Ecology

Ecology

• Ecology – is the scientific study of the interactions among organisms and between organisms and their environments.

Habitats

• The place where an organism lives and that provides the things the organism needs is called its habitat!– Food, water, and shelter.

• Biotic Factors – The living parts of an ecosystem. – Animals, plants, fungi, bacteria.

• Abiotic Factors – The nonliving parts of an ecosystem.– Water, Sunlight, Oxygen, Temperature, and soil.

Organism

• The smallest unit of ecological study.– Wildebeest

Populations

• A population is a group of individual organisms of the same species living in a particular area. – Herd of Wildebeest

Exponential Growth

• Occurs when the population multiplies by a constant factor at constant time intervals.

Limiting Factors

• A factor that restricts the growth of a population. – Space– Food availability– Disease

Community

• All of the organisms inhabiting a particular area make up a community.

Ecosystem and Biosphere

• An ecosystem includes the abiotic and biotic factors in an area.

• The biosphere is the sum of all Earth’s ecosystems.

How do organisms get energy?

• Every organism requires energy to carry out life processes such as growing, moving, and reproducing. – Producers (autotroph) – synthesize their own food

through the process of photosynthesis. – Consumers (heterotrophs) – obtain their energy

by eating other organisms. – Decomposers -

Types of Consumers

• Herbivore – eats plants.• Omnivore – eats plants

and animals.• Carnivore – eats

animals.

Food Chains

• The pathway of energy transfer form one organism to another is called a food chain.

• What would happen if one organism is overhunted and removed from the food chain?

• What is the source of all energy?

Food Web

• A pattern of feeding represented by interconnected and branching food chains is called a food web.

Energy Pyramid

• Emphasizes the energy loss from one organism to the next in a food chain. Only 10 % is passed on to the next level, the rest is lost to the ecosystem in the form of heat.

Types of Relationships among species!

• Predation – an interaction in which one organism eats another. There are two individuals that participate.

• Predator and Prey• Fox is a predator and

the rabbit is the prey.

Symbiotic Relationships

• A symbiotic relationship is a close interaction between species in which one of the species lives in or on the other. – Parasitism – one benefits and the other is harmed.– Mutualism – both species benefit– Commensalism – one benefits and the other is

neither helped or harmed

Ecological Succession

• The process of community change is called ecological succession.

• What would happen if you left the field behind Heritage uncut for a couple of years?

Primary Succession

• When a community arises in a lifeless area that has no soil.

• Pioneer species are the first to colonize barren rock.

• Climax community takes hold several hundred or thousand years later. The forest has grown to its full capacity.

Secondary Succession

• When a disturbance damages an existing community but leaves the soil intact, the change that follows is called secondary succession. – Fires– Land cleared for

farming, then abandoned.

The Carbon and Oxygen Cycle• Carbon starts its cycle in the

atmosphere as Carbon Dioxide.

• Plants take in the carbon dioxide and make organic compounds known as glucose.

• That glucose gets passed on to consumers through the food chain.

• They then release carbon dioxide back into the atmosphere through the process of cellular respiration.

Human Activities can alter ecosystems!

Population Growth

• As the human population continues to grow, the environment will be negatively impacted by the following.– Habitat destruction– Deforestation– Air Pollution – Acid Rain– Water pollution– Global Warming– Introduced Species– Reduced Biodiversity– Overexploitation

Deforestation

• The clearing of forest for agriculture, lumber, and other uses also affects the carbon cycle by eliminating plants that absorb CO2 for photosynthesis.

Alternatives to Clear cutting

• Don’t cut down every single tree!!!!!!

• Selective Cutting

Greenhouse Effect

• They process by which atmospheric gases trap heat.

• Greenhouses trap heat.

Global Warming

• The overall rise in Earth’s average temperature. – Caused by increasing

carbon levels in the atmosphere.

• What causes increased carbon levels in the atmosphere?– Deforestation– Burning of Fossil Fuels

• Effects of Global warming– Rising sea levels– Large effects on weather– Loss of Species

Acid Rain• Precipitation that carries

acid to the Earth’s surface. – Smokestacks and automobile

exhaust pipes release nitrogen and sulfur compounds into the atmosphere. They then combine with water and form acid rain.

– Can lower pH of soil and aquatic ecosystems causing species to become extinct.

• Acid Rain

Water and Air Pollution

• Burning Fossil Fuels – Releases chemicals into the atmosphere.

• Fertilizers – end up in water supplies.

Introduced Species

• Starlings and house sparrows are introduced species from Europe. They competed with the bluebird population drastically reducing its population.

Snakeheads

• Snakeheads are very aggressive and are outcompeting all native fish populations. Examples include Bass, Pickerel,

Overexploitation

• The practice of overhunting. – Elephants were hunted for their tusks

What can Humans do to reduce our negative impact on the

environment?• Selective cutting• Make our homes more energy efficient• Use cars get higher gas mileage• Tougher regulations