Test Week 4 Flashcards
Population
a group of individuals of the same species occupying a particular space at a particular time
Density
The number of organisms per unit area / volume
Natality
the reproductive output of a population
Mortality
the death of organisms in a population
Immigration
the number of organisms moving into the area occupied by the population
Emigration
the number of organisms moving out of an area occupied by the population
Morphological species
a group of indivduals that is morphologically, physiologically, or biochemically distinct from other groups
Biological species
a group of individuals that can potentially breed among themselves but not with individuals of other groups
Ecological community
an set of interacting natural species populations in a prescribed area or habitat
Name the 4 characteristics of ecological communities
- Biodiversity
- Relative abundance
- Growth form and structure
- Trophic structure
What is a trophic structure
who eats whom
determines flow of energy/materials from plant to carnivores
What does limiting factors look at
Distribution and abundance
Dispersal
The tendency of an organism to move away from birth or breeding sites
how do you analyse dispersal
Different spatial and temporal scales
- space
- time
Forms of dispersal
Diffusion - SLOW
Jump dispersal - QUICK
secular dispersal - EXTREMELY SLOW
transplant dispersal - MAN-MADE
What is the difference between diffusion and jump dispersal
- Diffusion is a slow process over many generations while jump dispersal is quick
- Diffusion is in hospitable terrain but jump is in inhospitable
What limits transplant experiments distribution
successful - area or time
unsuccessful - other species, physical or chemical factors
Give an example of a transplant experiment
African honey bees
non-natives species distribution rule
tens-rule
At which scale does barriers of dispersal limit the distribution of most animals
Continental scale
At what scale does do many species have good-excellent dispersal mechanisms
Local scale
Habitat
Any part of the biosphere where a particular species can live, temporarily or permanently
Habitat selection
limited to animals, which ‘choose’ where to live by moving between habitats
Example of habitat selection
Kangaroo rat and pocket mouse
- KR prefers open habitats as developed to avoid predators
- PM prefers open habitats
What scale are most animals behavioural reactions limited
Microhabitat
few are landscape
In descending order list the factors limiting geographic ranges
Dispersal > behaviour > other species > Physical and chemical factors
What negative interactions with other species may limit survival and reproduction
Predation
Disease
Competition
True predation
Predators kill their prey
Herbivory
animals eats plants, but not always killed in process (plant)
Parasitism
parasites live in on or outside host, don’t normally kill in process
What happened when the red fox was introduced to Australia
Burrowing bettong distribution servery restricted - only on islands and ~ half mainland
What is the management for the burrowing bettong
Eradication of red fox
Rock wallaby changes since the red fox
Spend more time on rocky hills rather then forage so less of them
Name a specialist and non specialist predator and their prey
Specialist - Canadian Lynx , prey = Snowshoe hare
Non-specialist - Red fox , prey = changes
Name two extinctions of bird fauna in Hawaii and reason
1st - due to habitat destruction so moved in land and not near sea
2nd - malaria introduced so away from any wetlands
Now only found in the high elevations on Island
Resource competition
The negative interaction between two organisms, of the same or different species, over resources that are in short supply
Interference competition
Organisms seeking a resource harm one another in the process, even if resources are not in short supply
Checkboard competition
Cross over but not together
Black fly larvae v Midge thing (look up)
BUT in real life ignore each other
- When larvae there less midge
- When midge there less larvae but more
- Larvae ‘bully’ midge
> think due to larvae needing its own patch (not just another organisms)
Can predators or prey limit their distribution (mostly)
Predators
Major limiting factors of physio-chemical effects on species distribution
- Temperature
- Moisture
- Light
Where are temp ranges smallest and largest?
Smallest = at low latitudes over oceans Largest = over continents
Range
Difference in average temp of warmest and coldest months
Where does high and low precip occur
High - around equator
Low = 30 degrees north of equator
Temp and moisture as limiting factors - what can organisms do
Tolerate
Escape (via evolutionary adaption)
Two types of barnacles strength and weakness
North - Weak tolerance but strong competitor as wide
South - Weak competitor but strong tolerance as tall so can shield each other
How cam species extend their distribution
Local adaption to limiting factors
Ecotype
a group of organisms within species that are adapted to different environmental conditions and therefore differ from one another in structure and physiology
How can ecotypes be distinguished ?
Collect seeds along a gradient and grow in common garden (USA, grand canyon?)
How does light limit daily cycle of plants
Timing - daily activity cycle, breeding, photoperiodism
Photosynthesis
3 photosynthesis pathways
C3
C4
Crassulacean acid metabolism (CAM)
C3 plant equation
Fix 3 carbon molecules
Fix CO2 + RuDP –RuDP carboxylase–> phosphglyceric acid
Where are C3 plants found
Lower light areas (high latitudes)
dark wetter and more clay soils
C4 plants equation
Fix 4 carbon molecules
Fix CO2 + PEP –PEP carboxylase–> malic acid + aspartic acid
What’s better about C4 plants
- Fixes 4 carbon molecules so more competitive
- more efficient anatomically
- more light should = ore c4 plants
How does CAM modification help desert plants
- minimise water loss so open stomata at night
- CO2 stored as malic acid at night
