lecture 9 Flashcards
Eologically sustainable economy
sustainable devlopment while maintaining biodiversity
Exponential growth observed only when
allmost extinct populations recover or when new habitats are being colonized
Per capita growth rate of small mammals decrease when
density increceases
Allee effect
Growth rate may decrease when population size decreases
Examples of allee effect
mate location, habitat alteration, cooperative feeding, cooperative defence
Fecundity
reproductive capacity
Determinate growth
fecundity constant- cease to grow after maturity
interderminate growth
fecundity increases with age and byond maturity
semelparous
reproduce once then die (annual plants)
iteroparous
reproduce more then once in their life time (perennial plants)
Advantage and disadvantage of semelparous
Advan. ability to invest all resources to new generation
Disadvan. Reproduction is a one time advent with risk to loose all
Exploitation competition
When two species grow together the carrying capacity is reduced for both species compared to pure populations
Community
group of organisms that live to gether at the same place/ time and interact directly/ indirectly
Discrete/ continuous organization
transition called ecotones
abrubt transition
coninsides with steep gradients/ changes in land
organismal community concept
clements
closely intergrated entity of mutually interdependent organisms with discrete borders
predictable end-point: Climax community
Discrete units pargmatic for applied disciplines
individualistic community concept
Gleason individualistic distrubution patterns along gradients resulting in continuous change of composition
Shannon Diversity & evenness
diversity influenced by richness(#) and evenness(pi)
