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Unit 1: Sustainable EcosystemsIn this unit you will learn about:

Why sustainable ecosystems are crucial to life

What people can do to help protect themTRANSITIONs1BIG IdeasPeople have the responsibility to regulate their impact on the sustainability of ecosystems

WHY?

In order to preserve them for future generations

Big ideas well be looking at throughout this unit

So life can continue, plants and animals alike, and in turn humans can flourish also2BIG IdeasEcosystems are dynamic

Meaning they have the ability to respond to change- within limits though

Beyond those limits the ecosystem cannot recover its ecological balance

Clear cutting a forest would exceed a limit31.1 SustainabilityAn ecosystem includes all the interacting parts of a biological community and its physical environment

What are examples of the parts of an ecosystem?

Eco- means home, ecosystems are the homes for organisms

Give me some examples of part of an ecosystem, plants, animals, water, oxygen4Sustainability is the use of resources at levels that can continue forever

To sustain is to endure and to support

Sustainable ecosystems are ecosystems that are capable of enduring stressors and supporting organisms

What are some stressors that an ecosystem can experience? Too much or too little water, disasters such as hurricanes or volcanic eruptions, harvesting of resources by animals, pollution or destruction by humans5The Need for Sustainable EcosystemsEaster Island ExampleVideoThere was once a thriving population and thick forests on the islandThey built houses, planted crops, built statues Cutting of trees was NOT sustainable for forest lifeWithout forests the island ecosystem collapsed!Video http://www.youtube.com/watch?v=gfbQA-Krx9Q searched: Easter Island Sustainability 2:42 minWhy wasnt the harvesting of trees sustainable? Because they cut too much down, they used the resource at a level that could not continue forever, takes longer for trees to grow back then to cut them down, can cut a tree down in a few hours but its takes many years if not decades for the tree to grow to that size6Without trees there was:Loss of other plants Loss of animalsSoil erosionNo materials to build houses, boats and of course no way to move statues

Overharvesting by humans caused an ecological imbalance

= Loss of life

Plants for food or animals and humans, soil erosion cant plant crops7Ecosystems and SurvivalAll organisms require sustainable ecosystems for survival

Many organisms depend on more than one ecosystem for survival, such as migrating birds

For example geese spend the summer in Canada and fly south in the winter

Remember Easter Island example, without sustainability life perished 8Parts of an EcosystemEvery ecosystem has biotic and abiotic parts

Biotic refers to the living parts

Ex: plants, animals and fungi

Abiotic refers to the non-living parts

Ex: water, oxygen, light, nutrients and soilEcosystems can be large or small, an ecosystem could be the boreal forest of Ontario or a small pondRemember bio- means life9Biotic CharacteristicsIncludes all living things as well as the interactions among them

1. Symbiosis interaction between members of two different species that live together in a close association

Ex: mushrooms provide tree with water and some nutrients, tree provides mushroom with sugar

Positive interaction102. Predation occurs when one organism consumes another organism for food

Ex: frog eats insect

3. Competition occurs when two or more organisms compete for the same resource

Ex: dandelions compete with grass for sunlight, water, nutrients

Predator and prey food chain effects ecosystem as a whole, the frog predator can also a prey item thoughDandelions can put energy towards becoming better competitors by growing taller than the grass, or have deeper roots to give it an advantage in obtaining those resourcesNegative interactions11Abiotic CharacteristicsThe factors that living things need to survive

WaterOxygenLightNutrientsSoil

Abiotic characteristics are just as important as biotic characteristicsName some non-living things that we need to survive?Water, all life needs it, oxygen, most of life needs it from air or water, light, required for photosynthesis which all other energy comes from, nutrients, all life needs a variety of nutrients such as nitrogen, phosphorus etc., soil, required for plants, which again are the primary producers from which other organisms gain energyHow can human activities effect sustainability of these abiotic characteristics?12Cycling of MatterEcological processes move matter from the biotic and abiotic parts of an ecosystem, and then back again, in continuous cycles

Cycling of MatterEx: Hummingbirds consume water, insects, nectar to survive

The hummingbird, water, insects and nectar are different forms of living and non-living matter

The hummingbird uses the matter it consumes to fly, build muscle, reproduce etc.

