Biology – Unit 2 Ecology. Opening Assignment: Explain in your own words what the term “ecology” means.

Biology – Unit 2Ecology

• Opening Assignment:

• Explain in your own words what the term “ecology” means.

Ecology- the study of how organisms interact with each other and with their environment

Part 1 – Lesson 3.1 What is Ecology?

Abiotic FactorsAbiotic factors- the nonliving parts of the environment.• They include:

• Sunlight• Water• Temperature• Wind• Soil type• The atmosphere

• The types and amounts of abiotic factors that are available in an ecosystem help determine which organisms can live there.

Biotic Factorsbiotic factors- all the living things or once-living things in an environment.• Ex:

• Animals• Plants• Bacteria• Fungi

Organization In The EnvironmentThe biosphere consists of all life on Earth and all parts of the Earth in which life exists, including land, water, and the atmosphere.

Biome — a geographic area that contain groups of ecosystems with similar biotic and abiotic features.

• Terrestrial (land) Biomes include:• Forests• Deserts• Tundra• Grasslands

• Aquatic Biomes include:• Marine• Freshwater (rivers & lakes)• Estuaries

Ecosystem—all the organisms that live in a place, together with their physical environment(abiotic factors)

• The types and amounts of abiotic factors that are available in an ecosystem help determine which organisms can live there

Community—All the populations of species that live in the same area and interact

Population-a group of individuals that belong to the same species and live in the same area

Organism- any unicellular or multicellular form exhibiting all of the characteristics of life, an individual

Part 1 – Lesson 3.2 Energy, Producers, and Consumers

• All Life on Earth needs energy for cell processes.

• For most life on Earth, sunlight is the ultimate energy source.

• Organisms get energy by using light or chemical energy to make food or by eating other organisms

PRODUCERS• Producers change the energy available in their

environment into food energy. • They make their own food (autotrophs)

• Plants, algae, and some microorganisms use a chemical process called photosynthesis to change light energy into chemical energy (Glucose)

• This process adds oxygen to the atmosphere and removes carbon dioxide.

Producers That Use Sunlight

cyanobacteria

Algal colony

phytoplankton

Plants & Trees

Life Without Light• Biologists have discovered thriving

ecosystems around volcanic vents in total darkness on the deep ocean floor.

• Deep-sea ecosystems depend on primary producers that harness chemical energy from inorganic molecules such as hydrogen sulfide.

• The use of chemical energy to produce carbohydrates is called chemosynthesis. giant tube worms

live in symbiosis with the chemosynthetic bacteria

Consumers

• Consumers- organisms that cannot make their own food and get their energy from eating other organisms. (heterotrophs)

• Producers and Consumers use the chemical process of Cellular Respiration to break down food in the presence of oxygen to produce energy.

Types of Consumers

• Consumers are classified by the ways in which they acquire energy and nutrients.

• Herbivores-obtain energy and nutrients by eating plant leaves, roots, seeds, or fruits.

Types of Consumers

Carnivores- kill and eat other consumers

Types of Consumers

• Decomposers-such as bacteria and fungi, feed by chemically breaking down organic matter.

• The decay caused by decomposers is part of the process that produces detritus—small pieces of dead and decaying plant and animal remains.

• Decomposers that live on, and in, detritus particles are called Detrivores.• They feed on detritus particles,

often chewing or grinding them into smaller pieces. Ex: giant earthworms

Opening Assignment:

• List the levels of organization of life.

• Explain the difference between biotic and abiotic factors in ecosystems and give 3 examples of each.

• Each time one organism eats another organism, a transfer of energy occurs

• Food chain- models how energy flows in an ecosystem through feeding relationships.

Part 2 – Lesson 3.3 Energy Flow in Ecosystems

Food Webs Food web- links all of the food chains in an ecosystem together.

• It shows many feeding relationships that are possible in an ecosystem

An example of a food web in the Everglades is shown.

Trophic Levels and Energy Pyramids

• Each step in a food chain or food web is called a trophic level.

• Primary producers always make up the first trophic level.

• Various consumers occupy every other level

• Energy pyramids- show the amount of food energy available at each trophic level

Trophic Levels and Energy Pyramids

• Energy pyramids- show the amount of food energy available at each trophic level

• Each time energy is transferred from one organism to another, lost and less energy is available at the next trophic level.

Trophic Levels and Energy Pyramids

• Energy is lost: as heat through cellular respiration.

o this energy is used to carry out functions of living things such as producing new cells, regulation of body temperature, and moving around

Trophic Levels and Energy Pyramids

• The remaining 10% of the energy becomes part of the organism’s body and is stored in its molecules.

• This 10% is available to the next trophic level when one organism consumes another organism

Part 2 – Lesson 3.4 Cycles of Matter• Learning Goals: Students will be able to . . • Identify and describe the flow of nutrients in

each biogeochemical cycle. • Explain the impact that humans have on the

biogeochemical cycles.

• http://www.youtube.com/watch?v=09_sWPxQymA

Two Secrets of Survival: Energy Flow and Matter Recycle

• An ecosystem survives by a combination of energy flow and matter recycling.

