Energy and Matter Exchange in the Biosphere

Unit A

What is the BIOSPHERE? Narrow zone of the planet that supports life

and living organisms within it Includes: ocean to lower atmosphere Not included: earths core and upper atmosphere

3 zones1. Lithosphere (land) 2. Hydrosphere (water) 3. Atmosphere (air)

Made up of living (biotic) and non living (abiotic) components

Ex. Biotic = plant and animals Abiotic = geological (rocks, minerals, land) and physical elements (temperature, precipitation, light, air, gas)

Organized into levels for study Closed system which means matter (nitrogen,

oxygen etc.) is not exchanged with surroundings it has to be recycled but energy is constantly flowing

Levels of Biosphere

Made up of

Made up of

Made up of

Made up of

ENERGY FLOWS AND MATTER CYCLES

Energy Flow in the BiosphereEnergy enters the ecosystem is passed

from organism to organism and is used up or exits the system via heat

Source of earth’s energy is the sun

Energy Flow in the Biosphere

30% reflected by clouds or surface of earth

40% heats atmosphere and earth’s surface

25% heats and evaporates water

1% generates wind

>0.02 % is used by plants to create useable energy

30% of sun energy is reflected by clouds or the earths surface

ALBEDO EFFECTthe extent at which material can reflect

sunlight The greater the ability of a material to reflect

sun the higher the albedo therefore the lower the energy absorption

The lower the ability of a material to reflect sun the lower the albedo therefore the higher the energy absorption

Areas that are snow covered, cloudy, dusty or are desert or deforested areas all have a higher albedo (more reflection) therefore have lower energy absorption

PHOTOSYNTHESIS AND CELLULAR RESPIRATION

The two chemical processes that occur in nature to help animals and plants turn solar energy into useable energy

Plants use PHOTOSYNTHESIS to convert energy

6CO2 + 6H2O + energy -->  6O2 + C6H12O6 Animals use CELLULAR RESPIRATION to

convert energy6O2 + C6H12O6 -->  6H2O + 6CO2 + energy

These two processes are complementary Because they both use 02 and C02 there

should be a balance of those gases in the environment

0.023% of suns energy is used by living organisms

0.023% of suns energy is used by living organisms

Tracing the path energy takes from the sun to organisms living on earth

FOOD WEBS/CHAINS visually show us the step by step or interlocking “feeding” relationships between organisms

Putting organisms into classifications helps to organize the way they gain energy from the sun

Three main levels in basic food chains/webs1. 1st Trophic Level = Producers = Autotrophs2. 2nd Trophic Level = Primary Consumers =

Heterotrophs3. 3rd Trophic Level = Secondary Consumers =

Heterotrophs

1st Trophic LevelBottom of the food chainPlants, trees, grasses, algae etc. Autotroph

Can make own “food” (energy) Producer

Takes direct sun energy and turns it into usable energy using the process of photosynthesis

2nd Trophic LevelAnimals lower on the food chain (ie

herbivores)Moose, gopher, deer, mice etc.Heterotroph

Does not make own “food” Primary consumer

Eats a producers

3rd Trophic LevelAnimals higher on the food chain (ie

carnivores and omnivores, decomposers)Bear, Wolf etc.Heterotroph

Does not make own “food”Secondary consumer

Eats producers and/or primary consumers

Put labels on diagramspg 23 Food Web

Can organisms fit into more than one level/category? Why?Why not? Is this a good or bad thing?

Do you think the amount of energy increases or decreases as you move up the trophic levels?

JUSTIFY

Energy and the food chain

Energy is neither created nor destroyed therefore once it enters a system it stays and is either used up or lost as heat into the system

As you move up the trophic levels the amount of energy available goes down

Only 10% of energy from each level is passed on

The number of organisms at each level is directly controlled by the amount of energy available to each level

How do humans interfere with natural energy flow

Pg 33

Chemosynthetic Food Chains

Exist in ecosystems where there is little to no solar energy Caves, deep ocean, extreme environments

A chemotroph (bacteria) replaces the autotroph in the first trophic level of the food chain

Chemotrophs use energy from a variety of other sources Chemical energy from minerals, thermal energy

from the core

Food Chains Handout

ECOLOGICAL PYRAMIDS

(pg 28-32)

Visuals that help represent the energy flow in a system

Three types of pyramids1. Pyramid of Biomass

A measure of total dry mass of all living things in the ecosystem

2. Pyramid of EnergyA measure of energy at each level

3. Pyramid of NumbersA count of the number or organisms at each level

Stability in an ecosystem

Ecosystem is a community of species and its physical and chemical environment

Organisms are interconnected and rely on each other

What would make a stable ecosystem?

Stability in an ecosystem

Stable ecosystems that small changes would not cause major disruptions or disturbances to other organisms

The greater the biodiversity the greater the stability

WHY?Read “Why biodiversity is a good thing” and answer

the questions

What factors largely determine an areas biodiversity?

Why do tropical rainforests usually have high biodiversity?

Why would deserts and arctic have low biodiversity?

Why do areas of high biodiversity seem to continue to function well and species have good chance to survive?

