Ecosystems and Biodiversity

Question 1

Biodiversity

Answer 1

o The variability among living organisms from all sources, including inter alia, marine and other aquatic ecosystems, and the ecological complexes of which they are a part of
o This includes variability within species, between species and of ecosystems

Question 2

Significance of Biodiversity

Answer 2

• If a species has the exact same genetic make-up, it could eventually become extinct – lacks resistance and resilience, lack diversity to adapt quickly to environmental changes
• Genetic diversity is key to species health
• Can have impact on other species
• E.g. frogs (sensitive to habitat degradation) have pharmaceutical potential (powerful antibiotics, blood pressure drugs, pain killers x 200 strength)
• Preserve habitats for a long term gain rather that a short term gain that will have a long term loss

Question 3

Australian Species and Medicine

Answer 3

o > 21,000 plant have medical uses
o Potential for multi-million dollar industry based on biodiversity
o 80% of population relies on traditional medicine
o Many important drugs cannot be reproduced synthetically

Question 4

Why Biodiversity Matters

Answer 4

o Threats: land clearing, deforestation, urban sprawl
• Environments changed and habitats lost
o Critical economic value to humans
• Ultimate source of different strains for food crops
• Various plants & animals are sources of pharmaceuticals
• Bio-diverse regions are major source of tourism revenue
• At least 50% of anti-cancer drugs are from nature
o Every species has an inherent right to exist – view point of environmentalists
• We cannot safely contribute to the extinction of any species
• Do not understand the role of all individuals species within ecosystems

Question 5

Types of Biodiversity

Answer 5

Genetic
Variation in genetic make up amongst individuals of a given species
Important for adaptation to changing environment
Humans use this to improve animal & plant strains
Species
Variety of species living in a given habitat
Immature ecosystem: low species diversity
Mature ecosystem: high species diversity
Agricultural, medical, ecological and economic value of many species remain to be discovered
Grouped together according to shared characteristics
Endemic = only occur naturally in one country/region
Measurement: manual sampling using transect designs
Quantifying species biodiversity
Species richness = number of species observed in a given area
Species diversity index (SDI)
SDI = s / N
S = number of species in area (species richness)
N = total number of individuals observed in area
Ranges between 0 – 1
1 = high biodiversity
Can take a sample of a population and calculate SDI
Simpsons Index (D)
D = 1-((∑▒〖n_i (n_i-1) 〗)/(N(N-1)))
Ni = number of individuals observed from a given species
N = total number of individuals observed in the area
Shannons index
H = ∑▒〖(p_i ×ln⁡〖p_i 〗 ) 〗
Pi = ni / N
Ecosystem
Variety of ecosystems / habitats within a given region
Necessary to maintain species & genetic diversity
Ecosystems: combination of soil type, vegetation type, climate, flora & fauna species – community of organisms and physical environment interacting together
Variety of forest types, grasslands, aquatic systems etc.
Mega-diverse country:
Less than 10% of global surface, but supports more than 70% of biological biodiversity on earth

Question 6

Biodiversity Hotspots

Answer 6

o Areas that support highly diverse natural ecosystems, largely intact with native endemic species – often support species that are not/rarely found outside the hotspot

Question 7

Loss of Biodiversity

Answer 7

o E.g. Amazon Rainforest
• World’s largest tropical rainforest, highly biodiverse
• Rapid deforestation – wood, cattle, soy, sugarcane
o In Australia:
• 3000 whole bushland systems (1500 species) are disappearing
• Northern NSW has 50% of ecosystems under threat (150 species, esp. frogs)
• Caused by:
• Habitat destruction (land clearing, overgrazing, salinity)
• Introduction of pests (rabbits, cats, pigs)
• Diseases
o Food webs & predators
• Keystone predator: predator that has disproportionate effect on ecosystem
• One species that have great effect on other species
o Invasive species
• Introduced into ecosystems to control another species
• End up having worse effect, become pests

Question 8

Environmental Protection & Biodiversity Conservation Act 1999

Answer 8

o Primary piece of environmental legislation
o Biodiversity conservation
• Identifying and monitoring biodiversity
• Threatened species and ecological communities
• Preparing conservation advice & plans
• Identifying key threatening processes and preparing threat abatement plans
• Access to biological resources in Commonwealth areas
• Invasive species
• Import & export of plants and animals, and products derived from wildlife

Question 9

Ecosystem Services

Answer 9

o Ecosystem service: a service people obtain from the environment
• Provisioning: food & water
• Regulating: flood & disease control
• Cultural: spiritual, recreational
• Supporting: nutrient cycling that maintain the condition for life on earth
• Goods: food, medicinal plants, construction materials, tourism & recreation, wild genes for domestic animals
o Materials flux analysis: employed to quantify the ‘service’ various ecosystems provide