Ecosystems: What Are They and How Do They Work?Ecosystems: What Are They and How Do They Work?

G. Tyler Miller’sLiving in the Environment

14th EditionModified By Mr. Manskopf

Chapter 4

G. Tyler Miller’sLiving in the Environment

14th EditionModified By Mr. Manskopf

Chapter 4

Key ConceptsKey Concepts

Basic ecological principlesBasic ecological principles

Major components of ecosystemsMajor components of ecosystems

Matter cycles and energy flowMatter cycles and energy flow

Ecosystem studiesEcosystem studies

Principles of SustainabilityPrinciples of Sustainability

Section 1: The Nature of EcologySection 1: The Nature of Ecology

• What is ecology?

• What species rule the world?

• What is population and levels of organization of matter in nature?

• What are communities and ecosystems?

What is ecology?What is ecology?

Ecology: is the study of how organisms interact with another and the nonliving world.

• Connections in nature

Organism: any form of life

Cell: basic unit of life

Eukaryotic: nucleus/organelles

Prokaryotic: bacteria/algae

What is ecology?What is ecology?

Species: groups of organisms that resemble each other in appearance, behavior, chemistry and genetic makeup…able to reproduce

• 3.6 to 100 million species (1.4 identified)

• Mostly insects/micro• Tropical forests

Insects751,000

Protists57,700

Plants248,400

Prokaryotes4,800

Fungi69,000

Other animals281,000

Known species1,412,000

What species rule the world?What species rule the world?

• What types of organisms do you think your body contains billions of?

Hint: they can be both very important to your survival or make you ill.

What species rule the world?What species rule the world?

Microbes (bacteria, protozoa, fungus, yeast) rule the world.

• Malaria

• Germs

• Good versus bad microbes

• Help keep us alive

What are levels of organization in natureWhat are levels of organization in nature

Ecology focuses on 5 levels of organization in nature:

1) Organisms

2) Populations

3) Communities

4) Ecosystems

5) Biosphere

The Nature of EcologyThe Nature of Ecology

Ecosystem organizationEcosystem organization

OrganismsOrganisms

PopulationsPopulations

CommunitiesCommunities

EcosystemsEcosystems

BiosphereBiosphereFig. 4-2 p. 57Fig. 4-2 p. 57

Section 2: The Earth’s Life Support SystemsSection 2: The Earth’s Life Support Systems

• What are the major parts of earth’s life-supporting systems?

• How does the sun sustain life of earth?

Earth’s Life Supporting SystemsEarth’s Life Supporting Systems

The Earth is made up of interconnected spherical layers that contain:

• Air• Water• Soil• Minerals• Life

All parts are interconnected and the goal is to understand how they all interact.

The Earth’s Life-Support SystemsThe Earth’s Life-Support Systems

TroposphereTroposphere

StratosphereStratosphere

HydrosphereHydrosphere

LithosphereLithosphere

BiosphereBiosphereFig. 4-7 p. 60

Natural Capital: Sustaining Life of EarthNatural Capital: Sustaining Life of Earth

Solar energy, the cycling of matter and nutrients, and gravity all sustain life on earth as we know it.

KEY IDEA: remember energy and matter can not be created or destroyed.

Natural Capital: Sustaining Life of EarthNatural Capital: Sustaining Life of Earth

One-way flowof energy from Sun

One-way flowof energy from Sun

Cycling ofCrucial Elements

Cycling ofCrucial Elements

Gravity Gravity

Fig. 4-8 p.60

Solar Capital: Flow of Energy to and from the EarthSolar Capital: Flow of Energy to and from the Earth

Gigantic nuclear fusion 93 million miles away sustains life.•One-billionth of sun’s energy reaches earth.

•Energy in MUST equal energy out…WHY?

Section 3: Ecosystem ComponentsSection 3: Ecosystem Components

• What are the major components of ecosystems?

• What are tolerance limits?

• What factors limit population growth?

• What are producers, consumers, decomposers and what role do they play in ecosystems?

• What is biodiversity?

