This page will serve as an index for many ecological issues.

Chapter 3 – The Biosphere

Ecology deals with interactions among organisms as well as interactions among organisms and their environment.

Biosphere – includes the land, water and air in which life exists

            Interactions in the biosphere create interdependence among organisms

Levels of organization

Simplest--------------------------------------------------------------------àMost Complex

       Species          Population         Community         Ecosystem          Biome

A group of organisms that are similar and are able to reproduce are known as a SPECIES.

Organisms that belong to the same species and live in the same area make up a POPULATION.

Populations that interact and live together in a specific area create a COMMUNITY.

All of the organisms and nonliving factors in a specific place make up an ECOSYSTEM.

A BIOME includes all the ecosystems that have the same climate and similar communities.

Energy Flow

            In order for life to exist and organisms to carry out life functions there must be an energy source

Since energy is not created, nor destroyed, energy must be transferred from one organism to another within the biosphere.

Organisms that can transfer inorganic raw materials into organic, usable energy are known as AUTOTROPHS (producers)

            Energy from the sun is converted into usable energy for that organism

            These organisms make their own food!

During PHOTOSYNTHESIS, light energy, CO₂ and water is converted into energy rich carbohydrates

            This process adds O₂ to the atmosphere.  O₂ is a waste product in this process.

During CHEMOSYNTHESIS, autotrophs that live in the absence of light produce carbohydrates (energy) by breaking chemical bonds

            Such organisms include bacteria living on the deep ocean floor, volcanic vents, or even in dark caves in Belize.

Some organisms acquire energy by consuming other organisms, they are known as HETEROTROPHS (consumers)

a.       herbivores

b.      carnivores

c.       omnivores

d.      decomposers

Energy stored by autotrophs can be passed on through the ecosystem along a food chain

            Food chains are simple and are linear.

Food Webs are more complex and realistic in the always changing environment.  Food webs link food chains in an ecosystem together.

Cycles of Matter

Unlike the unidirectional flow of energy, matter is recycled throughout different ecosystems

The Water Cycle – Where does the water come from?

            Evaporation

            Transpiration

            Condensation

            Precipitation

                        Runoff

                        Seepage

The Carbon Cycle – Carbon is an important ingredient in living tissue

            Carbon is transferred throughout the biosphere in many different phases

                        In the atmosphere – gas

                        In the ocean – dissolved in the water

                        On land – in solid and liquid form

The Nitrogen Cycle – All organisms need nitrogen in order to make proteins (one of the organic molecules)

            Nitrogen Gas makes appox. 78% of the Earth’s Atmosphere

                        Only certain types of bacteria can use this form of nitrogen directly

            Nitrogen Fixation – the process of converting nitrogen gas into ammonia

                        Other bacteria use the ammonia to convert it into Nitrates and Nitrites, which are then used by autotrophs to make proteins. 

Chapter 4 – Ecosystems and Communities

The temperature within the biosphere remains with a range suitable for life to exist.  The atmosphere is the natural insulating blanket that makes this possible.

                        Carbon Dioxide

                        Water Vapor

                        Methane

The Greenhouse Effect – the natural situation in which heat is retained by a layer of greenhouse gases

            The solar energy is able to pass into the atmosphere in the form of sunlight.  The gases do not let the energy to leave the atmosphere as easily, therefore heat gets trapped inside the Earth’s atmosphere. 

Biotic and Abiotic factors in an Ecosystem

            Living and nonliving influence in an ecosystem

Biotic Factors   Interactions among living organisms            - Food webs

Abiotic Factors   Non-living factors that shape an ecosystem -          Climate of an area -          Temperature -          Precipitation -          Sunlight -          pH

An organism’s HABITAT is the place in which it lives in the environment (address)

The NICHE is the role of the species in the environment (occupation)

Community Interactions – organisms constantly interact in ecological communities

            These interactions shape the community

P92 to be continued…

Biology Extra Credit Worksheet - (Only complete pages 1 and 2)

Biomes – Internet Lesson

ECOLOGY POWER POINT PRESENTATION

1. Science Movies
Summary: This webpage contains interactive movies about deserts, atmosphere, food chains, land biomes, ozone, tundra and underwater biomes.

BIOMES

1. URL: http://ths.sps.lane.edu/biomes/
Summary: This webpage is includes information on Marine, Tundra, Desert, Savannah, Grassland, Tropical Rain Forest, Deciduous Forest, and the Coniferous Forest also known as the Taiga. Each biome is described by the climate, health issues, animals & vegetation the inhabit each region.

FOOD WEB

To find out population statistics click

Principles of Ecology Quiz

1. Why are tropical forests important? answer

2. What are PCBs? answer

3. Is the world getting warmer? answer

4. What is the status of elephants in Africa?answer

5. What is a biome? answer

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