Mr. Bouyer
Day 1 - 2 | Day 3 - 4 | Lab | Vocabulary Test

This Week's

Ecosystem Abiotic Light Climate Greenhouse effect Milankovitch Cycles Obliquity Eccentricity Precession Surface water	Ground water Biotic Heat Temperature Calorimeter Thermometer Atmospheric pressure Isobars Wind Convection current	Coriolis effect Humidity Relative humidity Dew point Clouds Cumulus Stratus Precipitation Weather Ecology

Ecosystem components:   (bio lab 275)

Abiotic - nonliving components: (15 min)

1. Light - the Sun provides all the energy for an ecosystem.
2. Climate - defined by the long-term combination of temperature and moisture in an area.
   • Man's impact on climate:
     • CO₂ and the Greenhouse Effect
     • Ozone depletion
   • Global climate change:
     • The Milankovitch Cycles:
       • obliquity - changes in Earth's tilt between 21.2 and 24.5 degrees
         (41,000 year cycles)
       • eccentricity - shape of Earth's orbit around the Sun
         (100,000 year cycles)
       • precession - wobble in Earth's spinning on its axis lake a top
         (11,500 year cycles)
3. Slope of the land - affects not only the movement of water and surface particles, but the type of plants and animals in an area as well.
   • mass wasting - the downslope movement of soil, rock, mud, or other material caused by the force of gravity.
   • angle of response - the maximum angle at which a slope of loose material is stable. Slopes steeper than this angle tend to collapse.
4. Soil chemistry - affects the types of plants and animals that can live in an area, as well as the weathering and shaping of the land.
5. Surface and ground water

Biotic - living components:

1. Plants
2. Animals
3. Microorganisms

Determining the characteristics of an ecosystem:

Abiotic components combine to define the environmental charactersitics of the ecosystem. Biotic components interact with each other to determine the success of life in the ecosystem. Biotic components interact with abiotic components to determine the overall characteristics of the ecosystem.

Atmospheric Influences:

It is difficult to understand surfaces processes on the Earth without first knowning how the atmosphere influences these processes. There are four basic atmospheric elements:

• Heat - Earth's relatively constant orbit around the Sun provides about 100 watts of electromagnetic radiation for every square foot of surface that faces the sun. Electromagnetic waves cause molecules to vibrate as they pass by. The total vibration of all the molecules is called heat energy. The vibration rate of individual molecules is called temperature. In practical terms, temperature is the concentration of heat. Heat is measured using calorimeters, but temperature is measured using thermometers.

  The atmosphere is in a delicate balance between the energy that arrives from the sun during the day and the amount that is continuously radiated back into space in the form of infrared waves. The angle and duration of sunlight affects temperature equilibrium in local areas. Different atmospheric gases have different abilities to absorb heat. Oxygen and nitrogen are poor heat absorbers. It is carbon dioxide and water vapor, the "greenhouse gases", that are mostly responsible for heating the atmosphere.

  

• Pressure - Atmospheric pressure dramatically affects the breathing of livining things. Atmospheric gases exert about 15 pounds of pressure on every square inch of land at sea level. Half of Earth's atmosphere is below an elevation of 5 kilometers. Pressure continues to be cut in half every additional 5 km above the earth. Air pressure also changes in response to temperature because hot air weights less than cold air. This is way an area of warm air is called a Low and are area of cooler air is called a High. Lines on a weather map that connect points of equal pressure are called isobars.

• Wind - Sunlight increases the molecular motion of gas molecules, causing the gas to expand and become less dense. The gas returns to the surface after it cools and becomes more dense. This cyclic behavior is called a convection current. Surface winds are the returning portion of a convection cycle - air moving from cool high pressure back to the low pressure zone where the gases were originally heated.

  Surface obstructions like building and mountains deflect or squeeze air flow, thus causing gusty, shifting winds within a few hundred feet of the surfact. Earth's rotation also influences wind speed and direction. Winds veer to the right in the northern hemisphere and to the left in the southern hemisphere. This is known as the coriolis effect.

• Moisture - Water evaporates faster when it is hot, when it has a lot of exposed surface area, and when a wind blows over it. After evaporation, it is referred to as water vapor or humidity. Water vapor is a dry gas composing from 0 to 4% of the atmosphere. When it reaches a maximum of about 4%, we say the relative humidity is 100%. Because water requires energy to evaporate, it borrows heat to do so, thus sweating is a "cooling" experience. Sweat can't evaporate if humidity is very high. This causes use to mistakenly think of humidity as a moist gas.

  Water vapor must be cooled before condensation can occur. The condensation temperature at which liquid reappears is the dew point. Cooling is commonly produced where air is forced to rise. The rising may be due to heating or an upward deflection caused by hitting a mountain or mass of cold air. It also happens when wind spirals into a Low and has no place to go except up.

  Clouds are tiny droplets of liquid water suspended in the air by slight updrafts. Clouds take the shape of the wind that suspends them. Rising hot winds form towering cumulus clouds. Cold winds are more horizontal, shaping clouds into layers across the sky called stratus clouds. In order for precipitation to form, cloud droplets must coalesce until they are sizable enough to fall.

(27 min)

Weather is defined as short-term changes in the state of the atmosphere. Climate is defined as long-term changes in the average state of the atmosphere.

Ecology is the study of the interactions between organisms and the living and nonliving components of their environment. In other words, ecology is the study of ecosystems.

Four Laws of Ecology:

Everything is connected to everything else.
Everything must go somewhere.
Nature knows best.
There is no such thing as a free lunch.

Ecology involves collecting information about organisms and their environment, looking for patterns, and seeking to explain these patterns. Over the past few decades, humans have changed the environment on a greater scale than ever before. The most significant environmental change is probably the rapid increase in the numbers of people on Earth. An increasing population requires increasing amounts of energy, food, and space for the disposal of waste. Providing for the needs of this growing population will take an increasingly greater share of Earth's resources.

(7 min)

• A map of the High Plains Aquifer and other major aquifers.

Day 3 - 4

What is meant by the term "invasive species"?

Environmental Scientist

The term "environmental scientist" covers a very wide range of specialities. The career link gives you some idea of the possibilities.   Other ecological concerns:

In-class Assignment 254:
This assignment must be turned in by the end of class tomorrow to receive credit.

Choose one of the following essays:
1. Study this website and use this planning guide to write an essay about "invasive species".

2. Study this website and use this planning guide to write an essay about global warming.

An increase in the number of human beings and the stress that places on Earth's resources is the greatest change humans have made to the Earth's environment.

An invasive species is one that moves into an area and pushes native species out.