Core Case Study: Tropical Rain Forests Are Disappearing Cover about 2% of the earth’s land surface Contain about 50% of the world’s known plant and

Core Case Study: Tropical Rain Forests Are Disappearing

Cover about 2% of the earth’s land surface

Contain about 50% of the world’s known plant and animal species

Disruption will have three major harmful effects Reduce biodiversity Accelerate global warming Change regional weather patterns

Natural Capital Degradation: Satellite Image of the Loss of Tropical Rain Forest

Fig. 3-1a, p. 54

The Earth’s Life-Support System Has Four Major Components

Atmosphere Troposphere: where weather happens Stratosphere: contains ozone layer

Hydrosphere

Geosphere

Biosphere

Fig. 3-2, p. 56

Soil

Biosphere (living organisms)

Atmosphere

RockCrust

Mantle

Geosphere (crust, mantle, core)Mantle

Core Atmosphere (air)

Hydrosphere (water)

© 2012 John Wiley & Sons, Inc. All rights reserved.

Overview of Chapter 3

What is Ecology? The Energy of Life

Laws of Thermodynamics Photosynthesis and Cellular Respiration

Flow of Energy Through Ecosystems Producers, Consumers & Decomposers Ecological Pyramid Ecosystem Productivity


Ecology

I. What is Ecology?A. Ernst Haeckel developed the concept of ecology

in the 19th century

i. Ecology literally means “the study of one’s house”; it is the broadest field within the biological sciences , and is linked to many other disciplines (i.e., geology, earth science, chemistry, physics)


Ecology

ii. It examines the systems that include interactions among organisms and between organisms and their abiotic environment

1. The biotic environment includes all living organisms

2. The abiotic environment includes living space, temperature, sunlight, soil, wind and precipitation


Major Biotic and Abiotic Components of an Ecosystem

Fig. 3-6, p. 59



Ecology

Ecologists are most interested in the levels of biological organization that include or are above the level of the individual organism.


Ecology cont…..

i. A group of similar organisms whose members freely interbreed with one another in the wild to produce fertile offspring is termed a species

ii. A population is a group of organisms of the same species that live in the same area at the same time

iii. A natural association that consists of all the populations of different species that live and interact within an area at the same time is called a community.

iv. A community and its physical environment comprise an ecosystem

1. An ecosystem is a system in which all of the biological, physical, and chemical components of an area form a complex, interacting network of energy flow and materials cycling

2. Ecosystem processes collectively regulate global cycles of water, carbon, nitrogen, phosphorus, and sulfur essential to the survival of humans and all other organisms

© 2012 John Wiley & Sons, Inc. All rights reserved.Fig. 3-5, p. 58

Parts of the earth's air, water, and soil where life is found

Biosphere

A community of different species interacting with one another and with their nonliving environment of matter and energy

Ecosystem

Populations of different species living in a particular place, and potentially interacting with each other

Community

Population A group of individuals of the same species living in a particular place

Organism An individual living being

The fundamental structural and functional unit of life

Cell

Chemical combination of two or more atoms of the same or different elements

Molecule

Smallest unit of a chemical element that exhibits its chemical properties

Atom


Solar energyChemical nutrients

(carbon dioxide, oxygen, nitrogen,

minerals)

Heat

Heat Heat

Decomposers (bacteria, fungi)

Producers (plants)

Consumers (plant eaters, meat eaters)

Heat Heat


Ecology cont…..

C. Landscape ecology is a subdiscipline of ecology

i. It studies ecological processes that operate over large areas

ii. A landscape is a region that includes several interacting ecosystems


Ecology

D. Ecologists who study the biosphere examine global interrelationships among Earth’s atmosphere, land, water, and organisms

i. The parts of Earth’s atmosphere, ocean, land surface, and soil that contain all living organisms is termed the biosphereii. The atmosphere is a gaseous envelope surrounding Earthiii. The hydrosphere is Earth’s supply of wateriv. The lithosphere is the soil and rock of Earth’s crust


Energy

II. The Energy of Life

A. Energy is the capacity or ability to do work

i. Energy exists in several forms: chemical radiant, thermal, mechanical, nuclear, and electrical

ii. Energy can exist as stored energy (potential) or as the energy of motion (kinetic)


Energy

B. The study of energy and its transformations is called thermodynamics i. In thermodynamics, the word system is used to refer to a group of atoms, molecules, or objects being studied

1. A closed system is self-contained and isolated; it does not exchange energy with its surroundings2. An open system exhibits an exchange of energy with its surroundings


Thermodynamics

ii. The first law of thermodynamics holds that energy cannot be created or destroyed, although it can change from one form to anotheriii. The second law of thermodynamics holds that when energy is converted from one form to another, some of it is degraded into heat, a less usable form that disperses into the environment

1. The less usable energy is more diffuse, or disorganized; entropy is a measure of this disorder or randomness

2. No process requiring an energy conversion is ever 100% efficient because much of the energy is dispersed as heat, resulting in an increase in entropy


Photosynthesis

6 CO6 CO2 2 + 12 H+ 12 H22O + radiant energyO + radiant energy

CC66HH1212OO66 + 6 H + 6 H22O + 6 OO + 6 O22

i. Photosynthesis is the biological process in which light energy from the sun is captured and transformed into the chemical energy of carbohydrate (glucose) molecules2. bacteria, and algae perform photosynthesis

1.


