ESS (Ecology) End of Year Exam Grade 9

can affect distribution and abundance can influence evolution

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.

mutualism, commensalism, parasitism, predation, competition

both organisms benefit (both species provide resources or services to each other, enhancing fitness for both)

one organism benefits, one organism is unaffected (ex: rhino/elephant - birds getting food and protection)

one organism benefits on organism is harmed (ex: parasites feeding on plants, killing it) - reduces fitness of host

one organisms benefits, one organism is killed (herbivore eating a plant, carnivore eating an animal)

one organism benefits, one organisms harmed, or both (same or different species in competition for resources)

a physical area where a species lives - they (species) also rely on the living and non-living things that surround them

the model we use to measure the energy that flows between organisms

• 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

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

• may have many food options available to it in its environment • may also be a food source for many potential predators and consumers

all the possible food sources and interactions are called the organisms fundamental niche - ex: would be all tree regions for a bird

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 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

adapting to more unique feeding - this might allow two species with similar niches to exist together

the situation when two species vie for a limited amount of the same resource - interspecific = between different species - infraspecific

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

two species will alter their use of the niche to avoid direct competition, allowing for co-existence

cute/endearing: aesthetically pleasing - humans have decided are worth saving (pandas, dolphins, etc…)

“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

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

how the trophic cascade (top-down) started