Life on Land and SeaLife on Land and Sea

Biomes: land portions of the biosphere…

• Forests, deserts, grasslands, tundra classified by climate and species adapted to it.

Aquatic Life Zones: watery parts of biosphere…

• Fresh water (lakes, streams, etc.)

• Marine Life Zones (coral reefs, deep ocean, etc.)

Natural Capital: Major BiomesNatural Capital: Major Biomes

Biomes Biomes

Fig. 4-10 p. 62Fig. 4-10 p. 62

Role of climate

Role of climate

Aquatic life zones

Aquatic life zones

Ecosystem FactorsEcosystem Factors

Abiotic factorsAbiotic factorsBiotic factorsBiotic factors

Range of toleranceRange of toleranceLimiting factorsLimiting factors

Availability of matter and energy resources can limit organisms population.

Ecosystem FactorsEcosystem Factors

Limiting Factor Principle: too much or too little of any abiotic factor can limit or prevent growth of a population, even if all other factors are near or above optimum.

• Why are there no citrus fruit growing in NJ?

• Why do trees grow toward the sky?

Major Biomes found across the US at 390 North Latitude.

Major components of a freshwater ecosystemMajor components of a freshwater ecosystem

Major components of a field ecosystemMajor components of a field ecosystem

What are the biotic and abiotic factors?

What might some limiting factors be?

Major components of a marine ecosystem Major components of a marine ecosystem

Limiting factors

may include:

•Salinity

•Ph

•Sunlight

•Dissolved oxygen

•Temperature

Components of EcosystemsComponents of Ecosystems

Producers(autotrophs)

Producers(autotrophs)

Photosynthesis Photosynthesis

Consumers(heterotrophs)

Consumers(heterotrophs)

Aerobicrespiration

Aerobicrespiration

Decomposers Decomposers Fig. 4-17 p. 67Fig. 4-17 p. 67

Abiotic chemicals Abiotic chemicals

Photosynthesis: Producers Photosynthesis: Producers

CO2 + H2O + Solar Energy >>> Glucose + Oxygen

6CO2 + 6 H2O + Solar Energy >>> C6H12O6 + 6O2

Detritus Feeders (Detritivores)no waste in natural ecosystems Detritus Feeders (Detritivores)no waste in natural ecosystems

Aerobic Respiration Aerobic Respiration Glucose + Oxygen >>> Carbon Dioxide + Water + Energy

C6H12O6 + 6O2 >>> 6CO2 + 6H2O + energy

What is Biodiversity?What is Biodiversity?

Genetic diversityGenetic diversity

Species diversitySpecies diversity

Ecological diversityEcological diversity

Many scientists feel the loss of biodiversity is the greatest threat humans face.

Importance of BiodiversityImportance of Biodiversity

• http://www.undp.org/biodiversity/biodiversitycd/bioImport.htm

Extinctions…Extinctions…

• Extinction occurs when there are no longer any living individuals of a species left.

• There have been five periods of mass extinction's on earth 440m, 370m, 250m, 210m and 65m years ago.

• Scientists estimate that currently, living organisms represent only 1% of all the species that have ever been (i.e. 99% have been and gone)

Energy Flow in EcosystemsEnergy Flow in Ecosystems

There is a decrease in the amount of energy available to each succeeding organisms in a food chain or web.

• What does that mean?

• Where does the energy go?

Connections: Energy Flow in EcosystemsConnections: Energy Flow in Ecosystems

Trophic Levels: producer to primary consumer to secondary consumer and so on…

Trophic Levels: producer to primary consumer to secondary consumer and so on…

Food webs: real ecosystems are more complexas most consumers feed on more than one organism.

Food webs: real ecosystems are more complexas most consumers feed on more than one organism.

