Unit 3: Population Ecology

Unit 3: Population Ecology
Placeholder opening page, but maybe we can duplicate the look of the SE chapter opener page by using the same fonts and colors (and maybe that Ch 14 icon?)

Finding Gold in a Costa Rican Cloud Forest
Golden toads lived in Costa Rica’s Monteverde cloud forest. Golden toads were first described in They were extinct by 1989. Talk About It Why is the extinction of the golden toad a global concern?

Lesson 4.1 Studying Ecology

Levels of Ecological Organization
Lesson 4.1 Studying Ecology Levels of Ecological Organization ECOLOGY __________________ - The study of how organisms interact with each other and with their environments Scientists study ecology at various levels of organization. Individual Population Community Ecosystem Biosphere

Lesson 4.1 Studying Ecology Levels of Ecological Organization Individual __________________ - One organism Individual Population Community Ecosystem Biosphere

Lesson 4.1 Studying Ecology Levels of Ecological Organization POPULATION ____________________ - members of a species that live in the same area at the same time _________________ - a group of individuals that interbreed and produce fertile offspring Population Ecology is the study of how individuals within a population interact with one another SPECIES Individual Population Community Ecosystem Biosphere

Lesson 4.1 Studying Ecology Levels of Ecological Organization COMMUNITY ____________________ - All of the populations in a particular area Community Ecology is the study of interactions between species Individual Population Community Ecosystem Biosphere

Lesson 4.1 Studying Ecology Levels of Ecological Organization ECOSYSTEM ____________________ - Includes all of the living things and nonliving things in a particular area Ecosystem Ecology is the study of the living and nonliving components of a system together Individual Population Community Ecosystem Biosphere

Lesson 4.1 Studying Ecology Levels of Ecological Organization BIOSPHERE ____________________ - All parts of Earth that host life, with all its organisms and environments Individual Population Community Ecosystem Biosphere

Biotic and Abiotic Factors
Lesson 4.1 Studying Ecology Biotic and Abiotic Factors BIOTIC ____________ factors: Parts of an ecosystem that are ____________ or used to be living Examples: Plants Animals Fungus Bacteria LIVING Did You Know? Decaying organisms are biotic factors as long as their structure remains cellular.

Biotic and Abiotic Factors
Lesson 4.1 Studying Ecology Biotic and Abiotic Factors ABIOTIC _______________ factors: Parts of an ecosystem that have never been living Examples: Sun (Sunlight) Oxygen Water Rocks Temperature Wind pH

Habitat ORGANISM Habitat
Lesson 4.1 Studying Ecology Habitat Habitat _____________ -The specific environment in which an organism lives Includes biotic and abiotic factors Boundaries are defined by the particular ________________ that lives there Earthworm vs. Hawk ORGANISM

Lesson 4.1 Studying Ecology
Habitat RESOURCES Habitats provide an organism with ____________________ —anything an organism needs to survive and reproduce, including food, shelter, and mates.

Lesson 4.2 Describing Populations
From 1900 to 2000, the white-tailed deer population of New York state grew from about 20,000 to more than 1 million. Densities of more than 100 deer per sq mi occur in some metropolitan areas.

SPECIES TIME AREA Population What is a population again?
Lesson 4.2 Describing Populations Population What is a population again? Members of the same ______________ that live in the same ____________ at the same _____________ Population ecology studies how members of the population interact with one another SPECIES AREA TIME

NUMBER INCREASES STEADY DECREASES
Lesson 4.2 Describing Populations Population Size NUMBER Population Size -The _____________ of individuals in a population at a given time When population size ___________________ or remains ____________, it is a sign that the population is healthy Sudden and dramatic ____________________ in population size can indicate an unhealthy population headed toward extinction. Ex. Golden Toads 1987 – 1500 toads 1988 – 10 toads 1989 – 1 toad 1990 – no toads INCREASES STEADY DECREASES

Population Size The Decline of the Passenger Pigeon
Lesson 4.2 Describing Populations Population Size The Decline of the Passenger Pigeon Once the most abundant bird in North America In the early 1880s a scientist described a flock of 2 billion birds that covered 240 miles of sky, took 5 hours to pass overhead and sounded like a tornado! Then, due to deforestation and hunting, the population slowly dwindled away with the last one dying in 1914

