7C ecosystems

• Give a few examples of methods of conservation.

  Fishing quotas - limiting the amount of fish which are allowed to be catched.

  
  

  Seed banks - storing seeds so new plants can be made if they become extinct.

  
  

  Protected areas - restrict urban and industrial development as well as farming.

  
  

  Breeding programs and captivity - increases the number of endangered animals.
• What is sustainability?

  meeting the needs of the present without compromising the ability of future generations to meet their own needs.
• What is conservation?

  The protection and management of species and habitats (ecosystems) in a sustainable way.
• What is a plagioclimax?

  When succession is stopped artificially by human activities. E.g. a regularly mowed lawn.
• Give two examples how different ecosystems have different climax communities.

  In temperate climates there is plenty of water available, mild temperatures, and little seasonal variation. So large trees can grow and survive here.

  
  

  
  

  In polar climates there is little water available, low temperatures, and large seasonal variation. So large trees will not grown and survive here, but shrubs and herbs will.
• Describe the stages of succession.

  a species colonise a new land surface.

  
  

  Speeds and spores are blown by the wind and begin to grow.

  
  

  The abiotic conditions are hostile so only pioneer species can grow as they are adapted to cope with such harsh conditions e.g. marram grass.

  
  

  The pioneer species die microorganisms decompose the humus to form a basic soil.

  
  

  This makes the conditions less hostile meaning new organisms can move in and grow.

  
  

  This continues as better adapted organisms move in and outcompete the original organisms, to become the dominant species.

  
  

  As succession continues more species habitat there so the ecosystem becomes more complex and biodiversity increases.

  
  

  The final stage is the climax community - the largest and most complex stable ecosystem that can exist.
• Give an example of where secondary succession would occur.

  After a forest fire or deforestation.
• What is secondary succession?

  Succession on land that has been cleared of plants but the soil remains.
• Give an example of where primary succession could occur.

  Volcano eruption or where sea level has dropped.
• What is primary succession?

  Succession on newly formed or exposed land.
• What is succession?


  The process by which an ecosystem changes over time.
• Ecosystems are dynamic - what does this mean?

  They are constantly changing.
• How do you use a quadrat with a transect?

  In a belt transect quadrats are placed one after another.

  
  

  In an interrupted belt transect, quadrats are placed at intervals along the line.

  
  

  Calculate species frequency (%cover) or number of individuals.

  
  

  Repeat.
• How do you use a quadrat with a RNG?

  Create a grid for the area being investigated.

  
  

  Random number generator to find coordinates for quadrat.

  
  

  Calculate species frequency (%cover) or number of individuals.

  
  

  Repeat.

  
  

  Calculate a mean for all results and multiply it up to find mean for the whole area.
• What are the two ways to use quadrats?

  Using a RNG to find coordinates, using a transect to do regular intervals.
• What method is used to investigate populations?

  Quadrants.
• What assumptions need to be made in order to successfully do capture recapture?

  - the marked sample has has enough time to adequately mix with the pop.

  
  

  - the markings have not affected the individuals chance of survival.

  
  

  - there are no natural changes in the population size.

  
  

  - no markings have fallen off.
• How do you calculate total population size?

  The number caught in 1st sample X number caught in 2nd sample / number marked in 2nd sample
• Describe the method of mark release recapture.

  - capture a sample using an appropriate technique e.g. pitfall trap.

  
  

  - mark in a harmless way e.g. tags or paint.

  
  

  - release them back.

  
  

  - wait a decided time.

  
  

  - take a second sample.

  
  

  - count how many of the second sample are marked.
• What is mark release recapture used for?

  To measure abundance of more motile species.
• Describe the change in pop size in relation to predation over time.

  - Prey pop increases so there is more food availability for predators so predator pop increases.

  - more predators now eat the prey so prey pp decreases.

  - less prey means less food for predators so predator pop decreases.

  - the cycle repeats.
• What is predation?

  One one organism kills and eats another.
• Describe what happens during intraspecific competition for the population size.

  - pop increases when resources are plentiful.

  - Resources become limiting so pop decreases.

  - smaller pop means less competition, increasing growth and reproduction and therefore increasing the pop.

  - the cycle repeats.
• What is intraspecific competition?

  When organisms of the same species compete with eachother for resources.
• Give an example of interspecific competition.

  Red and grey squirrels in the UK.
• What is interspecific competition?

  When organisms of different species compete with each other for resources.
• Give an example of how abiotic conditions can affect population size.

  When the temp of mammal habitats are ideal, less energy is needed to maintain body heat so more energy can be used for growth and reproduction, increasing population size.
• How do abiotic conditions affect population size?

  When they are ideal, organisms can grow fast and successfully reproduce but when they are not this is not true.
• What is carying capacity?

  The maximum population size that an ecosystem can stably support.
• What is population size?

  The total number of organisms of one species in a habitat.
• Give an example of a biotic adaptation.

  Otters have learnt to use rocks to open shellfish, increasing survival chances as they now have another food source.
• Give an example of an abiotic adaptation.

  Otters have webbed paws increasing their survival chances because they can hunt on land and water.
• What are physiological adaptations?

  Processes inside the body e.g. venom production.
• What are behavioural adaptations?

  The way an organism act e.g. courtship.
• What are anatomical adaptations?

  Structural features e.g. claws.
• Name the three types of adaptations?

  Anatomical, behavioural, physiological.
• Why are niches called unique, what happens if two species occupy the same niche?

  They are unique because only one specie can occupy it. If two species occupy the same niche then they will compete with eachother until one is forced to occupy a different one.
• What are adaptations?

  Features of organisms that increase survival and reproduction.
• What are niches?

  The role of a species within its habitat.
• What are biotic factors, give an example?

  Living features e.g. competition, predators, food availability.