Change in the Biosphere Environmental Science

1.1 The Changing Environment Earth is about 4.5 billion years old, but humans have existed for fewer than 500,000 years. Many rapid changes have taken place as a result of human activity.

Changes in the Lithosphere The lithosphere is made up of several large, moveable plates called tectonic plates. As hot, liquid rock meets the cool ocean water, the rock cools and hardens. New rock forms, pushes the plates apart, causing a shift in position.

Changes in Lithosphere Weather and flowing water also affect the shape of the land. The breaking down of rocks by weather and water is called weathering. The broken down material is then carried off in the process of erosion.

Changes in the Hydrosphere Ice Age: An ice age is a long period of cooling during which huge ice masses, called glaciers, grow and extend from Earth’s polar regions, covering much of the planets surface. Scientists have found evidence of at least five major ice ages in Earth’s history.

Glaciers

Changes in the Hydrosphere El Nino: Every year near the end of December, a current of warm, nutrient- poor water flows Southward along the cost of South America. Normally the flow of warm water lasts a few weeks, but sometimes the water current lasts for several months, a condition called El Nino.

Changes in the Hydrosphere El Nino is one of many recurring patterns of change in ocean currents. The change in water temperature and nutrient content can affect the survival o fish: 1. Drop in fish population 2. Damage to crops 3. Loss of income

El Nino

n97/en97.html Oceanography – tracking El Nino through the years. Diagrams of the current.

Changes in the Atmosphere The greenhouse effect is one way in which humans may be changing Earth’s atmosphere. –Loss of the ozone from the stratosphere and increased pollution in the troposphere are other examples of atmosphere changes caused by humans.

Changes in the Atmosphere Natural causes such as volcanoes eruptions, continue to send gases into the atmosphere that are transported by winds around the world.

Classwork Assignment Use the handout and work with a partner, and discuss one way each of the listed events cause a change in the atmosphere, lithosphere, and hydrosphere: –Hurricane (Katrina) –Forest Fire –Flood –El Nino –Ice Age –Volcano Eruptions

1.2 – Needs of Organisms Organisms depend on their environment for everything they need in order to live. Every kind of organism has a different set of specific needs: –List needs of each example below and compare: HumansGoldfish

1.2 Needs of Organisms Despite differences all organisms have certain needs in common:

1.2 - Water Fresh water is one of the most important factors in the ability of land to support life. The amount of rainfall on an area of land directly affects the characteristics and abundance of life in that area. Organisms in waters aside from oceans are affected by water quality: nutrients, dissolved oxygen, other chemicals and the kinds of numbers of organisms present affect water quality. –Warm water contains less oxygen than cold!

1.2 Food and Energy Almost all the energy used by living things comes from the sun. (Photosynthesis) Food contains not only energy, but also minerals, vitamins, and other chemicals. –Together, all the substances that an organism requires from food are called nutrients. Problem: We store nutrients to build cells in the body tissues. If a stored substance is harmful, the tissues become poisonous. The buildup of poisonous materials in an organism’s tissues allows poisons in the environment to pass from one organism to another. Can you think of an example?

Example Pesticides are sprayed on grasses to kill insects. Cows eat grass. We eat cows. Toxins enter our body. (DDT) Chemical dumping into our waters. Fish are exposed to the chemicals and we eat fish. (Mercury) Cows are injected with chemicals to produce more milk. We drink milk! –All of these problems can cause cancer in humans.

Homework Please research and find one example of a poisonous toxin that can be transmitted to humans through food. –Include the name of the toxin, a brief description, and what food sources we eat that can transfer the toxin to a human. – Use an index card.

Example Aflatoxin Aflatoxin may cause growth retardation, neonatal jaundice, and prenatal death, however, current evidence is limited. Aflatoxin is a toxin produced by mold in contaminated nuts. Avoid eating nuts which are old.

1.2 Living Space All organisms need space to live. Living space enables organisms to obtain the materials they need from the environment. Animals need space in which to seek food, water, shelter, and mates. Many animals claim specific areas as their own. An area that is claimed as a living space by an individual animal or group of animals is called a territory.

1.2 Living Space Many territorial animals mark their territory with scents to let intruders know the area is off limits.

Climate The body temperature of most organisms is determined by the temperature of the environment. Most organisms can survive only within a certain range of temperatures. Many organisms, especially plants that live in colder areas, survive the cold by becoming dormant. When an organism becomes dormant, the life processes within the body slow down. Like plants, many animals become dormant during periods of cold temperatures and low food supply. Dormancy in animals is called hibernation.

Isopod Lab If isopods can be obtained from Carolina, we will evaluate the needs of land isopods. Question: What environmental conditions do land isopods need?

1.3 The Ecosystem An ecosystem is not simply a random collection of organisms and environmental factors. An ecosystem is a highly organized, structured environment in which all parts exist in a delicate balance. An ecosystem can be studied at many levels:

1.3 Ecosystem Levels 1. Species: a group of organisms so similar to one anther that they can breed and produce fertile offspring. All members of a species have similar needs: range of climate tolerance, size of territory, and types of food.

1.3 Ecosystem Levels 2. Habitats are the specific environments in which particular species live. For example, a shallow, fast-moving, cold- water stream may be the habitat of a species of trout. Within their habitats, individual organisms find the appropriate food, shelter, temperatures, and other factors needed to survive. The destruction of habitat is a serious threat to the survival of many species.

1.3 Ecosystem Levels 3. The total area in which a species can live is called its geographical range. The size of the geographical range depends on the availability of suitable habitat. For example, the mountain lion requires a habitat with diverse plant life, a large hunting territory, and a variety of prey animals. Farm development has restricted the growth of population of the mountain lion.

1.3 Population and Communities All the members of a species that live in the same geographic area make up a population. Populations do not live alone in their environments. In any region, many different populations share the same living space. All the different populations that live and interact in the same area make up a community.

Homework Assignment Make a list of all the populations you can think of in Kearny, that come together as a community. Think about insects, water habitats, rodents, and animals. Don’t forget to include humans.

1.3 Ecosystems An ecosystem includes all the communities in an area, as well as the abiotic factors in the environment. Ecosystems therefore include water, soil, and atmosphere in an area, as well as the energy that passes through it. A health ecosystem includes a wide variety of species in its community. The variety of species in an ecosystem is known as biodiversity. –If enough of a particular type of habitat is destroyed, the species that live in the habitat can die out completely, or become extinct.

Concluding: Change in The Biosphere 1.Complete Review Sheet questions. 2.Review 3.Test 4.Lab Activity: An ecosystem Map