Semester 2, Day 2

Ecosystem & Energy

Agenda Turn in Cornell Notes & Question Responses Biodiversity Quiz Ecosystem Lecture 4 Minute Break Reading/Work Time Hand Quizzes back and review

Turn in Cornell Notes and Question Responses Order

Cornell Notes 34.1 Cornell Notes 34.2 Cornell Notes 34.3 Cornell Notes 34.4 Responses to Section 34.1-34.4 and Chapter 34 Review

Make sure that your name is on your notes/responses Initial each following page Keep the papers together, fold the corner if not stapled

Biodiversity Quiz Complete the quiz silently When you are finished, place quiz facedown

on desk When everyone is finished, pass quizzes

forward

Ecosystem Changes

How do certain changes affect an ecosystem?

Climate Changes

Temperature, flooding, global warming, freezing

Can eliminate entire biological communities

New communities will repopulate the area NEW

ECOSYSTEM!

From natural resources (volcanoes)

Ecosystem Changes How do certain changes affect an ecosystem?

Human Activity

Human-caused global warming, pesticides, deforestation, urban

encroachment, endangered species, acid rain, water contamination,

fossil fuels, dams for hydroelectricity, radioactive waste, oil spills, air

pollution, soil erosion, salting roads, crop irrigation

All of these can kill populations, resulting in the entire ecosystem being

disrupted

Ecosystem Changes How do certain changes affect an ecosystem?

Human Activity (cont.)

Spirogyra

PopulationExplodes

EFFECT

Daphnia

Kill withPesticides

CAUSE

Bluegill

Dies from Lack of Food

EFFECT

Smallmouth Bass

Dies from Lackof Food

EFFECT

Ecosystem Changes How do certain changes affect an ecosystem?

Introduction of Non-Native / Invasive Species Harmful No predators Displace native species Carry disease

Population Size Caused by humans Example: Too many predators, prey die out, then predators

die, and plants the prey ate grow out of control.

Population Size in Ecosystem

PopulationSize

BIRTH

IMMIGRATION EMIGRATION

DEATH

Rates that increasepopulation size

Rates that decreasepopulation size

Organisms enter ecosystem Organisms enter ecosystem

Population Size in Ecosystem Graph of Births and Deaths. Look at the gap

between births and deaths.

Gap gets biggerTherefore, population INCREASESNumber

ofOrganisms

Time

Births

Deaths

Population Size in Ecosystem Graph of Births and Deaths. Look at the gap

between births and deaths.

Gap gets smallerTherefore, population INCREASESNumber

ofOrganisms

Time

Births

Deaths

Population Size in Ecosystem Graph of Births and Deaths. Look at the gap

between births and deaths.

Gap stays the sameTherefore, population INCREASESNumber

ofOrganisms

Time

Births

Deaths

Energy Flow in an Ecosystem Autotrophs: produce their own food. 2 types:

Autotrophs make ENERGY available for all other organisms in the ecosystem.

“self” Phototrophs Chemotrophs

•Organisms with chlorophyll•Chlorophyll absorbs light energy for photosynthesis•Converts light energy to food energy

•When sunlight is unavailable•Hydrogen sulfide (H2S) or carbon dioxide (CO2) converted to organic (“life”) molecules.

“Light” “Chemical”

Energy Flow in an Ecosystem Heterotrophs: get energy by consuming other

organisms.

Note: Decomposers: secrete enzymes to break down dead matter & then absorb the nutrients (bacteria and fungi)

Herbivore Carnivore Omnivore Detritivore

•Organisms that consume only plants

•Organisms that consume only other heterotrophs

•Organisms that consume both autotrophs and heterotrophs

•Organisms that consume dead matter (any).•Tend to be bugs.

AKA “Consumers”

Energy Flow in an Ecosystem Decomposers & Detritivores are similar, BUT

DECOMPOSERS

Secrete enzymes to break down

Absorb nutrients

Bacteria, Fungi

DETRITIVORES

Eat & digest

Bugs (generally)

Dead Matte

r

*Note: Scavengers technically eat dead organisms, but will also eat live organisms

Energy Flow: Food Webs Food Chain: simple model; one-way energy

flow Primary Producer Primary Consumer Secondary Consumer Tertiary

Consumer

Arrow shows direction of

ENERGY

*Note:•All primary producers are autotrophs•All primary consumers are herbivores (a type of heterotroph)•Higher consumers can be omnivores OR carnivores

Energy Flow: Food Web Food Web: Interconnected food chains;

complex

Energy Flow: Ecological Pyramids Ecological pyramids: show relative amounts of

energy, biomass, or # of organisms.Tertiary

Consumer

Secondary Consumer

Primary Consumer

Primary Producer

Trophic Levels

Template

Energy Flow: Ecological Pyramids Pyramid of Energy

0.1%1%

Energy10% Energy

100% Energy

Energ

y Los

t as H

eat (

90%)

AvailableEnergyDecreases

Energy Flow: Ecological Pyramids Pyramid of Biomass (total mass of life @ each

level) 1.5 g/m211 g/m2

37 g/m2

809 g/m2

AvailableBiomassDecreases

Note: Mass/Area

Energy Flow: Ecological Pyramids Pyramid of Numbers (# of Organisms)1

0,000

90,000200,000

1,500,000

PopulationSizeDecreases

4 Minute Break

Stay on this floor, otherwise privilege will be

revoked

Be back in the class by ______.

Reading / Work Time Read Chapter 2 Do the Chapter 2 Assessment Questions #1-

15, 17-24 Come show me your responses when you are

finished. If you don’t finish, it is homework!

Reminder dp.davincischools.org/staff/blarkin