SAMPLING SMALLER 1000 Population Size
Lesson 4.2 Describing Populations Population Size SAMPLING Ecologists often use ________________ techniques to estimate population size. Count organisms in a _______________ sample area and use it to estimate how many there are in the larger overall area Ex. If there are 100 oak trees in one square km, it would be reasonable to estimate that there are __________ in ten square kms SMALLER 1000 Counting Laysan Albatross Nests

MARK & RECAPTURE Population Size
Lesson 4.2 Describing Populations Population Size What if what you are counting doesn’t stay still? Use the “________________________________” Technique Catch organisms, tag them, release them Catch another sample of organisms Assume that the number of marked organism that are recaptured in the sample is proportionate to the number of marked organisms in the whole population # marked in sample = # marked in total population ____# in sample # population MARK & RECAPTURE

Population Size Ex. Suppose you capture and mark 20 turtles at a pond. After releasing these turtles, you return a few days later and catch 10 turtles. Of these 10 turtles, 5 are already marked. How many turtles are in the total population? # marked in sample = # marked in total population ____# in sample # population 5 = ? 5*? = (20)*(10) 5*? = 200 ? (# population) = 40

CROWDED 1500/4 375 Population Density
Lesson 4.2 Describing Populations Population Density Measure of how ________________ a population is (number of individuals within a population per unit area Ex. If 1500 golden toads were found within 4 square kilometers, the population density would be _________ or _______ toads/square km. Larger organisms generally have lower population densities (ex. Lions). CROWDED 1500/4 375

LOW Population Density
Lesson 4.2 Describing Populations Population Density LOW ________ population density: More space and resources but finding mates can be difficult

Finding a mate can be difficult with a low population density

HIGH COMPETITION DISEASE
Lesson 4.2 Describing Populations Population Density HIGH _________ population density: Finding mates is easier but there tends to be more ____________________, more infectious _____________, & more vulnerability to predators Ex. Harlequin Frog COMPETITION DISEASE Northern pintail ducks

Population Distribution
Lesson 4.2 Describing Populations Population Distribution ARRANGED How organisms are __________________ within an area: 1) _______________ distribution: Organisms arranged in no particular pattern Resources are found _____________________ the area and others organisms do not influence where members of the population settle RANDOM THROUGHOUT

Lesson 4.2 Describing Populations Population Distribution UNIFORM 2) _______________ distribution: Organisms evenly spaced Individuals hold territories or _______________ for space COMPETE

Lesson 4.2 Describing Populations Population Distribution CLUMPED 3) ________________ distribution: Organisms grouped near ___________________ __________________________ distribution in nature RESOURCES MOST COMMON

NUMBER AGE GROWTH Age Structure
Lesson 4.2 Describing Populations Age Structure NUMBER Age Structure Diagram - Relative _______________ of organisms of each ________ group within population displayed in a pyramid Can be used to predict future population _______________ AGE GROWTH

STABLE DECLINING GROWING
Lesson 4.2 Describing Populations Age Structure Three Main Types of Populations _______________ - Even distribution of ages (births keep pace with deaths) __________________ - Mostly older individuals _______________ - Mostly younger STABLE DECLINING GROWING

Age Structure

MALES FEMALES 50:50 Sex Ratios
Lesson 4.2 Describing Populations Sex Ratios MALES FEMALES Proportion of _____________ to _______________ Age structure diagrams give information about sex ratios. For a monogamous species, the ideal sex ratio is _________. Why? 50:50

Lesson 4.3 Population Growth
From 1800 to today, the human population has grown from about 1 billion to more than 6.8 billion—an exponential rate of increase.

A few bacteria can multiply to millions in hours
Lesson 4.3 Population Growth A few bacteria can multiply to millions in hours A few whales must have at least a year to produce just one baby. Why??

