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Science 421 Ecology The study of the interaction of living things & their environment What else does it mean these days? Ecology is...

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Science 421. Ecology The study of the interaction of living things & their environment What else does it mean these days? Ecology is. Chapter 1 - Diversity in Ecosystems. The Earth’s regions differ in their: Temperatures Light intensity Water availability Weather Species - PowerPoint PPT Presentation

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Science 421

Science 421Ecology

The study of the interaction of living things & their environmentWhat else does it mean these days? Ecology is...1

2Chapter 1 - Diversity in EcosystemsThe Earths regions differ in their:TemperaturesLight intensityWater availabilityWeather SpeciesRead pages 8 & 9 and complete question 1.

31.1 The Silence of the FrogsAmphibians are found almost everywhere there is water on the planet.Amphibians have two lives and live within two ecosystems: 1. Eggs laid in water grow into a tadpole; 2. Froglet (lose their tail and adapt to living on land and breathing air). Croaking Frogs...

4Over 30% of North American frogs and toads are in trouble. A change in either of their ecosystems can result in a decline in amphibian population.Amphibians are an indicator species, meaning if they start to die off, it is a sign that the ecosystem is in trouble.Complete questions 1 - 6 on page 13.

5Factors Affecting Frog Populations

1. Loss of Habitat Road construction, deforestation, etc.

2. Air and Water Quality - Frogs are able to breath through their thin skin, therefore pollutants are able to pass through their skin.

3. Ultraviolet Radiation Causes skin damage to amphibians.

4. Climate Change - Global warming increases temperatures and reduces wetlands/habitats.

Planet Earth Frogs...

6Use your text & define the following terms in your notes:EcosystemDecomposersHerbivoresFood ChainDetritusCarnivoresProducersOmnivoresConsumers

71.2 Canadas Endangered Species

Canada has over 250 species of plants and animals that are at risk. There is a classification system to describe the risk to each species.

8ClassificationDescription/ExampleVulnerableAt risk due to declining numbers in some areas.Example:Grey Fox Ontario

9ClassificationDescription/ExampleThreatenedLikely to become endangered if factors are not reversed. Ex.-Wood Bison

10ClassificationDescription/ExampleExtirpatedNo longer exists in specific areas, but can be found in others.(Black bear no longer on PEI since 1930.)

11ClassificationDescription/ExampleEndangeredClose to extinction in all parts of Canada. Ex.-Eastern Cougar

12ClassificationDescription/ExampleExtinctA species that does not exist anywhere.Ex.-Passenger Pigeon

Complete questions 1, 2 and 4 on page 15.

131.3 Extinction in the Modern WorldHumans have influenced the process of extinction for many species over the past 50 years.14Extinction Timeline1600 - 1900 -An average of one species every 4 years.

1980 present - An average of over 10,000 per year.

15Causes of Extinctions

Asteroids - Asteroids impacted with the Earth & caused a large cloud of dust blocked light from the sun, & set off many volcanoes.

16Climate Change - A change in a species environment forces them to adapt or die.

17Pressure of Competition- 2 species may compete for the same food sources and/or habitat. One wins, the other adapts or dies.

Human Factors - Logging, oil exploration, expanding cities, expansion of agriculture, introduction of new species (purple loosestrife)

18Effects of ExtinctionBiodiversity is the variety of life on Earth. It is the number of species in an ecosystem. The loss of one species impacts the entire food chain & ecosystem.YouTube - Official video of the International Year of Biodiversity 201019Restoring BalanceDue to the effects on a food chain, it is extremely difficult to restore the balance once a species has been removed

Questions 1-3 pg. 1920Pests are organisms that cause problems for humans.

Why are pests such as mosquitoes, termites, caterpillars and weeds needed?

Mosquito larvae provide food for fish and adult mosquitoes are food for birds. Some insect pests are needed by plants for pollination, while others, such as wasps, help decompose tissues of dead plants and animals. Weeds: source of food for animals, & can help anchor the soil, preventing erosion.

