Skip to content
Dabour HubLEARN · PRACTICE · EXPLORESign inStudent

BIOLOGY · Stage 8 · Chapter 7: The Health of the Environment

Biology 7.2 Habitats within an ecosystem

5 min read 7 parts Lesson 2 of 8

0%read
Lesson summary

7.2 Habitats within an ecosystem — Alhussan International Academy — Biology (Stages 7–9) notes: Define habitat, population, community and niche, and explain how organisms are adapted to different habitats within one ecosystem.Habitat = the place where an organism lives, its home.…

  • Abiotic factors
  • Every tree is a small ecosystem
  • Parts of a tree
  • Leaf litter and soil
  • Tree canopy
  • Rocky shore

Section 1 of 7Habitat, population and community

  • Habitat = the place where an organism lives, its home.
    • An ecosystem such as a woodland contains many different habitats, for example leaf litter, tree canopy, a pond or the soil.
  • Population = all the organisms of one species living in a habitat.
  • Community = all the populations of different species living together in the same habitat.
  • Ecosystem
    • it includes the community together with the non-living environment.
  • Niche = the job an organism does in its habitat, such as seed eater, nectar feeder or decomposer.
    • Organisms in a habitat each have their own niche so that they avoid competing for food.

Section 2 of 7Abiotic and biotic factors

  • Abiotic factors
    • they are non-living, such as light intensity, temperature, water availability, pH and wind.
  • Biotic factors
    • they are living, such as competition, predation, disease and food supply.
  • Conditions decide which organisms can live in a habitat.
    • The woodland floor is dark and damp, so shade-tolerant ferns and mosses and moisture-loving woodlice live there.
    • The woodland canopy receives full sunlight, so many insects and birds live there.

Section 3 of 7A tree as a habitat

1Every tree is a small ecosystem2 points
  • some species of tree are home to hundreds of other species.
  • A single tree may contain around 1000 different habitats.
2Parts of a tree5 points
  • each gives a different habitat.
  • The leaf canopy, branches, flowers and fruit are home to bees, wasps, moths, squirrels, sparrows and hawks.
  • The trunk and bark are home to insects and larvae.
  • The roots spread through the soil and are home to organisms such as tarantulas.
  • Leaf litter and decaying leaves support frogs and fungi.

Section 4 of 7Different habitats, different adaptations

  • Pond
    • water lilies have flat floating leaves with stomata on the upper surface, and fish have gills and streamlined bodies.
  • Leaf litter and soil
    • earthworms have soft bodies that burrow and improve soil aeration, and woodlice avoid dry conditions.
  • Tree canopy
    • birds have wings and keen eyesight, and leaves have a large surface area to capture light.
  • Rocky shore
    • limpets clamp to rock to avoid being washed away and to hold in water at low tide.

Section 5 of 7Larger ecosystems and their habitats

1Lake3 points
  • it has different habitats at all levels of the water.
  • Light and temperature affect which species live there.
  • The bottom has habitats under stones and among water weeds, and the edge ranges from reed beds to shingle shores.
2African savannah3 points
  • habitats range from huge grasslands to dung.
  • The grasslands are home to large animals such as zebra, lions and elephants.
  • Dung is a rich habitat for bacteria, fungi (decomposers), worms and insects such as beetles.
3Alpine mountain3 points
  • it is high and cold.
  • Habitats include bare rock, flat and sloping surfaces, and sunny and shady areas.
  • Organisms range from tiny plants on sheltered surfaces to birds of prey nesting on high ledges.

Section 6 of 7Investigating a habitat

  1. Choose one factor to vary, for example a shaded and a sunny part of a field, and keep other factors the same.
  2. Measure the abiotic factor, such as light with a light meter, at several points.
  3. Place a quadrat at random and count the species and numbers of organisms.
  4. Repeat in each area at least five times and calculate a mean to reduce the effect of chance.
  5. Present results in a table, then a bar chart, and link the abiotic difference to the difference in organisms.

Section 7 of 7Habitats change with time

  • Seasonal change
    • a pond in summer has warmer water with less dissolved oxygen, and a woodland floor receives more light in spring before the leaves open.
  • Movement between habitats
    • some animals use several habitats through the year, such as birds that nest in a wood and feed in a field.
    • Protecting an ecosystem therefore means protecting several connected habitats.

Last updated: