

test the match between organisms and their environment - Comparing performance when they are grown at home with performance away - Local adaptation

biospecies

do not exchange genese

cological speciatoin

speciation where there is both an ecological source of divergent selection and a means of reproductive isolation

allopatric

subpopulations in differnt places

sympatric

subpopulations in same placee

endemic

species known only form one island or area

endemism

occurince together of many endemic species

convergent evolution

same function (analogous), not same ancestor (not homologous)

divergent

Same ancestor (homologous), not same function (not analogous)

parallel

Same ancestor AND same function (analogous and homologous)

conditions

physiochemical features of the environment: temperature, humidity, pH, salinity

resources

consumed by organisms

response curves

**Extreme conditions lethal but in-between favorable conditions - Only high intensities of condition lethal - Low amounts required but too much letha**

chilling injury

organisms forced into extended periods of inactivity and cell membranes of sensitive species may begin to break down

photoperiod

period of daylight within daily cyclediap

diapuase

approach of winter

metabolic activity msassively reduced

acclimatization

Conditions may trigger an altered response to the same or even more extreme conditions (exposure to relatively low temperatures may lead to increased tolerance of even lower temperatures

ectotherms

relu on external sources of heat to detemine the pace of their metabolism

endotherms

regulatoe own body heat

when water is scare

cam approach

resources

Decomposers - Parasites - Predators - Grazers

mutualistic

beneficial to both partiesepi

phytes

plants that grow on other plantswa

watershed

the land area where all the water draining from it comes to the particular stream or river

photic zone

surface layer where light penetrates

modular organisms

Grow by the repeated production of modules - Most rooted or fixed, not mobile - Both structure and precise program of development not predictable but indeterminate

genet

genetic individual

Start life as single-celled zygote and considered dead when all its component modules have died

module

starts life as a multicellular outgrowth from another module and proceeds through its own life cycle to maturity and death, even through own life cycle to maturity and death

unitary organism

\- Predictable - Determinate

annuals

one generation each year

perannials

life cycle extended over several or many years

iterparous species

breed repeadetly

semelparous species

one signel reproductive episode with no resources set aside for future survival

cohort

all individuals born within a particular period

cohort life table

records survivorship of the members of the cohort over time

static life table

Describe numbers of survivors of different ages

survivorship types

Type 1: mortality concentrated toward end of maximum life span Type 2: constant mortality rate from birth to maximum age Type 3: exensive early mortality, but high rate of subsequent survival - Species that produce many offspring

dispersal

describes the way indivudal spread away from each other

dispersal types

Density dependent: too many individuals, resulting in leaving of some individuals - Natal dispersal: animals leabing their breeding grounds - Inbreeding avoidance - Age-and sex biased dispersal

migration

mass directionalmovement of large numbers of a species from one location to another

patterns migration

leapfrog

chain

telescopic

the earths magnetic field

\- The bird retina has light dependent magneto reception

average density

total number of individuals divided by total size of the habitat

carrying capacity

density at crossover point: K - Populations at low densities grow by simple multiplication over successive intervals of time - exponential growth Intrinsic rate of natural increase

cost of reproduction

trade off

trade off

Organism has limited resources available for reproduction  natural selection will influence how these are packaged

r/K concept

interprete many of the differences in form and behaviour of organismsma

lthus growth rate

predicts the limit of the growht of a populationcapita

capital breeders

reproductive event is ‘financed’with stored capital

income breeders

reproductive evet is ‘financed; with curren tincome

reproductive effort model

Profit of having numerous offsping, against cost of reproduction - Convex curve: fast growth of cost and profit against effort - Concave curve: slow growth of cost and profit against effort

eusociality

Cooperative care of young - Reproductive division of labor - Overlapping generations

cooperative systems

Few adults reproduce - Other individuals do not reproduce, but help raise the offspring (helpers)

communication

Ecology of sound - Percussion: movement of solid body part against another solid - Calls: waves are generated through ripples that radiate away from the initial disturbance - Resonance and impedance: additive effect of waves of frequesncies in phase and consequent amplification - Impedance matching devicesL throat sacs and horns - FUnction - - mating - Territoral defence - Social interaction - Defence

spatial distribution

how animals are distributed in space - Family of species - One single species - Individuals 1 - - clump distribution - - Random distribution - - Even distribution - Influence of time and availability of resources

intraspecific competition

Crowding - Density-dependent birth and death - Carrying capacity: the density at the crossover point at which birth and death rates are equal and because they are equal there is no overall tendency at this density fort he population either to increase or to decrease

r-species

The production of large numbers of progeny, early in the life cycle, rather than investing in either growth or survival - Produce many small progeny

K-species

the individuals that are successful in leaving descendant are those that have captures and often held on to the larer share of resources - Produce few large progeny

ecological niche

Realized niche: with competing species - Fundamental niche: no competing speciest

he competitive exclusion principle

If two species coexist in a stable environment  result of niche differentiation - No niche differentiation: one competing species will exclude the othe

niche differentiation

Conditional partioning - Resource partitioning - Reource and conditional partitioning: niche complementarity - Reversible process: ecological release

niche complementarity

niche differentiation involves several niche dimensions

prey

Repreduce detection chance - Once detected by predator: reduce consumption

predator

Increase prey detection chance - Once prey is detected: increase consumtion - Foraging

differnces between prey

Distribution and abundance - Defense mechanisms - Nutritional value

population dynamics

\- More prey does not autoatically mean more predators - Predators do not always reduce prey populations size  depends on competition and predation

trophic cascsade

Density mediated - Behaviorally mediated

predator-mediated coexistence

r - Preventing competition fr sources - - generalist predator: select abundant species (prey switching)

specialist predator: select dominant rpey species

mesopredator release

removing of apex predator resuts in increase of its prey

foraging decisions

Choosing between habitats - Conflict between increasing input and avoiding predation - Patch stay-time decisions - Ideal free  conflict between patch quality and competitor density - Optimal diets: to include or not to include an item in the diet Recognize the underlying tendency of populations of predators and prey to cycle and the damping effect of crowding and patchy distributions - Mutual interference amongst predators reduces the predation rate - Crowding: tends to dampen or eliminate predator-prey cycles

species richness

the number of species ina community

coutning difficult

Miss-identifying or missing species - Counting common species, but missing rare species - Rarefaction curve: to see if you are approaching the maximum amount of species in a community

species evenness

refers to how close in abundance each species is

species diversity

takes both species richness and species evenness into account - Shannon diversity index (0-3) Gedownload door Laura Berbee ([e-mail]) lOMoARcPSD|10370931 - Rand-abundance fraphs: give more complete picture of distribution of species abunance, instead of considering comnity diversity into a single value - Species richness and resources - - species interactions have an influence - Interspecific competition allows for resources to be fully utilized - Richness will depend on range of resources, extent of specialism and permitted niche overlap - Predation can exclude species, resulting in reduction of richness - Predation can also stimulate richness by reducing interspecific competition, thus allowing more niche overlap