The Living World

The Living World

The biosphere is the layer around the Earth containing all living organisms.

The other spheres are:◦ Lithosphere

◦ Hydrosphere

◦ Atmosphere

What is the biosphere?

A biogeochemical cycle is a set of processes by which an element passes from one environment to the next and eventually returns to its original environment, in an infinite loop of recycling

There are two cycles we will be dealing with

◦ Carbon cycle◦ Nitrogen cycle

Biogeochemical Cycles

This biogeochemical cycle involves the exchange of carbon on Earth

There are 9 parts to the carbon cycle

They are not steps which follow (1-9), but rather a list of the different processes which take place

The Carbon Cycle

1- Photosynthesis : Plants using solar energy to capture and convert atmospheric carbon (CO2) into glucose (C6H12O6)

2- Ingestion : Animals eat plants or other animals

3- Respiration : As living organisms breathe, they exhale the carbon ingested back into the atmosphere

The Carbon Cycle

4- Decomposition of waste : Waste of animals not released during respiration (urine, feces, dead organisms, etc.) are decomposed by organisms which emit CO2 and methane CH4

5- Forest fires – Combustion of tree trunks and leaves are converted into CO2

The Carbon Cycle

6- Shells and skeletons : Part of the carbon dissolved in the water reacts with calcium to form calcium carbonate (CaCO3) which is part of shells and skeletons

7- Carbonate rock : The calcium carbonate from the skeletons and shells accumulates at the bottom of the ocean floor which forms carbonate rock.

The Carbon Cycle

8- Volcanic eruptions : When the carbonate rock meets the magma, it melts and releases some of the CO2 back into the atmosphere

9- Fossil fuels : When dead organisms fall to the ocean floors, the carbon in them remains buried in the sediment. This carbon can be turned into fossil fuels (coal, oil and natural gas)

The Carbon Cycle

A biogeochemical cycle involving all the exchanges of Nitrogen on Earth

There are 5 parts to the Nitrogen cycle

The Nitrogen Cycle

1- Nitrogen Fixation : Certain bacteria take atmospheric nitrogen and convert it to ammonium (NH4

+)

2- Nitrification : Bacteria oxidize ammonium to form nitrites

3- Nitrogen absorption : Plants absorb the ammonium and the nitrites. Herbivores only source of nitrogen

The Nitrogen Cycle

4- Decomposition of waste : Bacteria and fungi break down nitrogen containing substances. They produce ammonia which then forms ammonium

5- Denitrification : Bacteria converts nitrates into molecular nitrogen which returns to the atmosphere.

The Nitrogen Cycle

A biome is a large region of the world with distinctive climates, wildlife and vegetation

Flora = Plants

Fauna = Animals

Biomes

Terrestrial Biomes Aquatic BiomesLatitude SalinityAltitude Turbidity (water clarity)Temperature TemperaturePrecipitation Direction and strength of the

currentSoil type Presence of oxygen O2 and

carbon dioxide CO2 for respiration and photosynthesis

Solar energy Solar energyWinds Nutrients (type, amount, etc.)Proximity to bodies of water Water depth

Factors Determining Biome Distribution

Terrestrial biomes are described mainly by temperature and precipitation.

These factors determine the plant species which can live there

The plants determine the animal species which can live there.

Terrestrial Biomes

Terrestrial Biomes

There are 7 terrestrial biomes on the Earth

1- Tropical forests 2- Boreal forests 3- Temperate forests 4- Grasslands and shrublands 5- Arctic tundra 6- Deserts 7- Alpine

Terrestrial Biomes

The tropical forests are along either side of the equator between the tropic of Cancer and the tropic of Capricorn

The mean annual temperatures vary between 20°C and 34°C

The tropical forests have both seasonal forests and evergreen forests

Tropical Forests

Located in the Northern Hemisphere. Forms a belt below the arctic.

Long cold winters. Long days in Summer.

Conifers, forest floor carpeted with moss and lichen

Boreal Forest

Located in southern Canada, the United-States, Europe and part of Asia

Mean annual temperatures of 8°C to 10°C. High precipitation throughout the year.

Northern regions of Quebec, mixture of conifers and deciduous varieties. Farther south, primarily deciduous trees.

Temperate forest

Many are located in central North America

In the temperate grasslands: Hot summers and long cold winters. In the savannas: Hot all year long

Grasses and shrubs. Three types: Temperate grasslands, savannas, derived grasslands

Grasslands and Shrublands

Located to the north of the boreal tundra. Forms a ring around the North Pole

Long, cold winters. Very short summers. Permanently frozen ground.

Grasses, stunted bushes, moss, lichen

Arctic Tundra

At all latitudes

Low precipitations (less than 25cm per year) Extreme temperatures

Rare plant life

Deserts

Any high-altitude area in the world

Temperature varies according to altitude (about 0.6˚C per 100m)

Vegetation zones: Submontane, montane, subalpine, alpine and nival.

