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SNC1P Sustainable Ecosystems and Human Activity

Ecology is the branch of biology concerned with

The atmosphere The atmosphere

. This insulates the surface of the earth by retaining heat and reducing temperature extremes between day and night.

The atmosphere is made up of 78% nitrogen, 21% oxygen, and the remaining 1% is a mixture of other gases.

The lithosphere is The lithosphere extends from the highest mountain peak to the

deepest ocean floor.

The hydrosphere includes • Hydrosphere can be found in streams, lakes, rivers, soil,

groundwater, and even evaporated in the air!

The biosphere is the • The biosphere interacts with and exchanges matter and energy

with other spheres.

Earth's spheres are so closely connected that a change in one sphere often “causes” a change or impact in one or more of the other spheres.

An ecosystem includes

Non living organisms are

Examples:

Living organisms in an ecosystem are biotic factors. Biotic factors

Examples:

Green plants are . Green plants are called producers.

Consumers are

Decomposers . They also break down the waste (poop) of other organisms. Decomposers are very important for any ecosystem.

Scavengers are . While they eat them, they break them into small bits.

Examples:

Sustainable Ecosystem: An ecosystem that is capable of withstanding pressure while giving support to a variety of organisms.

• Sustainability is the ability of biological systems .

• Invisible chemical cycles redistribute water, oxygen, nitrogen, and carbon through the world’s living and non-living systems. These cycles have sustained life for millions of years.

• Increases in human population and over consumption of natural resources have changed the balance of natural cycles in the ecosystem. This has had a negative impact on both humans and other living systems, rendering a once sustainable ecosystem - unsustainable.

An organism: A Species: Is

A population:

A community: Is

Your habitat

The niche

Natural Selection: You have i n your population.

Evolution is

An adaptation – Webbed toes to swim faster– A wooly coat to stay warmer– Longer claws with which to fight better– Larger eyes to see more

Organisms are consumers of energy.•

• The , and the fuel for ecosystems, is the sun.

• It is stored as chemical energy in carbohydrate molecules

Food chains•

when herbivores eat plants, and carnivores eat herbivores.• These interactions form food chains.• In a food chain,

Food Webs A single food chain illustrate only part of what happens in an

ecosystem.

Herbivore –

Carnivore –

Omivore –

Decomposer –

In Summary:• Because green plants convert radiant energy into chemical energy

for ecosystems, they are called • Animals that eat plants are called

• Animals that feed on the plant-eaters are called

• To maintain an ecosystem, there must be continual input of energy from the sun.

Nutrient Cycles• Producers . • Herbivores (plant eaters) get their nutrients

• Carnivores (meat eaters) get their nutrients

• Decomposers get their nutrients from

The Water Cycle

•

• Water vapour enters the atmosphere through transpiration from vegetation (transpiration is the loss of water through pores in the leaves of plants).

• Water vapour also enters the atmosphere by evaporation from bodies of water.

• In the cool atmosphere, the water vapour condenses, forming clouds.

• When enough water is collected in the clouds, the water returns to the ground as precipitation.

• Some of the water runs along the surface (surface run-off) of the ground to a stream, pond, or other body of water.

• Some of the water soaks into the ground through percolation to become ground water. The ground water may eventually run back to lakes, ponds and other bodies of water.

• Some of the water in the soil moves up to the roots of plants. The roots absorb the water and this is how plants obtain the needed hydrogen and oxygen.

• Animals can obtain some hydrogen and oxygen by eating the plants or drinking the water.

The Carbon Cycle

• Carbon is another nutrient that organisms need.

• Carbon is found in air and in water as carbon dioxide.

• .

• Once carbon is in the producers,

•

• Photosynthesis and cellular respiration

• CO2 is returned to the atmosphere from body wastes and dead decaying organisms. Decomposers break down animal and plant waste and this too returns the carbon dioxide to the soil and atmosphere.

Disrupting the Carbon Cycle• Over the centuries, the amount of carbon dioxide produced by

cellular respiration has tended to equal the amount of carbon dioxide absorbed by photosynthesis. Thus

• About 300 million years ago, vast areas of swamp became filled with decaying plant material.