Go back a slide and repeat14Earths SpheresAt any time, matter can occupy any of the 4 spheres that make up Earth:

Lithosphere: the hard part of Earths surface(land)Hydrosphere: the salt water in the oceans (water) and fresh water on the continentsAtmosphere: the layer of air above Earth`s (sky) surfaceEarth`s SpheresThe lithosphere, hydrosphere and atmosphere are abiotic spheres

4. Biosphere: the living surface of Earth

No other planet is known to have a biosphere!

Ex: Mars has the first 3 spheres, but its hydrosphere is mostly ice and its atmosphere has very little oxygen16Nutrient CyclesEcosystems provide living things with the matter they need, including nutrients

Nutrients are chemicals that are needed by living things and are continually cycled through ecosystems

Ex: water, carbon, nitrogen and phosphorusThe Water CycleWater continually cycles through the hydrosphere, atmosphere, lithosphere and biosphere through the processes of:

Evaporation

Condensation

Precipitation

E: liquid to gasC: gas to liquidP: condensed liquid falls to ground as rain, sleet, snow, hail18

Information for this diagram is on the next slide19The Water CycleHeat from the Sun evaporates water from the hydrosphere

The water vapour rises in the atmosphere and as it cools it condenses and forms clouds from these condensed water droplets

The water falls back to the lithosphere as precipitation

20What about the biosphere?

As the water returns to the oceans through river systems and the ground, it erodes rocks and picks up other materials

It is also absorbed by plants or consumed by animals

The movement of water among Earths spheres is critical to the operation of sustainable ecosystems

21The Carbon CycleLike water, carbon moves through Earths spheres as it is cycled through ecosystems

Carbon dioxide gas moves from the atmosphere into the biosphere and back again

CO2 is also released back into the atmosphere when organisms die and are decomposed by micro-organisms

Carbon is another essential nutrient for all living thingsDecomposers are also fungi22The Carbon CycleCarbon enters the lithosphere when the remains of organisms are trapped underground

After millions of years, these remains are converted into fossil fuels such as coal, oil and natural gas

CO2 is returned to the atmosphere when humans burn the fossil fuels and wood for energy

Burning fossil fuels can be a problem, we call it pollution for a reason, makes the air toxic lung cancer, weakens protective ozone layer

23The Carbon CyclePlants and algae attain carbon in the form of CO2 from the atmosphere during the process of photosynthesis

Animals release CO2 as waste product from the process of cellular respiration

Complete carbon cycle handout as a class, use overheadHomework page 20 #1-3 and page 128 #1, 7, 8, 24The Nitrogen CycleEarths atmosphere is 78% nitrogen (N2)

Most organisms cannot use nitrogen in that form

An important part of the nitrogen cycle involves processes that convert the nitrogen into usable formsNitrogen is very important because proteins are the only macromolecules that contain nitrogen, proteins are crucial to lifeDiatomic25The Nitrogen CycleEx: in terrestrial ecosystems some soil bacteria convert nitrogen (N2) into ammonium (NH4+) and other types of soil bacteria convert ammonium (NH4+) into nitrate (NO3-)

Plants absorb both forms of nitrogen through their roots but most of it is absorbed in the form of nitrate (NO3-)

Polyatomic ionPlants are primary producers26The Nitrogen CycleEx: in aquatic ecosystems cyanobacteria convert nitrogen (N2) into ammonium (NH4+) which is then absorbed by plants

Nitrogen in the form of ammonium and nitrate can also enter both terrestrial and aquatic ecosystems when humans fertilize soil

This can be a problem because there is a balance in ecosystems, human interference can disrupt this balance and cause problems which can lead to the ecosystem not being sustainable 27The Nitrogen CycleBacteria found on land and in water convert nitrate (NO3-) back into nitrogen gas (N2) returning it to the atmosphere

