bio1ps201201
.pdf
Australian Soils
Generally nutrient-poor
Very ancient soils
•long periods of erosion and leaching
•no recent geological processes such as volcanic, glacial or alluvial activity to build up ‘new’ soil rich in nutrients
•low biological activity (because hot and dry)
•very low in phosphate
Compare with very fertile soils in Java
•current volcanic activity
•heavy rains (alluvial activity)
•year-round biological activity
•supports large human population (100 million)
C, N, and P Cycles
•All the nutrient cycles are based in soil
•Pools of all nutrients on earth are limited
•Constant recycling necessary in order to provide nutrients to support continued life on earth
Knox p 357, 1185-1193
C, N, and P Cycles
Carbon
•woody structures of vegetation (cellulose!)
•must be recycled to provide CO2 for ongoing
photosynthesis |
C in forest biomass: 288.8 billion t |
Nitrogen |
Global Forest Resources Assessment 2010 |
|
•proteins etc. in plants and animals
•must be recycled to give the N salts required by plants
Phosphorus
•
•
ATP, nucleic acids
easily immobilised in soil
Carbon Cycle
C Cycle Animation:
http://vro.dpi.vic.gov.au/dpi/vro/vrosite.nsf/pages/soilhealth_organic_carbon-cycle
Ladiges et al. (2010), 4th ed., Fig. 44.19
Nitrogen Cycle
N Cycle Animation:
http://vro.dpi.vic.gov.au/dpi/vro/vrosite.nsf/pages/soilhealth_nitrogen-cycle |
Ladiges et al. (2010), 4th ed., Fig. 44.20 |
Phosphorus Cycle
Ladiges et al. (2010), 4th ed., Fig. 44.22