• This material was buried under thick layers of sediment. There was no oxygen so the plant material could not be broken down by the decomposers. Large amounts of carbon were locked up in the ground.

• Over millions of years, .

• This balance can be changed however,

Soil• Soil is a complex mixture of

.

• Soil is also the home to countless organisms ranging from microscopic bacteria to large burrowing mammals.

• Soil is made up of a number of layers, each having its own distinctive colour and texture.

o) a) b) c)

Littero The upper layer is known as the

o The litter acts as a fluffy blanket that limits the temperature variation and reduces water loss.

Topsoilo Topsoil is the layer made up of small particles of

o

o Topsoil is rich in nutrients and minerals, which is good for plant growth.

Subsoilo The subsoil is a layer that contains

o

o The subsoil does contain a lot of iron, aluminum, and phosphorus.

Bedrocko At the bottom of the soil profile is the bedrock.o

. This process is called weathering.

Soil Nutrients Plants require nutrients to grow. The most important nutrients

are nitrogen, phosphorus, and potassium.

When farmers harvest the crops, the nutrients contained in the tissues are removed from the system.

If human and animal wastes are not returned to the farmland,

Fertilizers• The

•

• . In the 1960’s, farmers began using synthetic fertilizers and caused the Green Revolution! Food production and farm profitability increased dramatically.

• Synthetic fertilizers are highly concentrated and may enter the soil rapidly. This will alter the community of soil organisms.

Water above the soil To raise healthy livestock and grow crops, farmers must have a

reliable supply of water.

Terrestrial Ecosystems• There are a few prominent and easily recognizable types of

ecosystems in the earth’s biosphere.• These ecosystems have characteristic features

• Desert• Coral reef• Tropical rainforests

• The most important factor in determining the location and makeup of a terrestrial ecosystem is climate.

• .

• The natural landscape in Canada is dominated by four major biomes:

• • • •

• BC contains several smaller biomes, including the mountain forest biome, which extends into Alberta.

• Eastern Canada also has a few smaller biomes.

Tundra Biome

Abiotic Factors Communities

••••• Thin topsoil• Slow decomposition rate (soil never gets the

nutrients so it is poor quality)

• Rapid flowering plants• Mosses and lichens• Ptarmigan• Caribou• Lemmings• Arctic foxes• Wolverines

Boreal Forest

Temperate Deciduous Forest

Abiotic Features Communities

• Harsh climate,

• (extreme hots and colds)

•

• 40 cm precipitation per year

• Coniferous trees (spruce, cedar, tamarack, pine)• Shade loving plants• Seed-eating birds• Squirrels• Deer• Grey wolves

Abiotic Features Communities

••• Faster decomposition rate so better soil

fertility• 100 cm/year precipitation

• Leafy trees such as oak and maple• Shrubs and ferns• Ground and tree squirrels• Many insects and rodents• Wood peckers• Deer• Black bears• Wolves

Grassland

Mountain Forest

Abiotic Features Communities

•

•

•• 25 to 75 cm precipitation per year

• Grasses• Grasshoppers• Bison• Mice• Voles• Snakes• Hawks• Wolves

Abiotic Features Communities

••••• Fast flowing rivers

• Marmots• Squirrels• Elk• Black and grizzly bears• Cougars• Coniferous trees• Ferns

Aquatic Ecosystems

• Aquatic ecosystems are divided into two broad categories.•

•

• Rivers and streams are continually being flushed with fresh water from upstream.

• Lakes are classified based on nutrient level.•

•

• Wetlands (bogs and marshes) are large areas of shallow water or wet soil that are nutrient rich and support a lot of populations.

• A Wetland is an area through which all water drains into a single river or lake.

• All water flows downhill so if a watershed becomes polluted, so does the area downstream.

Marine Ecosystems•

• Most of the water that evaporates into the air and falls as rain or snow comes from oceans.

• Even though there is a lot of ocean, The ocean is nutrient

poor and unable to support photosynthesizing organisms. Plus the deep ocean is a lightless environment so photosynthesis is impossible!

