✭ topic 5: on the wild side

• define community

  different species sharing a habitat
• what are abiotic factors that effect growth

  light intensity, soil moisture, gradient, soil pH, temperature of air and soil
• habitat


  a place with a distinct set of conditions where an organism lives
• population

  group of interbreeding individuals of the same species found in an area

  individuals of one species living in a habitat
• community

  multiple populations living and interacting in the same area, various populations sharing a habitat or an ecosystem make up a community
• what are the abundance and distribution of organisms controlled by

  they are determined by a combination of biotic and abiotic factors
• biotic factors


  living factors that come about as a result of the activity of other organisms
• examples of biotic factors

  competition, grazing, predation, disease, parasitism, food availability
• biotic factors are usually density dependent - the larger the population density, the greater the competition for food, space etc
• competition for resources like food, light, water and space can be INTERSPECIFIC - between diff species or INTRASPECIFIC - within the same species
• availability of food - biotic factor

  more food means organisms have a higher chance of surviving and reproducing, this means their populations can increase
• new predators

  in balanced ecosystems, predators catch enough prey to survive but not so many that they wipe out the prey population

  if a new predator is introduced to the ecosystem it may become unbalanced
• competition - biotic factor


  if two species compete for the same resources and one is better adapted to take advantage of these resources then that species will outcompete the other
• what are the conditions of a species' habitat defined by

  abiotic and biotic factors, which determine which species occur in a habitat
• abiotic factors

  non-living or physical and chemical factors that influence species in a habitat / populations in a community
• examples of abiotic factors

  light intensity, temperature, cloudiness of water, humidity, soil pH, water pH, soil or water salinity, soil composition, oxygen or carbon dioxide concentration, climate, topography, pollution
• light as an abiotic factor needed by plants for photosynthesis, more light leads to an increase in the rate of photosynthesis
• temperature abiotic factor -affects rate of photosynthesis
• soil pH and mineral content abiotic factor - different species of plants are adapted to diff soil pH levels and nutrient conc levels
• oxygen concentration - important in aquatic systems
• co2 concentration as abiotic factor - required for photosynthesis in plants affects rate of photosynthesis
• niche

  the role of a species within its habitat (what it eats, which species it depends on for food, what time it is active, where it lives and feeds)
• no two species can fill the same niche within a habitat if this ever happens the two species will be in direct competition and one of the two species will out compete each other
• What can be inferred about species occupying the same niche?

  They may have subtle differences in their roles, such as feeding at different times or having different food sources.
• How does the niche filled by a species affect its abundance?

  The niche determines the species' abundance within a habitat.
• How is abundance defined in ecological terms?

  Abundance is the number of individuals of a particular species living in a habitat.
• What happens to the populations of two species occupying a similar niche?

  They will compete with each other, leading to smaller populations and lower abundance.
• How does the niche filled by a species influence its distribution?

  The niche determines the distribution of the species.
• What is the definition of distribution in ecological terms?

  Distribution refers to where a species lives.
• What factors determine whether a species can survive in a habitat?

  Species can only survive in habitats to which they are well adapted to the biotic and abiotic factors.
• What occurs if a species is not well suited to a habitat's factors?

  They will move to a more suitable habitat, resulting in a change in their distribution.
• What can be inferred about species occupying the same niche?

  There will still be subtle differences in their role, such as feeding at different times or having different food sources.
• How does the niche filled by a species affect its abundance?

  The niche determines the species' abundance within a habitat.
• How is abundance defined in ecological terms?

  Abundance is the number of individuals of a particular species living in a habitat.
• What happens to the populations of two species that occupy a similar niche within a habitat?

  Their populations will be smaller due to competition, resulting in lower abundance.
• What does the niche filled by a species determine besides abundance?

  The niche also determines the species' distribution.
• How is distribution defined in ecological terms?

  Distribution is where a species lives.
• What is required for a species to survive in a habitat?

  Species must be well adapted to the habitat's biotic and abiotic factors.
• What occurs if a species is not well suited to a habitat's conditions?

  The species will move to a more suitable habitat, resulting in a change in distribution.