APS 123 Flashcards
Define Community
All of the individuals of all the species that inhabit a particular geographic are
Organismal ecology concerns…
Behavioural, Physiological and Morphological traits and the mediate interactions:
among individuals, between species and with the environment
What is Semelparity?
Big bang reproduction
Large number of offspring are produced in a reproductive event, after which the individual dies.
What is Iteroparity?
When organisms produce several eggs/offspring during repeated reproductive strategies
What are Empheral species?
When desert plants and animals lie dormant.
Reproduce in the occasional years that the conditions are ok.
Most complete life cycles in less than 8 weeks.
What is Ro (little o)
the net reproduction rate
mean number of offspring per female over her life time
Elements of the Leslie Matrix
Sx, Mx, Fx
What do you get out of the Leslie Matrix
µ= population growth rate and the Stable age distribution
3 factors increasing population growth:
Increased survival
Increased reproduction
Decreased generation time
r=
intrinsic rate of increase
=births-deaths
What is density dependence?
(Negative Feedback)
When insufficient resources may reduce per capita birth rate.
Carrying capacity (K) determined by…
…energy/resource limitations
Eg availability of nesting sites, roosting sites
Sea otters as an example of exponential growth..
reintroduced in 1960s, 30 fold increase in 30 years
100,000 population
Carrying capacity (K) rules?
K of a habitat is the maximum stable population size that can be supported
As density increases, per capita resources decline…. bird rates decline and death rates increase.
Assumptions of the logistic model?
Density dependence is linear
Population approaches K smoothly
K is constant
r & K are…
… population level parameters (selection does not act on r&k)
Gause’s theory
Competition exclusion principle:
No 2 species can share the same resource
No 2 species can occupy the same niche
2 species cannot co exist when they have identical needs of a limited resource.
Competition theory
Population growth rate= exponential growth - intraspecific competition- interspecific competition
Equation for a line
Intraspecific=
Interspecific=
Intraspecific= intercept (K) Interspecific= gradient (adjustment of K) ALPHA
How to spot coexistence on a graph
Isoclines cross, when intra specific effects are stronger (K’s inside) than inter-specific effects.
(Exclusion=isoclines do not cross)
Categories of predation
Overgrowth, Chemical, Territorial, Encounter, Exploitation, Consumptive
2 types of competition
Scramble- exploitation, consumption
Contest- Interference, encounter
Define pre-emptive
Using space (depleting space)
MacArthurs 3 rules
No species can coexist unless they….
different resources
same resources in different places
same resources at different times