• In contrast,

• Coral reefs develop in warm shallow oceans and support a huge variety of organisms. Coral reefs though, are extremely sensitive to changes in water temperature, acidity, and pollution.

•

•

•

• Mangroves contain specialized tree species adapted to live at and beyond the water’s edge. This reduces coastline erosion and creates habitats for marine organisms.

Intertidal Zones• Ocean coastlines are ecosystems that are part time terrestrial and

part time aquatic. They are home to unusual communities that occur in the area between

Biodiversity• Biological Diversity, or biodiversity,

•

Species at Risk• When a population’s size declines below a critical level, the

species will no longer be able to fill its ecological niche.

• This has biotic and abiotic consequences on an ecosystem.

•

• There are five categories according to the COSEWIC experts:• • • • •

Classification Definition Examples in Canada

Extinct • Great auk• Passenger pigeon• Sea mink

Extirpated • Paddlefish• Atlantic walrus

Endangered • Barn owl• Swift fox• Northern cricket frog

Threatened • Humpback whale• Wood bison• Kentucky coffee tree

Special Concern • Polar bear• Red-headed woodpecker• Atlantic cod

Habitat Loss• Farmland, human settlement and highways have replaced much of

Ontario’s Forest Ecosystem.• In Canada, most of the natural landscape was lost to

urban developments in the 19th and 20th centuries. A lot of land was cleared for farming and more recently, land has been taken over by developments and transportation routes.

. This exposes more of the outside influences to habitats.

Non Native Species•

. Introducing a species from another area by humans has been a major cause for the loss of some precious native species.

• An invasive species is a non-native species whose introduction to an area has had negative impacts on the environment.

Controlling Non Native Species• Preventing accidental introduction of a non-native species is an

ideal way to control species, but difficult.–

– Mechanical control is another way to control species.

– Biological control is challenging, but effective. BC (Species are controlled in their native land this way, why not try it here).• Biological control rarely eradicates a species. It is

more of a reduction to tolerable levels that is achieved.

Pollution• For thousands of years, Aboriginal peoples lived in relative

harmony with their environment.

• Two factors have changed the relationship humans have with their environment:

• •

•

•

Chemicalo Many toxic and persistent chemicals have been invented to

support our lifestyle.o

o Auto exhaust and product packaging are by products of our consumer society.

o Even biodegradable products can pollute the environment when put out in high concentrations.

Acid Precipitation• Sulfur Dioxide and Nitrogen oxides are two damaging air

pollutants.

• Sulfur dioxide and nitrogen oxides

• They become part of the water cycle

• Acid precipitation impacts aquatic and terrestrial ecosystems.

• Rivers and lakes become more acidic, species decline and disappear.

• Not all rivers and lakes are equally affected .

• Acid precipitation affects humans as well.

• Acid precipitation speeds up the corrosion of

• Acid precipitation dissolves

Consumption and Resource Management• most

notable – wood and wood fibre.• Forest harvesting methods fall into three categories:

• • •

Clear cutting is

• Clear cuts take the shape of large blocks, strips or patches. Regeneration can then take place.

Shelter wood cutting is , permitting regeneration of the remaining trees, usually the ones that were under the shelter of the mature trees.

Selective cutting is when the forest is managed as an uneven aged system.

This is .

• Natural forests sustain themselves without being managed but when producing wood fibre, management is widely practiced.

• Clear-cutting is easy, efficient but nutrients are lost from the soil and erosion increases. Sediments can also run off into streams, increasing nutrients and then increasing algae.

• Clear-cutting reduces biodiversity.

Urban Ecosystem• Cities are major sources of air and pollution

• Air pollution is caused by

• Water pollution comes from

• . Highways radiate outward from cities like a web.

• People who live in cities rely on forestry and mining for a variety of materials, on agroeosystems for food, and on natural ecosystems for recreation.

Greener Cities• Humans are becoming more concerned about how we impact the

environment.

• City planners and politicians have developed strategies to make cities more sustainable. They must consider the impact of human actions in cities and surrounding ecosystems.