Quiz 1 Flashcards
Abiotic Factor
A non-living, physical factor that may influence an organism or ecosystem; i.e. temperature, sunlight, pH, salinity, precipitation
Biotic Factor
A living, biological factor that may influence an organism or ecosystem; i.e. predation, parasitism, disease, competition.
Biome
A collection of ecosystems sharing similar climatic conditions; i.e. tundra, tropical rainforest, desert.
Carrying Capacity
The maximum number of species or “load” that can be sustainably supported by a given environment.
Climax Community
A community of organisms that is more or less stable, and that is in equilibrium with natural environmental conditions such as climate; the end point of ecological succession.
Competition
A common demand by 2 or more organisms upon limited supply of a resource; i.e. food, water, light, space, mates, nesting sites. It may be intraspecific or interspecific.
Crude Birth Rate
The number of births per thousand individuals in a population per year.
Crude Death Rate
The number of deaths per thousand individuals in a population per year.
Ecosystem
A community of interdependent organisms and the physical environment they inhabit
K Strategist Species
Species that concentrate their reproductive efforts on a small number of offspring, thus increasing the survival rate and adapting them for living in long- term climax communities.
Mutualism
A relationship between animals where none suffer and both benefit.
Niche
An organisms role in the ecosystem. What and how it responds to resources and the physical environment it adapts to. Fundamental and realized.
Parasitism
A relationship between two animals where one benefits, living of the other who suffers.
Population A group of organisms of the same species living in the same area at the same time, and which are capable of interbreeding.
A group of organisms of the same species living in the same area at the same time, and which are capable of interbreeding.
R- Strategist Species
Species that tend to spread their reproductive investment among a large number of offspring so that they are well adapted to colonize new habitats rapidly and make opportunistic use of short- lived resources.
Species
A group of organisms that interbreed and produce fertile offspring.
Succession
The orderly process of change over time in a community. Changes in the community of organisms frequently cause changes in the physical environment that allow another community to become established and replace the former through competition. Often, but not inevitably, the later communities in such a sequence or sere are more complex than those that appear earlier.
Predation
The interaction between two organisms - the predator (which has a higher trophic level) and the prey (which has a lower trophic level). Predators differ from parasites in that they kill their prey before eating it.
Population Dynamics
Factors that affect carrying capacity
S Shaped Growth Curve
A pattern of growth in which, in a new environment, the population density of an organism increases slowly initially, in a positive acceleration phase; then increases rapidly, approaching an exponential growth rate as in the J-shaped curve; but then declines in a negative acceleration phase until at zero growth rate the population stabilizes. This decline reflects increasing environmental resistance which becomes proportionately more important at higher population densities. This type of population growth is termed density-dependent, since growth rate depends on the numbers present in the population.
J Shaped Growth Curve
the population density of an organism increases rapidly in an exponential or logarithmic form, but then stops abruptly as environmental resistance (e.g. seasonality) or some other factor (e.g. the end of the breeding phase) suddenly becomes effective. The actual rate of population change depends on the biotic potential and the population size. This type of population growth is termed ‘density-independent’ as the regulation of growth rate is not tied to the population density until the final crash.
Biotic Potential
the number of offspring a species can produce when they have ideal circumstances, including unlimited food and water, safe habitat, and any other conditions that would promote successful reproduction.
Natural Increase Rate
Crude Birth Rate- Crude Death Rate. Influenced by:
- clutch Size( density dependent fertility)
- reproductive age
- reproductive episodes
- size of breeding territory
- degree of parental care
Limiting factors
factors which slow down growth of a population as it reaches its carrying capacity
