Environmental landscapes Flashcards
Southwest Western Australia has 7380 native plants. How many of these are endemic?
49%
What are the four ‘switches’ required for a fire to occur?
- Suitable weather conditions
- low fuel moisture
- Ignition source
- adequate fuel biomass
Very sandy soils with little clay have a …
low water holding capacity and low nutrient retention capacity.
Which factor does NOT have a big influence on the structure of vegetation communities along the Swan Coastal Plain?
Rainfall
What are the five main factors influencing vegetation?
Climate, soil type, geology, topography, humans
Wetland soils are likely to be rich in …
organic matter.
What is NOT an abiotic driver of Western Australia’s vegetation?
Native wildlife influences
A catchment cleared of vegetation is likely to have …
little evapotranspiration.
Which country has the largest area coverage by forests?
Russia
Properly managed forest plantations allow for what?
Pressure to be taken off natural forests
Materials of Australian soils
- Sandy soil materials
- Iron and aluminum oxide
- Duplex soils
Formation of soils in Yilgarn Crater
- Weathering and decomposition of
granite and gneiss - Tectonic stability
- Climate change
- Evolution of the laterite profile
Geology of the Yilgarn Craton
- Granite
- Gneiss
- Dolerite
Perth/Southwest Australia has two main geological structural units?
- Yilgarn craton
- Perth Basin (SCP)
Main Geology of the SCP
- Tamala Limestone (aeolianite)
- Spearwood Dune System
- Bassendean Dune System
- Alluvial deposits (clay and sand)
How soil is formed in the SCP
- Weathering of the Tamala Limestone
- Modification of sand deposits
- Development of soil horizons and the formation of Podzols
Five distinct soil zones of the SCP
- Quindalup dunes
- Tamala limestone (Spearwood dunes)
- Bassendean dunes
- Guilford Formation
- Yoganup Formation
Abiotic drivers of WA’s vegetation
- Climate influences-> Temp & Moisture
- Geological influences
- Soils Influences-> Nutrients & Depth
- Topographical influences
- Historical influences
Where in South-west WA does the highest species richness occur?
Uplands
What factor is critical in making South West WA a biodiversity hotspot?
Severely threatened
What is the biggest threat to vegetation communities on the Swan Coastal Plain?
Land Clearing
The sands of the Swan Coastal are mainly composed of
Quartz
How does “Harsh Hakea” cope with nutrient poor soil
- Develop cluster root system
- For purpose of absorbing more Phosphorus
An example of Parasitism
Nuytsia Floribunda (Australian Christmas tree)
* Modifies roots to attach to host plants and steal water & Nutrients
