Chapter 3 Flashcards
Define ecosystem
An interacting community of populations of organisms and the physical environment in which they live
Define environment
Abiotic and biotic factors of an area
Define abiotic
The non-living components of an ecosystem (light intensity, temperature, pH of soil, salinity, water availability)
Define biotic
The living components of an ecosystem (parasites, competitors)
Define community
The sum of the different species inhabiting a particular habitat at one time
Define habit
An area or environment where an individual or species lives within an ecosystem
Define biosphere
Sum of all the ecosystems across the world
Define biome
Main categories of ecosystems across a large geographical area
What are the four main types of terrestrial biomes
Tropical rainforests, deserts, grasslands and tundras
What are terrestrial biomes classified by
Vegetation types, climate, topography and soil type
define topography
The composition of the natural and man made features of an area
What factors influence the kind of organisms that inhabit an aquatic biome
How permanent the body of water is, salinity, depth and nutrient availability
Three examples of moving aquatic biome
Oceans, bays, rivers
What are some examples of still aquatic biomes
Lakes, ponds and swamps
Population
A group of individuals belonging to the same species living in a particular area at the same time
Limiting factors
An element of the environment that restricts the survival of an organism to a region. Are usually expressed as a lack of a particular resource eg, food, competition, altitude etc)
Tolerance range
a set of abiotic conditions in which an organism functions at its optimal
Zone of intolerance
The organism cannot survive
Dominant species
The most common species in a particular ecosystem (eg mangrove swamp, spinifex grassland, coral reefs)
Ecological niches
The way in which species function within their environment. (Eg, time they feed, what they feed on, where they live)
what is a Fundamental (potential) niche
The idea niche a species would occupy if there were no predators, competitors or parasites
Realised (actual) niche
The actual niche that a species inhabits
Resource partitioning
organisms can’t feed on the same food at the same time. Reduces competition
Example of resource partitioning
Different forest birds feed at vary heights, some animals feed at night, others during day.
Competitive exclusion principle
Occurs when 2 species compete for the same resource and cant coexist in the same community as one will obtain the resource more effectively and drive the other to extinction
Example of competitive exclusion principle
When a lab test was conducted between P. aurelia and P. caudatum, P. Aurelia was able to obtain food more effectively, reproduce faster and drive P. caudatum to extinction
Define competitors
Competition within and between a species
Define collaborator
Members of a group that help each other catch prey
Intraspecific interaction
Relationships between members of the same species
Interspecific interaction
Relationship between members of the different species
How can the numbers of prey effect the numbers of predators
With increased availability of prey, the number of predators can increase (but will always stay less than prey). When the prey population decreases, there is intraspecific competition between predators. They then turn to alternative prey, allowing the original prey to repopulate
Symbiosis
Describes the relationship in which individuals of 2 or more different species live together and at least 1 of the species benefits
What are the three main types of symbiosis
Parasitism, mutualism and commensalism
Define parasitism
When an organism lives on or in another organism (eg bacteria, virus, fungi. Native mistletoe is a parasitic plant to eucalyptus trees )
Mutualism
When the organisms work together and share the same ecosystem. Both benefit and neither is harmed. (Eg pistol shrimp and the goby fish. Shrimp is blind, fish acts as eyes and uses burrow)
Commensalism
A one sided interaction between species, only one benefits but the other is unaffected (eg, remora fish and sharks. Fish gets a free ride and leftovers)
Keystone species
A species of low population that is seen to have a large influence over lower trophic levels to allow the co existence of other species in a particular area
Example of keystone species
The purple sea star is a natural predator of mussels. When sea starts are removed, the mussel population increases. The mussels then displace other organisms. The diversity of invertebrates and algae decreased. The predator allowed the coexistence of other species with the same requirements for food + space
Zones of physiological stress
an organism can grow but the conditions are not ideal for survival
define dichotomous key
Classification system where each branch has two options
