HOLY SPIRIT HIGH SCHOOL

2010-2011

Science 1206

Mr. Woodland

By: Emily V. Walsh

T E X T : S C I E N C E 1 0 ( N E L S O N – T H O M S O N L E A R N I N G )

1

Unit 1: Sustaining Ecosystems

Vocabulary

1. Ecosystem: a term used to describe the biodiversity among the many species

living in an environment as well as the relationships among those species and

the non-living parts of their environment. All ecosystems vary in their

organism composition and numbers.

2. Ecology: a specific branch of biology, which studies how organisms interact

with each other.

3. Biodiversity: the number of species in an ecosystem; and the variety within

those species; also known as biological diversity. It is very important to

ecosystems because every organism in an environment is connected to all other

organisms in one way or another.

4. Abiotic Factor: non-living factors in the environment, which influences living

(biotic) organisms. (Light, oxygen, water, temperature, space, nutrients)

5. Biotic Factor: a factor in an ecosystem created by the presence and roles of

other living things. (Producers, consumers, disease, competition for food,

symbiosis, predator-prey relationships, CO2)

6. Ecotone: the “grey” area between ecosystems where organisms from both

ecosystems interact with each other. They contain species from both bordering

ecosystem and often contain greater biodiversity than each individual

ecosystem (ex. Where forest meets field).

2

7. Climax Community: a biological community of plants and animals which,

through the process of ecological succession — the development of vegetation

in an area over time — has reached a steady state or equilibrium.

8. Biosphere: the ecosystem comprising the entire earth and the living

organisms that inhabit it.

9. Pest: any organism that we believe is harmful or undesirable, has a negative

impact on the human environment, or is in competition with human use of a

resource, either natural, or cultivated. (ex. Dandelions, Rodents, Insects, micro-

organisms that cause disease, etc.)

10. Pesticide: chemicals designed to kill pests.

o Insecticide: kills insects (ex. DDT)

o Herbicide: kills weeds (ex. Roundup)

o Fungicide: kills mould; fungi (ex. Captan)

o Bactericide (Antibiotics): kills bacteria (ex. Penicillin; Purell)

11. Bioamplification (Bioaccumulation): as organisms feed on each other, fat-

soluble pesticides are passed on from the prey to the predator. As the

predators eats more and more infected prey, the chemicals begin to accumulate

and concentrate. Once we reach the top of the food chain, this accumulation

can actually be deadly, because organisms eat far more than their own body

mass in food, therefore the farther up the food chain we go, the more

concentrated these fat-soluble chemicals are.

3

12. Water-soluble pesticides: pesticides have been developed that are not stored

in fat but are soluble in water; animals can remove these pesticides from their

bodies by breaking them down with their liver and excreting them

13. Biogeochemical Cycles: the cycling of material between living things and the

environment. (ex. The Nitrogen Cycle)

14. Organic Matter: always contains atoms of carbon and hydrogen; often contains

oxygen and nitrogen (ex. Proteins, Sugars, Fats, etc.)

15. Inorganic Matter: does not contain a combination of carbon and hydrogen

atoms. (ex. Carbon Dioxide, Water, etc.)

16. Photosynthesis: the process in which Green plants (other autotrophs) use the

energy from the sun to convert inorganic carbon (CO2) into organic forms food

molecules (carbohydrates). The formula is:

6 CO2 + 6 H2O + light = C6H12O6 + 6O2

17. Cellular Respiration: The chemical breakdown of complex organic substances,

such as carbohydrates and fats, that takes place in the cells and tissues of

animals and plants, during which energy is released and carbon dioxide and

water are produced. The formula is:

C6H12O6 + 6O2 = 6CO2 + 6H2O + energy

18. Nitrogen Fixation: a process in which nitrogen is converted.

1. Atmosphere (by lightning): The energy of lightning breaks nitrogen

molecules into nitrogen atoms, which react with oxygen in the air to

produce nitrogen oxides. These compounds then dissolve in rain to

produce nitrates, which seep into the soil.

2. Biological: Nitrogen-fixing bacteria found live in root legume plants

(such as peas, clovers, alfalfa, beans) and in the soil convert nitrogen gas

from the air into ammonia (NH3) and ammonium (NH4+).