In areas of high biodiversity, why is there little population fluctuation?

Why are areas of low biodiversity at such high risk of extinction? Give a specific example.

Why is loss of biodiversity a “vicious cycle”?

Is Biodiversity a “good thing”? Justify

Why is biodiversity a good thing?

More organisms mean more complex and developed food webs

The less vulnerable to changes in the ecosystem Removal of a species or drastic weather changes Domino effect (pg 9 cause and effect Sea Urchins and

Whooping Cranes)

Creating a Food WebAssignment

ENERGY FLOWS AND

MATTER CYCLES

Matter Cycling in the Biosphere

The biosphere is a closed system so every living thing depends on the matter already available on earth It is possible that a carbon atom that helped make up a T

Rex 70 million years ago can be somewhere in your bodyNew matter is not introduced so nutrients

are cycled and recycled between the environment and organisms These cycles are called the BIOGEOCHEMICAL

CYCLES

Biogeochemical Cycles

Matter is mostly made up of the following elements and there is a specific cycle for each: Carbon Hydrogen Oxygen Nitrogen

These four elements make up all basic compounds used by living organisms Carbohydrates (energy for cells) Lipids (storage in cells) Proteins (structure in cells) Nucleic Acids (genetic material in cells)

Biogeochemical Cycles

Cycling of matter through biotic and abiotic parts of ecosystems allow all organisms including plants to obtain essential nutrients

At each step in every cycle, substances are temporarily stored in nutrient reservoirs (organisms, soil, air, water)

O, C, N, S travel easily in both water in airP and Fe do NOT travel in atmosphere but in

soil and waterSimilar and interrelated

Disruptions in one can affect another

The Cycling of Matter in the Biosphere Worksheet and

Diagrams

Nutrient ReservoirsNutrients are either stored or move from

reservoir to reservoirCarbon cycles from producer to consumer

to decomposers and back to atmosphere rapidly

Fossil fuels is stored carbon that is unavailable to organisms for millions of years

Hydrological CycleWater

absorbs and release thermal energy and moderates temperature fluctuations

Medium in which metabolic reactions take place Is an excellent solvent Makes up over 60% of the cell’s mass Product and reactant of photosynthesis and cellular

respiration

Carbon CycleCarbon

Key element for living thingsRapid Cycling

Plants animals and decomposers play important role

Carbon CycleSlow Cycling

3 main reservoirs of carbon in the atmosphere, oceans, earth’s crust

Phosphorus CyclePhosphates

Key elements in making ATP and calcium in bones Animals obtain phosphorus by consuming foods

such as milk, grain and meal Producers such as plants and algae can only use it

in forms of phosphates which dissolve in waterShort Term Cycle

living organisms

Phosphorus CycleLong Term Cycle

Rocks in Earth’s crust

Nitrogen CycleNitrogen

Makes up 78.1% of atmosphere Essential part of proteins and DNA

Nitrogen Fixation Process to convert atmospheric nitrogen into useable

ammonium by bacteria or lightningAmmonification

Process of converting ammonium into nitrite then useable nitrate by bacteria so plant can use it

Denitrification Process of converting nitrite and nitrate back into

nitrogen gas

Human Impact on Cycles

Carbon-deforestation, burning fossil fuels add carbon to reservoir

Nitrogen and Phosphorus- FertilizerWater-burning fossil fuels add sulfuric acid

and nitric acid

Biogeochemical Cycles, Human Impact and Environmental Problems

Assignment

Flow of Matter and Transfer of Energy are linked

Six cycles involve biotic and abiotic environment

When living organisms take on nutrients those nutrients become part of the biotic environment

Transfers of energy from producers to consumers affects biogeochemical cycles

Balance of Matter and EnergyEarth is similar to organisms must

maintain conditions within certain limits to ensure a state of balance (EQUILIBRIUM)

Gaia hypothesis-James Lovelock- Biosphere regulates itself, needs constant input of

energy and cycling of nutrients

Ecosystem Productivity

Is the rate at which an ecosystem’s producers capture and store energy within organic compounds over a certain length of time

Rate of productivity depends on a number of variables Biotic factors

Number of organisms at each level especially producers and decomposers

Abiotic factors Temperature, amount of light and heat, rainfall,

nutrient availability

Biosphere 2Large scale biosphere experiment

constructed closed systemsSeveral months until the oxygen levels

dropped and carbon dioxide levels roseProved that energy and matter exchange

is extremely complexResearch facility showed that delicate

balance

http://www.b2science.org/

NASA: Advanced Life Support (ALS)

Research plants grown in space for oxygen and food

Conversion of waste into usable energySelf sustaining colonies for humansDevon Island (Canada) hypothetical colony

on Mars

http://www.nasa.gov/centers/ames/research/technology-onepagers/advanced-life-support.html

Imagine that in the future humans live in domed cities protected from high UV radiation. Describe all the necessary

conditions that must exist in this closed system for life to continue. Include the kind of dome needed and the sources of

energy, water, carbon dioxide and oxygen. Also include a plan for cycling nitrates and phosphates and recycling wastes.

Final Task and Review for Test