ecological niche
the distinct role a species plays in its ecosystem
ex. habitat, nutrition, behaviour
keystone species
maintains balance in ecosystem (wolves, sharks)
indicator species
sensitive to environmental change; monitors change (moss, frogs)
foundational species
enhances habitat for others (beaver, elephant)
generalist species
survive in broad niche — can eat anything, reproduce at anytime, live in extreme temperatures (cockroach)
specialist species
survive in specific niche — certain nutrition, produce at certain times, wary of environments (salamander)
in-situ
protected on natural reserves or natural parks; stay in their natural environment
ex-situ
removed from their natural environment
captive breeding, botanical gardens, seed banks
biological factors that impact diversity
edge effect, fragmentation, “island” size
edge effect
changes in the ecosystem on the edge of a reserve or park
fragmentation
often natural reserves/parks become fragmented into smaller parts, usually by roads
consequences: isolation, increased edge effect, decrease in gene pools, impact migration routes, decreased space
“island” size
larger reserves/parks are ecologically better than smaller ones because: more habitats, decreased edge effect, allows more migration, more resources
biotic index
monitor ecosystem health using indicator species
simpson’s index
measuring biodiversity through evenness and richness
limiting factors
most scarce resource in relation to an organism’s needs; puts a limit on population size
zone of tolerance
where the species thrives
zones of stress
where the species can survive
zones of intolerance
where the species cannot live
transects
a line across a habitat that helps explore relationships between organisms and an abiotic factor
fundamental niche
potential mode of existence within its tolerance range with no external pressures.
realized niche
represents the actual mode of existence in which the species is really found
competitive exclusion
two species cannot coexist together indefinitely in the same habitat if their niches are identical
ecological succession
predictable changes in an ecosystem caused by living organisms over time from a simple pioneer community
pioneer species
starts the reformation of an ecosystem
primary succession
colonization from a lifeless environment (glacier retreating, volcano)
secondary succession
occurs when there has been an ecosystem that has recently been disturbed (forest fire, flood)
ecosystem productivity
refers to the rate of biomass generation in an ecosystem
net productivity
amount of energy available to consume after respiration by plants
net production = gross production - respiration (kJm-2yr-1)
interspecific competition
competition between different species
intraspecific competition
competition between same species
predator/prey
hunting vs hunted
herbivory
consumes plants only
parasitism
takes resources from a host
mutualism
benefits both parties
commensalism
benefits one party, neither benefits nor harms the other party
food conversion ratio
the ratio of food mass provided to body mass output
(mass of food consumed)/(body mass gain)
poikilotherm
a species that has a variable body temperature according to the surrounding environment
homeotherm
a species that maintains a regulated body temperature through physiological mechanisms
gersmehl nutrient cycle
diagrams used to model how biomass, litter, and soil interconnect to recycle nutrients for the environment
reasons why energy is lost between trophic levels
not all biomass is eaten in one trophic level and is broken down by decomposers
some of the biomass is indigestible and egested
some of the biomass exits the body as urine
energy is lost through cellular respiration
gersmehl cycle - B
the total mass of living organisms, mainly plant tissue per unit area (rainforest)
gersmehl cycle - L
the total amount ’organic’ matter, including humus and leaf litter (temperate forest)
gersmehl cycle - S
the mineral (inorganic) and organic nutrients that are found in the soil (desert)
endemic species
a species that is native to an area
alien species
a species that moves to an area in which it previously did not occur.
methods of controlling an alien species
biological, mechanical, chemical
biological control
introducing a natural predator to limit its spread
mechanical control
physically removing the species or creating barriers so the invasive species cannot spread
chemical control
using pesticides/chemicals to destroy the species
bioaccumulation
living organisms, in one trophic level, accumulate toxins in their body when they consume food. the fat-soluble chemicals build up in tissues because they are not easily excreted.
biomagnification
the increasing concentration of toxins in an organism as you move up trophic levels. it results from ingesting many plants or animals in lower trophic levels that contain toxins in their tissues.
microplastics
small (0.33 – 1 mm in size) plastic that is being assimilated into ocean organisms by ingestion or filter feeding.
macroplatics
large (over 200 mm in size) plastic materials that can be found littering the streets, lakes, oceans found floating in naturally rotating ocean currents called gyres
ocean gyres
a large system of rotating ocean currents
the 6th mass extinction
the result of human activity, or anthropogenic causes
anthropogenic species extinctions are caused by:
overexploitation
habitat loss
invasive or alien species outcompeting native species.
habitat degradation due to pollution
climate change