population ecology re purposed slides

1. Wendy Mahlangu
POPULATION ECOLOGY

2. What is population ecology?
 Population ecology is the study of populations in relation
to environment , including environmental influences on
density and distribution, age structure and population size

3. Factors influencing population size

4. Terminology used in population ecology
 Population is a group of individuals that belong to the same species
living in the same area at the same time
 Dispersion is the pattern of spacing among individuals within the
boundries of the population
 Density is the number of individuals per unit area
 Demography is the study of the vital statistics of a population, looking
at how they change over time.

5. Patterns of dispersion
 Clumped dispersion is when individuals aggregate in patches. This
type of dispersion can be influenced by resource availability and
behavior
 Uniform dispersion is when individuals are distributed evenly. It may
be influenced by social interactions such as territoriality
 Random dispersion is when the position of each individual is
independent of the other. It is influenced by the absence of strong
attractions or repulsions

7. Two main patterns of population growth
 Logistic growth/ S- pattern: members experience many reproductive
events throughout their lifetime. Most trees and vertebrates have this
pattern of reproduction
 Exponential growth/J-pattern: only one reproductive chance is given
to members of the population during their entire lifespan . Once the
mission is accomplished, they die. Annual plants and many insects
reproduce in this manner

9. Patterns of population growth in an
ecosystem
 There are lots of factors that influence population growth but one
factor is a species intrinsic growth rate .
 The birth rate minus death rate with no environmental restrictions
defines a species intrinsic rate growth rate
 Within an ecosystem, but resource limits and predation also effect
population growth

10. References
 Chris, P (2015 ) BioKnowledgy C.5 Population ecology(AHL). Available from
https://www.slideshare.net/diverzippy/bioknowledgy-c5-population-
ecology?qid=4ece270c-2cd5-4cbf-9c8e-e5f3604d4f30&v=&b=&from_search=1
 Jalil, A (2012) Population ecology. Available from
https://www.slideshare.net/gurya87/population-ecology-11685161
 Bambon, R (2008) Population ecology. Available from
https://www.slideshare.net/gobuktaragang/population-ecology
 Susiana, L (2012) Ch. 5 Population regulation. Available from
https://www.slideshare.net/lindasusianaa/ch-5-population-regulation-part
 Tsotetsi, T (2014) Population ecology. Available from
https://www.slideshare.net/ttsotetsi/population-ecology-32121442