Chapter 3 Changes in the Biosphere 3.1 The Changing Environment 3.2 Needs of Organisms 3.3 The Ecosystem

3.1 The Changing Environment Objectives: Describe ways in which the three layers of the biosphere change over time.

Changes in the Lithosphere What is the lithosphere? How does the lithosphere change? One way is through tectonic plates. Tectonic plates- one of several large, movable plates that make up the lithosphere. Figure 3.1 page 35 – tectonic plates

Tectonic Plates Liquid rock rises through cracks between the plates. Deep in the ocean when this liquid rock meets the cool ocean water it hardens and forms new rock. The new rock pushes the tectonic plates apart, causing them to shift their position. When tectonic plates shift positions, earthquakes occur. Mountains rise when this movement of the plates causes the earth to buckle

Weathering and Erosion Besides tectonic plates; weathering and erosion is another way the lithosphere is changed. Weathering- the breaking down of rocks by weather and water. Erosion- the wearing away of land by weather and water; a natural process where soil is lost, transported, and reformed.

Weathering and Erosion What is the difference? Weathering and erosion shape mountain ranges and help to form streams Together with tectonic plates weathering and erosion have produced the land formations we see today.

Changes in the Hydrosphere What is the hydrosphere? Changes to the hydrosphere in some areas have progressed slowly and steadily. Other changes occur in cycles Ice Ages El Niño

Ice Ages Ice age- long period of cooling during which huge ice masses, called glaciers, grow and extend from Earth’s polar regions. During ice ages the sea levels lower. Why?

Scientist have found evidence for a least five major ice ages The most recent being 10,000 – 12, 000 years Not only do ice ages effect the hydrosphere, but the glaciers cause significant changes to the lithosphere. As the glaciers move across the land the pick up rocks. These rocks then move across the land scraping the surface. When the glaciers retreat the rocks and other materials are now deposited in another area. Bolder Field and Blue Mountain

El Niño El Niño – a disturbance of ocean winds and currents when a warm-water current lasts for several months along the western coast of South America This current usually only lasts of few weeks, but when it last longer it become the condition El Niño It is a recurring pattern with far reaching effects on climate and the economy

The Effect of El Niño The change in water temperature and the nutrients affects the survival of fish When the fish begin to die then the fishing industry suffers. This also effect the poultry industry which depends on fish meal The climate change also damages crops No body knows the exact cause of El Niño

Changes in the Atmosphere What is the atmosphere? Sunlight and Earth’s rotation drive many of the changes in the atmosphere Organisms have a huge effect on the atmosphere

Early Atmosphere Before there was life the atmosphere was made up of many gases: Water vapor Carbon dioxide Sulfur gases These gases are released by volcanoes, which was the source of Earth’s early atmosphere As organism evolved that could combine water vapor and carbon dioxide and release oxygen the atmosphere changed

Atmosphere For about 3.5 billion years, oxygen, carbon dioxide, water vapor, and nitrogen have been cycling from the atmosphere to organisms and back again. Much of the carbon on earth is stored in the bodies of organisms, both alive and dead Coal and other fossil fuels is an example of how carbon is stored When fossil fuels are burned they release this carbon back into the atmosphere

Greenhouse Effect Burning of fossil fuels release carbon back into the atmosphere causing and increase in atmosphere temperature. Greenhouse effect- the trapping of radiated heat by gases in the atmosphere.

Causes of Change to the Atmosphere Human: Greenhouse effect Pollution resulting in the depletion of the ozone layer Natural: Volcanic eruption

Review How does change occur in the lithosphere? How does change occur in the hydrosphere? How does change occur in the atmosphere?

3.2 Needs of Organisms Objectives List factors that affect an area’s ability to support life. Predict how changes in the environment might affect organisms.

What does my fish need? Alone or in a group of two; determine what my fish needs to survive. Include everything I need to maintain a happy, healthy fish. Let’s see what group will have the happiest fish?

What do organisms need to survive? For this chapter we will look at four things that are necessary for an organisms to survive: Water Food and Energy Living Space Climate

Water Fresh water is one of the most important things organisms need to survive. Water is needed for plants to grow and animals need both water and plants to survive. The amount of rainfall an area receives directly effect the number and kind of life that exists there.