4

19. Nitrification: a biological process during which nitrifying bacteria convert

ammonia (NH3) and ammonium (NH4+) into nitrites, then into nitrate.

20. Denitrification: a biological process during which denitrifying bacteria

convert nitrates back into nitrogen gas and release it back into the atmosphere.

21. Biomes: A biome is a large geographical region that has a particular type of

climax community. There are two major types of ecosystems:

22. Aquatic Eco system: an underwater ecosystem.

1. Can be subdivided into fresh water, estuarine and marine. These are

divided based upon their chemical composition, such as salt content, also

known as salinity.

23. Terrestrial Ecosystem: an ecosystem on land.

1. Terrestrial are subdivided into grassland, boreal forests (taiga), temperate

deciduous forest and tundra.

2. These are divided based upon the predominant vegetation (dominant

plant species) such as grasses or trees, etc.

3. These major terrestrial ecosystems are often referred to as biomes.

4. The major land biomes are encountered with changes in latitude as one

moves from the equator towards the poles. This concept is referred to as

latitudinal succession. The key to the concept is to realize that the

different lines of latitude receive different amounts of solar radiation,

which affects temperature and precipitation. As one moves over lines of

latitude, changes in climate occur that impact the types of organisms to be

found in any given biome.

5. Abiotic factors determine what type of plants can grow which, in turn,

determines the type of animals that exist in a particular biome. Abiotic

factors include temperature, precipitation, soil quality, length of growing

season and altitude.

6. Terrestrial biomes found in Canada are the tundra, boreal forest (Taiga)

or the coniferous forest, temperate deciduous forest, and grasslands (the

Prairies).

5

24. Permafrost: ground that is permanently frozen, often to great depths, the

surface sometimes thawing in the summer.

25. Active Layer: the layer of a tundra that defrosts in the summer; the layer above

the permafrost.

26. Clear-Cutting: when a section of a forest is completely cut down.

27. Strip Cutting: when strips of forest are cut down; this is done to prevent killing

off the entire forest, and to keep the ecosystem alive.

28. Nutrients: any mineral absorbed by plants or animals that are needed to

sustain life.

29. Peat: a highly organic material found in marshy or damp regions, composed of

partially decayed matter.

30. Fertilizers: any substance used to apply extra minerals and nutrients to soil.

31. Oligotrophic: used to describe a deep cold lake.

6

Biogeochemical Cycles

The Oxygen Cycle

The movement of oxygen between the atmosphere and living things by means of

respiration, evaporation and photosynthesis.

The Carbon Cycle

Multiple things delay this cycle:

o Inorganic reservoirs that Delay the Cycle are (carbon stored in) atmosphere,

oceans, and earth’s crust (limestone).

o Organic reservoirs that Delay the Cycle are (carbon stored in) bodies of living

things, peat bogs and fossil fuels.

Human Impact on the Carbon Cycle

- Releasing carbon from organic reserves faster than it occurs naturally.

- Increasing amounts of carbon in organic reserves (from combustion).

7

The Nitrogen Cycle

The movement of nitrogen through the ecosystems, the soil, and the atmosphere

is called the nitrogen cycle.

In order for nitrogen to be useful to organisms, it must be available as a nitrate

ion (NO3-).

Atmospheric nitrogen is converted into nitrates by the process of nitrogen

fixation, or nitrification, either by lightning or by bacteria in the soil.

Nitrogen is required to make proteins and DNA, which is the genetic material

found in every cell.

Decomposers break down the nitrogen compounds in the decaying material into

ammonia, which reacts with hydrogen ions to produce ammonium which, in

turn, undergo nitrification to give nitrates.

8

Phosphorous Cycle

Phosphorous is needed to make cell membranes, DNA and bones.

Phosphorous is cycled in two ways:

Involving the rocks of the Earth’s crust (a long-term process)

o Phosphates erode from rocks and dissolve in water; they are then

absorbed by algae and other plants.

Involving living organisms (a short-term process).

o Decomposers release phosphates from wastes and dead tissue.

