3.4 Carrying Capacity and 3.5 Resource Availability

carrying capacity

the maximum # of individuals an ecosystem can sustain (no population can grow indefinitely due to limiting factors)

intrinsic growth rate (r) or biotic potential

the rate of population growth with unlimited resources

4 characteristic of rapidly growing populations

timing of reproduction early in life, length of generation time (short), length of reproductive lives (long), number of offspring/fecundity (high)

carrying capacity is…

determined by biotic potential=the maximum reproductive rate of a population in ideal conditions, as populations reach carrying capacity, growth rate decreases because resources become scarcer (mortality goes up, fecundity goes down), if carrying capacity is overshot, a dieback follows

j-shaped curve (exponential)

after secondary succession, intrinsic growth rate (no limiting factors)

s-shaped curve (logistic growth)

exponential growth in the beginning, becomes s-shaped as limiting factors take effect

density-dependent factors

disease, competition, predation, can have positive or negative correlation

density-independent factors

environmental stressors and catastrophe, dependent (biotic), independent (abiotic)