Figure 3-14

MATTER CYCLING IN ECOSYSTEMS

• Nutrient Cycles: Global Recycling• Global Cycles recycle nutrients through the earth’s air,

land, water, and living organisms.• Nutrients are the elements and compounds that

organisms need to live, grow, and reproduce.• Biogeochemical cycles move these substances

through air, water, soil, rock and living organisms.

What Sustains Life on Earth?

• Solar energy, the cycling of matter, and gravity sustain the earth’s life.

Figure 3-7

Fig. 3-26, p. 72

PrecipitationPrecipitation

Transpiration

Condensation

Evaporation

Ocean storage

Transpiration from plants

Precipitation to land

Groundwater movement (slow)

Evaporation from land Evaporation

from ocean Precipitation to ocean

Infiltration and Percolation

Rain clouds

RunoffSurface runoff

(rapid)

Surface runoff (rapid)

The Water Cycle

Effects of Human Activities on Water Cycle

• We alter the water cycle by:• Withdrawing large amounts of freshwater.• Clearing vegetation and eroding soils.• Polluting surface and underground water.• Contributing to climate change.

The Carbon Cycle

1. Plants remove carbon dioxide from the air. 2. When the plants died, they were buried in the earth. 3. After millions of years, their remains turned into coal and oil. 4. People mine the earth for coal and oil, which are called

"fossil fuels". 5. When people burn fossil fuels, they send carbon dioxide and

other greenhouse gases into the air.

Effects of Human Activities on Carbon Cycle

• We alter the carbon cycle by adding excess CO2 to the atmosphere through:• Burning fossil fuels.• Clearing vegetation

faster than it is replaced.

Figure 3-28

The Nitrogen Cycle

• This picture shows the flow of the nitrogen cycle. The most important part of the cycle is bacteria. Bacteria help the nitrogen change between states so it can be used. When nitrogen is absorbed by the soil, different bacteria help it to change states so it can be absorbed by plants. Animals then get their nitrogen from the plants.

Steps in the Nitrogen cycle1. Fixation - Fixation is the first step in the process of making

nitrogen usable by plants. Here bacteria change nitrogen into ammonium.

2. Nitrification - this is the process by which ammonium gets changed into nitrates by bacteria. Nitrates are what the plants can then absorb.

3. Assimilation - This is how plants get nitrogen. They absorb nitrates from the soil into their roots. Then the nitrogen gets used in amino acids, nucleic acids, and chlorophyll.

4. Ammonification - This is part of the decaying process. When a plant or animal dies, decomposers like fungi and bacteria turn the nitrogen back in ammonium so it can reenter the nitrogen cycle.

5. Denitrification - Extra nitrogen in the soil gets put back out into the air. There are special bacteria that perform this task as well.

Fig. 3-31, p. 77

Dissolvedin Ocean

Water

Marine Sediments Rocks

uplifting overgeologic time

settling out weatheringsedimentation

LandFoodWebs

Dissolvedin Soil Water,Lakes, Rivers

death,decomposition

uptake byautotrophs

agriculture

leaching, runoff

uptake byautotrophs

excretion

death,decomposition

mining Fertilizer

weathering

Guano

MarineFoodWebs

The Phosphorous Cycle

Steps of the Phosphorous Cycle

• 1. Phosphate is released by the erosion of rocks.2. Plants and fungi take up the phosphate with their roots.3. Phosphorus moves from producers to consumers via food chain.4. Phosphorus may seep into groundwater from soil, over time forming into rock.5. When these rocks erode, the cycle begins again.

Effects of Human Activities on the Phosphorous Cycle

• We remove large amounts of phosphate from the earth to make fertilizer.

• We reduce phosphorous in tropical soils by clearing forests.

• We add excess phosphates to aquatic systems from runoff of animal wastes and fertilizers.

Fig. 3-32, p. 78

Hydrogen sulfide

Sulfur

Sulfate salts

Decaying matter

Animals

Plants

Ocean

IndustriesVolcano

Hydrogen sulfideOxygen

Dimethyl sulfide

Ammoniumsulfate

Ammonia

Acidic fog and precipitationSulfuric acid

WaterSulfurtrioxide

Sulfur dioxide

Metallicsulfidedeposits

The Sulfur Cycle

The Sulfur Cycle

The Steps of the Sulfur Cycle

1. Mineralization of organic sulfur into inorganic forms, such as hydrogen sulfide (H2S), elemental sulfur, as well as sulfide minerals.

2. Oxidation of hydrogen sulfide, sulfide, and elemental sulfur (S) to sulfate (SO4

2–).3. Reduction of sulfate to sulfide.4. Incorporation of sulfide into organic

compounds (including metal-containing derivatives).

Effects of Human Activities on the Sulfur Cycle

• We add sulfur dioxide to the atmosphere by:• Burning coal and oil• Refining sulfur containing petroleum.• Convert sulfur-containing metallic ores into free

metals such as copper, lead, and zinc releasing sulfur dioxide into the environment.