Updated 10-29-01(c) Tim Bass1 Matter and Energy in the Ecosystem Environmental Science Chapter 4 Mr....

Updated 10-29-01 (c) Tim Bass 1

Matter and Energy in the Ecosystem

Environmental Science

Chapter 4

Mr. Bass


Matter and Energy in the Ecosystem 4.1 Roles of Living Things 4.2 Ecosystem Structure 4.3 Energy in the Ecosystem 4.4 Cycles of Matter


4.1 Roles of Living Things

Objectives Energy in the Ecosystem Food Consumption Feeding Levels of Organisms 4.1 Section Review


Objectives: SWBAT

describe the process of photosynthesis in terms of a chemical reaction.

identify the roles of producers, consumers, and decomposers.

explain the concept of the trophic level.


A. Energy in the ecosystem.

We will describe this in section 4.3 Almost all energy comes from the sun. Only the energy converted to glucose is

available for use. There is a limit to the amount of energy that

can be absorbed and transferred to an ecosystem.


B. Food Consumption

Producers Consumers

• Herbivores• Carnivores• Omnivores• Scavengers

Decomposers

•Consumers

•Primary

•Secondary

•Tertiary

•Autotrophs

•Heterotrophs

•Level 1

•Level 2

•Level 3


Producers Producers: Organisms that make their own food

from inorganic molecules and energy.• Plants and diatoms (plankton) are the most important

producers.

• All producers form energy through the Photosynthesis Reaction.

Photosynthesis: the production of energy from light, water and carbon dioxide.

Chlorophyll: Green chemical that captures energy from the sun.


Photosynthesis Reaction

Reactants:

Light + Water + Carbon Dioxide -->

Products:

Glucose + Water + Oxygen

12 H2O + 6 CO2

C6H12O6 + 6 H2O + 6 O2


Respiration

The opposite of photosynthesis• Plants and animals both use respiration.

• Photosynthesis:• Light + 6 CO2 + 12 H2O --> C6H12O6 + 6 O2 + 6 H2O

• Respiration:• C6H12O6 + 6 O2 + 6 H2O --> 6 CO2 + 12 H2O + energy

• Respiration is how plants and animals use the energy stored in glucose.

• In a cell this occurs in the mitochondria.


Photosynthesis and Respiration: Energy Cycle


Consumers

Consumers: Organisms that cannot make their own food.• Primary Consumer: Eats producers.• Secondary Consumer: Eats Primary Consumer

(may also eat producers).• Tertiary Consumer: Eats secondary consumer

(may also eat primary consumers and/or producers).


Consumer Overview:

Producers

Primary Consumers

Secondary Consumers

Tertiary Consumers


Consumers

Herbivores: only eat plants.• Primary Consumers• Examples: Elk, Cow, Insects, Birds, Buffalo,

Antelope Carnivores: only eat meat (Insects are treated

as meat).• Can be secondary, or tertiary consumers depending

on what they eat.• Examples: Lions, snakes, hawks, spiders.


Consumers

• Omnivores: eat either plants or meat.• Can be Primary, Secondary, or Tertiary Consumers

depending on what they eat.

• Examples: Humans, Bears, Chimpanzees

• Scavengers: do not hunt live prey, instead they eat bodies of dead organisms.

• Can be Secondary, or Tertiary Consumers

• Examples: Vultures, hyenas, many insects.


Decomposers

Decomposers: Bacteria and fungi that consume the bodies of dead organisms.• Includes the breakdown of plants as well as bodies of

animals.

• Decompose the organic matter in animal waste.

• Decomposers take complex organic material and return them to simple inorganic materials.

• inorganic materials are returned to the soil.

• As plants use the nutrients to grow, the cycle of matter through the ecosystem begins again.


Feeding Levels of Organisms.Trophic Level Troph: to feed or nourish. Trophic Level: A layer in the structure of

feeding relationships in an ecosystem.• Different ecosystems have different numbers of

tropic levels. Usually there are 3-5 tropic levels.

3

2

1

4

3

2

1

54321


Basic feeding levels

• Autotrophs: Make their own food.• All of these are producers.

• This is always in the first trophic level.

• Heterotrophs: Obtain their energy by eating other organisms.

• These are always above the first trophic level.

54321

Heterotrophs

Autotrophs


Trophic Levels: Feeding Levels of Organisms

Trophic Level 1

Trophic Level 2

Level 3

4

Consumers

Producer


Compare & Contrast

Producer Producer 1

Primary Herbivore 2

Secondary 3

Tertiary

Heterotrophs

4Omnivore

Carnivore

Scavengers

Decomposers

Autotroph

Decomposers

Consume

rs

Next Screen


4.1 Section Review

Give an example of a (tiger, bear, vulture) being primary, secondary, and tertiary consumers.