21Define the following Ecology Terms:AbioticBioticPopulationCommunity

22Ecology -the study of how organisms interact with each other.

Abiotic factors- non-living things in an ecosystem. Ex:- light, soil, wind, temperatureBiotic factors -living things in an ecosystem

Population -all of the members of the same species living in an ecosystem.Community - all of the populations of species in an ecosystem.Do # 1-5 on pg. 23.

23Example: A pond ecosystem Consists of a habitat with populations of aquatic plants, waterside plants, micro-organisms (in the mud at the bottom of the pond), fish and birds. The organisms together make up a community of living things.

24DO NOT COPY DOWNEcologists can study:

- A population and how it interacts in the ecosystem. (Coyotes)- A community and how all species interact (biotic factors). - An ecosystem including all biotic factors and the physical environment, or abiotic factors.

25Quiz!Identify each of the following as either biotic or abiotic.

Identify each of the following as either a species, a population, community or ecosystem.TemperatureWormsGrassSoilAll fish in the streamThe white spruce trees behind the schoolThe trees, birds, insects, mammals, plants and amphibians in the forestBrookvale Demonstration WoodlotMarshThe Mallard ducks in a marsh26An ecotone is a transition area between two different ecosystems where species from each can interact. There is often greater diversity in the ecotone than in either of the two ecosystems bordering it.

An area with greater biodiversity is less fragile consumers have more food sources; dont have to rely on only 1 source. An ecotone guards against extinction.271.8 Comparing Ecosystems

Artificial ecosystems -human made. (Ex. farms, parks)

A natural ecosystem - made by nature. Species are able to interact with their surroundings freely. Humans will still have an impact on the ecosystem but they do not control it.

Section 1.8 #a-j and #1-4 and #5 as class discussion.28Albedo effect - % of light an object reflects. The higher the Earths albedo, less energy is absorbed and therefore less energy is available for maintaining the Earths temperature.

30%0.023%Photosynthesis:70%291.11 Following Energy Movement in Ecosystems YouTube - How Ecosystems Work | Biology | EcologyEnergy is constantly moving within our ecosystems. To understand how living things gain their energy we must look at trophic levels (position in the food chain).

Most ecosystems only contain about three trophic levels consisting of:

1. Autotrophs - make their own food - producers.

2. Heterotrophs - cant make their own food consumers (can be broken down into sub-levels)

30Fourth Trophic LevelTertiary Consumers Eat secondary and primary consumers. (Heterotroph)Bear, cougar Third Trophic LevelSecondary ConsumersEat primary consumers and producers. (Heterotroph)Eagles, wolvesSecond Trophic Level Primary ConsumersEat producers for food. (Heterotroph)Deer, mice, bugsFirst Trophic LevelProducers Make their own food from basic nutrients and sunlight. (Autotrophs)Grass, berries, trees

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A food web is graphical representation of the feeding relationships between organisms in an ecosystem. In reality a single organism can be a part of many food chains.

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33DO NOT COPYEcosystems with the greatest biodiversity are the most stable they have complex food webs and therefore the removal of one consumer or one producer may have only a small impact on the ecosystem and the overall web.

34SunlightSource of all energy on earthLess than 1% is used for photosynthesis (conversion of solar energy into chemical energy sugar molecules)

35Energy TransferEach time energy is transferred from one organism to another, there is a change of form. (i.e. plant used most of the suns energy to grow only a small fraction of suns energy is passed onto an animal that eats the plant)As you move through a food chain, less energy is available to each organism.

36LAWS OF THERMODYNAMICS1st Law Energy is not created nor destroyed, only changed from 1 form to another

2nd Law During an energy transfer, some of the energy is converted into thermal energy or heat which is released to the environment37Energy use by organisms:

- Growth, repair and survival- Given off as heat and used in respiration.- Excretion (although decomposers actually use this energy in a different food chain).- Transport of materials in the body, and for movement.

