EQ1 Flashcards
What can biodiversity be defined as?
Genetic diversity, species diversity and ecosystem diversity.
What is genetic diversity?
Range of genes found within a particular species determining disease/pest resistance.
What is species diversity?
Variety of plant and animal species present in an ecosystem measured by abundance, richness, number and disparity.
What is ecosystem diversity?
Number of different ecosystems within a given area, controlled by climate, geology, relief, soils and humans
What natural global factors influence biodiversity and how?
- size of an area (larger biomes support wider species range and encourage migration)
- history & age (oldest and least disturbed have greatest biodiversity)
- isolation (reduces number of species but encourages endemism)
- altitudinal range (larger range means more habitat range)
What natural regional factors influence biodiversity and how?
- productivity
- habitat architecture (many ecological niches supports high level of biodiversity)
- habitat heterogeneity (wider range of habitats)
What conditions enable high productivity?
Humidity, nutrients & light
Define habitat architecture
Complexity of a trophic pyramid.
Define habitat heterogeneity
Varied physical environment
What natural local factors influence biodiversity?
Succession
Species interactions (competition, extinction, introduction of new species)
Disturbance
Dispersal and colonisation
What direct human factors affect biodiversity?
Land use Species introduction/removal Use of technology External input (fertilisers/irrigation) Resource consumption CC Evolution
What indirect human factors affect biodiversity?
Demographic
Economic (globalisation/trade)
Science & Tech.
Culture & religion (affects consumption choices/beliefs)
Where is the greatest biodiversity?
Brazil
Tropical countries
Developing countries where there are little resources to support conservation strategies
Where is the lowest biodiversity?
At higher latitudes
What is an exception to the geographical biodiversity distribution?
Australia - high levels of endemism
Define a hotspot
An area containing a huge number of species where a large percentage of them are endemic
Define continental hotspots
Richest in terms of biodiversity
Define large island hotspots
Harbour diverse distinctive species including relict fauna
Define relict
something which has survived from an earlier period or in a primitive form
Define small island hotspots
Low species number but high proportion of endemics
Species here are susceptible to extinction due to small pop.
Physical disturbance
Human exploitation and vulnerability to alien species
How is the value of ecosystems measured and give examples of each.
Provisioning - food, water, fuel, wood, fruits, nuts
Regulating - green lungs, carbon sinks, flood protection, disease
Cultural - aesthetic, spiritual enjoyment, education, recreation
Supporting - nutrient cycling, soil formation, primary production, habitats
How does biodiversity impact human wellbeing and give examples.
Security - safety, secure resources, security form disasters
Material for life - adequate livelihoods, shelter, goods access, nutritional food
Health - strength, feeling well, clear air, water access
Social relations - cohesion, mutual respect, ability to help others
Define limiting factors and give examples
Restrict growth in extreme regions
Lack of sunlight in Arctic
Aridity in central Australia
Define endemism
Unique species evolved on islands
Where is there minimal seasonality and what does this mean?
On the equator
It maximises biomass
