4.1.1 Population Dynamics Flashcards
Abiotic factors on environment
Shapes the ecosystem + distribution and abundance of organisms. Examples:
- Climate
- Altitude
- Temperature
- Geology
- Light intensity
Biogeography vs biodiversity
Biogeography: study of distribution of organisms
Biodiversity: range of kinds of organisms on Earth. High biodiversity near the Equator, lower near the poles
Ecosystem naming
- Focus on major abiotic factors
- Identify most abundant species in the system
- Describe it according to the plant community: combo of tallest/most dominant plant + percentage of sunlight coverage of the canopy
Tropical habitat characteristics
- High rainfall
- Warm temperature
- Rainforests
Temperate habitat characteristics
- Cool
- High altitudes
- Winter snow
Semi-arid to arid desert habitat characteristics
- Low rainfall
- Desert-like environment
- Hot
Freshwater habitat characteristics
- Relatively low water salt concentration
- Inland lakes, rivers, streams
Marine habitat characteristics
- Relatively high water salt concentrations
- Sea/oceans
Competitive exclusion
When one species successfully uses a resource to the exclusion of another.
E.g.
- 2 species of paramecium cultured together will eventually cause one species to dominate over the other in utilising a resource, causing the dominant species to thrive and the other species’ population growth to slow.
Allelopathy
Competition between plants. Biomolecules produced by a plant can benefit or detriment another plant.
E.g. black walnut releases a chemical that inhibits respiration in other plants, causing plants exposed to it to wilt and die
Obligate symbiosis
One/both species cannot survive without the other
E.g. fungi and algae rely on each other to survive as lichen
Mycorrhizal fungus lives on plant roots. Plant: gets higher water uptake from fungi. Mycorrhizal: gets nutrients from plants.
Facultative symbiosis
Both species can live independently of one another.
E.g. aphids and ants” ants protect aphids from predation, ants receive food from the fluid produced by aphids
Mutualism
Both species benefit (+/+)
E.g. anemone offer protection and shelter to clownfish. Clownfish provide anemone with nutrients
Commensalism
One benefits, other unaffected (+/0)
E.g. moss grows on tree bark for surface area, but doesn’t take nutrients from the tree
Parasitism
One benefits, other harmed (+/-)
E.g. Ectoparasites like ticks live on host. Endoparasites like roundworms live inside host.