All the energy used in these ways returns to the environment, and is not available to the next trophic level. 38

39Human Use of the Energy in EcosystemsTwo main revolutions have increased our energy demands on ecosystems and have reduced the amount of energy available to other organisms.

1. Agricultural Revolution 2. Industrial Revolution

40End of Chapter 1 class test on Tuesday, June 2nd.41Section 2.1 Cycling of Matter in EcosystemsPlease answer the following questions in your notebooks. Please use your textbook and provide complete answers.Define matter.What is an organic compound?What is an inorganic compound?What does the term cycling (or recycling) mean?What do we mean when we say that matter is recycled?Is food organic or inorganic? Explain the cycling of organic matter within living things.Decay is a process involved in the cycling of matter. Please explain this process.Using the information in this section make a diagram (or drawing) to show how matter is cycled within an ecosystem. Please use the following terms and organisms in your explanation: plants, inorganic molecules, inorganic nutrients, soil bacteria, fecal matter, rabbit, fox, decomposing bodies. Please ensure that your diagram looks like a cycle.Please complete Questions 1, 2, 4-6 on page 51.42Chapter 2Cycling of Matter in Ecosystems

Matter anything that has mass & takes up spaceOrganic substances contain: carbonHydrogenSometimes nitrogensometimes oxygenExample: proteins, sugars, and fats.

Inorganic substancesDo not contain the combination of carbon AND hydrogen. Ex: carbon dioxide (CO2), water (H2O) and ammonia (NH3).

43Cycling of Organic Matter

Continuously being recycled.Limited amount of materials found on the Earth means they must be recycled for life to continue. Example: Carbon molecules are recycled over and over . some part of your body may contain a carbon molecule which was part of a dinosaur over 70 million years ago!

44Cycling of Organic Matter

45 (Eaten by) (Eaten by) (Eaten by)Plant Rabbit Fox (feces) (Turns it into) (Eaten by)soil bacteria inorganic molecules plant roots plant462.2 Pesticides

Pests are organisms considered to be harmful or inconvenient (e.g. weeds, insects, fungi or rodents.)

47Pesticides are chemicals designed to kill pests.

48Why use pesticides?

30% of the annual crop in Canada is lost to pests (i.e weeds, rusts, moulds, insects, birds and small mammals). This may increase the cost of food.Malaria (causes fever and can lead to death) is transmitted by a mosquito.Increases the yield of crops.Prevents allergies from mold and mildew49First Generation Pesticides

500 BC sulfur was used to repel insects15th century arsenic, lead and mercury were applied to crops as insecticides2 Problems: substances killed insects but were also highly poisonous to people AND these pesticides remained in the soil for a long time.1763 - gardeners began to use natural plant extracts ( uses the plants own chemical defenses) to kill insects.

50Second Generation Pesticides

Made in the laboratoryDDT first used in 1939 as an insecticide.DO NOT COPY:Now more than 500 chemical pesticides registered for use in Canada.Worldwide approximately 2.3 million tonnes of pesticides are used yearly (0.4 kg for every person on earth)Pesticides are added to shampoos, carpets, mattresses, paints, and even wax on produce.More than 25% of pesticides are used to get rid of pests in homes, gardens and parks.51Pesticides are classified into 4 groups:

Insecticide - targets insects Example: DDTPersistence: high - stays in ecosystem for 2 - 15 years

Herbicide - targets weeds Example: RoundupPersistence: mostly low - stays in ecosystem for days to weeksFungicide-targets moulds and fungiExamples: CaptanPersistence: low - stays in ecosystem for daysBactericide- targets bacteriaExamples: penicillin, vancomyecinPersistence: mostly low

