THE LIVING WORLD

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THE LIVING WORLD
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Ecosystem

• An ecological community and its local, non
  biological community. An ecosystem is the
  minimum system that includes and sustains life.
  It must include at least an autotroph, a
  decomposer, a liquid medium, a source and sink of
  energy, and all the chemical elements required by
  the autotroph and decomposer.

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Keystone Species

• A species that has a large effect on its
  community or ecosystem so that its removal or
  addition to community leads to major changes in
  the abundances of many or all species

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Photosynthesis

• Synthesis of sugars from carbon dioxide and water
  by living organisms using light as energy.
  Oxygen is given off as a by-product.

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Cellular Respiration

• The process in which the chemical bonds of
  energy-rich molecules such as glucose are
  converted into energy usable for life processes.
  Pd9xation of organic material in a bonfire, for
  example is an exothermic reaction that releases a
  large amount of energy rather quickly.

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Energy Flow

• Photosynthesis and cellular respiration, food
  webs and trophic levels, ecological pyramids

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Ecological Niches

• The general concept is that the niche is a
  species profession. The term is also used to
  refer to a general set of environmental
  conditions within which a species is able to
  persist.

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Earths 17 Major Biomes

• Tundra Treeless plains that occur in the harsh
  climates of low rainfall and low average
  temperatures. Dominant vegetation includes
  grasses, lichens, mosses, flowering dwarf shrubs,
  and mat-forming plants.
• Taiga Also known as the boreal forest. Biome
  includes forests of the cold climates of high
  latitudes and high altitudes.
• Temperate Forests Occur in climates somewhat
  warmer than those of the boreal forests. These
  forests occur throughout North America, Eurasia,
  and Japan. Dominant vegetation includes tall
  deciduous trees.
• Temperate Rain Forests Occur under moderate
  temperature regimes where rainfall exceeds 250
  cm/year.
• Temperate Woodlands Occurs in temperature
  patterns like those of deciduous forests but the
  climate is slightly drier. These areas are
  dominated by small trees such as pinon pines and
  evergreen oaks.
• Temperate Shrub Lands Also known as chaparral.
  Occur under still drier climates like that of the
  Mediterranean.
• Temperate Grasslands Occur in regions too dry
  for forests and too moist for deserts. Major
  biome in terms of area covered.
• Tropical Rain Forests Average high temperature
  and stays relatively constant throughout the
  year. Rainfall is high and relatively frequent.
• Tropical Seasonal Forests Low latitudes where
  average temperature is high and constant,
  rainfall is high but very seasonal.

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Geological Time Scale

• Record of Earths history form its origin to the
  present used to correlate geologic events,
  environmental changes, and development of life
  forms that are preserved in rocks.
• Plate tectonics responsible for the formation of
  some mineral deposits. As the plate tectonics
  slowly move across the Earths surface so do the
  continents. Slow movements of earths outermost
  rock shell.
• Earthquakes- Most occur at boundaries between
  plates. They occur when the brittle upper
  Lithosphere fractures along faults.
• Volcanism most volcanoes occur at plate
  boundaries. 80 found along convergent
  boundaries, 15 divergent boundaries 5 far from
  plate boundaries.
• Season short-term period of climatic changed
  caused by regular variations in temperature,
  hours o daylight, and weather patterns that are
  due to the tilt of earths axis as it revolves
  around the sun, causing different areas of Earth
  to receive different amounts of solar radiations.
• Latitude Distance in degrees north and south of
  the equator.

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Food Web
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Trophic Levels

• In an ecological community all the organisms that
  are the same number of food chain steps from the
  primary source of energy. For example, in a
  grassland the green grasses are on the first
  trophic level, grasshoppers are on the second,
  birds that feed on grasshoppers are on the third,
  and so forth.

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Ecological Pyramids

• Graphical representations of the number of
  individuals in different nutritional levels

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Seasons

• Autumnal equinox Occurs when the sun is directly
  overhead at the equator and results in day and
  night of equal length for both northern and
  southern hemispheres.
• Summer Solstice Occurs when the sun is directly
  overhead at 23.5 north latitude, around June 21,
  and results in the maximum number of day light
  hours for the northern hemisphere and the minimum
  number for the southern hemisphere.
• Winter Solstice Occurs when the sun is directly
  overhead at 23.5 south latitude, around December
  21, and results in the minimum number of daylight
  hours for the northern hemisphere and the maximum
  number for the southern hemisphere

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The Atmosphere

• Ozone (O3) gas formed by the addition of a third
  oxygen atom to an oxygen molecule, absorbs
  ultraviolet radiation from the sun.
• Troposphere- contains most of the mass of the
  mass of the atmosphere, most weather takes place,
  air pollution is collected.
• Stratosphere concentrated ozone, absorbs more
  ultraviolet radiation than the troposphere
• Mesosphere no concentrated ozone mesopause,
  boundary between mesosphere, and thermosphere
• Thermosphere molecules sparse widely spaced
  despite temperature, wouldn't seem warm
• Exosphere outermost layer of Earths
  atmosphere, Helium and Hydrogen.
• Weather Current state of the atmosphere,
  including short-term variations such as
  temperature and precipitation.
• Climate Average weather of a particular area
  over a long period of time, it includes annual
  variations in temperature and precipitation,
  which are influences by latitude, closeness of
  lakes, and oceans, topography, wind, patterns,
  and air masses.
• Coriolis effect Deflects moving particles such
  as air to the night above the equator and to the
  left below the equator caused by earths
  rotation and combines with the heat imbalance
  found on earth o create the trade winds, polar
  easterlies, and prevailing westerly's.
• Water form the ocean evaporates into the
  atmosphere. As water vapor rises it cools and
  becomes a liquid Cold air pushed warm air upward,
  creating a convection current.

