all Flashcards
(230 cards)
what is organismal ecology concerned with?
concerned with behavioural, physiological and morphological traits mediating interactions
what is a population?
group of individuals of the same species interacting in a specific geographic area
- fluctuating but measurable numbers
- variable dispersion
what does population ecology examine?
factors that limit and regulate pop size and composition
what is a community?
all individuals of all species that inhabit a particular area
what does community ecology examine?
interactions interactions among populations and how factors like predation, competition, disease, environment affect community structure and organisation
what 6 processes drive distribution and abundance?
immigration, colonisation, birth
immigration, extinction, death
what are unitary organisms?
form programmed from birth
easy to recognise genetically operate organisms
determinate structure
usually strict number of body parts
what are modular organisms?
- genetic individual (genet) begins as single celled zygote
- growth by repeated production of modules
- growth indeterminate
- structure unpredictable
- genet not dead until all modules are
in detail what are the 2 reproductive patterns?
- semelparity
- reproduce once
- lots of offspring
- parent often die - iteoparity
- several eggs/ offspring in repeated reproductive episodes
how long can some seeds remain viable for?
1600 years
what are ephemeral plants?
eg. desert plants- lifecycle usually <8 weeks reproduce in occasional years short lived usually 1 or more generations per year only during favourable periods
age. nx. Ix sx mx. Ixmx
0. 1000 1.0 0.5 0 0
1. 500 0.5 0.2 0 0
2. 100 0.1 0.5 4.0 0.5
a) what is nx?
b) what is Ix?
c) what is sx and how do you calculate?
d) what is mx and how do you calculate?
e) by calculating total of Ixmx what is this?
a) number at each stage
b) prop. of individuals that survive at each stage
c) age specific survival ( nx at 1/ nx at 0) then (nx at 2/nx at 1)
d) reproduction = number of female babies/ reproductive female
age specific fecundity
e) Ro= net reproductive rate
what does it mean for the pop. if net reproductive rate (Ro) is:
a) =1
b) <1
c) >1
a) stable, females replaced perfectly
b) fewer females–> pop decline
c) pop increase
what is a super spreader and a super shedder?
super spreader: males lots of contact to spread disease
super shedder: produces lots of infection
what is the Ro of each of these diseases and put them in order of least to most contagious?
- HIV
- mumps
- ebola
- SARS
- measles
- Hepatisis C
Hepatisis C =2 ebola =2 HIV =4 SARS =4 mumps =10 measles =18
what is the generation time and whats the equation for it?
average time between birth of individual and birth of offspring
G = total [( x) X (Ix) X (mx)] / Ro
if lots of energy is invested into reproduction one year what happens the next year?
there will be less the next year due to the energetic costs of caring for offspring
how do you work out fertility?
no. produced by one class X survival to age class
a) how do you work out Fx?
b) what is the Leslie matrix?
c) what are 3 +ves of it?
a) sxmx
b) F0 F1 F2 F3
S0 0 0 0
0 S1 0 0
0 0 S2 0
c) - derive finite pop change rate (λ) and distribution
- can identify main age specific vital rates affecting abundance and age structure
- modify analyses to include density
what is λ? and what happens in each scenario? a) λ<1 b) λ>1 c) λ=1
pop growth rate
a) pop decline
b) pop increase
c) stable pop
for exponential growth, how do we work out the change in pop size during time interval?
births in time interval - deaths in time interval
r= b-d
what was the exponential growth see in sea otters?
by 1911 decrease to few thousand
re introduced 1960s
30 fold increase in 30 years to 100,000
what is the most common determinant of K?
energy/ resource limitation
what are the 3 rules of population limitation?
- K of a habitat is the max stable population size that can be supported over time
- as density increases, per capita resource declines
- as density increases and per capita resource decline, births decline and deaths increase