Unit 2, Outcome 1 DISCOVERING OUTDOOR ENVIRONMENTS
2.1.1 Types and characteristics of selected outdoor environments Australians are the custodians of some of the most diverse ecosystems on the planet. Our continent is one of the world’s 12 biologically ‘mega-diverse’ regions, with a high proportion of endemic species — those that are found nowhere else in the world. For example, 93% of our marsupial species and 88% of our native rodents are endemic.
Victoria’s land area supports a wider range of broad ecosystems than any area of a similar size in Australia: Alpine, marine, coastal, heathlands. wetlands, grasslands, forest and arid. Each have specific features/characteristics that make them unique and different from others. These environments support at least 3140 native species of vascular plants, 111 mammals, 447 birds, 46 freshwater and 600 marine fish, 133 reptiles, 33 amphibians and 750 mosses. This richness — in the number of different ecosystems and different species, and the genetic variety they exhibit — is what we call biodiversity.
KEY CONCEPT Victoria contains a variety of natural environments that have evolved and developed over millions of years.
KEY CONCEPT The specific type of environment you find yourself in in dependent on a number of factors. These include: Geology Climate Position & Aspect
GEOLOGY GEOLOGY The influence of Geology can be seen in an area by the type of rock found there, the soil characteristics and drainage. Soil changes occur through the parent rock, the elements (wind/rain/sun), living and decomposing plants, and groundwater. The shape of the land (topography) is also important, such as is found at the Cathedral Range (upswept rocks ).
CLIMATE Annual rainfall, extremes in temperature, and average daylight hours are examples of climatic factors that can affect a landscape. HOW? Other aspects include wind patterns, evaporation, ground temperature, frost frequency and snow cover. Australian rainfall is seasonal and erratic, producing extended periods of drought.
POSITION & ASPECT Geographic location is very important when determining the development of environment types. In physical geography, aspect generally refers to the horizontal direction to which a mountain slope faces. Aspect can have a strong influence on temperature. This is because aspect affects the angle of the sun rays when they come in contact with the ground, and therefore affects the concentration of the sun's rays hitting the Earth. The aspect of a slope can make very significant influences on its local climate. The sun's rays are in the west at the hottest time of day in the afternoon, in most cases a west-facing slope will be warmer than a sheltered east-facing slope
Example: In Australia, remnants of rainforest are almost always found on east facing slopes which are protected from dry westerly wind. In eastern Australia, southerly and easterly aspects receive: - Lower radiation loads, resulting in reduced water-loss - Are fire protected, thus permitting the survival of rainforest species.
Factors affecting natural environments. Read pages 61 – 62 Complete a table in your workbook like this: Summarise as many key points as you can from the text which influence the characteristics of Australian outdoor environments. Factors affecting natural environments: Environmental influences of each factor GEOLOGY CLIMATE POSITION AND ASPECT
Different types of outdoor environments. Research and map – Activity 1 1.Work with a partner to create a poster depicting the characteristics of a specific outdoor environment. *See Mrs. G for a detail handout of the topic. 2. Present your poster to the class in pairs. Individuals will be required to take notes for their - ‘Biodiversity table of Victorian Ecosystems.
Activity 2 To expand your understanding of the different types of outdoor ecosystem, use ‘Victoria’s Biodiversity – Our living Wealth’ or ‘Viridians’ to complete an unfinished sections of your ‘Biodiversity table of Victorian Ecosystems. http://www.nre.vic.gov.au/plntanml/biodiversity/wealth/cont ents.htm or http://www.viridans.com/ECOVEG/
Activity 3 On a large map of Victoria, outline the main environment types and their distribution. Make sure you follow appropriate mapping conventions (BOLTSS+D) where possible. (Viridians website will be useful here)
The Great Dividing Range forms a barrier across Victoria. It protects many north-facing slopes from the cool/moist winds sweeping from Bass Straight. This results in the northern foothills being relatively dry. Different forest ecosystems include: Stringybark forests (these dominate the near-coastal landscape east of Western Port) Red gum forests survive along major rivers in the north of the State Box–Ironbark forests lie in a wide arc from west of Stawell to east of Wangaratta
Dry forest & woodlands Most of the dry forest & woodlands that would have been found are now gone due to clearing. Dry forests and woodlands are biologically diverse and support a variety of plants and animals, included some vary rare flowers and birds. Habitat modification, vegetation clearance, weed invasion, feral predators and loss of hollow-bearing trees are significant concern.
