Population Ecology
description
Transcript of Population Ecology
![Page 1: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/1.jpg)
POPULATION ECOLOGY
Campbell & Reece Chapter 53
![Page 2: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/2.jpg)
Population Ecology the study of populations in relation to
their environment
![Page 3: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/3.jpg)
Dynamic Biologic Processes that Influence Population Density
Population: is a group of individuals of a single species living in same generral area
Members of a population rely on same resources & are influenced by same environmental factors
They are likely to interact & breed with each other
![Page 4: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/4.jpg)
Populations often described by their boundaries & #s boundaries may be natural ones or
ecologists may arbitrarily define them
![Page 5: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/5.jpg)
Population Density # of individuals per unit area or volume
![Page 6: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/6.jpg)
Dispersion the pattern of spacing among individuals
w/in boundaries of the population
![Page 7: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/7.jpg)
Mark-Recapture Method way to determine population size: ecologists cannot count all individuals in
a population if organisms move too quickly or are hidden from view
Technique: capture a random sample of individuals & “mark” & then release them.
Some species can be identified w/out physically capturing them: dolphin, whale
![Page 8: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/8.jpg)
Mark-Recapture Method
![Page 9: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/9.jpg)
Population Dynamics Population
density is not a static property:
Births Deaths Immigration Emmigration
![Page 10: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/10.jpg)
Patterns of Dispersion
![Page 11: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/11.jpg)
Patterns of Dispersion: Clumped
*most common plants & fungi clumped where soil
conditions & other environmental factors favor germination & growth
animal clumping may have to do with being successful in some way:
Mayflies swarm in great #s which increases their chances of mating (only have ~2 days)
Wolf pack more likely to kill a moose or deer than a single wolf
![Page 12: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/12.jpg)
Mayfly Swarm
![Page 13: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/13.jpg)
Patterns of Dispersion: Uniform
may result from direct interactions between individuals in a population
some plants secrete chemicals that inhibit germination & & growth of nearby individuals that could compete for resources
animals that show territoriality are spaced apart: often as result of antagonistic interactions
![Page 14: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/14.jpg)
![Page 15: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/15.jpg)
Patterns of Dispersion: Random
unpredictable spacing 1 individual’s position is unrelated to
other individuals
![Page 16: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/16.jpg)
Demographics study of the vital statistics of a
population & how it changes over time especially important are birth rates &
death rates
![Page 17: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/17.jpg)
Life Table age-specific summaries of the survival
pattern of a population construct one by following the fate of a
cohort: a group of individuals of the same age, from birth until all of them are dead
![Page 18: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/18.jpg)
Life Table of Belding’s Ground Squirrels
![Page 19: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/19.jpg)
Survivorship Curves a graphic method of representing some
of the data in a life table plots proportion or #s in a cohort still
alive at each age
![Page 20: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/20.jpg)
Idealized Survivorship Curves
![Page 21: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/21.jpg)
Type I Curve flat @ first reflecting low death rate
during early & middle life then steep drop as death rate increases
with increasing age typical curve for large mammals that
produce few young but take good care of them
![Page 22: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/22.jpg)
Type III Curve drops sharply at start reflecting high
death rate among the young flattens out as death rate for those
individuals that make it out of early life decreases
typical for species that produce many offspring but provide little or no care for them:
fishes, invertebrates
![Page 23: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/23.jpg)
Type II Curve intermediate have a constant death rate typical of rodents, some invertebrates,
some lizards, & some annuals
![Page 24: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/24.jpg)
Survivorship Curves not all species fall into 1 of the 3 types some invertebrates have a “stair-step”
pattern: more vulnerable during periods when molting, less vulnerable when not molting
![Page 25: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/25.jpg)
Reproductive Rates Demographers tend to just look @ #s of
females & how many female offspring they have
simplest way to describe the reproductive pattern of a population is to ask how reproductive output varies with the age of females
![Page 26: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/26.jpg)
Reproductive Table aka a fertility schedule an age-specific summary of the
reproductive rates in a population constructed by measuring reproductive
output of a cohort from birth to death
![Page 27: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/27.jpg)
![Page 28: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/28.jpg)
![Page 29: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/29.jpg)
Natural Selection favors traits that improve an organism’s
chances of survival & reproductive success
every species has trade-offs between survival & traits such as frequency of reproduction, # of offspring
traits that affect an organism’s schedule of reproduction & survival make up its life history
![Page 30: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/30.jpg)
Life Histories are very divers but exhibit patterns in
the variability have 3 basic variables:1. when reproduction begins2. how often the organism reproduces3. how many offspring produced during
each reproductive episode
![Page 31: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/31.jpg)