What is the relationship between the largest trophic level and the levels below it?

Another name for consumer? What are the two types of organisms that

consume the bodies of dead organisms? What is another name for producer?


4.1 Section Review

What chemical process do all producers have in common?

Decomposers not only eat dead organisms, but also ____________.

What is the opposite of photosynthesis? What role do decomposers fill in the

recycling of matter in nature?


4.2 Ecosystem Structure

Objectives Food Chain Food Web Diversity and Stability Biological Magnification


Objectives SWBAT

describe food chains and food webs. examine how ecosystem structure is related

to population changes and the transfer of pollutants.


Food Chain


Food Chain

Food Chain: a series of different organisms that transfer food between the trophic levels of an ecosystem.• Is viewed as cyclical.

• All food chains begin with producers.

• The next level is usually herbivores.

• The upper levels are usually carnivores and omnivores.

• Decomposers operate at all the levels of the food chain.

• The food chain is a simplistic look at the food relationships in an ecosystem.


Food Chain Example


Food Web

Food Web: a network of food chains representing the feeding relationships among the organisms.• Includes all the food chains in an ecosystem.• Shows the interaction between various organisms

in an ecosystem.• Demonstrates how a change in one population

can effect many other populations.• Especially true when a consumer is removed.

• Krill and Baleen whales in Antarctica (Figure 4.6, pg 58)


Food Web Example


Interrelationships


Connections to Consumers


Food Chain and Web Review

Which is the most complex? Which is the least realistic? Which is an accurate predictor of the effects

of the extinction of a species? Which is cyclical in nature?

Next Screen


Biological Magnification

Biological Magnification: increasing concentration of a pollutant in organisms at higher trophic levels in a food web.• Example of eagles and DDT (Dateline 1972, pg

59)• Many pollutants (toxins) can be concentrated in

this way, especially heavy metals• Show how pollutants taken in by a few

organisms can affect the whole food web.


Concentration of DDT in A Long Island Marsh sprayed for Mosquito Control

1967 ppm

Water .00005

Plankton .04

Silverside Minnow .23

Sheephead Minnow

.94

Pickerel 1.23

Needlefish 2.07

Heron 3.57

Tern 3.91

Osprey 13.8

Merganser 22.8

Cormorant 26.4



DDT Concentrations

.025 %

.125 %

.625 %

3.125 %

This is an example of a 5X multiplier!

Next Screen


Diversity and Stability

Stability: the ability of an ecosystem to withstand dramatic changes.

Two Major Factors of Stability:• Biodiversity: the variety of species that lives in

an ecosystem.• The greater the biodiversity the greater the stability.

• Number of Trophic Levels.• The more trophic levels the more stable the

ecosystem.


Stability

A food web with more diversity in species (biodiversity) is more stable.• The greater the number of species the greater

the interconnections between species.• The greater the number of connections between

species, the more avenues that individual species have to find alternative ways of finding food.

A food web with more trophic levels is more stable.


Relative Stability

Low

Stability

High

Stability

Trophic Levels


Stability

Stability can help an ecosystem recover faster from natural or human-caused disasters.• Deciduous forest is an example of a stable

ecosystem.• Forests tend to recover quickly from disasters.

• A tundra food web is an example of a fragile ecosystem.

• A small disturbance can have long-lasting effects.


4.2 Section Review

What is the most accurate way of portraying feeding relationships in an ecosystem?

What type of organisms is always contained in the beginning portion of the food chain?

What are the two major factors of stability? As biodiversity increases what happens to

the amount of interconnection between species?


4.2 Section Review

Which system will have the greatest stability?• Rainforest• Dessert

What does biodiversity mean? When comparing two systems, one with

three trophic levels and one with five trophic levels, which is the most stable?

What does stability mean in an ecosystem?


4.3 Energy in the Ecosystem

Objectives Energy and Food Ecological Pyramids 4.3 Section Review


Objectives SWBAT

investigate the movement of energy through an ecosystem.

define ecological pyramid. explain the relationship between the

ecological pyramid and energy in an ecosystem.


Energy in Ecosystems

Source of all energy is the sun. Source of biological energy is glucose

formed through photosynthesis

Sun < .001 % of Sun’s Energy(Electromagnetic Spectrum) Earth

Of the energy that reaches the Earth, < 1% is absorbed by plantsSun



The theme of this section is that energy is lost at every level of an ecosystem.

