Environmental studies definitions Flashcards
Define population ecology
Changes in the size or a population and the factors that regulate these changes
Define Ecology
The study of the interactions of organisms with their physical and biological environments and how these determine the distribution and make up of populations within an ecosystem
Define the Biosphere
The part of the earth where living organisms are found
Define an Ecosystem
A group of different species of organisms that interact with each other and the environment
Define an organism
An individual form of life, such as a bacterium, protist, fungus, plant or animal, composed of a single cell or a complex of cells that are capable of growing and reproducing.
Define a community
A group of different species that inhabit and interact in a particular area.
Define a species
A group of closely related organisms that are very similar to each other and are usually capable of interbreeding under natural conditions to produce fertile offspring.
Define a population
A group of organisms of the same species that occupy the same area and can breed freely with each other.
Define population size
The total number of individuals in a population. It can increase or decrease over time with a change in one or more of the population parameters.
Define Natality
Birth rate in animals or the production of seeds in plants
Define mortality
The death rate
Define Emigration
Individuals leave a population and do not return
Define immigration
Individuals move into a population and stay
Define migration
The non-permanent movement according to seasonal patterns
Define carrying capacity (k)
The maximum number of organisms of a population that the environment can support at a particular time.
Define Environmental Resistance
The total number of factors that stop a population from reproducing at its maximum rate.
Define limiting factors
The factors that help to regulate the growth of a population. Anything that constrains a population’s size and slows or stops it from growing.
What is the formula for mark-recapture?
P= M.C/R
M= Total caught and marked
C: Total caught 2nd
R= Number of marked second
What is the formula for the quadrat method?
Total population= Average number in quadrat x size of habitat/ size of quadrat
Define Ecological succession
A predictable pattern of gradual change in the types of species in an ecosystem that has previously been uninhabited or following a disturbance.
Define predation
The biological interaction where one species, the predator, kills and eats another species, the prey. Predator and prey evolve together and are part of the same environment.
Define a food web
An interconnected set of all the food chains in an ecosystem.
Define a keystone species
A species that has a disproportionately large effect on its environment relative to its abundance
Define competition
When two or more individuals compete for the same resources that are in short supply
Define interspecific competition
Competition that occurs between individuals of different species where the ecological niches in the habitat are very similar and overlap to a greater or lesser extent.
Define intraspecific competition
Competition between individuals of the same species.
Define resource partitioning
The evolutionary process whereby species with similar requirements living in the same habitats have specialised traits that enable them to utilise the resource differently, creating separate niches to reduce interspecific competitions and make co-existence possible.
Define an ecological niche
All the resources, biotic and abiotic, necessary for a species to survive and reproduce as well as the role the organism plays in the ecosystem.
Define culling
The reduction of a wild animal population by selective slaughter.
Define a bioindicator/indicator species
A living organism that gives us an idea of the health of an ecosystem.
Define a population pyramid
An age-sex pyramid — a bar graph that shows the composition, by age and sex of a nation’s population at the time of a census.
Define an ecological footprint
A measure of the human demand on the Earth’s ecosystems. It represents the amount of biologically productive land and sea area necessary to supply the resources a human population consumes, and to assimilate the waste generated.
Define bio capacity
The amount of productive land and water available to produce the resources we use and to absorb the wastes we produce
Define sustainable development
The development that meets the needs of the present while not compromising the needs of the future generations
Define density dependent factors
Factors which limit the growth of a population as a direct result of the density of the population. The greater the density, the more it limits the population growth
Define density independent factors
Factors which limit the size of the population regardless of the population density
