Ecology12.1

Learning Targets

• I can identify ways that organisms interact with other organisms and non-living things• I can describe feeding relationships among

organisms in a community• I can explain how energy flows through

ecosystems• I can identify materials that cycle through

ecosystems

Ecosystems

Ecosystems

Populations Communities Energy Materials

Living Things Non-living Things

How do Organisms interact?• All organisms interact with one another and non-

living things in their environment

• Ecology is the study of the interactions among living things and non-living things in their environment

• Examples: • 1. Animals interact with the air when they inhale oxygen and

exhale carbon dioxide

• 2. Animals interact with plants when they eat fruit or vegetables

Levels of Organization

EcosystemCommunity

Population

Organism

Biosphere

Levels of Interaction

• Life on Earth is organized into levels• The higher the level, the more interactions there are• To interact means to act upon or influence something

• ORGANISM• The lowest level of organization is the individual

organism• The place where an organism lives is called its habitat • Each organism is adapted to live in its habitat

Population

• A group of organisms of the same species that live in the same area form a population

• The individual members of a population interact with one another

• Examples of interactions: Mating and competing for food, water and space

Community

• Populations of different species that live in the same area make up a community

• Bears, rabbits, pine trees and grass are different populations of organisms, but may live together in the same forest community

• Populations in a community interact with one another in many ways

Ecosystem

• All the interactions among populations of a community and the non-living things in their environment make up an ecosystem

• Ecosystems occur on land, in water, and in the air

• As the community (living and non-living) of an ecosystem interacts, they may cause changes to the community

Changes in an Ecosystem

• Changes in the community may result in a completely different type of community

• These changes over long periods of time are known as succession

• Eventually, a community reaches a point at which it changes little over time

• A community that is stable is called a climax community

Effects of Pollution on Ecosystems• Pollution is anything added to the environment

that is harmful to living organisms

• Pollution is most often caused by human activity

• Activities that cause pollution:• -burning coal, oil, gas -acid rain (sulfur)• -construction -fertilizers• -chemicals dumped by factories

Biomes

• Some ecosystems are found over large geographic areas

• These are called Biomes

• Different biomes are found in different climates (temperature, sunlight, rainfall)• Examples of biomes: desert, rain forest, tundra,

grassland, forest

The Biosphere• The highest level of organization is the Biosphere

• All the biomes on Earth together form the biosphere

• The biosphere includes all organisms living on Earth’s surface, in the water, underground and in the air

• The biosphere also includes non-living things, such as water, minerals and air

Vocabulary

• Ecology• Habitat• Climax Community• Biome

• Self-Check Questions 1-5 pg. 267• COMPLETE SENTENCES

Food Chains and Food Webs12.2

Food Chains vs. Food Webs

• Plant Small Fish Larger Fish Bird • This feeding order is called a Food Chain• Almost all food chains begin with plants

• All the food chains in a community that are linked to each other are called Food Webs

• Most organisms eat a variety of food sources• Food chains are linked to one another at certain points• Together, the food chains form food webs (pg. 272)

Producers

• Organisms that make their own food

• Every food chain begins with a producer

• Most producers use the energy of sunlight to make food by the process of photosynthesis

Consumers

• Organisms that feed on or eat other organisms are consumers

• All animals and fungi and some bacteria are consumers

• Consumers can be:• Herbivores – plant eating only• Carnivores – meat eating only• Omnivores – plant and meat eating

Feeding Order of Consumers

• First-order consumers eat plants (ex. rabbit)

• Second-order consumers eat animals that eat plants (ex. snake eats rabbit)

• Third-order consumer eats animals that eat animals (ex. hawk eats snake)

Pyramid of Numbers• The pyramid is organized in order of consumers

and producers

• It begins with a producer at the bottom (grass)

• The highest level of consumer is at the top

• The size of the population decreases at each higher level of a food chain (pg. 271)

Decomposers

• Decomposers continue the food chain by feeding on a dead organism• Decomposers feed on dead organisms at every

level of the pyramid (both producer and consumer)• Decomposers get food by breaking down

complex chemicals in dead organisms into simple chemicals • The chemicals become part of the soil and plants

take in these chemicals to help them grow

Vocabulary

• Consumer• Producer• Food Chain• Food Web

• Self-Check Questions 1-5 pg. 273• COMPLETE SENTENCES

How does Energy flow through Ecosystems?12.3

How does Energy flow through Ecosystems?• Plants use energy from the sun to make food• You get energy from the food you eat• Energy is the ability to do work • Energy comes in many forms• Light and heat from the sun• Electricity • Batteries store chemical energy• A moving bicycle has mechanical energy

• All living organisms need energy to live

Energy in Food

• Plants make their own food through photosynthesis

• Photosynthesis creates energy that the plant stores in sugar molecules

• When the plant needs energy, to grow or reproduce, it releases the stored energy

• When you eat potatoes, asparagus, or other plant parts, you are taking in the plants’ stored energy

Flow of Energy Through Food Chains• The flow of energy in a food chain begins with the

producer, such as grass or other plants

• The energy stored in plants is passed on to the organisms that eat the plants

• These first-order consumers use some of the food energy and lose some energy in the form of heat

• The rest is stored as chemical energy in the first-order consumer

Energy Pyramid

• The energy stored in first-consumers is passed on to second-order consumers and so on

• The most energy is available to the producers; it comes directly from the sun

• The amount of available energy decreases at each higher level of a food chain (pg. 277)

• This is due to the consumers using energy for their own needs and losing some energy in the form of heat

Importance of Sun

• Without the sun, there would be no life on Earth

• All plants and animals and most other organisms depend on energy from the sun

• Energy flows from the sun to producers (plants)

• Some of that stored energy flows to consumers while some is lost to the environment (heat)

• The sun continuously replaces lost energy

Vocabulary

• Energy Pyramid

• Self Check Questions 1-5 pg. 278• COMPLETE SENTENCES

How do Materials cycle through Ecosystems?12.4

Materials

• If a material exists naturally in the Earth, its supply can eventually run out if over used

• Materials must be recycled and used again

• Some chemicals important for life are:• Water Oxygen• Carbon Nitrogen

The Water Cycle