Alpine biomes

Aquatic biomes cover a large area of the surface of the Earth. (Approximately 75% of the Earth)

Freshwater biomes cover about 2.5% of the aquatic biomes and marine biomes cover the remaining 97.5%

Aquatic Biomes

Freshwater has a salinity of less than 0.05%

Saltwater has a salinity greater than 3%

There are 3 freshwater biomes and 3 marine biomes

Lakes, Rivers and Wetlands for freshwater Estuaries, Oceans and seas, and Coral reefs

for Marine

Salinity of Water

Bodies of water surrounded by land and fed by springs, rivers or precipitation

The organisms living there are microorganisms, plants, plankton, fish, amphibians, reptiles and birds.

Lakes

Streams and rivers that form permanently or seasonal drainage channels for surface drainage.

Moss, grass, fish, etc. live in rivers and streams

Rivers

Includes marshes, swamps and peat bogs.

They are areas permanently or temporary covered with water.

Life there includes plants which grow well in water-saturated soil

Wetlands

Broadening at the mouths of rivers acting as a mixed zone between the maritime and river environments.

Examples of organisms living there are belugas, oysters and sponges

Estuaries

Bodies of water that are subdivided according to the depth of the water

Phytoplankton, crustaceans, fish, jellyfish, mollusks, birds and mammals all live there.

Oceans and seas

Environments characterized by the presence of calcium carbonate produced by coral

Between 500,000 and two million plant and animals species live there.

Coral reefs

Populations

What is a population?

Density

Distribution

Biological Cycles

Study of populations

A population is a group of individuals of the same species, living in a shared space at a specific point in time.

The population size refers to the number of individuals in a population

What is a population?

What can affect the size of a population?

Populations

Raise the population Decrease the population

Birth Death

Immigration Emigration

Counting individuals◦ When possible, scientists will count every

individual of a population.◦ This is not possible in a very large population, or

in a very large area.

Counting by sample area◦ By counting a small sample of a territory,

scientists can extrapolate from there to estimate the total population

How to measure the population

Mark and Recapture◦ Scientists capture a number of individuals and

mark them.

◦ Scientists return and recapture individuals again.

◦ By counting how many of the individuals were recaptured, the total population can be estimated.

◦ Number of marked animals recaptured = Number of marked animals

◦ Total number of animals captured 2nd time Population size

How to measure the population

The number of individuals in a given space◦ Ex: 64927 people in 125 km2

Ans: 519.416 people/km2

How would you find the density of the population of Canada?◦ Population: 34,734,000 (2012 est.)◦ Surface Area: 9,984,670 km2

Density = 3.47/ km2

Density

1.Monaco 15,293/km2

2.Singapore 6,843/km2

3.Vatican City 1,884/km2

4.Maldives 1,328/km2

5.Malta 1,287/km2

6.Bangladesh 1,199/km2

7.Bahrain 971/km2

8.Taiwan 714/km2

9.Barbados 664/km2

10.Mauritius 637/km2

Top Population Densities

228thDensity ~3.5/km2

Which rank is Canada?

Russia vs Canada

Russia Canada

Size 17,075,400 km2 (1st)

Population 143,030,106 (8th)

Density 8.3 (271st)

Size 9,984,670 km2 (2nd)

Population 34,754,000 (35th)

Density 3.5 (228th)

Distribution

Alternating rise and fall of population sizes◦ They are of fixed duration and are repeated

continually

Biological Cycles

Lynx and Hare

Biotic factor (living)◦ Related to the actions of living organisms

Abiotic (non-living)◦ Physical or chemical aspects of the environment.

Influence of Biotic and Abiotic Factors

Biotic vs Abiotic

Biotic Abiotic

Birth rate Disease Amount of food Predation Competition Human Activity

Amount of light Soil or water pH Terrain Depth of snow Temperature Air Humidity

Conditions can favour the predators or the prey which will affect the other◦ An increase in predators will cause a decrease in

the prey population If conditions go against the predators, they

wont be able to hunt and die off◦ This will cause a massive increase in the prey

population

How do these factors affect biological cycles?

Community vs Ecosystem

Community Ecosystem

A set of populations of different species sharing the same habitat

Community of living organisms interacting with one another and with nonliving components of the environment they inhabit

What is Biodiversity?◦ The relative abundance of the species in a

community

What can affect the biodiversity of an ecosystem?◦ Competition◦ Predation◦ Mutualism◦ Commensalism

Dynamics of Communities

Interaction between living organisms that seek the same resource in their habitat.

Can be between individuals of the same species (intraspecific) or between individuals of different species (interspecific)

Both animals and plants can be competing for a limit number of resources.

Competition

If two predators are both competing for the same prey, the more successful predator will win out.

Two animals both trying to use the same site for a habitat will also compete.

Plants will compete for light and water in a forest or jungle. The plant that can get the most light or water will be the winner.

