Population Growth 2.2 Flashcards
Population change
Sizes fluctuate
Natality and mortality
Immigration and emigration
Limiting factor
The first resource that hinders growth
Carrying capacity
Upper boundary of how large a population of a certain species that an ecosystem can sustain
Exponential growth
Exponential growth curve, growth continues until the limiting factor stops/reduces it.
Ex: bacteria
Density dependent limiting factor
Are always biotic, the effect of the limiting favored increases with increasing population
–> negative feedback
Internal density dependent
Within species, leads to intraspecific competition for resources
External density dependent
Acts between species, predation or disease
Density independent limiting factor
Tends to be abiotic, not related to density, not a feedback system
Weather or climate
Growth curves
S-curves vs. J-curves
S-shaped growth curve
Starts with exponential growth but then slows down to constant level. Density dependent
Phase 1: exponential
Phase 2: transitional
Phase 3: plateau
J-shaped growth curve
Follows a “boom-bust” pattern, rapid exponential growth and then a collapse.
Density independent
Population
Total number of individuals of a certain species in a defined area at a certain point in time
Population dynamics
The study of the factors that cause changes to population size.
Population dynamics
The study of the factors that cause changes to population size.