Water Cycle

9

How Humans Have Altered Biogeochemical Cycles

Humans have influenced the biogeochemical cycles in FOUR ways:

1. Greenhouse Effect

It is the gradual increase in carbon dioxide levels in the atmosphere.

Excess CO2 causes more heat to be trapped by the atmosphere.

The atmospheric temperature will rise gradually, leading to the phenomenon

called global warming (the overall warming of the earth’s temperature) (see p.

64).

2. Ozone Depletion

The ozone layer is a t hin layer of a bluish gas located in the stratosphere (O3)

that helps to screen out ultraviolet radiation.

CFC’s (chlorofluorocarbons) are the main cause of ozone depletion which

turns O3 into oxygen O2.

Cl + O3 = ClO + O2

ClO + O3 = Cl + 2O2

2O3 = 3O2

Ozone holes above the Canadian Arctic and Antarctica have been identified.

An ozone hole is a region in the ozone layer in which ozone levels have been

considerably reduced and the layer has become thin.

This causes an increase in UV radiation reach the earth’s surface, which can

lead to increases in skin cancer.

3. Eutrophication

A b uild-up of nutrients (such as nitrogen and phosphate fertilizers) in water

can lead to the environmental problem of eutrophication.

These nutrients cause algae to grow rapidly and lead

to the problem of algal bloom. Algal blooms are one

of the consequences of eutrophication.

Masses of blue-green algae can literally choke the life

out of a lake or pond by depriving it of much needed

oxygen.

Under extreme conditions, an eutrophic lake or pond may be left entirely

deprived of fish (p. 70).

An eutrophic lake is a shallow and warm body of water which contains an

abundant supply of nutrients. (p. 127)

10

4. Deforestation

Deforestation refers to the total removal of trees and/or vegetation from a

particular area or site.

It may have an effect on the cycling of

materials in an ecosystem.

For example, the tropical rainforest is a

fragile environment that is threatened by

human activities.

Large areas are being cut for wood and also

for farming. Once vegetation has been

removed, the soil loses its fertility quickly

and in a few years the land must be abandoned.

Plant and animal life do not usually recover from such destruction (p. 72).

Terrestrial Biomes

THE TUNDRA

Location: South of the ice caps of the Arctic extending across North America.

Climate: Low average temperature; Average yearly precipitation of 10-12 cm. Due to

low evaporation, the region is wet with ponds and bogs during the short, warm

summer (poor drainage); The bogs consist of peat soaked within melt water form

because melting snow cannot drain into the permafrost; Short growing season of about

60 days.

Plants: mosses, lichen (reindeer moss), grasses, sedges and shrubs

Animals: Musk oxen, caribou, wolves, Arctic hares, Arctic fox, lemmings (shrew-type

animal) and snowy owls; Insects include black flies and mosquitoes

Soils: Permafrost (permanently frozen soil) is present; This makes the growth of large

plants impossible; It ranges in depth from a few inches to several feet; The thin,

uppermost layer of the soil (active layer) will thaw during summer but is of poor

quality because the cold reduces activity of decomposers (bacteria and fungi) so there is

slow cycling of matter and little organic matter, thus slow decomposition.

11

BOREAL FOREST (TAIGA)

Location: South of the tundra extending across North America; Newfoundland is

considered part of the boreal forest biome

Climate: Cold winters with the ground covered in snow and warm summers causing

the ground to thaw completely; Average precipitation of 50-100 cm???; Growing season

is about 120 days.

Plants: Conifers (pine, fir, spruce), deciduous conifers (tamarack), some deciduous trees

(birch, maple), blueberry and cranberry shrubs, ferns, moss, etc.

Animals: Moose, bears, marten (pine marten), lynx, snowshoe hares, foxes, beavers;

Variety of birds such as warblers (coniferous nesters); Wide variety of insects, includes

pests of trees like the sawflies and spruce budworms.

Soils: A deep litter layer and higher temperatures allow more rapid decomposition;

Acidic and mineral deficient, due to large amounts of water moving through the soil.

TEMPERATE DECIDUOUS FOREST

Location: South of the boreal forest in southern an d central Canada.

