Lecture 2 Flashcards
Frameworks of how nature benefits humans
1) Values
2) Ecosystem services
Values of biodiversity
Use values and non-use values
Use values
1) Direct e.g. fruit - direct benefit of eating it
2) Indirect e.g. decomposition, use trees that have utilised nutrients produced by decomposition
Non-use values
1) Option value - keeping something gives option to use it in the future
2) Bequest value - idea of leaving something desirable for future generation
3) Existence/intrinsic value - idea that biodiversity has value even in absence of humans, it has a right and reason to exist even in absence of humans
Ecosystem services
The conditions and processes through which natural ecosystems, and the species that make them up, sustain and fulfil human life (Daily 1997)
The set of ecosystem functions that are useful to humans (Kremen 2005)
Millennium ecosystem assessment
- Called for by UN secretary general in 2000
- Includes info from 33 sub-global assessments
- Prepared by 1360 experts from 95 countries
- To assess the consequences of ecosystem change for human well-being and the scientific basis for actions needed to enhance the conservation and sustainable use of those systems and their contribution to human well-being
Capture fishery problems
1/4 of marine fish stocks are overexploited or significantly depleted
Problems associated with crossing fishing thresholds
- Fisheries collapse
- Eutrophication
- Coral reef regime shifts
- Disease emergence
- Species introductions
- Regional climate change
Mangrove services
- Nursery and adult fishery habitat
- Fuelwood and timber
- Carbon sequestration
- Traps sediment
- Detoxifies pollutants
- Protection from erosion and disaster
What are mangrove ecosystems being replaced by?
Housing
Prawn farming
Crops
Value of mangrove compared to prawn farm: public net present value per hectare
Mangrove $1000 to $3600 (mainly due to coastal protection)
Prawn farm $-5400 to $200
Natural capital
The world’s stocks of natural assets which include geology, soil, air, water and all living things
Important to quantify biodiversity and ecosystem degradation to manage these risks - use natural capital to quantify
Threats to biodiversity
Habitat destruction Habitat fragmentation Overharvesting Invasive alien species Climate change Fire Pollution