Approx. 4 million yrs ago, a vast inland sea covered what we now call the Mallee and the north-western part of Victoria. This has left this area with a legacy of sand and shallow soils that cover the area today. The area is dominated by low Mallee scrub and small eucalyptus that can withstand prolonged dry periods and harsh conditions. The flora and fauna in this place is remarkably diverse – this being an area that seems very lifeless.
Grasslands Prior to European settlers arriving in Victoria, extensive grasslands covered the plains between the Murray Valley and the Great Dividing Range Indigenous people had used fire in the past to maintain the open nature of the landscape. These grasslands contain a variety of floral species, kangaroo grass, wallaby and spear grass. This environment attracted Europeans for uses in cattle grazing, cropping and pasturelands.
Grasslands As a result of these things listed, less than 1% of Victoria’s native grasslands remains intact today. These areas are however in very small areas and therefore face the risk of weed invasion, salinity and urban development.
Heathlands Heathlands are found within Vic from the Coast to the mountains. Characteristically a low and shrubby environment, trees twisted by the dry winds they are typically subjects to.
Heathlands Nutrient levels in the soil are generally low, and the soils are also acidic. These areas have a close relationship with fire, some plants needing this to re-germinate. The grass tree is one example. (Xanthorrhoea australias)
Heathlands These environments are dominated by hard-leaved plants such as banksias, bottlebrushes, tea trees and eucalypts. As their name suggest they are also populated by a number of heaths.
Wet Forests and Rainforests Victoria’s wet forests and rainforests are found in southern, central and northeast regions of the state. They include the Otways, Wilson’s Prom, and the Alps. The worlds largest flowering plant (the Mountain Ash) occurs in these ecosystems.
Wet Forests and Rainforests Other plants/trees include manna gum, messmate stringybark, mountain grey gum, Blackwood, and various tree ferns. Several rare mammals including possums and birds require hollow trees to nest and habitat. Many forest plants have adapted well to fire and can re-establish them afterwards, however rainforest plants have not adapted well and can reduce significantly after a fire.
The Alps (Alpine) The word ‘Alpine’ is often used to describe any high mountain area. Theoretically, the term refers to the area above a certain altitude where there are no trees because of prolonged cold. Snow covered areas of Australia cover approx 0.15% of the country (11,700 square km’s). Mt Kosciusko is Australia’s highest peak (2228 m) and Mt Bogong is Victoria's highest (1986 meters).
The Alps (Alpine) Aust. Alps have eroded over 500 million yrs, unlike others around the world. This has formed rounded mountains and plateaus. Sphagnum moss is a very unique vegetation that has adapted to suit the Victorian Alps. Bogong High Plains
Victoria has over 2000 km of coastline It ranges from sheltered bays and inlets to rugged eroded cliffs. The west coast is sometimes exposed to gale forced winds that have contributed to the amazing scenery along the Great Ocean Road. The coast is constantly changing due to the relentless effects of the wind, rain and waves. Some factors that influence coastal ve getation are related to wind, salt and natural land instability.
The Coast Dunes are held together by grasses and herbs, while salt marsh and mangroves inhabit the mudflats. These plants play a crucial role in holding the subsoil together in these environments. Birds are the most common types of fauna in this environment, ranging from Fairy Penguins to a large number of migratory birds from Siberia, Japan and the North Pacific Ocean.