Biology 2483A : Ecology Lec 11 (population dynamics) summary.docx

• School: Western University
• Department: Biology
• Course: Biology 2483A
• Professor: Hugh Henry

Document Summary

Pop dynamics: ways in which pop"s change in abundance overtime. Nt+1 = nt + b d + i e. Pop growth patterns: exponential growth, logistic growth, fluctuations, regular cycles (any and all at different times) Exponential growth- in a new area, exponential growth for limited time. After a while dd factors regulate its growth. E. g. jump dispersal- long distance move to colonize. Logistic growth- for pop to be constant at k, need b = d rare rather fluctuations near k. K is not a number, rather a range, in real life. Deviations from a growth pattern (e. g. fluctuate around k) Completely erratic (e. g. phytoplankton populations- cannot model it) Pop outbreak- # individuals increases rapidly (e. g. usually short gen times- cockroach, beetles) Pop cycles- sometimes driven by predators, or by something else (not always predator driven) Delayed density dependence- delays in the effect density has on the pop size.