Ecology Flashcards
considerations for the SLOSS debate of conservation
SLOSS = single large or several small:
- size: bigger better than smaller;
- subdivision - contiguous better than broken up;
- separation: closer together rather than farther apart;
- linearity; globular rathr than linear;
- connection: connected rather than discrete;
- edge/ interior ratio (consider edge effect): lower edge to interior ratio is better
Scales of interactions (BLECPO scales)
organism population community ecosystem landscape biosphere
descriptions of organismal locations
biogeography, biome, habitat
- biogeography - distribution through space and time; abundance and diversity of orgs depends on available resources, especially water;
- biome (not a very helpful term) - usually terrestrial; these include: tropical rainforest, savanna, desert, heathlands, temperate grasslands, temperate broadleadf forest, northern coniferous forest, tundra, high mountains, polar ice
- habitat
niche (including fundamental niche and realised niche) AND population dynamics
where an organism lives AND what function it serves in the environment;
- fundamental: the possible distribution of the organism as determined bu its evolutionary history;
- realised niche: the actual distribution of the org, as limited by interactions with other orgs;
- population dynamics: how orgs are utilising their niches (eg abundance / thriving or dwindling)
population ecology
accounts for the “life history” of organisms in a particular environment
purpose of ecology: solving problems of DISTRIBUTION and ABUNDANCE
distribution: where orgs are found
abundance: what is the population? are there more or less than there should be?
biotic and abiotic factors
biotic - between organism interactions
abiotic - including light, water, temperature, etc.
climate (macro and micro)
temperature, sunlight, wind and precipitation
- macro: patterns on the global, ecosystem and landscape scales;
- micro: finer scale patterns, eg community of orgs on a tree trunk
Hopkins’ bioclimatic law
air cools as it rises
bioaccumulation AND biomagnification
bioacc: the increase in chemicals in a single organism over its lifespan or a single trophic level over time;
- biomag: accumulation of chemicals through trophic levels, increasing as you go up through the consumption levels
trophic levels AND food web
or “food chains”;
constrained to be about 5 levels long;
-food webs are perhaps more accurate representations of trophic interactions between orgs in an environment
production efficiency
the percentage of energy from food source that is used for growth and reproduction, ie keeping energy in the system, as opposed to it being lost as heat along the way
ecological efficiency
an organisms production efficiency (see card) as well as how efficiently it uses energy for movement and metabolism;
determines a species’ abundance
biomass
factors abundance and mass in conceptualising trophic pyramids
biodiversity
the number of species present, limited by the number of available niches;
the variety, distribution and abundance of species in an environment;
measured according to the number of vascular plants
island equilibrium theory of biogeography
species diversity on islands will represent a dunamic balance btwn the prob of successful colonisation by immigrant species, and extinction of resident species
competitive exclusion
competitive advantage will lead to success for 1 and extinction for the other;
a type of niche division
disturbance AND
intermediate disturbance hypothesis
pressures in an environment, eg intro of predators, climate change, etc.
- can be stocastic ie one-off cataclysmic events
- IDH: diversity will be highest when interference prevents competitive exclusion, but is of low enough intensity or frequency to allow many species to prosper;
disturbances can be biotic or abiotic
keystone species
those with the highest number of interactions in an ecosys
red queen hypothesis
evolutionary arms race’ ie running to stay in the same place;
- occurs between prey and hunter species;
- drives mimickry
symbiosis (paracitism, mutualism, commensalism)
also Facilitation
- fac: when species have pos effects on others without direct symbiotic contact
biodiversity hotspots
- high diversity of >1500 endemic vascular plant species;
- have lost 70% or more of their original habitat
dispersion v. dispersal
dispersion: how members of a species are arranged throughout an environment; can be:
- random
- regular (rare; competitive)
- clumped (common; cooperative)
dispersal: where the offspring go to
factors controlling population size (four)
- sources of increase:
1. birth
2. immigration - sources of decrease:
3. death
4. emigration
growth rate AND intrinsic rate of growth
represented by “r”
calculated by:
b(birth rate) - m (mortality rate)
rmax = intrinsic rate of growth, ie built into the species
allee effect
pop density becomes so low that mating ceases
vital rates
birth rates (b) ie fecundity death rates (m) ie survivorship
life history traits
these reflect evolutionary adaptations:
- repro strategies:
- number of offspring;
- level of investment;
- age-specific distribution of repro and mortality:
- age of sexual maturity
- senescence and death
survivorship (3 types)
- mortality accelerate with age
- have few young; invest a lot of time and energy - constant mortality rate
- mortality decelerates over time
- orgs with lots of offspring that getting bigger and more robust through time
levels of parental care (precocial and altricial)
altricial - dependant; weak
precocial: strong, independent
semelparity AND iteroparity
semel: one-shot reproduction; multiple young; maybe short lifespan
itero: many chances for repro; 1 or few young each time; over many years