Nitrogen is also returned to the atmosphere as ammonia (NH3) during volcanic eruptions and when fossil fuels are burned

28The Nitrogen CycleIn a sustainable ecosystem the amount of nitrogen converted into usable forms is equal to the amount of nitrogen returned to the atmosphere= Balance

Excess ammonium (NH4+) and nitrate (NO3-) eventually enter the lithosphere becoming part of rocks this nitrogen will only return to the atmosphere after rocks are broken down over time

Complete nitrogen cycle handout as a class, use overhead29The Phosphorus CycleUnlike carbon and nitrogen, which both exist as gases in the atmosphere, phosphorus is stored in the lithosphere

Phosphorus is stored in rocks and in sediment

When rocks are broken down into smaller pieces from weathering, phosphorus in the form of phosphate (PO43-) is released into the soil

The Phosphorus CycleHumans mine the lithosphere for phosphate rock which can be used to maker fertilizers and detergents

Once in the soil the phosphate is absorbed by plants through their roots

The phosphate continues to move through the biosphere as animals eat the plants and other animalsThe Phosphorus CycleDecomposers break down dead organisms and animal waste, releasing the phosphate back into the soil

Therefore bacteria and other decomposers ensure that phosphorus is recycled within the biosphere

The Phosphorus CyclePhosphate enters aquatic ecosystems through leaching and runoff from land

Aquatic plants absorb the phosphate and are later consumed by animals, followed by bacteria returning the phosphate to the water when they decompose dead organisms

Some of the phosphate that enters aquatic ecosystems settles to the bottom to become part of the sediment rather than part of the biosphere

Once in the sediment it usually takes a long period of time for it to become part of the biosphere again33Human Activities and Nutrient CyclesHuman activities can throw off the balance in a sustainable ecosystem by affecting nutrient cycles

What are some examples? Too much runoff, pollution, carbon emissions,34Human Activities and Nutrient CyclesFertilizers and the Phosphorus Cycle Example

Some aquatic ecosystems experienced excessive algal growth

Lake Erie algal growth increased by as much as 30 times, upsetting natural balances

Eutrophication: the process in which deposits of excess nutrients cause an overgrowth of algaeHuman Activities and Nutrient CyclesThe alarming rate of eutrophication during the mid-20th century suggested that human activities were the cause

In 1968, 58 lakes in Ontario were experimented on

They found that when excess phosphorus was added to the water eutrophication occurred

Explain picture, curtain divided the lake, excessive phosphorus on right caused eutrophication where algae grew so abundantly their was an imbalance causing ecosystem to be unsustainable = life could not continue, how does this happen? Fertilizer containing phosphorus runs off from farmland into water, the algae bloom, submerged plants die due to reduced light, bacteria decompose plants and use oxygen to the point where the levels get too low that other animals such as fish cannot survive, resulting in ecosystem collapse 36Science and Social PolicyAs a result of the work done on the effects of excess nutrients in Ontarios lakes, a multi-billion dollar phosphorus control program was established

This was done to restore and maintain the chemical, physical and biological integrity of the waters of the Great Lakes Basin Ecosystem

Why would we do this? So we can keep the ecosystem in balance, meaning it can be sustained, meaning life can persistAlso, farmers take part in the program by reducing phosphorus use, anti-pesticide laws have also been put in use in some areas such as Toronto since 2005Homework page 20 #1, 2, 3, 5, page 128 #6, 12371.2 The Biosphere and EnergyAll activities require a source of energy

Even though energy takes many forms, all energy originates from the same source, which is solar energy from the Sun

Solar energy gets converted and stored as chemical energy by primary producers

A fire requires wood, cars need gasoline38Photosynthesis and the Suns EnergyLots of energy reaches Earth from the Sun, there is also lots of energy loss from Earth when it is reflected back as heat

