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.