ENVS10011 Lecture Notes - Lecture 7: Millennium Ecosystem Assessment, Biodiversity Hotspot, Ecosystem Services
17 May 2018
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WEEK 7: ECOSYSTEM SERVICES
Ecosystem Services: all benefits people obtain from ecosystems (UN Millennium Ecosystem
Assessment)
Basic Services
• Products (food, fibre, energy)
• Services
o Carbon (c.c mitigation)
o Water
o Recreation (parks, beaches)
o Biodiversity + conservation (National Parks)
o Spiritual (indigenous land)
Biodiversity
‘The variety of all life-forms (plants, animals + microorganisms), and the ecosystem of
which they are a part’ – Aus Gov’t
• Comes on different levels of organisation:
o Gene, species, population, ecosystem
• Ecological indicators:
o Total species richness (TSR): number of all species in one area
o Diversity of specific DNA sequences
o Diversity of functional groups
• Why do we need biodiversity?: value in itself, supports ecosystem functions
Ways of Measuring Biodiversity
• Diversity – genetic, species, ecosystem
• Variation – within one species/population
• Abundance – how many of one species
• Function – role of the ecosystem
• Distribution – where are the variations in biodiversity
Where is the biodiversity?
• Concentrated in tropical biomes (tropical + sub-tropical forest), least in colder biomes
• Diversity decreases, as an overall trend, as you move from the equator to the pole
• Biodiversity Hotspots: greatest species richness often in isolated or geographically
varied areas
• Endemic Species: restricted to a certain area + occur nowhere else
• 17 megadiverse countries = less than 10% total land surface, yet > 70% known species
Extinctions
• Natural, always occurring, yet rate changing due to human activity
• Aus: bad after euro settlement
• Rates:
o Distant past: 1 species/mya
o Recent past: 100/mya
o Future: 1,000-100,000/mya
• Causes:
o Environmental change – habitat destruction
o Hunting + harvesting
o Invasive species
Conservation
Document Summary
Ecosystem services: all benefits people obtain from ecosystems (un millennium ecosystem. Basic services: products (food, fibre, energy, services, carbon (c. c mitigation, water, recreation (parks, beaches, biodiversity + conservation (national parks, spiritual (indigenous land) Ways of measuring biodiversity: diversity genetic, species, ecosystem, variation within one species/population, abundance how many of one species, function role of the ecosystem, distribution where are the variations in biodiversity. Extinctions: natural, always occurring, yet rate changing due to human activity, aus: bad after euro settlement, rates, distant past: 1 species/mya, recent past: 100/mya, future: 1,000-100,000/mya, causes, environmental change habitat destruction, hunting + harvesting. Conservation: a wide range of goals, generally conserving aspects of biodiversity, protected species: environments managed for particular species. Types: national + state parks, nature reserves, conservation corridors, protection of species in legislation: env. Introduced + invasive species may increase biodiversity measures eg. tsr, but generally decrease overall biodiversity.