Competition

The interaction between two living organisms where one feeds on the other.

The most obvious form of predation is one animal eating another animal. Another form is an animal eating a plant.

A specialised form of predator is a parasite which lives directly on or inside it’s prey and slowly feeds off of it.

Predation

Interaction where both species benefit from the relationship.

One example of this is the clown fish and the sea anemone.

The anemone feeds by poisoning fish with it’s tentacles and feeding off of them. The clown fish has a mucus on it’s skin which blocks the poison. The clown fish acts as bait for the anemone’s prey and also uses the anemone as a home.

Mutualism

Another common example is a flowering plant and a pollinator.

Without the flower, the pollinators would not have food to eat

Without the pollinators, the plants would have a much harder time to reproduce.

Mutualism

Interaction where one organism benefits and the second one is not affected

Seagulls and humans. They eat our garbage. They benefit and it doesn’t affect us at all.

Also, birds who build their nests in trees. The birds get shelter and safety, the tress are unaffected.

Commensalism

Type of interaction Effect on population A

Effect on population B

Competition

Predation

Mutualism

Commensalism

Interaction review

Type of interaction Effect on population A

Effect on population B

Competition- -

Predation+ -

Mutualism+ +

Commensalism+ 0

Interaction review

What is an ecosystem?◦ A community of living organisms interacting with

one another with the nonliving components of the environment they inhabit

An ecosystem can be anything from an aquarium to a lake or a forest

In an ecosystem there are 3 trophic levels.◦ Producer, consumer and decomposer

Dynamics of Ecosystems

These are organisms which can transform inorganic matter into organic matter.

Inorganic matter is something not produced by a living organism◦ Ex. Water, mineral salts

Organic matter is used in the composition of living organisms and is usually created by them.◦ Ex. Protein, lipids, carbohydrates

Producers

These are typically organisms such as plants, algae and certain bacteria

They are said to be autotrophs◦ Means they can feed themselves.

They can feed themselves by photosynthesis and by absorbing nutrients from the soil.

Producers

Heterotrophic organisms that feed on other living organisms.◦ Heterotrophic means they need others to feed.

Primary consumers feed directly on producers

Second, third or fourth consumers eat consumers which are below them.

This is all part of the food chain.

Consumers

What type of consumer would a herbivore be?◦ First

What type of consumer would a carnivore be?◦ Second or higher

What type of consumer would an omnivore be?◦ Any level◦ An omnivore is an organism which eats plants and

animals.

Consumers

Organisms that feed on the waste and remains of other living organisms.

This trophic class consists of certain worms, some bacteria, all fungi and certain insects.

They can also be prey to consumers.

They break down the organic matter into inorganic matter so that it can be used all over again.

Decomposer

Law of Conservation of Mass

Nothing is created, only transformed

Inorganic material becomes organic then becomes inorganic again

Nature is one big recycler...

Dynamics of Ecosystems

Energy is produced from inorganic sources by producers

Energy is then transferred to consumers by eating the producers

The waste and decaying bodies of the living are decomposed by the decomposers and converted back to inorganic matter

Energy Flow

Biomass is all of the living matter in a given Ecosystem

This will be different for each ecosystem

Primary Productivity is the amount of new Biomass being produced by the producers of a given ecosystem

The Primary Productivity can be influenced by four abiotic factors

Primary production in Ecosystems

1- Light◦ Necessary for photosynthesis

2- Water◦ Also necessary for photosynthesis

3- Essential Nutrients◦ These include Nitrogen, Carbon, Phosphorous and Potassium

4- Temperature◦ Temperature can have an influence on production

Factors that influence productivity

A Disturbance is an event that damages an ecosystem. It can lead to the elimination of organisms and alter the availability of resources

Disturbances can be of different types. They can be something like snowstorms, sandstorms, hurricanes or volcanic eruptions

Some are more frequent, like seasonal flooding, and some are less frequent, like a flood caused by torrential rains.

Disturbances

Disturbances can also be more or less serious in nature. A small ice storm which lasts only a few hours will cause much less damage than one that lasts a few days. That was the case in the ice storm of 1998 in Quebec

Disturbances can either be natural or human in origin.

Disturbances

They are events triggered by environmental phenomena rather than humans, but damage ecosystems nonetheless.

Every single ecosystem can be effected by a natural disturbance no matter how remote they may be.

Natural Disturbances

Volcanic eruptions

Forest fires

Drought

Floods

Periods of frost

Heat waves

Types of Natural Disasters

They are events that are triggered due to human activity.

Many human activities damage ecosystems

They can be small scale, such as littering, or large scale like oil spills or deforestation

Human Disruptances

After an ecological disturbance, an ecosystem will undergo a series of gradual changes, sometimes spread over hundreds of years

The ecosystem will try to obtain a state of balance

Ecological succession is the series of changes that occur in an ecosystem after a disturbance and that continue until the balance of the ecosystem is restored

Ecological Succession