Chapter 4: Living Things and their Environment

Aim: What is the difference between abiotic and biotic factors?

Ecosystems All the living and nonliving things in an area Ecology-the study how all these things interact in order to survive There are many different types of ecosystems All have the same parts: Abiotic factors Biotic factors

Abiotic Factors Biotic Factors Living parts of an ecosystem Plants, animals, fungi, protists and bacteria Nonliving parts of an ecosystem Living things need these nonliving things to survive Water, minerals, sunlight, air, climate and soil

Aim: What is a Prairie ecosystem like?

Blackland Prairie Located in Texas Largest remaining prairie in America Was once covered in wild grasses Rich black soil was found here Land was occupied by buffalo snakes, lizards, types of birds, raccoons, coyotes, deer and bats 50 different kinds of tall and short grasses Many types of flowers

Now the prairie is used for planting crops (wheat, corn) and cattle grazing When towns, cities and farms were built the buffalo and many other animals left, such as black bears and jaguars Some animals came, such as armadillos

Aim: What are populations and communities?

Population All the organisms of a species living in the same area Populations of the Blackland prairie Armadillos Badgers Indian grass Pond algae Soil bacteria Scientists want to know how these populations interact with one another

Communities All the populations living in an area Scientists study the interactions of different populations in an ecosystem’s community This helps them to understand what makes an ecosystem grow

Aim: What is the difference between niches and habitats?

Habitat The place where an organism lives Examples: red bat’s habitat is above ground Chorus frog-ponds of Blacklands Bees-beehive Sharks-live in the ocean

Niches Role of an organism in the community No 2 species can have the same niche They would have to be identical for this to occur No 2 species are identical Scientists study niches and habitats to find out if a community is healthy or in trouble Includes: What a species eats What eats the species Active by day or night Kind of environment the species needs to live in

Aim: What happens when habitats change?

Habitats can change year to year This affects the organisms Animals either finds a new habitat or adapt to the changes in their environment Ex: spadefoot toad is able to survive during a drought The toad digs with its hind feet to cover itself with soil Absorbs water from the soil which contains clay

Aim: What is the treasure of the Blackland Prairie?

Topsoil-dark brown to black Treasure is the soil Topsoil-dark brown to black Rich in humus-partly decayed plant matter produced by bacteria and fungi Full of minerals Magnesium-helps produce chlorophyll Calcium-important element of cell walls Good to grow crops

Aim: What does a food chain represent?

Food Chains Energy in an ecosystem comes from the sun The energy in food is passed from one organism to another Represents the movement of energy from one organism to another 1st organism is a plant (producers) Sun’s energy is stored in foods the plant makes

2nd organism is consumer (herbivore) 3rd organism is consumer (carnivore) All organisms receive the sun’s energy Food chains end with decomposers-eat dead animals and plants

Aim: What is a food web?

Food Webs Shows the relationship between all of the species in a community Shows how populations must compete for food Map of overlapping food chains Begin with producers use Sun’s energy to make their own food Ex: grasses, trees, algae (oceans)

Consumers-can’t make their own food Get energy from other organisms Grouped according to what they eat Herbivores-eat only plants (producers) Ex: grasshoppers, rabbits, mice Carnivores-eat only other animals Ex: wolves, foxes, sharks Omnivore-eats both plants and animals Ex: humans, bears

Decomposers: Every food web ends with decomposers Breakdown dead matter into substances that can be used by producers Some of the substances return to the soil Ex: insects, bacteria, fungi

Aim: How are populations connected?

Populations in an ecosystem are connected together If one animal population changes, it will affect the animal population that eats that animal A change in a population affects all the organisms in the food web Organisms may adapt to the changes, especially when they eat more than one animal Animals compete for food Sometimes competition causes an animal to change its habitat

Aim: How does energy move in a community?

Energy Pyramid Producers get energy from the sun Consumers get energy from the foods they eat Energy is lost as it passes from one organism to another This is shown in the energy pyramid Shows there is less food at the top of the pyramid than at the base Organisms decrease as you move up the pyramid

energy decreases as you move up the pyramid 90% of energy is lost from one level to the next

Aim: What is the water cycle? Transparencies/notes on board

Aim: What is the carbon cycle? Notes on board

Aim: What is the nitrogen cycle? Notes on board

Aim: Why is it important to recycle?

Dead matter is important to living things Decomposers turn dead matter into substances other organisms need to survive Break down dead plant parts into carbon dioxide and ammonia-contains nitrogen All organisms need nitrogen in order to make proteins Nitrogen found in plant fertilzers

Composting Is a way to recycle plant material Compost is used to make soil more fertile To make compost take 3 parts leaves and plant material, 1 part fresh grass and 1 part food scraps Earthworms can be used to turn the leaves, grass and food scraps into compost

Importance of Recycling Nonrenewable resources will eventually be used up, such as oil and natural gas Renewable resources, such as wood, can be replenished If we recycle paper and paper products we will be decreasing the destruction of forests