Food chains: the sequence of organisms food sources

Food chains: the sequence of organisms food sources

Trophic LevelsTrophic Levels

Primary consumer (herbivore)Primary consumer (herbivore)

Secondary consumer (carnivore)Secondary consumer (carnivore)

Tertiary consumerTertiary consumer

OmnivoreOmnivore

Detritivores and scavengersDetritivores and scavengers

DecomposersDecomposers

Connections: Food Chains and Energy Flow in EcosystemsConnections: Food Chains and Energy Flow in Ecosystems

Fig. 4-18 p. 68Fig. 4-18 p. 68

Ecological PyramidsEcological Pyramids

Pyramid ofenergy flow

Pyramid ofenergy flow

Ecologicalefficiency

Ecologicalefficiency

Pyramid ofbiomass

Pyramid ofbiomass

Pyramid ofnumbers

Pyramid ofnumbers 90% energy loss each step!

Ranges from 60 to 98% (90% is typical)

Primary Productivity of EcosystemsPrimary Productivity of Ecosystems

Estimated productivity per unit area of major ecosystems

Earth’s productivity: On land forests are highly productive in dark green, deserts least in brown. At sea, red indicates high productivity and deep oceans dark blue.

Productivity of EcosystemsProductivity of Ecosystems

The number of consumer organisms the earth can support is determined by how fast producers can supply them with energy.

Planet’s limiting factor

Productivity of EcosystemsProductivity of Ecosystems

Humans are using, wasting and destroying the world’s biomass faster than producers are able to make it.

• Habitat destructionClear Cut Forest in OR

Section 6: Soils Key IdeaSection 6: Soils Key Idea

Origins

Importance

Maturity and Horizons

Variations with Climate and Biomes

Variations in Texture and Porosity

Origins

Importance

Maturity and Horizons

Variations with Climate and Biomes

Variations in Texture and Porosity

What is Soil and Why Is It Important?What is Soil and Why Is It Important?

Soil is a thin layer over most land that is a complex mix of rock, nutrients, decaying matter, water, air and billions of organisms…many microscopic decomposers.

What is Soil and Why Is It Important?What is Soil and Why Is It Important?

• Renewable resource…SLOW

• Depends upon climate (1cm in 15yrs.)

• Basis of life

• Filters water

• Water storage

• Habitat

Soil ProfilesSoil Profiles

Mature Soil have a long time to form and are arranged into layers called horizons.

Simplified food web found in soils

Soil Horizons in Different Biomes

Soil Horizons in Different Biomes

Fig. 4-27, p. 75

Soil particles come in different textures…sand, clay, silt gravel

Section 7: Matter Cycling in EcosystemsSection 7: Matter Cycling in Ecosystems

Biogeochemical cycles Biogeochemical cycles

Group 1: Hydrologic cycle (H2O) Group 1: Hydrologic cycle (H2O)

Group 2: Carbon cycle Group 2: Carbon cycle

Group 4: Phosphorus cycle Group 4: Phosphorus cycle

Group 3: Nitrogen cycle Group 3: Nitrogen cycle

Group 5: Sulfur cycle Group 5: Sulfur cycle

Hydrologic (Water) Cycle: Group 1Hydrologic (Water) Cycle: Group 1

Fig. 4-28 p. 76

The Carbon Cycle (Marine): Group 2The Carbon Cycle (Marine): Group 2

Fig. 4-29, p. 78Fig. 4-29, p. 78

The Carbon Cycle (Terrestrial): Group 2The Carbon Cycle (Terrestrial): Group 2

Fig. 4-29, p. 78Fig. 4-29, p. 78

The Nitrogen Cycle: Group 3The Nitrogen Cycle: Group 3

Fig. 4-31 p. 80

The Phosphorus Cycle: Group 4The Phosphorus Cycle: Group 4

Fig. 4-33 p. 82

The Sulfur Cycle: Group 5The Sulfur Cycle: Group 5

Fig. 4-34 p. 83

How Do Ecologists Learn About Ecosystems?How Do Ecologists Learn About Ecosystems?

Field researchField research

Remote sensingRemote sensing

Geographic information systems (GIS)Geographic information systems (GIS)

Laboratory researchLaboratory research

Systems analysisSystems analysis

Geographic Information System (GIS) Geographic Information System (GIS)

Fig. 4-35 p. 84Fig. 4-35 p. 84

Systems AnalysisSystems Analysis

Fig. 4-36 p. 85Fig. 4-36 p. 85