Big-Bang Reproduction 1 individual
reproduces large # of offspring then die: called semelparity
![Page 32: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/32.jpg)
Iteroparity produce only a few offspring during
repeated reproductive episodes
![Page 33: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/33.jpg)
Semelparity or Iteroparity? Which is better? Critical factor is survival of offspring: *when survival of offspring is low as in
highly variable or unpredictable environments, semelparity is favored
*dependable environments where competition of resources is fierce favors iteroparity
![Page 34: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/34.jpg)
Limited Resources means Trade-Offs
sometimes see trade-offs between survival & reproduction when resources are limited
example: red deer females have higher mortality in winters following summers in which they reproduce
![Page 35: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/35.jpg)
Species whose Young have High Mortality Rates
often produce large #s of relatively small offspring
example: plants that colonize disturbed environments usually produce many small seeds only a few reach suitable habitat smaller seeds allow them to be carried
farther
![Page 36: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/36.jpg)
Parental Investment Increases Survival of Offspring
example: oak, walnut, & coconut trees have large seeds with large store of nrg & nutrients to help seedlings become established
example: primates provide an extended period of parental care
![Page 37: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/37.jpg)
Population Growth All populations have a tremendous
capacity for growth Unlimited increase does not occur
indefinitely for any species, in lab or in nature
![Page 38: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/38.jpg)
Exponential Model of Population Growth
unlimited growth does not occur for long in nature but it is assumed to be true in this model
Δ population = (# births + # immigrants ) - (# deaths + # emigrants)
Or, ignoring immigration & emigration: Δ N/Δt = B - D
![Page 39: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/39.jpg)
Exponential Model now use average #s of births & deaths
per individual during a specified period of time
If there are 34 births per year in a population of 1,000 then the annual per capita birth rate is 34/1,000 = 0.034 = b
![Page 40: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/40.jpg)
Exponential Growth Equation ΔN/dt = TMax N: represents a population’s
potential growth in an unlimited environment where TMax is the maximum per capita rate of increase & N is the # of individuals in the population
![Page 41: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/41.jpg)
Exponential Growth
![Page 42: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/42.jpg)
Exponential Model http://www.slideshare.net/MrDPMWest/po
pulation-growth-apbio
![Page 43: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/43.jpg)
Logistic Model in nature, as any population density
increases: each individual has access to fewer resources
eventually, there is a limit to the # of individuals that can occupy a habitat
Carrying Capacity: (K) the maximum population size that a particular environment can sustain
![Page 44: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/44.jpg)
Carrying Capacity varies over space & time with the
abundance of limiting resources: Energy Shelter Refuge from predators Nutrients Water Suitable nesting sites
![Page 45: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/45.jpg)
Carrying Capacity per capita birth rate decreases if there
are not enough nutrients for adults to maintain themselves or if disease or parasitism increases with density
per capita death rate increases for same reasons
either way: results in lower per capita rate of increase
![Page 46: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/46.jpg)
Logistic Growth Model per capita rate of increase approaches 0
as the carrying capacity is reached
![Page 47: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/47.jpg)
Logistic Growth Equation
![Page 48: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/48.jpg)
Logistic Model fits few real populations perfectly, but it
is useful for estimating possible growth
![Page 49: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/49.jpg)
Life History Traits are Products of Natural Selection
traits that affect an organism’s schedule of reproduction & survival make up its:
life history: 3 main variables:1. age @ 1st reproduction2. how often the organism reproduces3. # offspring produced/ reproductive episode
![Page 50: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/50.jpg)
Semelparous Organisms reproduce once & die aka “big-bang”
![Page 51: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/51.jpg)
Iteroparous Organisms produce offspring repeatedly
![Page 52: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/52.jpg)
Semelparous vs. Iteroparous? 2 critical factors:1. survival rate of offspring
low chance survival where environment variable or unpredictable: semelparity
2. likelihood adult will survive to reproduce again
adults less likely to survive: semelparity
![Page 53: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/53.jpg)
“Trade-Offs” & Life Histories trade-offs between reproduction & life
histories:
![Page 54: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/54.jpg)
Trade-Offs selective pressures influence the trade-
off between # & size of offspring Plants:
those that colonize disturbed environments have small seeds…only few reach suitable habitat
Animals: those with high predation rate have larger #s
offspring (quail, mice, sardines)
![Page 55: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/55.jpg)
Trade-Offs other species put large investment to
insure survival of offspring trees with large seeds (walnut, brazil nut)
provide nutrients that increases offspring’s chances of survival
![Page 56: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/56.jpg)
K-Selection/ R-Selection selection for traits sensitive to
population density & are favored @ high densities is known as K-selection = density dependent selection
selection for traits that maximize reproductive success in low density environments is called r-selection
![Page 57: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/57.jpg)
![Page 58: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/58.jpg)
Density-Dependent Factors refers to any characteristic that varies
with population density birth or death rate changes based on
