Biodiversity describes the variety of life in an area, including:
- the number of different species
- the genetic wealth within each species
- the interrelationships between them
- the natural areas where they occur.
These benefits of biodiversity are often referred to as ecosystem goods and services. These services are categorised:
- Provision – biodiversity provides all living organisms with water, food, fuel, medicine and fibres.
- Regulation – biodiversity and its life-support systems regulate climate, water and the spread of disease.
- Cultural – people need connection to nature. There are numerous spiritual, aesthetic, recreational and learning benefits.
- Supporting life systems – production, soil formation and nutrient cycles.
And biodiversity is also directly related to the quality of life you may expect.
The loss of biodiversity has lead to economic gains in some cases, but increasingly people are seeing that there are material costs that were not considered. The Green Jobs report, South Africa’s Green Fund and exploration of financing schemes for the payment of ecosystem services (PES) are important developments.
Incentives provided for the conserving of biodiversity set an economic value on this preservation. Areas served by this will include soil erosion prevention, landscape beauty, water flows, carbon sequestration and storage, and biodiversity protection generally. There is great job creation potential here (as evidenced in initiatives like government’s Working for Water programme), and the aligning of conservation efforts to national development goals should be encouraged.
Source: an excerpt from the opening page at (now defunct) www.stewardship.co.za
Biodiversity is the basis of agriculture. Maintaining biodiversity is essential for the production of food, agricultural goods, and all the benefits that come with these – food security, nutrition and livelihoods. The “Natural resources” section of this publication is a recognition that while agriculture contributes to the conservation and sustainable use of biodiversity, the opposite is also possible: agriculture can be responsible for biodiversity loss.
The reader should note that there is information elsewhere in the book that could well have been in this section e.g. the information on best fertiliser practice (see “Fertiliser” chapter). Also, in order to mainstream them, several chapters like biocontrol, renewable energy and rainwater harvesting have been moved to the “Inputs” section.
2. Threats to biodiversity
The biologist EO Wilson developed the acronym HIPPO to sum up the threats to biodiversity.
Habitat destruction, disturbance and fragmentation
Habitat destruction and the changes to ecosystems is possibly the greatest cause of biodiversity loss.
Introduced and invasive species
Introduced species often become invasive when they breed and out-compete or eat the endemic species. Invaders impact on fauna and flora, but also on the soil, land and water resource. Invaders tend to resource-hungry and deplete the natural assets.
Since the industrial revolution, countries – mostly in the “industrialised west” – have been polluting for two centuries. Joined now by emerging economies such as India, China and South Africa, the pollution levels world-wide are soaring. Key focus areas to address pollution include water contamination by fertilisers, pathogens, acid-mine drainage; pesticides affecting plants, animals and the receiving environment; coal-fired electricity plants which produce high levels of air pollution and contaminate water; untreated sewage and effluent contaminating water systems, including rivers and groundwater; and landfill waste which grows exponentially with pollution and affluence.
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