Sustainability - case studies
Case Study: Sustaining our forests
http://www.forest.nsw.gov.au/bush/autumn05/pdfs/bt-autumn-05-web-12.pdf
Case Study: Rainforests and crops
Strangler fig
We only have to look at rainforests in Australia to understand more about sustainability.
Over the past two hundred years large areas of Australian rainforest have been cleared for agricultural, industrial and urban development. Early settlers thought that if lush green rainforest could grow in an area, their crops were sure to succeed in its place.
The diversity (large variety of plants) and density (large number of plants in an area) of rainforest suggests that it occurs on very fertile soil, but often this is not so. In tropical and subtropical areas where high rainfall occurs, the soil nutrients are rapidly carried away or leached from the topsoil by rainfall. A large proportion of rainforest nutrients are released gradually into the soil and the plants' roots rapidly absorb the nutrients again and recycle them.
When a tropical or subtropical rainforest is cleared and burnt for crop or pasture development, the crop or pasture will typically grow well for a year or two until the soil nutrients are leached away. However, crops do not store and recycle soil nutrients, making future crop growing very difficult and expensive.
The clearing of tropical or subtropical rainforest for cropping was unsustainable. Crops failed and rainforests were depleted.
Rainforest communities are today considered special biologically diverse areas with very large numbers of plant and animal species. Rainforest in Australia covers a very small amount of land, and conservation of rainforest and other unique environments involves the careful planning and management of our natural resources. Rainforest in NSW is now protected and clearing is no longer permitted. (Source: NSW DPI)
Case Study: Pyrolysis technology an environmental and award winner
The results of a research partnership between NSW Department of Primary Industries (NSW DPI) and BEST Energies grabbed national attention for their exciting environmental potential and won the partners the major 2007 World Environment Day Awards category ‘Meeting the Greenhouse Challenge’.*
The partnership was established to investigate a renewable energy technology known as 'pyrolysis', that BEST Energies had developed.
Pyrolysis involves decomposing green waste or other biomass at high temperatures without oxygen. It generates clean renewable energy plus a stable form of solid carbon called 'biochar'.
Glasshouse and pilot field trials conducted at NSW DPI’s Wollongbar Agricultural Institute have shown that biochar can significantly increase crop biomass production, while improving many soil fertility indicators.
Recent work has indicated potential for biochar to reduce soil emissions of greenhouse gases such as nitrous oxide. Most importantly for the environment, soils can hold biochar long term, thereby acting as a carbon sink and reducing climate change.
The benefits of pyrolysis are such that noted Australian scientist and former Australian of the Year Tim Flannery has listed ‘fostering pyrolysis-based technologies’ in his five steps for saving the planet.
For further details see the website at www.dpi.nsw.gov.au/research/topics/climate-change.
* The awards are run annually by the United Nations Association of Australia