52Modern Chemical Pesticides

New pesticides are now water soluble and do not build up in the tissues of animals. They are safer but still have negative effects such as:-They break down quickly so they have to be spread more often.- They are not selective so they can also kill birds, reptiles, amphibians, and fish.- Animals that do not die immediately may still put others at risk through bioamplification.Pests can develop resistance to pesticides53Spruce Budworm Life CycleAdult moths emerge in late June and lay eggs on spruce or fir trees. The eggs hatch in 10 days and the larvae move into the trees. They spin a web and lay dormant for the winter. In May they wake and feed on buds, needles and flowers. They effect the growth and immune systems of the trees, and infestations year after year can kill the trees54BioamplificationSome toxins, such as pesticides, buildup in the fatty tissues of animals; they are not soluble in water.Pesticide

primary consumer (grasshopper)

secondary consumer (shrew) (eats several prey so the amount of toxin in its body will be larger.)

Tertiary consumer (hawk)(higher level predator gets all of its toxins plus those of all the other prey it eats.)

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57Concentration of toxin becomes greater at each level of the food chain. The higher the trophic level, the greater the concentration of toxins. This process is referred to as bioamplification582.5 The Carbon Cycle

Carbon is an essential element for living things. The cycling of carbon is conducted through 2 processes: photosynthesis & cellular respiration.

Photosynthesis - the process in which plants use solar energy, carbon dioxide from the atmosphere, and water from the soil to make food (sugar).

Carbon Dioxide + Water + Light Energy Sugar (glucose) + Oxygen 6CO2 + 6H2O + light C6H12O6 + 6O2

59Cellular Respiration -uses sugar and oxygen for energy and releases carbon back into the environment. Glucose + Oxygen Water + Carbon DioxideC6H12O6 + 6O2 6H2O + 6CO2

CO2 is removed from the atmosphere by photosynthesis and returned to the atmosphere by cellular respiration.

60NASA How Carbon Works...

61The carbon cycle usually works on an equal balance, however, the increase in the burning of fossil fuels(i.e. oil, gas) has caused the amount of CO2 in the atmosphere to increase, causing an increase in the Earths temperature known as the Greenhouse Effect.Carbon Cycle Game

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63Human Impact on the Carbon Cycle ...do not copy

Humans have modified the carbon cycle by releasing large quantities of organic carbon from reservoirs faster than they normally would. Example: mining coal, burning fossil fuels and burning forests ( less vegetation less photosynthesis less carbon dioxide is being absorbed)64Complete #1-4 on pg. 65 (understanding concepts)1. What is limestone?2. How can volcanic activity contribute to the release of CO2?3. What is peat?4. How do coal and oil form?

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67Effects:Melting ice capsSea levels to increase floodingChange in climate patternsMore/less rainfallLarge impact on agricultureNatural vegetation could change68

69QuestionsPlease do questions 1,2,3,4,5 on page 65 of your textbook.The Nitrogen CycleNitrogen needed for the production of proteins and nucleic acids (DNA)79% of atmosphere N2 gasbut is not usable. Nitrogen is very stable and does not react with many things. Therefore, it must be in the ion form (NO3 - nitrate) to be used by organisms.Most plants and animals cannot capture nitrogen from the atmosphere. Nitrogen Cycle video clip

71Nitrogen FixationProcess of converting atmospheric N2 into nitrates, the nitrate ion (NO3-)2 methods:1. Nitrogen-fixing bacteria: found on plant roots in nodules and in soil. Bacteria provide the plant with a built-in supply of usable nitrogen, while the plant supplies the nitrogen-fixing bacteria with sugar to make the nitrates. Excess nitrates move into soil.2. Lightning causes N2 to react with O2 to create nitrates (can dissolve in H2O)

72NitrificationAnimals produce waste, die and decayNitrogen compounds introduced to soilBacteria work on compounds breaking them into ammonium compounds then nitratesNitrates are absorbed by plants

73Plants: Use nitrogen in the form of NO3 (nitrates) to produce amino acids then proteinsAnimals eat plant protein digest it into amino acid use amino acids to build animal protein in the cells