Factors That Determine Population Growth Births and Deaths
Lesson 4.3 Population Growth Factors That Determine Population Growth Births and Deaths Immigration and Emigration

GROWS DENSITY AGE STRUCTURE INCREASES
Lesson 4.3 Population Growth Birth and Death Rates A population’s relative birth and death rates (mortality and natality) affect how it _______________. Population size, ______________, distribution, sex ratio and _______ ___________________ all influence how many are born and how many die. If everything else is equal, when a populations birthrate is greater than their death rate, the population ________________. GROWS DENSITY AGE STRUCTURE INCREASES

Birth and Death Rates OLDER EQUAL YOUNGER
Lesson 4.3 Population Growth Birth and Death Rates Survivorship curves show how the likelihood of death varies with age. Type I – Higher mortality rate at an _________ ages Ex. Humans Type II - _________ mortality at all ages Ex. Most birds Type III – Higher mortality rate at ______________ ages Ex. Golden Toad OLDER EQUAL YOUNGER

Immigration and Emigration
Lesson 4.3 Population Growth Immigration and Emigration In addition to births and deaths, population growth is affected by immigration and emigration Immigration – ______________ of individuals from outside a give area Emigration - ________________ of individuals from a given area ARRIVAL IN DEPARTURE EXIT

Immigration and Emigration
Lesson 4.3 Population Growth Immigration and Emigration MIGRATION _______________ seasonal movement into and out of an area, can temporarily affect population size.

Calculating Population Growth
Lesson 4.3 Population Growth Calculating Population Growth Determined by the following equation: a (individuals added) – (individuals subtracted) or.. (_________________ + _________________ rate) - (________________ + ________________ rate) Growing populations have a ___________ growth rate; shrinking populations have a _____________ growth rate. Usually expressed in terms of individuals per 1000 Birthrate Immigration Death rate Emigration Positive Negative

Lesson 4.3 Population Growth Calculating Population Growth

Lesson 4.3 Population Growth Calculating Population Growth Growth rate 100 -100 49 -180 -100 98 100

How Populations Grow EXPONENTIAL GROWTH IDEAL
Lesson 4.3 Population Growth How Populations Grow EXPONENTIAL GROWTH _________________ ___________ Population increases by a fixed percentage every year. Normally occurs only when small populations are introduced to an area with _________ environmental conditions Rarely lasts long IDEAL

How Populations Grow LOGISTIC GROWTH LIMIT
Lesson 4.3 Population Growth How Populations Grow LOGISTIC GROWTH ____________ __________ - Describes how a populations initial exponential growth is slowed and finally stopped by limiting factors Limiting factors are characteristics of the environment that ________ population growth LIMIT

How Populations Grow WATER DISEASE NOT DISASTERS
Lesson 4.3 Population Growth How Populations Grow 2 Types of Limiting factors: Density-dependent: Influence changes with population density. Ex. Food, __________, Space, ____________, Predation Density-independent: Influence does ______change with population density. Ex. Natural ______________, Climate Change WATER DISEASE NOT DISASTERS

How Populations Grow D I D Density Dependent or Density Independent?
Lesson 4.3 Population Growth How Populations Grow Density Dependent or Density Independent? _____ Due to severe overcrowding in an Asian village, many children do not survive to reach adulthood. _____ The eruption of Mt. St. Helens destroys most of the wildlife in the immediate vicinity of the volcano _____ Due to lack of food and nutrition, large numbers of female mice miscarry their young and fail to reproduce D I D

How Populations Grow LARGEST
Lesson 4.3 Population Growth How Populations Grow Limiting Factors determine a population’s carrying capacity. Carrying Capacity – the _____________ population an environment can sustainably support. It can change as limiting factors in the environment change LARGEST

Biotic Potential MAXIMUM BIOTIC POTENTIAL GESTATION GENERATION HIGH
Lesson 4.3 Population Growth Biotic Potential Limiting Factors are only part of the story.. We also have to look at the characteristics of the organism An organism’s ____________ ability to produce offspring in ideal conditions is called _________ _______________ Two main things influence biotic potential: 1) ______________ time – how long it takes for an embryo to develop and “be born” 2) ________________ time – the span from an organism’s birth to the time is has its own offspring. Organisms with _________ biotic potential can recover more ____________ from population declines than organisms with low biotic potential. MAXIMUM BIOTIC POTENTIAL GESTATION GENERATION HIGH QUICKLY

Biotic Potential Scorpion Fish Scorpion Fish vs. Orangutan
Lesson 4.3 Population Growth Biotic Potential Scorpion Fish vs. Orangutan Scorpion Fish – Sexually mature at age 3-5, they lay 50,000 to 100,000 eggs a year and they only take 12 to 16 days to hatch Orangutan – Sexually mature at age 10, they give birth to a single baby only once about every 8 years Which organism has the higher biotic potential? Scorpion Fish

Unit 3: Population Ecology

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