Climate: Cold winters with hot summers; Average precipitation of 75 to 150 cm;

Growing season is about 180 days.

Plants: Deciduous trees (maple, birch, chestnut, hickory, beech, oak) that lose their

leaves seasonally; Well-developed and diversified shrubs, ferns, moss, etc.

Animals: White-tailed deer, black bear, gray fox, squirrels, chipmunks, skunk, raccoons

and mice; Wide variety of birds including wild turkeys and woodpeckers; Amphibians,

reptiles and insects are also abundant and diverse.

Soils: Brown forest soils; Thin surface litter (decomposing leaves) layer due to rapid

decomposition, earthworms being active; Upper soil is mildly acidic due to the litter

layer. Acidity decreases with depth; More fertile than Taiga soils because of high levels

of nitrates and other soil nutrients held by clays.

12

GRASSLANDS

Location: Interior of North America (usually referred to in Canada as “the Prairies”)

Climate: Very cold winters with hot summers; Average precipitation of 25 to 75 cm;

Growing season is about 180 days

Plants: Grasses and wild flowers; Trees are limited to low valleys and low mountains

Animals: Snakes, badgers, prairie dogs, ground squirrel (burrowers), antelope, elk,

coyote, wolves; Bison were once numerous; Grassland birds are limited due to the

consumers (???) such as sparrows, rodent- eating hawks; Most abundant insect is the

grasshopper

Soils: Soil is deep and rick (fertile), causing this biome to become the most productive

farmland on Earth; Called chermozam?? soils, or black earths, organic matter

accumulates in the upper portion of the soil, making it dark; Neutral or slightly

alkaline.

Aquatic Biomes

Marine Biomes

Marine biomes are oceans on the Earth that are interconnected, which contain a

salt water environment.

The marine biome covers more than 70% of the Earth’s surface.

Temperatures remain fairly constant in the marine biome, with a variation with

latitude.

Ocean temperatures vary from 0 degrees in the Polar regions to 32 degrees near

the Equator.

The evaporation of the marine biome provides most of the Earth’s rainfall, and

the ocean’s temperature has a major effect on the world climate and wind

patterns.

Marine algae supply a substantial portion of the world’s oxygen.

Marine biomes are divided into two zones. These marine communities are

classified based upon depth:

Coastal zones (Intertidal/Littoral zone & Neritic zone)

Open ocean/Pelagic zone

13

Intertidal Zone (Littoral)

Regulated by the tides caused by force of the moon.

It is home to many small species of fish and plant life.

This area is covered by water during high tide and uncovered at low tide.

Many types of seaweeds live here, along with clams, crabs, mussels, and star

fish.

Neritic Zone

Includes the shallow waters above the Continental Shelf, which extends out

about 300 km.

This zone contains the nutrients carried into oceans and rivers.

This zone is shallow; therefore, light reaches all the way to the ocean floor.

Oganisms such as algae, fish, mussels, crabs, barnacles, oysters, worms, and sea

cucumbers live here.

Open Ocean (Pelagic Zone)

Filled with many large animals like sharks and whales.

Because the water is deep in the ocean, light cannot reach the bottom so

photosynthesis cannot occur.

14

Freshwater Biomes

The freshwater biome is comprised of rivers, lakes, ponds, swamps, bogs, etc.

The volume of water in this biome is much smaller than that of the marine

biome.

The temperature variations are larger.

Organisms living in fresh water must be able to adapt to a greater seasonal

variation than those living in the ocean.

Freshwater Biomes Composed of Three Zones:

1. Littoral Zone: lots of light, warm/cold, oxygen; close to shore; and

organisms include waterlilies and sedges

2. Limnetic Zone: area of open lake; sufficient light and oxygen; heat will

decrease with depth; and organisms include plankton and fish.

3. Profundal Zone: deep area of lake; no light, very little oxygen; cold

water; and organisms include bacteria and bottom-dwelling

invertebrates.

15

Plankton

Plankton are generally slow-moving organisms that cannot swim strongly

enough to avoid being carried about by water currents. Most plankton is

microscopic.

