Australian ecosystems are usually described by a combination of living and non-living components – for example, tropical rainforest, temperate or dry sclerophyll woodlands, alpine meadows or mallee scrublands. The types of communities that live in these ecosystems will be dependent upon the range of temperature and rainfall as well as the soil type, which affects the plants that are able to thrive and therefor the animals that live there. Australian soils are mostly very nutrient poor, due to the fact that the landscape has been exposed to rain, wind and erosion for many millions of years, washing nutrients into the rivers and oceans. An exception to this is the areas where volcanic eruptions have brought nutrients to the surface, such as the western volcanic plains.
A biome is a major community of plants and animals classified according to its predominant vegetation and characterized by the adaptations of its organisms to that particular environment.
This chapter of work is about habitats and the factors that affect the survival of organisms in their environments. You will learn about biotic (living) factors – predators, competitors, pathogens, parasites – and abiotic (non-living) factors – temperature, wind speed, pH, atmospheric gases, turbidity, salinity, solar radiation etc. You will also learn about niches and resource use graphs. Match some Australian species to their habitats at DECC.
Living organisms survive in their environments due to structual, functional and behavioural adaptations. Evolution is the process by which living organisms have changed over thousands of years to become more suited to their environments. Google ‘evolution’ and you will find an enormous selection of contradictory articles confirming or condemning “The Theory of Evolution”, first proposed by Charles Darwin in 1859.
To summarise Darwin’s Theory of Evolution;
1. Variation: There is variation in every population.
2. Competition: Organisms compete for limited resources.
3. Offspring: Organisms produce more offspring than can survive.
4. Genetics: Organisms pass genetic traits on to their offspring.
5. Natural Selection: Those organisms with the most beneficial traits are more likely to survive and reproduce.
Year 11students in Tattersalls Lane, ChinaTown.
As I will be on year 9/10 Rubicon camp during the first week of term 3, you will need to work through Chapter 9 in class. Unit 2 is about “Organisms and their Environment” and Area of Study 1 is concerned with Adaptations of Organisms. First we look at habitats, environment and survival. By the end of this chapter you will:
- develop a knowledge and understanding of habitats and the environments that exist in them
- identify major factors that produce the environments of various habitats and distinguish between biotic (living) and abiotic (non-living) factors.
- give examples of structural adaptations that equip organisms for survival under particular environmental conditions
- explore technologies used to record environmental factors and track distribution of species within their habitats.
Read through Chapter 9 and make sure you can answer the “Quick Check” questions (no need to write the answers, just answer them quietly to yourselves). Answer the Chapter Review questions on pages 293 to 296. These will be due Friday 24th July (end of second week of term). There are more resources on the Biology wiki at http://hawkesbiology.wikispaces.com/. Please register as a member and add any links to resources you find useful on the appropriate page.
If you have any problems, Don may be able to help, or contact me via Twitter (brittgow); email or Facebook.