Water and Aquatic Organisms Aquatic organisms are as affected by the amount of rainfall, but by the quality of the water. Pollutants and amount of dissolved oxygen have a huge effect on aquatic organism.

Food and Energy Almost all of the energy used by living things originates from the sun. Plants capture energy from the sun during photosynthesis. Animal get their energy by eating plants and/or other animals

Food Contains energy, minerals, vitamins and other chemicals. These material are used for building tissues and carrying out biochemical reactions. Nutrients – a substance needed by the body for energy, growth, repair or maintenance. Animals obtain their nutrients from the things they eat. Fungi, protists, plants and some animals (worms) absorb nutrients directly into their cells

Poisons Some of the substance stored by organisms are harmful, making tissues poisonous if eaten by other organisms. This buildup allows poisonous to move from one organism to another in the environment

Living Space All organisms need enough space to live. It is from your living space that you obtain the things you need to survive Plants need enough space to obtain sunlight and enough space for their roots to spread out to absorb water and minerals. If plants are too close together they may die.

Living Space Animals need enough living space to seek food, water, shelter and mates. Some animals will claim a space as their own. Territory – a living space claimed by an individual or group of animals as their own. These animals are referred to as territorial animals

Territorial Animals Many territorial animals will mark their territory with their scent. Urinating Defecating Scent glands Another way is through sounds or gestures. The size of an animals territory is determined by his needs. Animals may compete with one another for territory. Sometimes even to the death. The competition for space and resources is an important factor in evolution.

Climate The body temperature of many organisms is determined by the temperature of the environment. When it becomes colder out – their body temperature drops. Most organisms have a small temperature range at which they can survive. It is this temperature range that determines where on the globe you will find certain organisms. You would not find a snake in the tundra.

Climate One of the adaptation the animals have to survive in colder temperature is becoming dormant. Dormant- the life processes within the body slow down Plants lose their leaves and stop growing Bacterial growth is reduced at colder temps.

Warm-blooded organisms Birds and mammals maintain high body temperatures regardless of the environmental temperature. Warm-blooded animals have a wider range of temperature tolerance and live in more diverse climate.

Adaptation Maintain this higher temperature requires a lot of energy Warm-blooded animals need about ten times more food than other animals the same size One adaptation animals have to help them is hibernation. Hibernation – dormancy in some animals when the heart rate and breathing slow down, the body temperature drops and the animal enters a sleeplike state.

Hibernation Energy requirements are lowered during this time. This enables animals to survive long, cold periods with little food. Example: Groundhogs Snakes

Review What does an organisms need to survive? How might a change in a organism’s environment effect its chance of surviving?

3.3 The Ecosystem Objectives: Describe the structure of an ecosystem. Relate the concept of habitat destruction to the loss of biodiversity.

Species Species - a group of organism so similar to one another that they can breed and produce fertile offspring. All members of a species have similar need: Range of climate tolerance Size of territory Types of food Because species have the same needs they often compete with one another.

Habitat Habitat – the specific environment in which a particular species lives Examples: The top of trees in the rainforest Stream-shallow, slow-moving and cold It is within habitats the organisms find food, shelter, temperature and all other factors needed to survive. The destruction of habitats is one of the most serious threats to species today.

Geographical Range Geographical Range - the total area in which a species can live. Mountain lions require a habitat with diverse plant life and a large hunting territory with a variety of prey. This type of habitat use to exist all over the US, so their geographical range was the US. That is not true today; their range is much smaller.

Populations and Communities Populations- all the members of a species that live in the same geographical area Example: All the dandelions in a field are a population. The ants in an anthill Populations do not live alone in their environment; many other populations of organisms are also present.

Communities Community - all the different populations that live and interact in the same area. Communities refer to the vegetation along with the animals that live there. Examples: Grassland communities Desert communities

Ecosystem Ecosystem - includes all the communities in an area, as well as the abiotic factors in the environment. Includes: Water, soil, atmosphere and energy cycles. A healthy ecosystem has a wide variety of organisms. Biodiversity - the variety of species in an ecosystem. When a habitat is destroyed everything living in it can become extinct. When species become extinct, biodiversity and stability are reduced

Review What is included in an ecosystem? How is habitat destruction and the loss of biodiversity related.