There are two types of plankton:

1. Phytoplankton (plant plankton)

Usually consists of one-celled

plants such as diatoms and

dinoflagellates.

Forms the base of the aquatic food

webs.

Growing using only the sunlight and the minerals in the water

(photosynthesis). Therefore, they are considered autotrophs.

2. Zooplankton (animal plankton)

They are heterotrophic and feed on phytoplankton.

What Abiotic Factors Affect Life in Aquatic Biomes?

1) Water

Is always present in the aquatic biomes unlike the terrestrial biomes.

2) Temperature

Water has a high heat capacity.

When the oceans absorb heat energy from the sun in the summer, they store it

in the colder months. Therefore, the ocean maintains a relatively constant

temperature throughout the year.

Lakes and ponds show more change than the oceans.

Oceans have an effect on the temperature of the land. Without oceans, the

temperature of the earth would vary much more than it does.

3) Latitude

Water temperature varies from 0 degrees (polar regions) to 32 degrees Celsius

(near equator).

This variation in latitude affects the kinds of marine life that can survive in

what areas of the ocean.

16

Estuaries (coastal marshes)

More productive biome than either the ocean or fresh water.

Water is mostly shallow allowing light to penetrate to the bottom.

Plant life is abundant and varied.

Animal life is abundant (Some fish use the estuary as a nursery. When the young

are large enough, they leave the estuary.).

Sources of Water Pollution

Human sewage Decaying plant life Pesticides

Industrial waste Animal waste Detergents

Runoff Fertilizers Herbicides

How Oil Enters Marine Ecosystems

Oil tanker accidents

Offshore wells spills

Onshore oil spills through drainage pipes

17

Disadvantages of the Oil Pollution on Marine Ecosystems (p. 148)

Floating oil harms birds because they no longer are waterproof and then freeze

to death.

Can prevent birds and marine mammals from breathing.

Heavy oil sinks and destroys bottom dwellers such as mussels, crabs, and

oysters. Since bottom dwellers are part of the food chain, oil eventually enters

the bodies of birds, fish and mammals.

Pesticides

First Generation Pesticides

Early pesticides include the use of toxic substances such as lead salts, arsenic, or

mercury. They worked to kill the intended pest, but also killed beneficial organisms and

caused pollution. They were non-biodegradable, and as a result they began to

accumulate in the environment, contaminating water and soils, which then lead to

killing humans.

Second Generation Pesticides

In the 20th century, organic pesticides were designed to be less toxic to humans,

and more specific to the intended pests. At the time, it seemed like a good idea until

other negative effects on the environment began to become clear through

bioaccumulation (ex. DDT accumulated majorly in Bald Eagles, who, as migratory

birds, accumulated the pesticide from eating large amounts of prey in different places,

slowly killing off the species.

Third Generation Pesticides

New pesticides have been developed that are not stored in fat (unlike the

previous ones) but are in fact soluble in water, meaning that animals could remove the

chemicals from their bodies much eaiser. But, these chemicals break down in the soil

much faster, meaning that more applications are required to kill the intended pest.

Because of multiple applications, the pests can become immune to it over time. Also,

bioaccumulation can still occur in food chains, and is considered the lesser of two evils.

18

Sustainability

A sustainable society satisfies the basic needs of its organisms (ex. Food, Shelter,

Water). It doesn’t deplete natural resources to a point where they connot recover.

To encourage sustainability, you can drive a hybrid car, cote for environmentally

conscious politicians, take things to your local recycling depot, and use reusable

shopping bags.

Some Questions to Think About

Q: What are the “Big Four”?

A: Hydrogen, Carbon, Nitrogen and Oxygen. They are the basis of all living things, and

cannot be created, therefore it must be recycled.

Q: How does oil get spilled into ecosystems and how does it affect them ?

A: It spills from oil tanker accidents, offshore wells spills, and onshore oil spills through

drainage pipes. Floating oil harms birds because they no longer are waterproof and

then freeze to death. Can prevent birds and marine mammals from breathing. Heavy

oil sinks and destroys bottom dwellers such as mussels, crabs, and oysters. Since

bottom dwellers are part of the food chain, oil eventually enters the bodies of birds, fish

and mammals.