Of the energy the plant receives only 30% is converted to glucose Glucose

Producers: 100% of energy captured from the sun.

Portion not eaten: 50%

Portion eaten: 50%

Not Digested: 20%

Decomposers

Digested by Consumer: 30 %

Energy Lost: 20 %

Growth:

10 %

Glucose

Next Screen



Biomass: The total mass of all organisms in a trophic level.• This was first created when satellites were first

used.

Ecological Pyramids: Shows the relative amounts in different trophic levels.

Rule of 10: Each level of a trophic system is 1/10th of the preceding level.


1,000,000

100,000

10,000

Next ScreenEcological Pyramid: Biomass


Ecological Pyramid: Biomass


Ecological Pyramid:Numbers

300,000

30,000

3,000


Ecological Pyramid: Numbers


Ecological Pyramid

10,000

1,000

100

Energy lost in an ecosystem

Next Screen


Ecological Pyramid: Energy


Practical Application: ***** World Hunger ******

15,000 lbsChicken Feed

1,500 lbsChicken

Man 150 lbs Man

150 lbs

1,500 lbs

Chicken Feed

Secondary Consumer

PrimaryConsumer

The impact?? 13,500 lbs additional food available

Next Screen


4.3 Section Review


4.4 Cycles of Matter

Objectives Body Composition Water Cycle Carbon Cycle Nitrogen Cycle Phosphorous Cycle Section 4.4 Review


Objectives

describe the chemical composition of the human body.

explain the water cycle, the carbon cycle, phosphorous cycle and the nitrogen cycle.


Chemical Composition of Body

About 96% of the human body is made of four elements: oxygen, carbon, hydrogen, and nitrogen.• In order for the body to use the elements, they

must be in the proper form.• Nitrogen is a great example.

• about 80% of the atmosphere is nitrogen.

• However, the nitrogen in the air is not suitable for most living organisms.

• A limit of suitable nitrogen limits growth in an ecosystem.


Water Cycle: Surface Water

Evaporation: the movement of water into the atmosphere as it changes from a liquid to a gas.

Precipitation: the formation of rain.


Surface Water Cycle


Water Cycle: Surface

Evaporation

Precipitation

Water Transport


Water Cycle: Ground Water

Aquifer: a porous layer of the earth that contains water.

Spring: when an aquifer leaks water to the surface.


Aquifer

AquiferSpring

Water


Ground Water

Artesian Well: when an aquifer has pressure placed on it and water is forced out of the aquifer.

Geyser: water descends deep into the earth, boils, then is forced to the surface.


Water Cycle: Ground

Seepage: water slowly goes through the layers of the earth until it trapped by a non-porous layer of earth.


Ground Water CycleGeyserSeepage

Artesian

Well

Spring: When an aquifer comes to the surface.


Water Cycle: Plants

Transpiration: the evaporation of water from the leaves of plants.

Capillary Action: the transport of a liquid due to the attraction between the liquid and the sides of the tube.


Water Cycle: Plants

Capillary Action

Transpiration


Carbon Cycle: Miscellaneous

Photosynthesis & Respiration: An important part of the Carbon Cycle.

Anhydrous Acid: A compound which becomes an acid in the presence of water.• CO2 becomes a mild acid in the presence of water.

Methane: the simplest organic compound (CH4). A product of decomposition.

Volcanoes: produce huge amounts of CO2 while erupting.


Carbon Cycle: Fossil Fuels

Fossil Fuels: Fuels composed of decomposed living matter (organic).• Coal• Oil• Natural Gas

When burned fossil fuels form water (H2O) and carbon dioxide (CO2).

Fossil Fuels + O2 H2O + CO2


Carbon Cycle: From Minerals

Certain Minerals produce Carbon Dioxide (CO2) naturally.

• Limestone• Dolomite

Plants need certain materials to grow, the element most often missing is nitrogen.• Plants can not use nitrogen from the air.• Nitrates are manufactured as fertilizers.


Carbon Cycle Diagram


Animals in the Carbon Cycle

Ingestion:

Urination

Respiration

Plants: Photosynthesis


Carbon Cycle: Handout

Methane

Decomposers


Carbon Cycle: Animals

Methane

Decomposers

Respiration

Ingestion

Photosynthesis


Nitrogen Cycle

All nitrogen originally came from the air.• 78% of air is N2 (pure nitrogen).

Most nitrogen is stored in organic materials.• Stored as proteins.

