GEOG20003 Lecture Notes - Lecture 6: Overexploitation, Species Richness, Social Change
16 May 2018
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LECTURE 6: BIODIVERSITY
• Biodiversity (Biological Diversity): measured in 3 levels – ecosystem,
species + genetic
• Weak data on species diversity – focus on macro organisms
• Survival of mega species (mostly mammals + larger organisms) – indicate
health of ecosystem/ecosystem diversity
• Most diversity in oceans – most of the ocean unexplored
• Pressures we place on the environment are complex: direct, indirect +
future
Value of Biodiversity
Use Value
• Economic – food, medicine, pest + disease control
• Recreational
• Cultural – aesthetic, religious
Ecological Value
• Stability – ability of a system to resist change
• Resilience – capacity of system to restore itself after disturbance
• Productivity – rate of biological production
Intrinsic Value: right to life
State of Biodiversity
• Assessing changes to species + ecosystems
o Species richness (diversity)
o Abundance
o Distribution (range)
o Health
• In combination, these provides a better sense of biodiversity, than extinction
• Extinction has become a phenomenon driving biodiversity policy
o In the future, extinction will become 10 times higher than current rate
• Currently, 36% of species: more than vulnerable (vulnerable, endangered or critically endangered)
Australia – SoE Report 2016
• The highest threatened ecosystems are the highest human populated areas
• Species status:
o 74 ecological communities
o 480 animal species
o 1294 plant species
Causes of Biodiversity Loss
• Socioeconomic root causes:
o Population pressures
o Inequality + poverty – areas of poverty + threatened species correlate
o Public policies, markets + politics
o Macro-economic policies + structure
o Social change + development biases
• Proximate causes: seen in blue box above
BIODIVERSITY PRESERVATION
• Value framework depends on how much biodiversity will be saved
Mechanisms for Preservation of Biodiversity
Direct regulation: prohibitions + limits on taking, reserves, international regimes (governed by international treaties + regimes)
Indirect regulation (economic instruments): licences + fees, incentives
Cultural means: education, co-operative land management
• Recent times, increase in biodiversity regime complexity
o International, national + regional organisation + documents, as responses
• In Aus: all biodiversity management occurs with influence by Indigenous people
Problems for Biodiversity Preservation
• Science (inadequate)
• Politics + political economy
• Cultural obstacles
• Institutional inadequacy
• Compliance
Threatening Processes to Biodiversity
Over-harvesting
• Impacts: pop size, patterns of reproduction,
distribution + genetic composition
Habitat Fragmentation + Loss
• Land clearing – for agriculture, forestry, urban
expansion + water extraction
Pollution
• Effects: ecosystems + species health +
reproduction
Feral Species
Genetic Erosion
Climate Change
• Changes to: fire, drought, flood, habitat loss,
species health + impacts on reproduction
• Processes are cumulative + occur in
combination = compounding affect
• Result: loss of biodiversity, 6th extinction
Document Summary
Biodiversity (biological diversity): measured in 3 levels ecosystem, species + genetic: weak data on species diversity focus on macro organisms. Survival of mega species (mostly mammals + larger organisms) indicate health of ecosystem/ecosystem diversity: most diversity in oceans most of the ocean unexplored. Pressures we place on the environment are complex: direct, indirect + future. Economic food, medicine, pest + disease control. Stability ability of a system to resist change. Resilience capacity of system to restore itself after disturbance. Impacts: pop size, patterns of reproduction, distribution + genetic composition. Land clearing for agriculture, forestry, urban expansion + water extraction. Climate change: changes to: fire, drought, flood, habitat loss, species health + impacts on reproduction. Processes are cumulative + occur in combination = compounding affect. In combination, these provides a better sense of biodiversity, than extinction. Extinction has become a phenomenon driving biodiversity policy.
