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BIOL 215 Study Guide - Final Guide: Biodiversity Hotspot, Northern Hemisphere, Transpiration

Biology (Sci)
Course Code
BIOL 215
Neil Price
Study Guide

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BIOL215 Lecture 13 Notes
Population biology is the study of individuals from one species that live together in space and time (Book pg.
Basic demography is something that focuses on a species; not of a community
Population is of a single species while community is formed of a few species interacting together in the same
place and same time. Ecosystem incorporates the abiotic functions of communities in the same time and same
Population dynamics studies the "behavior" of populations such as increases and decreases in population size.
Demography is the study of the age structure of population. It includes the study of death, birth, population
growth, and population decrease
When we're talking about demography, we must have a sense of the size of the population at a given time
(initial time). We want to estimate how the population will grow to predict the population in the future. Very
Consider births and immigration as factors that increase/brings individuals to a population
Consider deaths and emigration as factors that decrease/take away individuals to a population
Demography is the understanding of the balance between birth and death taking into account immigration and
Ecology means "the knowledge in the house" in Greek
To measure populations: 1) census for humans, 2) quadrants for plants, 3) marked captures for birds, 4) marked
capture (with tranquilizer) for deers
See list of methods for measuring populations: pg. 120
Density of number of individuals per unit area is measure of population size.
Individuals of small size are abundant on a small spatial scale and bigger individuals are less abundant
The two most important tenants of demography are: death and birth
Life table help to understand population growth. Life table is a table that records survivorship and mortality in a
Cohort table: follows all the individuals born at the same time from birth to death (very precise, but
complicated to do in nature because of long-lived species)
Static table: snapshot of a population over a short time interval. All individuals are of different ages

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See Table 8.3 to understand calculations for lx and qx
A plot of number of survivors (Y-axis) vs. Age (X-axis) is a survivorship curve. It is used to understand how
mortality changes with age in a population
Survivorship is proportion of population surviving to each age
Research in population ecology suggests that patterns of survivorship usually fall into three categories:
Type I: High juvenile survivorship (or low juvenile mortality)
Type II: Constant rates of survival
Type III: Low juvenile survivorship (or high juvenile mortality)
Another method to represent the demography is by drawing age
Age distribution consists of estimating the number of individuals of
different age in a population. It corresponds to the static life table.
Age distribution is less accurate then cohort table, but often much
easier to obtain
See Table 8.5 to see survivorship schedule (lx) and fertility schedule
The fecundity schedule is the table of values of (bx).bx is the
average number of offspring produced by each female individual in
each age interval
Capacity for increase is calculated together by lx and bx, which
allows for estimating population growth
Net reproductive rate is the sum of survivorship and reproduction
for each age class:

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The rate of increase of populations needs to take into account generation time
Generation time is calculated by this equation:
G= ∑ xlxbx where x is age between generations
Mean length of a generation, G, is mean period elapse between the "birth" of parent and "birth of offspring
As generation time increases, population increase happens slower
Knowing the net reproductive rate and generation time, we can calculate the instantaneous rate of increase of a
population by the following equation:
In the simplest case, (i.e. annual species, G = 1), therefore the instantaneous rate of increase:
Net productive rate is calculated by:
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