The Biosphere is the part of the Earth where living things are found. Life is found in all areas of the Earth's surface, as well as some distance above and below the surface.

Biomes are very large geographical areas described by their climate, soil, flora, and fauna.

Climate and soil are abiotic, non-living components of the biosphere while flora (plants) and fauna (animals) are biotic, living components of the biosphere.

Biomes are self-sustaining. A complex system of cycles between the biotic and abiotic portions insure that Earth's matter is not lost, but available through countless generations.

Terrestrial biomes are described by their average rainfall, temperature, and major plants and animals. Because environmental factors change gradually over a landscape, biomes seldom have distinct boundaries. As climate varies, one biome gradually changes into another.

• Tundra
• Boreal forest
• Temperate broadleaf forest
• Temperate grassland
• Tropical rain forest
• Tropical savanna
• Desert scrub

Biomes change from northwest to southeast across the state of Oklahoma. Elevation falls an average of 9 feet per mile from Black Mesa (just under 5000 feet above sea level) to where Little River flows into the Arkansas River (just under 300 feet above sea level).

The western portion of the Oklahoma panhandle touches the foothills of the Rockey Mountains. The southeastern corner of the state touches the coastal plane of the Gulf of Mexico. This dramatic change in elevation caused a major difference in average precipitation and temperature.

The USGS provides water data for any state.

Aquatic biomes are described by the characteristics of the water and the major plants and animals present.

The ocean contains 97% of Earth's total water.

Ocean water contains about 3% salt, which greatly affects the biology of the organisms that live there. Since water absorbs light, sunlight penetrates only the upper few hundred meters of the ocean, greatly affecting ocean life. Oceans are also very important in regulating the temperature on Earth. The Gulf Stream is one of several ocean currents that distribute heat.

Zones related to light penetration:

• Photic zone - receives sunlight
   
• Aphotic zone - sunlight does not reach

• Epipelagic zone, less than 200 meters - the continental shelf and surface layer are the major energy producing areas of the ocean.
   
• Mesopelagic zone, from 200 meters to 1,000 meters - the continental slope receives some sunlight, but not enough to support photosynthesis.
   
• Benthic zone, on or near the ocean bottom - ranging in depth from 1,000 to 2,000 meters.
   
• Abyssal zone, the bottom of the ocean plain - ranging in depth from 2,000 to 11,000 meters - there is no sunloght and the pressure is enormous.

Intertidal zone - shore areas that are alternately covered and uncovered by the tide.

Estuary - tidally-influenced ecological systems where rivers meet the sea and fresh water mixes with salt water.

Freshwater contains a relatively low mineral content.

• Lakes and ponds
   
  • Eutrophic waters are rich in organic matter and vegetation, making them murkey.
     
  • Oligotrophic waters contain little organic matter. The water is relatively clear and the bottom is usually sandy or rocky.
   
• Rivers and streams
   
  • Flow rate is an important characteristic determined by the gradient, or slope, of the land. Organisms must adapt to strong currents in swift flowing waters. For this reason, slow moving waters are richer in nutrients and support a greater diversity of life.
     
  • The Poteau river is the only Oklahoma river that flows to the north.
     
  • Corps of Engineers lakes

 
Weather is defined as short-term changes in the state of the atmosphere. Meteorology is the study of weather.

The Sun provides ALL the energy that drives a biome - about 100 watts of electromagnetic radiation for every square foot of surface it strikes. 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.

 
Atmospheric pressure dramatically affects the breathing of living 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 why an area of warm air is called a Low and area of cooler air is called a High.

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.

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.

Water evaporates faster when it is hot, when it has a lot of exposed surface area, and when a wind blows over it. The evaporated gas 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%.

Water requires energy to evaporate, absorbing heat as it does, thus sweating is a "cooling" experience. Sweat can't evaporate if humidity is very high. This causes us to mistakenly think of humidity as a moist gas.

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 (join) until they are large enough to fall.

Climate is defined by the long-term combination of temperature and moisture in a biosphere.

• Man's impact on climate includes:
   
  • Greenhouse gases (CO₂).
     
