SPEC FOR SOME ECO BITZ X Flashcards
lag phase
slow population growth
nutrient assimilation- activate genes to produce enzymes to eg metabolise food
few reproducing organism
exponential phase
fast population growth not limited by food or other resources
birth rate / death rate
large no of reproducing organism
stationary phases
population levels off = carrying capacity
br = dr
interspecific completion, predation and disease increase
decline phase
population may fall or even die out due to food shortages or disease
dr / br
waste accumulation
What influences exponential / stationary phase
competition for resources
waste accumulation
What influence stationary / decline phase
availability of resources (R and NR)
features of r-selected species
eg algae, bacteria, mice, grass small body size short lived reproduce rapidly disperse rapidly pioneer species population density variable evolve rapidly
features of k selected species
eg humans, trees large body size long lived reproduce slowly disperse slowly climax species population density constant- stay at carrying capacity evolve slowly
competition
- /- interaction which generally leads to the elimination of one species
- two or more organism are competing for a resource which is in short supply.
- interspecific/ interspecific
- neither species can grow as fast as they’d like
- one is better competitor
- competition exclusion
mutualism
+/+ interaction
both species benefit from living together
NFB and plant
parasitism
-/+
parasitism live on/in host and benefits and the host is harmed but stays alive.
grazing
-/ +
predator / prey
- / + prey always higher no- energy diagram no prey increase as few predators no predators will increase more food available prey will decrease due to predation. no predators fall. - oscillations fairly reg -time lag
ideal natural predator
- reduce pest no quickly
- only attack pest
- does not cause harm or interfere with other species
- thrive in habitat
- does not need reapplied
adv biological control
- cost effective
- no bioaccumulation of chemical through the food chain
- very specific to pest- sprays may kill useful organism too
- no resistance developed
- constantly keep pest at low level
disadvantage biological control
- pest not completely irradiated
- spread into other ecosystems
- must be able to thrive
Factors that influence population size
birth
death
immigration
emigration
ecological community
biotic component of an ecosystem and involving interaction between autotrophic and heterotopic population
secondary succession
predictable, faster, repeatable process of community development in an area where the climax community was destroyed by fire, flooding, wind, human activity
primary produces
1st trophic level
features of a succession
no soil, few minerals -/ deep fertile soil
low biomass -/ high biomass
low biodiversity -/ high biodiversity
small animals -/ large animals
pyramid of numbers
- large carnivore small parasites
- large plant and many wee herbivores
pyramid of biomass
- seasonal change
- difficulty obtaining mass of eg plant
- kj/ area
pyramid of energy
- always a pyramid
- kj/ unit area/ year
- kill organism obtain energy
agriculture probs
- extra energy cost of producing animal products
- fertiliser to increase primary productivity
- confinement to improve respiration/ production ratio
- high energy food eg silage or protein
