Introduction to Biodiversity
What are the three major levels of biodiversity?
Genetic, species, and ecosystem diversity
What is an ecosystem service?
A benefit humans receive from natural ecosystems
What two characteristics strongly influence species diversity on islands?
Island size and distance from the mainland
What is ecological tolerance?
The range of environmental conditions an organism can tolerate
Give one example of a natural disruption to an ecosystem.
Wildfire, hurricane, tornado, flood, drought, volcanic eruption, etc.
What is an adaptation?
A heritable trait that improves survival or reproductive success
What is ecological succession?
The gradual change in species composition in an ecosystem over time
What is genetic diversity?
The variety of genes/alleles within a population or species
Pollination of crops by bees is an example of what?
An ecosystem service
Which generally has more species: a large island or a small island?
A large island
What is an organism's optimal range?
The range of conditions where it performs and reproduces best
How can a wildfire affect an ecosystem?
It can remove vegetation, alter habitat and resources, and change species composition
What is natural selection?
Individuals with advantageous heritable traits survive and reproduce more successfully
What is primary succession?
Succession beginning in an area without soil
What is species diversity?
The variety of species within an ecosystem
Give one ecosystem service provided by forests.
Examples: carbon storage, water purification, erosion control, habitat, climate regulation
Which generally has a higher immigration rate: an island close to the mainland or one far away?
An island close to the mainland
What happens to organisms when environmental conditions move into a zone of physiological stress?
Survival, growth, or reproduction decreases
Why might an ecosystem with high biodiversity recover more effectively from a disturbance?
Greater diversity can increase ecosystem resilience
What must exist within a population for natural selection to occur?
Heritable genetic variation
What is secondary succession?
Succession after a disturbance where soil remains
What is species richness?
The number of different species in an ecosystem
What ecosystem service do wetlands provide that can help protect communities from flooding?
Flood control/floodwater storage
Why do larger islands generally have lower extinction rates?
They have more habitat, resources, niches, and can support larger populations
Name one abiotic factor that can determine an organism's range of tolerance.
Temperature, pH, salinity, dissolved oxygen, moisture, etc.
Are all natural disturbances harmful to ecosystems in the long term?
No; some disturbances are part of natural ecosystem processes and can promote renewal/diversity
A few insects survive pesticide exposure and reproduce. Eventually resistance becomes common. What process is occurring?
Natural selection
What organisms are common pioneer species on bare rock?
Lichens and mosses
Why is genetic diversity important to a population?
It increases the chance that some individuals can survive environmental changes
What is one way humans can economically benefit from biodiversity?
Food, medicine, timber, recreation/ecotourism, etc.
Which would probably have the greatest biodiversity: a large island close to the mainland or a small island far away?
A large island close to the mainland
What happens if environmental conditions exceed an organism's limits of tolerance?
The organism cannot survive
What is ecosystem resilience?
The ability of an ecosystem to recover after a disturbance
Do individual organisms evolve during their lifetimes? Explain.
No; populations evolve over generations
A volcanic eruption creates new bare rock with no soil. What type of succession follows?
Primary succession