Vocab and Terms - Ecology Flashcards
Survivorship curve
Curve/table showing number or percentage of survivors of a generation over a period of time.
r (in growth equation)
Intrinsic rate of growth (rate of growth per member of population)
K (in growth equation)
Carrying capacity.
Iteroparity / Iteroparous
Life strategy where an organism repeatedly create offspring throughout its life.
Semelparity / Semelparous
Life strategy where an organism reproduces only once in its lifetime.
r vs K selection
r - more offspring, less investment per offspring
K - less offspring, more investment per offspring
Density-dependent population regulation factors
Factors impacting birth, death, immigration & emigration rates that is influenced by population density.
Eg. territoriality increases death rate at high densities
Two types of population growth
Exponential & Logistic
Foundation vs Keystone species
Foundation - dominant and common.
Keystone - important to ecosystem without being particularly common.
Community structure
Three factors:
- Number of species
- Which particular species
- Abundance of each species
Competitive exclusion
Theory that if two species with identical niches, one will always eventually outcompete the other.
Resource partitioning
Partitioning of resources to different species with slightly different niches.
Aposematic colouration
Unpalatable, toxic organisms exhibiting bright, vibrant colours.
Commensalism
Interaction where one species benefits without much impact on the other.
Shannon diversity index (H)
H = -(pA ln(pA) + pB ln(pB) + pC ln(pC) …)
where pA is abundance of species A, pB is abundance of species B, etc.
Energetic hypothesis
Theory that food chains usually don’t have very many ‘links’ because of the ~10% conversion between trophic levels.
Bottom-up vs Top-down control
Ecological succession
After a disturbance, the progression of different species that colonise the disturbed area.
Primary succession
Ecological succession on a bare, new habitat (eg. new volcanic island or empty land left by retreating glaciers)
Detritus
Non-living organic material - eg. carcasses, leaf litter.
NPP
Net primary production. Amount of energy produced by autotrophs, minus energy used by these autotrophs for cellular respiration.
Can be described through biomass accumulation.
GPP
Gross primary production. Total primary production.
NEP
Net ecosystem production. Total primary production minus energy spent by ALL ORGANISMS in the ecosystem for cellular respiration. Describes total biomass accumulation or loss in a whole ecosystem.
Production efficiency
Percentage of energy in ASSIMILATED food (so excludes waste) that is used for growth or reproduction.
Three levels of biodiversity
Genetic - within a population
Species - within an ecosystem
Ecosystem - how many ecosystems
Two factors in species diversity
Number of species & Relative abundance of each species.
Extinction vortex
A small population going down a ‘vortex’ into extinction caused by loss of genetic diversity.
Biological magnification
Accumulation of toxic compounds on higher trophic levels.
Batesian mimicry
Harmless species mimic unpalatable ones
Mullerian mimicry
Unpalatable species mimic eachother
