ESS (Ecology) End of Year Exam Grade 9 Flashcards
Ecological interactions are important because…
can affect distribution and abundance
can influence evolution
Symbiosis
the act of living together
- two organisms that live together
- temporarily or a longer time
- (usually) at least one of the organisms benefits from the relationship.
Symbiotic relationships
mutualism, commensalism, parasitism, predation, competition
Mutualism
both organisms benefit (both species provide resources or services to each other, enhancing fitness for both)
Commensalism
one organism benefits, one organism is unaffected (ex: rhino/elephant - birds getting food and protection)
Parasitism
one organism benefits on organism is harmed (ex: parasites feeding on plants, killing it) - reduces fitness of host
Predation
one organisms benefits, one organism is killed (herbivore eating a plant, carnivore eating an animal)
Competition
one organism benefits, one organisms harmed, or both (same or different species in competition for resources)
Habitat
a physical area where a species lives
- they (species) also rely on the living and non-living things that surround them
Food chain
the model we use to measure the energy that flows between organisms
How are habitats described?
- using annual rainfall amounts
- average sunlight amounts
- annual temperature ranges
*for plants the type of soil is also a significant feature in describing its habitat
Niche
a role that an organism plays within its ecosystem
- the habitat in which the organism lives and the organisms patterns of living
- the resources it uses within the environment and the interactions it has with other species in the area
- what it eats and what eats it
An organism
- may have many food options available to it in its environment
- may also be a food source for many potential predators and consumers
Fundamental niche
all the possible food sources and interactions are called the organisms fundamental niche
- ex: would be all tree regions for a bird
Realized niche
an organisms actual interactions
- ex: while a bird may inhabit any part of a tree, it may inhabit only the upper tree regions
Two species with similar niches
two species may have overlapping niches, but they will not be completely identical
- competing for the same resources will lead one species to face the need to find a new food source or move to a different area
Resource partitioning
adapting to more unique feeding
- this might allow two species with similar niches to exist together
Interspecies competition
the situation when two species vie for a limited amount of the same resource
- interspecific = between different species
- infraspecific
The competitive exclusion principle
that two species can’t exist together if they occupy exactly the same niche (competing for identical resources)
- one species will use the resources more efficiently and drive the other species to local extinction
Resource partitioning
two species will alter their use of the niche to avoid direct competition, allowing for co-existence
Flagship species
cute/endearing: aesthetically pleasing
- humans have decided are worth saving (pandas, dolphins, etc…)
Keystone species
“ecosystem engineer”
a species that has a disproportionately large impact on its environment relative to its abundance
- play a vital role in maintaining the delicate balance of the ecosystems
Trophic cascade
an ecological phenomena that occur when there is a top-down regulation of ecosystem structure and function. They involve a series of interactions where changes in one trophic level (a position in the food chain) have serious effects on other trophic levels.
- the effects can reverberate throughout the ecosystem, often leading to changes in biodiversity and overall ecological balance
Greenworld hypothesis
how the trophic cascade (top-down) started
Apex predator
stabilize and regulate the composition of an entire community/ecosystem
Maximum sustainable yield
a number that cannot be exceeded if you want the population to recover