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75DenitrificationDenitrifying bacteria break down nitrates and nitrites into N2 gas gas re-enters atmosphereMaintains balance between soil nitrates and atmospheric nitrogen76Nitrogen Cycle

1. Atmospheric pool of N2 2. N2-fixing bacteria in root nodules of legumes3. Fertilizers4. Soil nitrate5. Nitrate take up by plant roots6. Plant and animal proteins7. Dead organisms8. Decomposers9. Nitrate bacteria10. Nitrate bacteria11. Denitrifying bacteria12. Lightning

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Short term cycleLong term cycle78The Phosphorous Cycle

Phosphorous cycles in two ways:Long term - in rocks in the Earths crustphosphates eroded from the rock are carried away by rivers and lakes and end up in the ocean where they enter the food chain.

Short term - in living organismsIn the short cycle, phosphate in dead organisms is recycled by decomposers, which break it down and release the phosphates back to the ecosystem.

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80Nutrient Cycling

Rate depends on the rate of decomposition. In warm moist areas process is rapid. In colder and dry areas process is slow. Soil chemistry and frequency of fire also affect the rate of cycling.

81Please do the following questions from your text#s 1,2,3,4,7,8,9,10, 11,12Page 69Population Growth Patterns

The 4 factors involved in population growth are:Natality:the number of offspring of a species born in one year

Mortality: the number of individuals of a species that die in one year

Immigration: the number of individuals of a species moving into an existing population

Emigration: the number of individuals of a species moving out of an existing population83 Pop. Growth = (Births +immigration) - (Deaths + emigration)

Open / Closed Populations

Open Population: when all 4 factors are acting on the population of each organism. 84Closed Population: when only natality and mortality affect their population size. (Example: human population, since people do not emigrate to other planets)852.10Limits on Populations

Biotic potential is the maximum number of offspring that a species can produce, if resources were limited.

Example: Black bears have 1 or 2 cubs; takes at least 2 years to mature. Mice give birth to six or more pups; can reproduce every 6 weeks. It also only takes six weeks for mice to reach sexual maturity (i.e. can start reproducing).

86Biotic potential is limited by four factors:

Birth potential: maximum number of offspring per birthCapacity of survival: number of offspring that reach reproductive age.Procreate: number of times a species reproduces each year. Length of reproductive life: the age of sexual maturity and the number of years the individual can reproduce.87Chapter 3A biome is a collection of ecosystems that are similar or related to each other, usually in the type of plants that they support.

Canada can be organized into 4 major biomes: tundra, boreal forest, temperate deciduous forest, & grassland

88The tundra biomeCanadas northernmost biomeis a cold desert - receives very little precipitation (10-12 cm/year)support s only a small number of organismsshort growing season (limits the types of plants that can survive)plants must deal with permafrost - a layer of soil that never thaws.active layer - the soil layer above permafrost that thaws in summer to allow the uptake of water and minerals by plant roots.cycling of matter is slow and there is only a small amount of organic matter in the thin soilCaribou have been present (eat lichens and mosses) but their population is in decline.See Table 1 -Page 89 for abiotic and biotic factors

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90The Boreal Forest Biome

immediately south of the tundra, also called the taiga biomedominated by conifers (trees with needle-shaped leaves)boreal forest is found in every province and makes up approximately 80% of the forested areasharsh climate with rapid changes in temperaturemore precipitation than the tundrano permafrost layer - soil thaws every summer and this permits the growth of plants with deeper root systemsorganic matter decomposes faster because of higher temps.Only 50 species of birds - only those birds with special beaks (for prying seeds out of cones or cracking cones)See abiotic and biotic factors in Table 2 on Page 90

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92Temperate Deciduous Forest

93Temperate Deciduous Forestsouth of the boreal forest in Eastern and central Canadadominated by deciduous trees such as maples and oaksconifers gradually give way to deciduous trees (less obvious shift than from tundra to boreal forest)broad leaves of deciduous trees maximize light capture for photosynthesishigher temps allow faster decomposition and the organic matter available from fallen leaves provides the basis for the formation of a richer soil.light can reach forest floor so more plants grow under large trees - this includes small trees , shrubs and ferns.presence of many types of plants allows deciduous forest to support many animals & insects (mice, deer, shrews, birds)Have three levels that support animals (the canopy, the understory and the litter)See Table 3 on Page 92.

