module 1 Flashcards
definition of ecology
the scientific study of the interactions that determine the distribution and abundance of organisms.
ecological hierarchy
- individual organisms
- population
- community (group of populations)
- the ecosystem (community together with its physical and chemical environment)
taxonomy hierarchy
- species
- genus
- family
- order
- class
- phylum
what is a species?
members can at least potentially breed together in nature to produce fertile offspring.
species are genetically independent kinds of organisms (in phylogeny)
what must occur to form a species?
reproductive isolation
microevolution allele changes build up until:
- sub-populations can no longer reproduce.
- genetic changes between sub-populations are bigger than within sub-populations.
allopatric speciation
gene flow interrupted when population divided by geographical barrier.
peripatetic speciation
new species formed from an isolated peripheral population
paripatric speciation
part of population enters new habitat bordering range of parent species.
behavioural speciation
behavioural isolation of populations living in the same geographical area.
for example - sub-populations feeding in the day or at night.
what are adaptations?
an inherited characteristic that helps an organism to survive long enough to reproduce more successfully in its changing environment and can either be structural or behavioural.
what are some structural adaptations?
camouflage
mimicry
bent hind legs
sharp teeth
what are some behavioural adaptations?
migration
hibernation
warning cells
mating dances
plant structural adaptations
protection
- thorns
- foul taste
seed dispersal
- wind
obtaining food
- photosynthesis
plant behavioural adaptations
tropism - movement of a plant towards (positive) or away (negative) from a stimulus
dormancy - state of rest or inactivity
what adaptation does coral have to light?
ability to diffuse light throughout skeleton.
what is the biosphere?
global sum of all ecosystems
what is a biome?
distinct biological communities that have formed in response to a shared physical climate.
what are terrestrial biomes distinguished by?
what are terrestrial biomes determined by?
- their predominant vegetation.
- determine by temperature and rainfall.
what is climate?
a long term average weather patterns that occurs at a location over decades.
what two components influence climate?
- sunlight intensity
- proximity to large bodies of water and mountain ranges
tropical rainforest biomes
- constantly high temperature during the year
- diurnal climate - temperature difference between day and night
- high precipitation
- deciduous trees
savannah biome
- constantly high temperatures
- seasonal rainfalls
- high amounts of grasses
- covers 25% of earths landmasses
desert biome
- very dry
- extreme diurnal temperatures
- occurs 15-30 degrees N and S.
- limited vegetation and slow soil development.
temperate grassland biome
- large seasonal variability in temperatures
- relatively low precipitation
- biome characterised by absence of trees.
temperate deciduous forest biome
- strong seasonal variability in temperature and precipitation
- deciduous trees
- four vertical layers of vegetation - mature canopy, juvenile canopy, shrubs and herbs.
boreal forest biome
- high latitudes between 50 and 60 degrees
- low annual temperatures and low precipitation
- environmental conditions promote the formation of permafrost
- low diversity of coniferous tree species
what are the layers in borial forest
TOP - active layer (seasonally frozen ground)
2ND - permafrost table (upper surface of inactive layer)
3RD - permafrost (permanently frozen ground)
4TH - talik (random band of unfrozen ground)
5TH - unfrozen ground below permafrost
tundra biome
- between 60 and 70 degree
- low temperatures and varying precipitations
- vegetation is overall scarce.
polar desert biome
- mean temp below 10 degrees celsius during warmest month of the year
- annual precipitation less than 250 mm
- most of these biomes are covered in ice sheets, ice fields or ice caps
- largely barren environments (presence of few lichens and moss)
anthromes
- anthropogenic biomes
- ecological patterns shaped by human interaction with ecosystems.
- divided into settlements, villages, croplands, rangelands, semi seminatural lands and woodlands.
what doe resources and conditions do?
determine where organisms can live.
resources
consumed by organisms in the course of their growth and reproduction. Once consumed, a resource is not
available to another organisms. This leads to competition between organisms and resource partition
conditions
physicochemical features of the environment. Conditions are not consumed nor used by the activities of
organisms but do influence these activities.
response curves
show range of a specific condition and how this influences survival, reproduction and growth.
kelp example of how organisms can alter local conditions
under the kelp canopy
- pH is higher
- pCO2 is lower
- aragonite saturation state is larger
- calcite saturation state is larger compared with benthos.
what is zonation?
ecological distribution pattern along the vertical dimension.
pattern driven by availability of resource and environmental conditions which change in space and time.
three forms of fundamental ecological interactions
- predation
- competition
- mutualism
types of competition
EXPLOITATIVE - individual interacts indirectly as they compete for common resources.
INTERFERENCE - one organism directly alters another’s access to resources.
APPARENT COMPETITION - individual that do not directly compete affect each other indirectly by being prey to the same predator.
competitive exclusion
superior competitor can eliminate an inferior one from the area.
definitions of mutualism, commensalism and parasitism.
MUTUALISM - both or all individuals benefit. can be obligate or facultative.
COMMENSALISM - one individual benefits and the other is not impacted in any way.
PARASITISM - one individual benefits and the other is harmed.
parasite mediated competition
parasite influences the competitive interaction between two species.
dispersal
movement of an individual or group away from the population in which they were born
- natal (active or passive)
- adult (usually active)
- gamete (common for non-motile adult individuals; passive)
migration
directional movement of many individuals from one location to another.
- seasonal
- tidal
- diurnal
dormancy
- form of migration through time
- enables organisms to decrease their dependence on the environment by spending a significant portion of the year out of unfavourable conditions.
- DIAPAUSE - development is suspended during unfavourable conditions.
3 types of generalised spatial patterns in ecology
- random
- regular
- aggregated - clustered
THE PERCEPTION OF PATTERN DEPEND ON THE SPATIAL SCALE CONSIDERED.
population
Group of individuals of the same species living and
interbreeding within a given area.
equation for size of population
(size of population at time point 0) + (births) - (deaths) + (immigrations) - (emigrations)
what influences birth death and migration
environmental factors
unitary organisms
unitary individuals are highly determinate in form and while growing pass through predictable (innately determined) sequences of life history stages
modular organisms
Modular organisms are structural individuals subdivided
into repeated morphological units, or modules, each
able to acquire, process and share resources. (eg. strawberries can produce other plants)
what is phenotypic plasticity
The ability of an organism to alter its development and life history in response to
changes in the environment
how does cold water coral desmophylllum dianthus display phenotypic plasticity?
variation in calcification rate depending on annual temperature variability is experienced by this population
semelparous life cycle
reproducing only once in a lifetime (long juvenile phase)
- many offspring produced in the hopes that at leat one makes it to reproduce
iteroparous life cycle
producing offspring more than once in a lifetime (short juvenile phase)
- small number of offspring with a large amount of care. more chance of survival.
r selected (8 things to remember)
- large number of offspring
- little or no parental investment
- low survivorship
- unstable environments
- small in size
- reach maturity early
- reproduce only once
- short life expectancy
k-selected (8 things to remember)
- small number of offspring
- large amount of parental investment
- high survivorship
- stable environments
- large in size
- reach maturity later
- reproduce many times
- long life expectancy
demography
studying vital statistics of populations
life tables
summarise information about births and deaths in a population.
they organise demography data so that relationships between variables can be examined and perhaps explained.
what is life history determined by
the frequency and timing of sexual reproduction, by longevity and by growth rate.