The atmosphere traps some of this heat, warming the Earth making it more habitable

Matter is used over and over as it moves through Earths 4 spheres

- Nutrient Cycles

PhotosynthesisPlants, algae and some bacteria contain chlorophyll which allows the biosphere to harvest some of this solar energy

Chlorophyll is a pigment that gives leaves their green colour

Photosynthesis uses chlorophyll and light to put together carbon, hydrogen and oxygen to make lifes universal energy supply

= a sugar called glucosePhotosynthesisTherefore photosynthesis converts solar energy into chemical energy

Sugars are in a class of molecules called carbohydrates (= carbon + oxygen + hydrogen)

If plants are going to make glucose sugar then they need these 3 elements

They gain hydrogen from water (H2O) and carbon and oxygen from carbon dioxide (CO2)

PhotosynthesisPlants absorb water using their roots and they absorb carbon dioxide through small pores in their leaves called stomata

The chemical formula for photosynthesis: Light Energy6CO2 + 6H2O C6H12O6 + 6O2CarbonDioxideWaterGlucoseSugarOxygenDiagram in text page 22 puts all this together in picture form42PhotosynthesisPhotosynthesis is vital for the biosphere

It produces glucose which is an energy source for the plants and the organisms that eat the plantsconverts solar energy into chemical energy!

Photosynthesis also adds oxygen to the atmosphere, which many organisms require for life

Photosynthesis also removes carbon dioxide from the atmosphereWhere ever there are chlorophyll containing organisms oxygen is generated43Trophic LevelsA trophic level is a category of organisms that is defined by how the organisms gain energy

Matter and energy are transferred between trophic levels within the biosphere

Trophic LevelsPrimary producers are organisms that can make their own food

Consumers are organisms that cannot make their own food

therefore must eat other organisms to get the matter and energy they need to survive

Top CarnivoreCarnivoreHerbivorePlantsTrophic Levels ExampleTrophic LevelsWhat about decomposers?

All the levels of the food web are linked to decomposers

They ultimately move the nutrients from decaying organisms, as well as waste from living organisms, back to the abiotic parts of the ecosystem as they take in the nutrients they need to surviveTrophic EfficiencyBiomass is the mass of living cells and tissues that has been assembled by organisms using solar energy

Meaning, it is the total mass of living organisms in an area

Trophic efficiency is a measure of how much of the energy in organisms at one trophic level is transferred to the next highest trophic levelTrophic EfficiencyTrophic efficiency is always less than 100% because organisms use much of the energy from the biomass they consume for their life functions

Trophic efficiencies are usually low, only about 10%

Name some life functions?49Trophic Efficiency

Trophic Efficiency Example50Trophic EfficiencyWhy is only 10% transferred to the next trophic level?

The rest of the energy is used up by the organism to sustain its life

For ex: a herbivore may not eat the entire plantnot all the biomass is consumed

Also energy is lost as heatMaybe they eat only the leaves and the steams and leave the roots51Trophic EfficiencyThe inefficiency of energy transfer among trophic levels results in fewer carnivores than herbivores, and fewer herbivores than plants

52Water PollutionBioaccumulation is the ingestion of toxins at a rate faster than they are eliminated

Biomagnification is the increase in the concentration of a toxin as it moves from one trophic level to the next

Therefore the two terms are related53Water PollutionDDT Example

DDT was an insecticide used in North America

When DDT entered the environment in runoff from land, it was absorbed by algae in the water

Microscopic animals ate the algae, then small fish ate them and bigger fish ate those etc.Runoff, from lithosphere to hydrosphere to biosphere, spheres are connects, energy and matter are cycled through them54DDT Example

At each trophic level in the food chain the concentration of DDT in the tissues of the organisms increased

At high concentrations the DDT affected reproduction in the birds that ate the fishthinning of egg shells = less eggs survived

Ban on DDT resulted in healthier bird population

See how the nutrients were cycled throughout the spheresHomework page 27 #1-6, page 128 #2, 455