population density often because water &/or nutrients become
scarce
![Page 59: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/59.jpg)
Density-Independent Factors any characteristic not affected by
ppulation density birth & death rates stable no matter
what the population density is
![Page 60: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/60.jpg)
Determining Equilibrium for Population Density
red line = density-independent death rate
blue line = density-dependent birth rate
junction = equilibrium density
![Page 61: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/61.jpg)
Mechanisms of Density-Dependent Population Regulation
w/out some type of (-) feedback between population density & rates of birth & death: a population would never stop growing
![Page 62: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/62.jpg)
Mechanisms of Density-Dependent Regulation
1. Competition for Resources
competing for nutrients & other resources decreases the birth rate
farmers add fertilizer to reduce competition for nutrients
![Page 63: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/63.jpg)
Mechanisms of Density- Dependent Regulation
2. Predation as # prey increases
a predator may develop preference for that species
![Page 64: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/64.jpg)
Mechanisms of Density- Dependent Regulation
3. Toxic Wastes Brewer’s Yeast
used to convert carbohydrates to ethanol in wine-making but anything > 13% alcohol it toxic to the yeast
![Page 65: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/65.jpg)
Mechanisms of Density- Dependent Regulation
4. Intrinsic Factors some species experience increased
death rate * decreased birth rate when population density reaches certain point even when there is sufficient nutrients white-footed mice: immune system altered
more deaths & reproductive maturity delayed fewer births when certain density reached
![Page 66: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/66.jpg)
Mechanisms of Density- Dependent Regulation
5. Territoriality when space becomes
resource competing for it can limit population size
maintaining a territory insures there will be enough food to live & reproduce
![Page 67: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/67.jpg)
Mechanisms of Density- Dependent Regulation
6. Disease if transmission rate
depends on certain level of crowding then it is density-dependent
respiratory viruses spread thru air: is more easily spread in large cities than in rural areas
![Page 68: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/68.jpg)
Mechanisms of Density- Dependent Regulation
7. Population Dynamics the normal fluctuations in population
size from yr to yr
![Page 69: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/69.jpg)
Mechanisms of Density- Dependent Regulation
8. Stability & Fluctuation because changing environmental
conditions disrupt populations, they all experience size fluctuations
![Page 70: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/70.jpg)
Emigration when a population becomes crowded &
resource competition increases often emigration #s increase
example: when slime mold resources become scarce some single celled individuals group together (amoeba group) a & form a slug
![Page 71: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/71.jpg)
![Page 72: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/72.jpg)
Metapopulation form when a # of local populations are
linked local populations in a metapopulation
can be thought of as occupying discrete patches of suitable habitat in a sea of unsuitable places
![Page 73: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/73.jpg)
![Page 74: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/74.jpg)
Human Population Growth since ~ 1650 has been growing
exponentially w/in last 55 yrs rate of growth has fallen
by nearly ½ predictions: rate will continue to decline
until ~2050 & reach equilibrium ~2100
![Page 75: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/75.jpg)
Human Population Growth
![Page 76: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/76.jpg)
Demographic Transition movement from high birth rate & high
death rate low birth rate, low death rate
occurred in human population with industrial revolution
![Page 77: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/77.jpg)
Age Structure relative # of individuals of each age use “pyramids”
USA: #s fairly steady except for “baby boomers”: increased birth rate that followed up to 20 yrs after WWII
![Page 78: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/78.jpg)
Age Structure: Rapid Growth bottom-heavy
pyramid skewed toward
more young individuals
ex: Afghanistan, Congo
![Page 79: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/79.jpg)
Age Structure: Slow Growth fairly steady
growth over time can be do to
steady birth rate or falling birth rate + steady increase in immigration
ex: USA
![Page 80: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/80.jpg)
Age-Structure: No Growth smaller base: #s
under reproductive age are under-represented
ex: Italy, Germany
![Page 81: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/81.jpg)
Infant MortalityLife Expectancy
Infant Mortality = # of infant deaths per 1,000 live births
Life Expectancy @ birth = predicted average length of life
both vary widely among human populations
if infant mortality high parents may choose to have more children to increase odds some will reach adulthood
![Page 82: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/82.jpg)
Comparing Industrialized & Developing Nations
![Page 83: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/83.jpg)
Global Carrying Capacity is uncertain has changed over time due to advances
in technology
![Page 84: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/84.jpg)
Ecological Footprint is the aggregate land & water area
needed to produce all the resources a person or group of people consume & to absorb their wastes
it‘s 1 measure of how close we are to Earth’s carrying capacity
We‘re using many of Earth’s resources in unsustainable manner
![Page 85: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/85.jpg)
![Page 86: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/86.jpg)
Annual per capita Energy Use
![Page 87: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/87.jpg)
http://www.worldometers.info/world-population/
http://www.worldometers.info/world-population/
![Page 88: Population Ecology](https://reader035.fdocuments.us/reader035/viewer/2022062501/56816247550346895dd28785/html5/thumbnails/88.jpg)