Ecology: Study of how organisms

interact with each other and with their

non-living surroundings.

Eco - is from the Greek word “Oikos” for

house

Levels of organization in nature.

The shaded portion is the five

levels that ecology is based upon.

The

Nature of

Ecology

Levels of study in Ecology:

Organisms – single animal

Populations – same species

Communities – pop’ns living

together

Ecosystems – community +

physical environment

Biosphere – all the earth’s

ecosystems

1. Abiotic factors –consists of non-living

components such as water, air, nutrients,

rocks, heat, and solar energy.

2. Biotic factors – consists of living biological

components such as plants, animals, and

microbes.

1. Producers (autotrophs)

2. Consumers (heterotrophs)

Producers (autotrophs)

- they make the nutrients they need from compounds and energy obtained from their environment

On land – producers are green plants

On fresh water or marine – algae and aquatic plants

On open water – major producers are phytoplankton

Consumers (heterotrophs)- These cannnot produce the nutrients they need through

photosysnthesis or other processes.

* Types of Consumers

• 1. Primary Consumer

• (Herbivores) – plant eaters or animals that eat producers, feeding mostly on green plants.

• (Carnivores) – animals that feed on the flesh pf other animals.

• 2. Secondary Consumer – feed the flesh of the Herbivores.

• 3. Tertiary Consumer – feed on flesh of other carnivores.

• 4. Omnivores – can eat plants and other animals.

Decomposers – consumers that release

nutrients from the dead bodies of plants and

animals and return them to soil, water, and

air for re-use by producers.

Detritus feeders / detrivores – feed on the

wastes or dead bodies of other organisms

Food chains – sequence of organisms

which is a source of food for the next.

Food webs – most species participate in

several food chains (they don’t just eat

one thing!).

Trophic levels

› each step in the flow of energy through an

ecosystem (feeding level)

Pyramid of

energy flow

Ecological

efficiency

Pyramid of

biomass

Pyramid of

numbers

reality

tends to be

more

complex

than a

linear food

chain

1. Atmosphere (Air)

2. Geosphere (Rock, Soil, Sediment)

3. Hydrosphere (Water)

4. Biosphere (Living Things)

1. Atmosphere

- thin spherical envelope of gases surrounding the earth’s surface.

* Layers of Atmosphere:› Troposphere 11 miles above sea level Contains majority of air we breathe (78%v Nitrogen, 21%v

Oxygen, 1%v Water Vapor, Carbon Dioxide and Methane known as Greenhouse gases.Greenhouse gases – absorb and release energy that warms the lower atmosphere.

› Stratosphere 12-30 miles above sea level Lower portion holds ozone layer which filters out harmful UV

radiation. Allows life to exist on earth

1. Hydrosphere

- Consists of all water on or near the earth’s surface.

- Oceans covers 71% of the globe and contain 97% of the earth’s water.

* Compostion:› Liquid Water On the surface and underground

› Ice Polar ice, icebergs, and permafrost (ice in frozen soil)

› Water Vapor

1. Geosphere (land sphere)

- Upper portion contains non-renewable resouces

(fossil fuels, and minerals) and renewable

resources (soil chemicals organisms need to live,

grow, and reproduce.

* Compostion:› Core

› Mantle

› Crust

1. Biosphere

- consist of the parts of atmosphere, hydrosphere,

and geosphere where life is found.

Life is sustained by the flow of energy

from the sun through the biosphere,

the cycling of nutrients within the

biosphere, and gravity.

1. One-way flow of energy from Sun

2. Cycling of crucial elements

3. Gravity

As greenhouse gasses

increase, temperature of

troposphere increases.

Biogeochemical cycles – global cycles

recycle nutrients through the air, land

and water

Cycles are driven directly or indirectly by

solar energy and gravity

Hydrologic cycle (H2O)

Carbon cycle

Nitrogen cycle

Phosphorus cycle

Hydrologic cycle – collects, purifies, and

distributes supply of water.

Hydrologic Cycle can be viewed as a

cycle of natural renewal of water quail

Water withdraw from lakes and streams

Clear vegetation

Construct impervious surfaces

Modify water quality by adding nutrients

Based on Carbon Dioxide

Terrestrial producers remove

CO2 from the air; aquatic

producers remove it from the

water.

Through photosynthesis,

Converts to carbohydrates.

O2 consuming producers

respire,breaking carbo-

hydrates back to CO2.

CO2 not released until burned.

Clear trees and other plants, often times

permanently

Burning fossil fuels and wood

Increased CO2 in the troposphere

enhance natural greenhouse effect

Results in global warming

Atmosphere’s most abundant

element.

Bacteria help recycle nitrogen.

Nitrogen cannot be used by plants

and animals without bacteria’s help.

Ammonia not taken up by plants

Toxic to plants

Usable by plants

Waterlogged

soil

Add large amounts of nitric oxide by burning fuel

Gas converted to nitrogen dioxide gas and nitric acid (acid rain)

Add nitrous oxide through anaerobic bacteria breaking down livestock wastes (global warming).

Release nitrogen stored in soils and plants by destroying forests, grasslands and wetlands.

Add excess nitrates for agriculture Remove nitrogen from topsoils through

harvesting various crops

Fig. 4-33 p. 82

Slow

Bacteria not a major player

Washes from the land into

streams, then the sea.

Can be deposited as sediment

and remain for millions of

years.

Often a limiting factor for

plant growth on land.

Also limits growth in lakes

And streams because

phosphate salts are only

slightly soluble in water.

We mine large quantities of phosphate

rock to make inorganic fertilizers.

We reduce the available phosphate in

tropical soils by clearing tropical forests.

We disrupt aquatic systems with

phosphates from runoff of animal wastes

and fertilizers, and sewage systems.

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