BIO20C | Week 8 - Population
BIO20C | Week 8 - Population BIOE 20C - 01
Popular in Ecology & Evolution
Popular in Department
This 4 page Class Notes was uploaded by echen30 on Saturday December 5, 2015. The Class Notes belongs to BIOE 20C - 01 at University of California - Santa Cruz taught by Marinovic,B.B. in Fall 2015. Since its upload, it has received 60 views.
Reviews for BIO20C | Week 8 - Population
Report this Material
What is Karma?
Karma is the currency of StudySoup.
Date Created: 12/05/15
Week 8 Population Ecology BIO 20C Baldo Marinovic Population 0 Group of individuals of the same species that I Live in a localized area I Utilize a common pool of resources Population Ecology 0 Population size change over time 0 Population distribution over time Population Parameters 0 Density I of unit area or volume 0 Dispersion I Distribution within that area or volume 0 Reproductive strategy I How and when you reproduce Dispersion o Clumped I Aggregated around resources 0 Regular Uniformed I Evenly distributed in space I Usually results from competition 0 Random I Lacking any discernible pattern Reproductive Strategy 0 Semelparity I Breed once and die 0 Iteroparity I Multiple breeding in lifetime I Can be seasonal or continuous Demography 0 Study of factors that in uence population size and structure over time o 4 main components that in uence size I Birth increase I Death decrease I Immigration increase I Emigration decrease Factors Needed to Predict Population Growth 0 How many individuals alive now 0 How many likely to survive survivorship o How many offspring will be produced fecundity o Immigrationemigration rates 0 Time from birth to first reproductive generation time Survivorship 0 Proportion surviving to a particular age class 0 Individuals born in same period cohort o Survivorship curves logsurvivorship vs time o 3 basic types Week 8 Population Ecology BIO 20C Baldo Marinovic I Type I young survivorship high old low I Type II survivorship constant through life I Type III young survivorship low old high Fecundity 0 Number of offspring produced 0 Often limited to number female offspring produced by female parents 0 Age specific fecundity average number of females produced by a female of a certain age class SurvivorshipFecunditv 0 Individuals have finite amount of energy Tradeoff between growth and reproduction Selection favors optimum allocation for fitness Low survivorship high age specific fecundity High survivorship low age specific fecundity Life Tables 0 Use for demographic analysis 0 Require information I Initial number born in a cohort N I of survive to each age class Lx I Average fecundity for each age class mx Calculate Population Growth with Life Table 0 If only consider females 0 Lx age specific survivorship 0 mx age specific fecundity o lxmx of female offspring produced by an individual in each age class Net Reproductive Rate 0 ZLxmx R0 net reproductive rate growth rate for generation 0 If R0 gt 1 then population is growing 0 If R0 lt 1 then population shrinking Per Capita Rate of Increase 0 R0 generation growth rate 0 r is per capita growth rate I Aka instantaneous growth rate Intrinsic Rate of Increase o rcanbe or0 o rmX intrinsic rate of increase 0 highest possible r for a species 0 determined by biological constraints 0 different species have different rmX Discrete vs Continuous Growth 0 Population with distinct breeding season demonstrate discrete growth 0 Population that reproduce year round demonstrate continuous growth Discrete Growth 0 N0 population size at time 0 0 N1 population size at time 1 0 Discrete growth rate k N1No O O O O Week 8 Population Ecology BIO 20C Baldo Marinovic 0 N1 NOXOI39N1 N0t 0 Continuous Growth 0 k like an annual interest rate I Growth rate over a discrete period of time r per capita growth rate at any particular instant 0 Simple relationship between X and r I k6 0 If is the k is the discrete growth rate I And N No N 0 And r is the instantaneous growth rate 0 I And k er 0 Then substituting er with k I Nt Noe 0 R0 vs r 0 R0 generational growth rate 0 r per capita or instantaneous growth rate 0 r lnRo g where g generation time o Exponential vs Logistic Growth 0 Exponential growth r constant over time I r doesn t change with density I density independent 0 Logistic growth r changes as a function of density I r decreases with increasing density I density dependent 0 Carrying Capacity K 0 Max of individuals that can be sustained in a given habitat 0 Function of abiotic and biotic factors 0 K varies with habitat o Logistic Growth Equation 0 dNdtrNKNK o If N is small r close to rmX 0 As N increases r decreases 0 As N approaches K r becomes 0 0 Factors Limited Population Growth 0 Density independent I Not affected by population size 0 Density dependent I Becomes more pronounced with increased density 0 r vs K selected species 0 r selected species I r refers to intrinsic growth rate I Rapid growth I Good dispersal I Short lifespan 0 K selected species I K refers to carrying capacity Week 8 Population Ecology BIO 20C Baldo Marinovic I Slow growth I Long lifespan I Large size