Changes in Ecosystems Chapter 4

How are ecosystems balanced? Living things count on other living things, as well as non-living things to survive. What do you need to survive? TNT All plants and animals need: –How many can you name? –-Fill in sheet- number 1

Living things can only survive in environments where all their needs are met.

A Balancing Act One Side : Food Space Shelter Water air The Other Side: Animals/plants What happens if the number of animals increases? (#2 )

All organisms help keep the balance of an ecosystem. Rabbits eat grasses, which helps keep grass from taking over the space that plants might need. If the rabbit population got too big, what would happen? (3) What prevents the rabbit population from getting too big? (4) The grass and other plants provide oxygen and moisture that the animals need.

The interactions in ecosystems keep them balanced. Rain goes into ponds- some water evaporates- then it rains again

Animals are born and die- nourish the soil

Oxygen is used by animals and made by plants (photosynthesis)

Constant changes keep things balanced.

What would happen if? Too many animals moved to an area?(5)

What would happen if the population of one type of animal in an ecosystem was killed?

Extinction Extinct- when there are no members of a kind of organism alive Ex: Dodo bird became extinct when its ecosystem changed.

Extinction caused by Animals not adjusting to climate changes. Volcanoes Meteors

Today- the main reasons that animals become extinct are due to human activities like: Habitat destructionHunting

Bald Eagle Almost became extinct DDT, a pesticide, was used to kill bugs on crops. DDT washed into lakes and streams. Fish got DDT in their bodies. Bald Eagle ate the fish. DDT made the Bald Eagles’ eggs have thin shells. Eggs broke or didn’t hatch. Eagle population decreased. DDT was outlawed and the eagle population is increasing.

Endangered Species So few left, likely to become extinct.

Species then and now Fossils: show us that life on earth has not always been the same as it is now. Animals: Mammoths Environment

How do organisms interact? Competition leads to adaptations.

Hawks and Owls: Sharing Resources

Organisms can help each other or live in harmony Lichens: Algae and Fungi Live side by side: moss and trees

Organisms can cause harm to other organisms: parasites and hosts

How do ecosystems change? Ecosystems are always changing- sometimes quickly, sometimes slowly. People and animals may bring on these changes.

Animals Change Ecosystems Ecosystems are always being changed by organisms, wind, water, or other parts of the environment. Examples: –Beavers make a new pond by damming streams –Earthworms improve the soil with digested materials they leave behind.

Changes in climate may affect ecosystems Climate is the average temperature, winds, and rainfall for an area over a period of time. Climates change very slowly over a long period of time. 15,000 years ago: snow and ice covered Parts of North America. Climate got warmer- plants and animals moved in. Over time- forest communities were formed

Some changes in ecosystems are slow and some are fast: Slow –Gradual succession- over thousands of years –Extinction of a population. List Rapid changes

Rapid changes Hurricanes Tornadoes Forest fires Floods Tsunamis

How do environments change? Is this primary or secondary succession?

What type of succession is this? Why?

Effects on ecosystem of Superstorm Sandy Animal habitats destroyed. Grasses/trees died Birds lost nesting grounds- moved inland to new areas Water can get too salty, kills some of the organisms. Freshwater fish end up in saltwater. Animals killed Grassland around water where sea animals nest were destroyed

People Change Ecosystems People change ecosystems when they build houses, clear forests, throw out garbage, or introduce new plants and animals.

People also affect ecosystems with waste from the products we make and use

Things people do that change the environment Messes up the balance in the ecosystem

Humans affect the balance in ecosystems by damaging the air! Waste products pollute the air Waste products pollute the water. Automobiles and factories release harmful chemicals into the air. Damaged air kills plants. Plants are the food source for many animals.

Natural Air Pollution Detector Lichen can grow just about anywhere (tree trunks, in the soil,on rocks, roofs, and walls). Lichen are sensitive to the air pollutant sulfur dioxide. The air surrounding some cities is so polluted with sulfur dioxide that lichen cannot live! If there is no lichen growing in an area= A LOT OF POLLUTION

People disturb the balance by polluting water. Caused by wastes and chemicals getting in the water from: –Sewer systems –Chemicals used on crops.

Chemicals get into rivers and streams and then move into Earth’s Oceans

Oil Spills from drilling/shipping kills birds, algae, plants, and fish.

People also disturb the balance with Land Pollution Garbage in landfills Hazardous wastes –Substances that are very harmful to humans and other organisms –Could be: Poisonous Disease-causing. Fire-starting React badly with other substances. Hazardous wastes If buried underground can leak out and damage the land and water

People also disturb the ecosystem balance through strip mining. Strip mining- leaves large holes underground. Soil and rock were washed away into ponds and rivers. This ruined ecosystems in the ponds and rivers.

Land Reclamation Federal law: –Mining companies must replace rock and soil that were removed. –Must replant crops or native trees and grasses –.

Surface Coal Mining Law: coal companies must study the ecosystems before any digging begins

Preserving the Environment National Park System: –Created by the United States to preserve nature’s beauty and the habitats of many plants and animals.

Yellowstone National Park Has bubbling mud pots and geysers. Most of it is in Wyoming.

Saguaro National Park Is in the Sonoran Desert in Arizona. The Sonoran Desert is home to more species of plants and animals than any other American desert.

Everglades National Park Florida It is a refuge for wildlife that live in wet habitats

Traits That Are Not Inherited Differences among organisms of the same species are not all due to different DNA. The ecosystem can affect how plants and animals grow. Hydrangea flowers can be different colors depending on what is in the soil.

Structural Adaptations Structural adaptations are changed body parts that help the organism survive in its ecosystem.