Change in the Biosphere Chapter 3 (pgs 34-49)

The Changing Environment Humans have only lived on earth for <0.5 million years How old is earth? How did earth form? Earth has been changing since it formed Do you know some ways that earth is changing? Most natural changes are so slow that you don’t see them in a lifetime Some rapid changes have taken place from human activities

Changes in the Lithosphere ***Remember – the lithosphere is the layer of land on earth*** The lithosphere is made of several large moveable tectonic plates Molten (liquid) rock from inside earth oozes out through the cracks between the plates The molten rock hardens (as it cools) pushing apart the plates – this may cause earthquakes Mountain chains form when the plates cause the Earth’s surface to buckle

Earthquakes: Vibrations caused by the Earth’s crust “slipping” along a fault line (break in the Earth’s crust) Richter Scale – scale used to measure earthquake intensity Ranges from 1 – 10 (9.5 is most powerful to ever be recorded) Most earthquakes take place on or near fault lines The biggest faults are near the boundaries where tectonic plates meet This is why California has more earthquakes than NJ

Volcanoes: A mountain built from magma (melted rock) that rises from the Earth’s interior to its surface. Often located near tectonic plate boundaries. On land or under sea. “Ring of Fire” contains 75% of world’s active volcanoes that are on land.

Other Lithospheric Changes Weathering – the breaking down of rock by heat, water, ice, wind, and pressure – no movement Erosion – the broken down rock is then carried off by water, wind, ice, and gravity - movement

Changes in the Hydrosphere ***Remember – the hydrosphere includes all parts of earth made up of water*** As the continents have changed, so have the bodies of water Most water changes occur slowly and steadily over time Other water changes occur in a series of cycles: Ice ages – millions of years El Nino – every 4-7 years

Ice Ages Long periods of cooling, when glaciers move from poles and cover much of Earth Glaciers - huge masses of ice form called After the ice age, the glaciers retreat back to the poles Evidence of five ice ages in the Earth’s history (most recent ended 12,000 to 10,000 years ago When glaciers move, they scrape across earth moving rocks and water to new places

El Nino Every December, a warm, nutrient-poor water current flows southward along the coast of South America Normally this warm current is quickly replaced by a cold, nutrient rich current during an upwelling Every 4-7 years, the upwelling doesn’t occur The nutrient poor water cannot support fish life

Changes in the Atmosphere Early Earth’s atmosphere was mostly water vapor, carbon dioxide & sulfur from volcanic eruptions. Bacteria evolved that could perform photosynthesis and released first oxygen into atmosphere. For the past 3.5 billion years, the atmosphere consists of recycled nitrogen, oxygen, carbon dioxide & water vapor

Changes in the Atmosphere Much of earth’s carbon is cycled through the carbon cycle Some is stored in the bodies of organisms – dead or alive Fossil fuels (coal, natural gas) – formed by breakdown of dead organisms When we burn fossil fuels, we release carbon dioxide

Greenhouse Effect-release of stored carbon into atmosphere by burning organic matter, which influences the temperature of the Earth.

Check for Understanding: 1. Through what process does weather affect the shape of land? 2. In what ways does El Nino affect the economy?

Needs of Organisms An environment should provide an organism with everything it needs to live Every organism has a different set of needs and has evolved to fit its environment All organisms have certain needs in common: Water Source of energy Living space Suitable climate

Water Fresh water is one of the most important abiotic factors in support of life Plants need water to grow Animal populations need plants and water Ocean organisms are affected by water quality Warm water contains less dissolved oxygen than cold water – can’t keep organisms alive

Food and Energy All energy used by organisms comes from the sun and is stored as food Plants capture energy from sun and make food through photosynthesis Animals eat plants and get energy Food contains energy, minerals, and vitamins Nutrients-all the substances that an organism requires from food.

Living Space All organisms need space to live and obtain materials Plants need space between them to get sunlight and water Animals need space to get food, water, mates Territory – area claimed as a living space by an individual animal (mark their territory) Size of territory – determined by animal They will compete till DEATH!

