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Environmental factors


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Environmental factors

  1. 1. Environmental Factors Image credit:
  2. 2. The type of community of organisms that can flourish in an ecosystem is directly influenced by the environmental conditions
  3. 3. Australian Ecosystems Diversity of ecosystems where many plant communities have adapted to Arid conditions Variable rainfalls High salinity Fire Poor soil
  4. 4. Environmental Factors Several factors have shaped the evolution of species Sunlight Energy source for photosynthesis Competition can be quite intense in a rainforest where plants at ground level receive low intensity light. In marine environments plants do not exist beyond 100 meters due to insufficient light Majority of producers – phytoplankton found mainly on surface
  5. 5. Other species of algae (brown algae) contain different pigments which are able to absorb light enabling them to survive at greater depths Water Plant communities have developed adaptations to suit the water availability of their environment. Saltbush, mallee trees etc. can deal with high temperatures and evaporation keeping water loss to a minimum
  6. 6. Plants have specialized leaves to store water i.e. cactus Waxy cuticles -prevent water loss Some mammals have developed specialized excretory systems that enable them to excrete crystalline uric acid to reduce water loss In rainforests many plants have high water requirements while moisture at ground level suits a range of insects and decomposers such as millipedes, bacteria and fungi. Lichen, mosses and other climbers grow in an attempt to access available light
  7. 7. Temperature Many organisms such as humans require a critical temperature – 370C for cellular metabolism and other homeostatic processes Nutrients Plants require essential nutrients to incorporate into their tissue and to build organic molecules such as Phosphates Nitrates Sulfates
  8. 8. Many plants need to adapt to nutrient poor soils, particularly in Australia Wind Strong winds force plants to adapt with deeper or more extensive root systems Salinity Plants and animals exposed to high solute concentrations need special adaptations to avoid dehydration. Many excrete salts.
  9. 9. Wave action Strong wave action countered by adaptations such as strong muscular tissue enabling them to hang on the rock substrate. There are several typical ecosystems found in Australia each containing its own biotic and abiotic factors and a wide range of species
  10. 10. Mallee Ecosystem
  11. 11. Savanna Woodland Ecosystem
  12. 12. Rainforest Ecosystem
  13. 13. Intertidal Zone Ecosystem
  14. 14. Mangrove Ecosystem
  15. 15. Desert / Grassland Ecosystem
  16. 16. Resources Resources are classified as either biotic or abiotic The productivity of the community is how effective a particular community is at converting the sun’s energy. Of the total amount of energy trapped by producers only a small % is available at the next trophic level- primary consumers The majority is required by the producer for life processes, growth, cell division, uptake and synthesis of molecules
  17. 17. The term biomass refers to the total weight of living matter in a community
  18. 18. The two main constraints on productivity of a community are Energy available Quality of resources Humans use fertilizers and irrigation to boost productivity Harvest of SA crops depends heavily on amount and timing of rainfall
  19. 19. All organisms require energy and matter to build up tissue. This energy is neither created or destroyed but recycled. The main elements include Carbon Oxygen Nitrogen This recycling is due the actions of decomposers such as bacteria and fungi which break down organic material into inorganic material Eventually returning the elements to the environment