The Nonliving Environment Ch. 13 p. 358

Abiotic Factors 13.1

A. Environmental Factors How might living organisms depend on each other to survive besides as food? Possible answer: protection (leaves, trees, bushes) Biotic – features of the environment that are alive or once living; means “living” Nonliving features of an environment are extremely important as a means of survival too Abiotic – nonliving, physical features

Examples Biotic (Living) Abiotic (non-Living) Animals Plants Insects Birds Air Water Soil Sunlight Temperature climate

Why would abiotic factors in an environment determine what kind of organisms live there? It depends on what abiotic factors organisms can survive in. Example: If there is plenty of sunlight, high temperatures, and no plants and little water, then a lot of organisms that need water and cool temperatures could not survive there.

B. Air Atmosphere – the air that surrounds the earth Air contains 78% nitrogen, 21% oxygen, .94% argon, .03% carbon dioxide and traces amount of other gases. All of these provide substances that support life. Carbon dioxide is required for photosynthesis in which oxygen is released

Through respiration, cells obtain energy needed for all life processes Respiration – when cells use oxygen to release the chemical energy stored in sugar molecules Through respiration, cells obtain energy needed for all life processes If oxygen is not supplied, then the organism will die or have terrible side affects Plants, some bacteria, algae, fish and most other organisms also need oxygen for respiration

C. Water Essential to life on Earth Most organisms are 50-95% water (humans start out at 75% as a baby and drop to 50-65% as an adult) Respiration, digestion, photosynthesis and other important processes can only happen with water The more water, the more organisms in an environment

D. Soil Soil – is a mixture of mineral and rock particles, the remains of dead organisms, water, and air Topmost layer of Earth’s crust and supports plant growth Soil is somewhat formed from broken pieces of rock turned into tiny particles

Considered abiotic because it is mostly made up of nonliving rock and mineral particles Contains living organisms and decaying remains which is called humus Soil life includes bacteria, fungi, insects, and worms Type of soil in a region determines what kinds of plants grow there

E. Sunlight All life requires energy which the sun is the energy source for almost all life on Earth Photosynthesis helps convert sun light energy into sugar as a food source for plants Consumers can’t make their own food/energy so they get their energy from producers or other consumers.

F. Temperature Sunlight supplies heat energy for warmth Most organisms cannot survive if their body temperature is too low Organisms adapt their body temperatures to their environment such as penguins in Antarctica or camels in the desert

Temperature of a region depends on the amount of sunlight it receives Temperature of a region depends on the amount of sunlight it receives. That can depend on the land’s latitude and elevation. Polar regions receive less of the Sun’s energy because sun light strikes it at an angle spreading the energy out. Equator is hotter because it receives direct sunlight. F. 1. Latitude

F. 2. Elevation Elevation – distance above or below sea level Temperatures get cooler the higher up you go in Earth’s atmosphere Air becomes warmer when sunlight heats air molecules The higher the elevation the fewer the air molecules and the less there are to be warmed Can you see where the highest points are based on the elevation map? Are those places cold?

G. Climate Climate – refers to an area’s average weather conditions over time, including temperature, rainfall or other precipitation and wind Fairbanks, Alaska has winters that get to -61.6 degrees Fahrenheit and 3 feet of snow falls in a month Key West, Florida barely gets to 41 degrees Fahrenheit and no snow

G. 1. Wind Heat energy not only determines temperature but also wind Air is made up molecules of gas As the temperature increases, the molecules spread farther apart warm air is lighter than cold air and cold air will sink pushing warm air up This motion causes air currents called wind Fun facts This is why old houses have tall ceilings A mixture of cold and hot air causes a tornado

G. 2. The Rain Shadow Effect Presence of mountains can affect rainfall patterns Wind blowing toward one side of the mountain is forced upward by the mountain’s shape As the air nears the top, it cools When air cools, the moisture it contains falls as rain or snow By the time the cool air passes over the mountain, it has lost most of its moisture and the other side of the mountain gets less precipitation One side may have a lot of greenery and one may be a desert