  • Ozone depletion  
     
  • Deforestation
   
• Climate is also impacted by the Milankovitch cycles as Earth moves through space.

 
Soil is the combined product of the weathering process by which rocks are degraded and the biological processes by which organic material is formed at the Earth's surface. Loams are soils made up of a combination of these basic particle sizes are:

• sand - largest particles, from 2 mm down to 0.05 mm (50 micrometers) in diameter.
   
• silt - particles ranging in size from 50 micrometers down to 2 micrometers in diameter.
   
• clay - particles have a diameter less than 2 micrometers.

Soil chemistry refers to the content of the soil. This greatly affects the types of plants and animals that can live in an area, as well as the weathering and shaping of the land.

In addition to rock particles, soil also contains:

• Inorganic ions, like nitrates and phosphates, make up the nutrients needed by plants.
   
• Life! Single cell organisms include algae, protozoa, and bacteria. Multicellular organisms include various plants, and animals from nematodes to earthworms and insects.
   
• Dead organic matter, humus, decayed by soil bacteria and fungi.
   
  • Mineral soils make up most soils in humid, temperate climates and contain relatively small amounts, 1% to 10%, of humus.
     
  • Organic soils are produced in bog conditions, consist primarily of organic matter, and have a spongy texture - holding lots of moisture.

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.

Weathering

• Agents of physical weathering:
   
  • Frost wedging - water increases its volume by 9% when it freezes, splitting rocks.
     
  • Wind
     
  • Thermal expansion
     
  • Tree roots
     
  • Animals
   
• Agents of chemical weathering:
   
  • Solution
     
  • Oxidation
     
  • Hydrolysis

Erosion is the removal and transportation of materials on the Earth's surface. Erosion is a physical process facilitated by wind and water.

Interception and Runoff: Earth intercepts precipitation, forming small puddles that overflow one into another, sheet flow, until the water reaches small channels marking the start of a river system. The area where all the precipitation is drained into a specific river is known as a drainage basin or watershed.

Water budget: drainage basins account for their water just as you account for your finances. Four terms are used to describe the variations of a water budget:

• Surplus occurs when precipitation exceeds evaporation/transpiration and the excess creates a stream.
   
• Usage occurs when evaporation/transpiration exceeds precipitation.
   
• Deficiency exists when all the water is used. A stream won't flow unless surplus water is available.
   
• Recharge is when precipitation again exceeds the loses and the deficiency is "paid back".

Flooding: The greater the discharge, the greater the depth of water in the channel. A flood results when a river channel is incapable of carrying all the water delivered to it.

Dams and Reservoirs: Dams can be built across river channels to capture excess water for later use. Some reservoirs are designed to produce a constant flow downstream. These are known as flood-control reservoirs.

Ground Water:  

Porosity and Permeability: The amount of water the ground can contain is determined by the porosity of the rock strata. Rounded particles will have the largest pores because they do not fit as closely together.

• Intrusive igneous rock and most metamorphic rock have no pores, 0% porous.
   
• Some extrusive rock may be almost 50% porous.
   
• Porosity of sedimentary rock varies:
   
  • Sandstone is 10% to 20%.
     
  • Shale is highly porous, but the pores are so microscopic that water is prevented from entering or leaving easily.

The ease with which water can pass through the subsurface is referred to as permeability.

Gravitational water drains freely through the largest pores (macropores). In most soils, gravitational water is present only just after rains or irrigation.

Capillary water is found in the smaller soil pores (micropores) which hold water against gravity, yet plant roots can absorb it. The finer textured the soil, the greater the amount of micropore space and the more useful water can be stored. When the micropore space is filled with water, as after a rain, the soil is said to be at its field capacity for water. When evaporation and removal by roots deplete a soil's capillary water, leaving only water that roots cannot take up, the soil is at its permanent wilting point - the lower limit of soil moisture that will support plant life.

Water flowing through a layer of rock that is relatively porous AND permeable is called an aquifer. Aquifers are generally classified by the type of rock through which they flow.