94Grassland

95Grassland Biomefound at approximately same latitude as deciduous forest;extends from Manitoba to the Rocky Mountainsabiotic factors of grassland mirror those of deciduous forest (because of similar latitude). One exception - grassland receives less moisturenot enough rainfall to support trees except near rivers, lakes and pondsfires periodically sweep through preventing growth of trees and also acting as decomposers, speeding the return of nutrients to the soilblack earth of grasslands is most fertile soil in the worldshort-lived grasses provide a great biomass for decomposition and high summer temps promote rapid decay ensuring high concentration of nutrients and organic matter in the soillength of grasses regulated by rain - more rain the longer the grassesnow much of the grassland is devoted to growing graingrassland ecosystems have only one layer that supports animals so biodiversity is limitedgrasses of this biome once supported herds of migrating bisonSee abiotic and biotic factors in Table 4 Page 93Complete Questions #1-3,5,8-10 on Page 93.96Section 3.3 Soil and Its Formation

Do not copyThe quality and amount of soil available are crucial factors in determining the size, and health, of the plant community and therefore the biodiversity of local ecosystems.

97Soil Layers:

Litter layer (upper layer) made of partially decomposed leaves or grasses. Acts as an insulator limits temperature variations & reduces water loss by evaporation.Topsoil (beneath litter) -made up of small particles of rock mixed with decaying plant and animal matter (humus). Humus is black, so topsoil is often dark.

Subsoil (below the topsoil) -usually contains more stones, mixed with only small amounts of organic matter. (Lighter in colour because of the lack of humus; may contain large amounts of minerals such as iron, aluminum, and phosphorous.Bedrock (beneath the soil) is a layer of rock which marks the end of the soil.

98Figure 2 in your textbook - page 98 draw this diagram into your notebooks99Formation of Soil

Soil begins as bedrock and is formed through the erosion of rock by water, wind, ice, or living things. Particles are broken off and mixed with organic matter to form the first soil (a thin layer). Process may take hundreds or thousands of years.

100Water Beneath the Soil

Surface water is precipitation that collects and flows above the ground. Lakes, ponds, and rivers are all surface water.

Ground water is the water found in the soil or rock layers of the Earths crust. It may flow into bodies of surface water.

101Percolation the process in which ground water, pulled by gravity, flows downward through the soil. (The larger the particles that make up the soil, the larger the spaces between particles and the faster the percolation rate.)

102Water table is the boundary, found either in the soil or the bedrock, between the area where ground water is percolating down and a layer that is saturated with water. In general, wherever rainfall is great, the water table will be higher (closer to the surface). See figure 3 on Page 98.

Leaching is a process in which nutrients such as organic matter and minerals are dissolved in percolating water and carried into lower layers of bedrock.

103What determines the pH of the soil?

The nature of the rock from which it was formedThe nature of the plants that grow in it the acidity of the rain and snow and therefore the ground water that enters the soilhumans by burning fossil fuels such as coal, oil and gasoline contribute to higher levels of acidity.

Acid deposition is a term used to describe the falling of acids from the atmosphere to the ground. Example: acid rain

104Section 3.3 Soil and Its Formation

Soil can be viewed as a series of layers. List and explain each of these layers.

Explain how soil is formed.

Define surface water and give examples of surface water.

What is ground water?

Define percolation and explain what increases percolation rate.

What is the water table?

Explain leaching.

What determines the pH of the soil?

What is acid deposition? Questions 1-3, 5,7,8 Page 99.105