Ch2 Biodiversity
What is Biodiversity?
The variety/amount of different living things within an environment
What is a producer? Give an example
Organisms that can convert light or chemicals into energy. E.g Plants
How is energy captured to enter the ecosystem?
Through photosynthesis conducted by producers
What is abundance?
The number of organisms of a particular species in a specific area at any time
Identify one reason an ecosystem may change
- Seasonal
- Natural disaster
- Influence of organisms
The independent development of similar traits between species as a result of their having similar ecological roles and selection pressures
What is an abioitic factor? Give an example
A non living factor - eg water availability/salinity/humidity/habitat availability
What is the role of a decomposer?
Break down dead matter and waste
What is the term for the speed at which a population changes?
Population Growth Rate
What is a sere?
an intermediate community found in ecological successions as it moves towards the climax community
How many alternatives are at each branch of a dichotomous key?
2
What is Intraspecific competition?
Competition between members of the same species
What is a "generalist" and how does this allow for better survival?
Generalists can eat a range of food sources, this means that they are less likely to be impacted if some food sources are reduced
Identify 3 density dependent factors
Competition
Infection
Predation
Identify 3 characteristics of pioneer species which allow them to begin primary sucession
- tolerant of extreme conditions
- Photosynthesise
- rapid seed germination
- Nitrogen fix from air
- r strategist - many offspring, fast life cycle
Which formula calculates the size of a population (also known as capture/recapture)
Lincoln Index
Define symbiosis
A sustained close relationship two members of different species
What is a keystone species?
A species which has a disproportionately large impact on the environment it exists within and maintaining good biodiversity
What is ecological homeostasis?
What are some indicators that a climax community has been established
Stable community
microenvironments exist with community
a dominant species usually present
large plant varieties present
What is a limitation of the current definition of a "species"
- Cannot always observe breeding habits
- Does not account for geographical isolation
How does biodiversity indicate the health of the ecosystem?
Greater biodiversity indicates better health as the environment can support a greater range of organisms
Describe one way nitrogen is cycled through the ecosystem
- Fixed by bacteria
- Removed by denitrifying bacteria
- Taken up by plants
- Animal waste and death
Justify why mice would be categorised as r strategists, giving 3 reasons to support this
- large numbers of offspring
- small size
- fast gestation/maturation
- Short lifespan
- little care for offspring
Describe the difference between primary and secondary sucession
Primary succession begins from bare rock, secondary sucession occurs after the dominant species has been cleared due to natural disaster eg bushfire, disease, or after land clearing