Cellular Respiration

CC66HH1212OO66 + 6 + 6 OO2 2 + 6 H+ 6 H22OO

6 CO6 CO22 + 12 H + 12 H22O + energyO + energy

ii. The chemical energy that plants store in carbohydrates and other molecules is released within cells of plants, animals, or other organisms through cellular respiration1. In aerobic cellular respiration, molecules such as glucose are broken down in the presence of oxygen and

water a. C6H12O6 +6O2 + 6H2O --> 6CO2 + 12H2O + energy2. Anaerobic bacteria that live in waterlogged soil, stagnant ponds, or animal intestines respire in the absence of oxygen


Photosynthesis and Cellular Respiration


Other Type of Respiration

D. Chemosynthesis is the process by which energy produced from inorganic raw materials such as enzymes, hydrogen sulfide and oxygen; water and sulfur/sulfate are additional byproducts


Food Chains- The Path of Energy Flow

III. The Flow of Energy Through Ecosystems A. Energy flow is the passage of energy in a one-

way direction through an ecosystem B. Producers, consumers, and decomposers


Food Web


Producers

i. Producers (aka autotrophs) 1. In photosynthesis, producers use the energy

from sunlight to make organic molecules from carbon dioxide and water

2. Plants, algae and certain types of bacteria are important producers


Consumers

ii. Consumers (aka heterotrophs) 1. Consumers obtain energy when they eat

producers or other consumers a. Consumers that eat producers are primary consumers

(herbivores) b. Secondary consumers (carnivore) eat primary

consumers c. Tertiary consumers (top carnivores) eat secondary

consumers 2. Omnivores eat a variety of organisms 3. Detritus feeders (detritivores) consume organic

matter that includes animal carcasses, leaf litter, and feces


Decomposers

iii. Decomposers (aka saprotrophs) 1. Wastes and dead organic material from

producers and consumers supply decomposers (i.e., bacteria, fungi) with energy

2. Bacteria and fungi are important decomposers


Path of Energy Flow

C. The path of energy flow: who eats whom in ecosystems i. In an ecosystem, energy flow occurs in food

chains, in which energy from food passes from one organism to the next in a sequence 1. Energy enters ecosystems from an external source

(the sun), flows linearly, and exits as heat loss


Path of Energy Flow cont.

2. Each level in a food chain is termed a trophic level a. Producers (photosynthetic organisms) form the first

trophic level b. Primary consumers (herbivores) form the second

trophic level c. Secondary consumers (carnivores) form the third

trophic level d. Decomposers occur at every step in a food chain

ii. Simple food chains rarely occur in nature, a food web is a more realistic model


Ecological Pyramids

D. Ecological pyramids i. Ecological pyramids graphically represent the relative energy values of each trophic level

1. A pyramid of numbers show the number of organisms at each trophic level in a given ecosystem 2. A pyramid of biomass illustrates the total biomass at each successive trophic level

a. Biomass is a quantitative estimate of the total mass of living material

b. Biomass indicates the amount of fixed energy at a particular time 3. A pyramid of energy illustrates the energy content,

often expressed as kilocalories per square meter per year, of the biomass at each trophic level


Pyramid of Numbers

Illustrates the number of organisms at each trophic level Fewer organisms

occupy each successive level

Does not indicate: biomass of organisms

at each level amount of energy

transferred between levels


Pyramid of Biomass

Illustrates the total biomass at each successive trophic level

Biomass: measure of the total amt of living material

90% reduction in biomass through trophic levels


Pyramid of Energy

Illustrates how much energy is present at each trophic level and how much is transferred to the next level

Most energy dissipates between trophic levels

Explains why there are so few trophic levels


Ecosystem Productivity

E. Gross Primary Productivity (GPP) Total amount of energy that plants capture and

assimilate in a given period of time Net Primary Productivity (NPP)

Plant growth per unit area per time Represents the rate at which organic material is

actually incorporated into the plant tissue for growth

GPP – cellular respiration = NPP Only NPP is available as food to organisms


Variation in NPP by Ecosystem


Human Impact on NPP

Humans represent 0.5% of land-based biomass, but use 32% of land-based NPP! This may contribute to loss of species (extinction)

This represents a threat to planet’s ability to support both human and non-human inhabitants

Documents

Core Case Study: Tropical Rain Forests Are Disappearing Cover about 2% of the earth’s land surface Contain about 50% of the world’s known plant and