Population dynamics Flashcards
Name the three types of niches and describe each one
Provide case study
Ecological niches refers to the part of the ecosystem occupied by an organism. It is the role the organism plays in the larger ecosystem.
The Fundamental niche is the potential niche they would occupy if there was no competition.
The realised niche is the actual niche due to limitations caused by other organisms.
CS:
Koalas
suitable for koalas to have a widespread distribution along east coast. This distribution is not realised due to predation, disease, fires and drought.
describe results of symbiosis
interactions between biotic factors create opportunity of resources available within an ecosystem
increase in biodiversity and more resilient ecosystems
define the 4 symbiotic relationships with examples
Mutualism (both species benefit from the interaction +/+)
Commensalism (benefits one organism while not affecting the other +/0)
Parasitism (benefits one organism while harming the other +/-)
Ammensalism (harms one organism with no benefit to the other -/0)
what are the 3 main relationships within an ecosystem
competition
symbiotic
prededation
describe predation prey relationship with mention to the graph
a relationship where the predator benefits and the prey is killed.
abundance of predator and prey fluctuates however prey always peaks first and predator population is the delay of prey
describe competition relationship
where two or more species (interspecific) or individuals of the same species (intraspecific) independently act and compete for the same resources
what are the 3 main selection pressures
resource availability- food, habitat, shelter, mates
environmental conditions- temp, weather, geographical access
biological factors- predators, pathogens
Define ecosystem
community of interacting organisms and their physical environment
List 6 abiotic factors
temperature, water, buoyancy, viscosity, air pressure, light penetration
what do abiotic factors effect within an ecosystem?
abundance and distribution of ecosystems according to the needs of organisms (tolerance range)
list terrestrial vs aquatic abiotic factors
terrestrial- water availability, rain, shelter climate
aquatic- light availability, salinity, dissolved oxygen, depth
define permeable
things can penetrate through it.
what is the process of osmosis?
osmosis is the process of water moving from a low concentration of solute to a high concentration of solute; the water goes through a semi permeable membrane
define abundance and distribution
abundance- how much
distribution- how evenly spread
define salinity
the amount of salt in a body of water. All natural water contains salt but some contain more than others
how do fish keep their internal water levels constant? explain how this is different for salt water fish and freshwater fish
they alter how concentrated or dilute their urine is.
freshwater fish
-live in a body of water with low salt content.
-through osmosis water travels into them through their permeable skin.
-release diluted urine
saltwater fish
-live in a body of water with high salt content
-release concentrated urine
-through osmosis water will flow out the fish
state the 3 factors of biodiversity
species diversity
ecosystem diversity
genetic diversity
what factors can effect biodiversity?
selection pressures
human impact
health of planet is effected by biodiversity
define the following terms…
ecosystem
community
population
organism
ecosystem- made up of organisms living in an area that interact with each other, biotic and abiotic
community- a community of organisms. biotic but not abiotic factors. The biotic factors within an ecosystem
population- group of organisms of the same species living together in a defined geographical area
organism- individual of a species
what is meant by the term carrying capacity
the maximum equilibrium number of individuals of a species that can be supported indefinitely within an environment (shelter, water, mate availability)
Describe Allelopathy state an example
Competition between plants
The production of specific biomolecules by one plant that can be detrimental or beneficial to another plant.
E.g Casuarina (she-oak) have allelochemicals in stems, leaves, roots and fruit which render soil around plant ecologically sterile (v. low nutrients for other plants)
What are the consequences to competition?
it affects reproduction and survival rates.
Some species may be more successful competitors than others, driving them to very low numbers or even extinction.
Describe disease in an ecosystem, provide a case study
A disease is any process that adversely affects the normal functioning of a living organism. Diseases can be infectious (caused by a pathogen) and non-infectious
Genetic variation in the host population can limit the spread of a pathogen. In a genetically diverse host population there is a higher likelihood of resistant individuals.
Disease alters the balance in food webs and some organisms can become endangered due to disease.
CS:
Tasmanian devils are susceptible to devil facial tumour disease (DFTD) which is a transmissible cancer passed when an infected animal bites another and transmits some cancer cells into the wound.
Describe Extinction
Provide Case Study
Extinction is the death of all the members of one species.
Major extinction- when a number of different species become extinct around the same time.
Remaining species- take advantage of the changes environment and available resources.
CS
Recent extinction: Tasmanian Tiger
The last known Tasmanian tiger died from exposure in an enclosure in Hobart Zoo in 1936 after the zookeeper forgot to secure it at night.