Plants cannot use the nitrogen in the air (N2)

• Plants can only use nitrogen (generally) when it is in the form of:

• Nitrates (NO3-1)

• Nitrites (NO2-1)


Nitrogen Cycle: Nitrogen Fixing Nitrogen Fixing: To combine nitrogen.

• Lightning: Whenever there is lightning nitrates (NO3

-1) are formed.

• Nitrogen Fixing Bacteria: A type of bacteria that forms ammonia (NH3) from pure nitrogen (N2). 3 H2 + 2 N2 ---> 2 NH3

• Legumes: A type of plant that has colonies of nitrogen fixing bacteria in their roots. Most beans and peas are legumes along with some woody plants.

Decomposers: a by-product of decomposition is ammonia (NH3).


Nitrogen Cycle:

Nitrogen

Fixing Denitrifying

Bacteria


Nitrogen Cycle: Denitrifying

Denitrifying: to change ammonia (NH3) to nitrogen (N2).

• Denitrifying Bacteria: changes ammonia in the ground to nitrogen gas.

Nitrification Bacteria: changes ammonia (NH3) to nitrates (NO3

-1) and nitrites (NO2-1).

• Plants use nitrates and nitrites to form proteins.

• Animals eat proteins and urinate ammonia (NH3).


Nitrogen Cycle: Atmosphere

Lightning Fixes Nitrogen to form ammonia

NH3

Denitrifying Bacteria

Denitrifying Bacteria changes ammonia to Nitrogen (N2)

N2

Next Slide


Nitrogen Cycle:Plants and Mammals Assimilation: plant roots and algae absorb

nitrate and ammonia incorporate the nitrogen into proteins and nucleic acids.

Ammonification: conversion of biological nitrogen compounds into ammonia. • Sources include:

• waste products urea (in urine)

• uric acid (from birds)

• ammonia from decomposing organisms


Nitrogen Cycle Handout

Nitrogen Fixing

BacteriaLegumesDecomposers

Nitrification

Bacteria


Nitrogen Cycle:Animal-Plant Cycle

Nitrification

BacteriaNitrates (NO3

-1)

Nitrites (NO2-1)

Plants use nitrates to form proteinsAnimals eat proteins

and urinate ammonia

NH3

Nitrification Bacteria takes ammonia and produce nitrates and nitrites

Decomposers

Next Slide


Nitrogen Cycle Diagram


Nitrogen Cycle Handout

Urine

Proteins

Animals

Fertilizers


Phosphorous Cycle Phosphorous is necessary for all life.

• Phosphorous is another element that plants need to grow.

• Phosphorous is the typically the second most needed mineral for plants (after nitrates and nitrites).

Unlike nitrogen, phosphorous is not found in the atmosphere.• Herbivores get phosphorous by eating plants.• Carnivores get phosphorous by eating herbivores.


Forms of Phosphorous

Phosphorous: Three Forms:• Element: P

• Inorganic Phosphate: PO4-3

• Organic Phosphorous: Water soluble


Sources of Phosphorous

Guano (fecal material) Phosphate detergents Human waste Fertilizer Industrial wastes Phosphate mining


Sources of Phosphorous


Phosphorous Cycle: Handout

Guano


Phosphorous Cycle

Most phosphorous is stored in the bottom of lakes and oceans.

Marine protozoa's are the main source of phosphate in rocks.

Soils can only contain a limited amount of phosphates.

Shown to be an important factor for Eutrophication.• Eutrophication: The filling in of bodies of water

with sediment and mud over time.


Phosphorous Cycle: Diagram


Phosphorous Cycle: Diagram2


Phosphorous Cycle: Diagram 3


Phosphorous Cycle: Handout

Erosion

Phosphate Rocks

Phosphate

Mining

Fertilizer

ManureSoil Phosphates

Animals

Crops


Phosphorous Cycle: HandoutDissolved Phosphates

AlgaeMarine Sediments

Excretion and Decomposition


Phosphorous Cycle Handout


Chemical Riddle

Cycle me, cycle me, you know whereInto the oceans and through the airAnd if you don't cycle me in the right placeI'll weed up your rivers and eutroph your lakes

What element am I?


Sulfur Cycle

Major Components• Assimilative reduction

• Release of -SH

• Oxidation of H2S

• Dissimilative reduction

• Anerobic oxidation


Sulfur Cycle


Section 4.4 Review


Matter and Energy in the Ecosystem 4.1 Roles of Living Things 4.2 Ecosystem Structure 4.3 Energy in the Ecosystem 4.4 Cycles of Matter

Updated 10-29-01(c) Tim Bass1 Matter and Energy in the Ecosystem Environmental Science Chapter 4 Mr....

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