Module 1 Flashcards
Ecosystem service
The various benefits that humans derive from ecosystems
Ecosystem functions
Ecological process in the environment that control the fluxes of energy, nutrients, and organic matter
-> Do not directly benefit humans, but prop up ecosystems
Provisioning ecosystem services
Products obtained from ecosystems, often traded in markets (e.g. honey), but some have value beyond money (e.g. water)
Regulating ecosystem services
Benefits obtained from the regulation of ecosystem services (e.g. disease control)
Biodiversity
The variety of all living things
Why are vertebrates highlighted in the biodiversity crisis?
Iconic + charismatic
More similar to us (humans)
Easier to count
Larger + more visible
Higher trophic positions .˙. more affected by ecosystem disturbance
Extinction cascade
The loss of keystone species triggers a series of extinctions
Extinction drivers
Habitat loss, degradation, and fragmentation, overexploitation, pollution, climate change, invasive species
Levels of biodiversity
Ecosystem diversity (broadest)
Species diversity
Genetic diversity (narrowest)
Species diversity
The variety of species in an ecosystem or throughout the biosphere in a country or other defined region
-> Richness = no. unique species
Genetic diversity
Genetic variation within and between populations
-> low genetic diversity increases risk of extinction (e.g. Tasmanian Devils)
Ecosystem diversity
The varieties of types of ecosystems within a geographical location
-> Diversity of ecosystems = diversity of services provided by ecosystems
-> Conserves biodiversity because different ecosystems = different adaptations requires .˙. diverse species
Ecology
The study of the interactions between organisms and their environment
Primary production
The rate of organic biomass growth or accumulation by plants
-> equator has higher biomass (due to biogeography)
Endemism
The proportion of species that are endemic, or restricted to a particular geographic location
-> In Australia, a species is endemic only if it has been here prior to European colonisation
Biodiversity hotspot
A biogeographic region with significant biodiversity and high endemism which is under threat
Requirements include:
-> Must have 1500+ endemic vascular plants
-> Must have lost ≥70% of habitat
Megadiversity
Having a high level of species diversity
-> Australia is megadiverse
What is the scale of the current biodiversity crisis?
Species are declining/going extinct at a rate 100x faster than through natural evolutionary processes
Approx. 1 mil (out of the estimated 8 mil) species are facing extinction
Australian examples of biodiversity loss
Approx. 100 extinctions since European invasion
Thylacines went extinct due to systematic hunting
Toolache wallaby
Extinctions: 34 mammals, 9 birds, 4 frogs, 3 reptiles, 38 plants, 10 invertebrates
Why are vertebrates not a helpful measure of biodiversity?
Only make up ~4% of species worldwide
Not representative of overall biodiversity
Usually adapt more easily to changes than more specialised organisms due to having large territories + diets and good movement capabilities
Monitoring only vertebrates is not helpful to understand smaller ecosystem changes
Exotic
An exotic species is any species that has been introduced to somewhere outside of its natural range
Key components of evolutionary theory
Similar traits among different organisms are explained by descent from a common ancestor
Differences among organisms are explained by the accumulation of heritable changes/mutations
Natural selection is the overriding mechanism of evolution
Natural selection
The process by which individuals that have certain heritable traits have enhanced ‘fitness’ because of those traits .˙. more likely to survive and reproduce
-> Biodiversity is therefore important as natural selection will not work with all organisms within a species being the same
Adaptation
An inherited trait of organisms that enhances their survival and reproductive success in specific environments