Climate Climate – the temperature and weather that an organism is adapted to live in – it produces varied responses in organisms Range of tolerance – acceptable range of temperature for an organism’s survival Most organisms’ body temperatures are determined by the environment (cold blooded) Many organisms become dormant to survive cold temperatures

Climate Dormant – all metabolic life processes slow down in an organism [ex: plants in winter bacteria in refrigerator] Other organisms (warm blooded) use energy to maintain a high body temperature Warm blooded animals need 10 X as much food! Some animals also become dormant (hamsters, worms) Hibernation – heart rate and breathing slow, body temperature drops, enters a sleep-like state

Hedgehogs: Usually, hedgehogs maintain a constant body temperature, i Hedgehogs: Usually, hedgehogs maintain a constant body temperature, i.e 35 degree centigrade, during summer but at the onset of winter, their temperature drops to 6 degree centigrade in order to cope with the scarcity of food. Hedgehogs go into hibernation for about 2 to 5 months with the males hibernating before the females.

Badgers: They are torpors or temporary hibernators and in winters they store enough food in their burrows, so that they may wake up, eat and go back to sleep again. Badgers are omnivores, that is they eat both plants and animals. Honey badgers, one of the types of badgers are nocturnal animals.

Frogs and Toads: Frogs living in colder climates, hibernate in winter in small creeks, cracks in logs and in rocky places. They store glucose in their bodies that keeps them from getting frozen. Some of the species of frogs even hibernate under water. Toads are cold blooded and nocturnal creatures. Their hibernation period begins from October and some toads are known to hibernate for as long as three to four years. They survive on body fat that has been stored in their bodies during the warm months.

Moths: Moths are a species of insects that closely resemble a butterfly. Moths hibernate in clusters and during the winters they sleep in creeks or cracks in the wood.

Check for Understanding: 1. In what ways does the behavior among territorial animals differ? 2. How does hibernation help animals to survive? 3. Do you think that the amount of water used by each person in the United States has changed over time? If so, in what way? Explain your answer. 4. Suppose a particular area was to experience a sudden change in rainfall and temperature that lasts a long time. Do you think the area would lose its ability to support life?

The Mississippi Flood Read page 41 in your textbook “The Mississippi Flood – Who should pay for property damage on a floodplain?” Answer the decision questions fully and hand in.

The Ecosystem Ecosystem is a highly organized, structured environment that is delicately balanced Ecosystems can be studied on many levels, from individual species to the interactions within the entire ecosystem. Includes all the biotic and abiotic factors in an area.

Species A group of organisms similar to one another, able to breed and produce fertile offspring All members have similar needs Range of tolerance Size of territory Type of food Members often compete with each other for resources

Habitat The type of environment in which a particular species lives Describe the habitat of a bird Describe the habitat of a fish Describe the habitat of a panda Provides appropriate food, shelter, temperature, etc that a species needs for survival Destruction of habitat is a serious threat to the survival of many species

Geographical Range The total area in which a species can live Depends on the size of the area where the habitat is suitable Mountain Lion Requires habitat with diverse plants, large hunting territory, variety of prey animals Used to roam all of continental U.S. Humans took over their range Now restricted to western mountains

Populations and Communities Population - all the members of a species that live in the same area For example: Ants in an ant hill Dandelions in a field Community - all the populations that live and interact in the same environment Foe example: The ants and the dandelions

Ecosystem Includes all the communities that live in area as well as the abiotic factors in that environment Include water, soil, climate Healthy ecosystem contains a wide variety of organisms

Biodiversity The variety of species in an environment If enough of a habitat is destroyed, the species that live there can become extinct This decreases biodiversity and stability For example – tropical rainforests

Check for Understanding: 1. What factors are included in an ecosystem? 2. What do you think is the geographical range for human beings? 3. Some ancient cultures, such as the societies that live in rain forests, are shrinking as a result of the destruction of their habitat. Do you think human societies should be protected, as are endangered species of plants and animals? Explain.