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Climatic Changes

• Global Warming A natural or human induced
  increase in the average global temperature of the
  atmosphere near the Earths Surface.
• The temperature at or near the surface of the
  Earth is determined by four main factors
• 1) The amount of sunlight Earth receives
• 2) The amount of sunlight Earth reflects.
• 3) Retention of heat by the atmosphere.
• 4) Evaporation and condensation of water vapor.

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Greenhouse Effect

• Process of trapping heat in the atmosphere.
  Water vapor and several other gases warm the
  Earths atmosphere because they absorb and remit
  radiation that is. They trap some of the heat
  radiating from the Earths atmospheric
  temperature.
• Greenhouse gases The suite of gases that have a
  greenhouse effect, such as carbon dioxide,
  methane, and water vapor.

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Biogeochemical Cycles
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Atmosphere

• Weather Current state of the atmosphere,
  including short-term variations such as
  temperature and precipitation.
• Climate Average weather of a particular area
  over a long period of time, it includes annual
  variations in temperature and precipitation,
  which are influences by latitude, closeness of
  lakes, and oceans, topography, wind, patterns,
  and air masses.

• Coriolis effect Deflects moving particles such
  as air to the night above the equator and to the
  left below the equator caused by earths
  rotation and combines with the heat imbalance
  found on earth o create the trade winds, polar
  easterlies, and prevailing westerly's.
• Water form the ocean evaporates into the
  atmosphere. As water vapor rises it cools and
  becomes a liquid Cold air pushed warm air upward,
  creating a convection current.

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Global Water Resources and Use

• The main process of the hydrologic cycle is the
  global transfer of water from the atmosphere to
  the land and oceans and back to the atmosphere.
• Globally, waters availability in the right place
  at the right time in the right form is a problem.
• Water on Earth is found in liquid, solid, and
  gaseous form.
• Water I used in very large quantities.
• Water shortages can lead to serious economic
  disruption and human suffering.

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Percentage of Total Water

• Oceans- 97.2
• Atmosphere 0.001
• Rivers and Streams 0.0001
• Groundwater - .31
• Lakes 0.0009
• Ice Caps and Glaciers 2.15

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Water

• Off stream Uses- Refers to the water removed from
  its source for use. The water is returned to the
  source after it is used.
• Consumptive Use Off- stream use in which water
  is consumed by plants and animals or used in
  individual processes.
• In-Stream Use- Includes the use of rivers for
  navigation, hydroelectric power generation, fish
  and wildlife habitats, and recreation.

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Soil

• Rock Cycle Continuous, dynamic set of processes
  by which rocks are changed into other types of
  rocks.
• Weathering and Erosion Sediments, sedimentary
  rocks, metamorphic rocks, magma, igneous rocks,
  weathering and erosion.\
• Soil The loose covering of broken rock particles
  and decaying organic matter, called humus,
  overlying the bedrock of Earths surface.

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Soil Dynamics

• Soil forming Process Begins when weathering
  breaks solid bedrock into smaller pieces. The
  pieces of rock continue to undergo weathering ad
  break down into smaller and smaller pieces.
  Organisms begin to live and die in these weather
  materials.
• Residual soil- Soil located above its parent
  material
• Transported soil - soil moved to a location away
  from its parent bedrock
• Conservation With respect to resources such as
  energy, refers to changing our patterns of use of
  simply getting by with less. In a pragmatic
  sense the term means adjusting our needs to
  minimize the use of a particular resource, such
  as energy

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Biodiversity

• Biological Diversity involves the following
  steps
• 1 Genetic Diversity The total number of genetic
  characteristics of a specific species, a
  subspecies, or a group of species. In terms of
  genetic engineering and our new understanding of
  DNA, this could mean Te total base-pare
  sequences in DNA, the total number of genes,
  active or not, or the total number of active
  genes.
• 2 Habitat diversity The diversity of habitats
  in a given unit area.
• 3 Species Diversity
• Species richness- the total number of species.
• Species evenness- the relative abundance of
  species.
• Species dominance- the most abundant species.

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Edge Effect

• An effect that occurs following the forming of a
  forest island in the early phases the species
  diversity along the edge is greater than in the
  interior. Species escape from the cut area and
  seek refuge in the boarder of the forest, where
  some may last only a short time.

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Natural Selection

• A process by which organisms whose biological
  characteristics better fit them to the
  environment are better represented by descendants
  in future generations than those whose
  characteristics are less fit for the environment.

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Four primary characteristics of natural
selection

• 1) Inheritance of traits from one generation to
  the next and some variation in these traits that
  is, genetic variability
• 2) Environmental variability
• 3) Differential reproduction that varies with the
  environment.
• 4) Influence of the environment on survival and
  reproduction.

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Evolution

• The Change in inherited characteristics of a
  population from generation to generation,
  sometimes resulting in a new species or
  populations.
• Advances in genetic engineering reinforces the
  basis of theory in evolution.

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Basic Characteristics of Ecosystems

• Structure An ecosystem is made up of two major
  parts living and nonliving. The nonliving part
  is the physical-chemical environment, including
  the local atmosphere, water and mineral soil or
  other substrate.
• The living part is called the ecological
  community which is also the set of species
  interacting within the ecosystem.
• Processes Two basic kinds of processes must
  occur in an ecosystem A cycling of chemical
  elements and a flow of energy.
• Change An ecosystem changes over time and can
  undergo development throuhg a process called
  succession.

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Ecosystem Services

• Disperse seeds
• Mitigate droughts and floods
• Cycle and move nutrients
• Detoxify and decompose waste
• Generate and preserve soil and their fertility
• Pollinate crops and natural vegetation