INTRODUCTION TO ENVIRONMENTAL SCIENCE

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INTRODUCTION TO ENVIRONMENTAL SCIENCE

• ? environmental science ? environmental
  interrelationship ? environmental issues ?
  interactions environment and organisms ? kinds
  of organism interactions ? laws of ecology ?
  energy flow in ecosystems ? biogeochemical cycles
  ?

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Environmental Science

• Environment
• everything (biotic and abiotic) that affects an
  organism during its lifetime
• Science
• a process of refining our understanding of nature
  by continual questioning and active investigation
  of questions
• not a collection of facts to be memorized
• Environmental Science
• An interdisciplinary area of study that includes
  both applied and theoretical aspects of human
  impact on the world.

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Environmental Interrelationship
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Environmental Issues

• Silent Spring by Rachel Carson (1960)
• Landmark on environmental awareness
• Stockholm, Sweden (1972)
• First major international conference on
  environmental issues
• United Nations Environmental Programme -- the
  Environmental Conscience of the United Nations
• Montreal Protocol (1987)
• Regulation of ozone-depleting substances
• Earth Summit, Brazil (1992)
• Reduction of emission of gases leading to global
  warming
• Protection of endangered species and habitats

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Environmental Studies
ENVIRONMENTAL CHEMISTRY
ENVIRONMENTAL BIOCHEMISTRY
TOXICOLOGICAL CHEMISTRY
ENERGY
CLEANER PRODUCTION
URBAN PLANNING
SUSTAINABLE DEVELOPMENT
AIR POLLUTION METEOROLOGY
HYDROLOGY
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Ecology

• Ecology
• the science that deals w/ the relationships
  between living organisms w/ their physical
  environment w/ each other

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Ecosystem

• Ecosystem
• consists of an assembly of mutually interacting
  organisms their environment in w/c materials
  are interchanged in a largely cyclical manner
  has physical, biological chemical components
  along w/ the energy sources pathways of energy
  materials interchange
• Components of Ecosystem
• Biotic
• community of living organisms the aspects of
  the environment pertaining directly to them
• Abiotic
• atmosphere, hydrosphere lithosphere

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• Habitat
• place where an organism lives
• Niche
• an organisms functional role in the environment

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Environmental Interaction The Case of DDT
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Major Levels of Ecological Interaction
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Major Levels of Ecological Interaction

• Individual
• any specie that has the ability to interact w/
  its environment the ability to produce
  offspring of its kind
• Population
• group of individuals occupying a specific habitat
• Communities
• interacting groups of organisms in w/c each
  organism has a specific niche or role to play

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Major Levels of Ecological Interaction

• Ecosystem
• the abiotic biotic parts of the environment
  interacting w/ each other
• Biomes
• terrestrial climax communities w/ wide geographic
  distribution (e.g. polar ice caps, desert, boreal
  forest or taiga, etc)
• Biosphere
• all living entities on earth it is where
  biogeochemical processes occur

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Biogeochemical Cycles

• Biogeochemical cycles
• the strong interactions among living organisms
  the various spheres of the abiotic environment
  described through cycles of matter that involve
  biological, chemical geological processes
  phenomena (e.g. carbon cycle, nitrogen cycle,
  phosphorus cycle, etc)

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Carbon Cycle
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Nitrogen Cycle
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Phosphorus Cycle
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Eutrophication

• Eutrophication
• is the word given to describe the effects of when
  a water body becomes so rich in nutrients that
  the natural wildlife is unable to survive. The
  area becomes swamped with algae and foreign
  species starving the water body of oxygen.

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A diagram showing how a water body looks when it
is healthy and free from excessive nutrients.
A diagram showing what happens when a water body
has excess nutrients.

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Kinds of Organism Interactions

• Predation
• one organism (predator) kill and eats another
  (prey)
• lions and zebras
• birds and worms
• Competition
• two organisms strive to obtain the same limited
  resource
• both organisms are harmed to some extent
• two birds
• grass and moss
• Symbiosis
• close, long lasting, physical relationship
  between two different species of organisms two
  organisms are usually in contact at least one
  organism derives some sort of benefit from this
  contact

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Kinds of Organism Interactions

• Symbiosis Parasitism
• one organism (parasite) lives in or on another
  organism (host) from which it derives nourishment
• fleas and birds
• mistletoe and trees
• Symbiosis Commensalism
• one organism benefits while the other is not
  affected
• orchids and trees
• remoras and sharks
• Symbiosis Mutualism
• both organism benefit
• flowers and insects
• nitrogen-fixing bacteria and plants

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Kinds of Organism Interactions
Predation
Competition
Interspecific
Intraspecific
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Kinds of Organism Interactions

Parasitism
ectoparasite parasites living on the surface of
their hosts endoparasite- living inside
the bodies of their hosts
Mutualism
Commensalism
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Energy Flows In Ecosystem

• Photosynthesis
• 12H2O 6CO2 709 kcal ?
• C6H12O6 6O2 6H2O
• Respiration
• C6H12O6 6O2 ?
• H2O 6CO2 energy

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Decomposition Nutrient Recycling

• Decomposers
• are based on detritus (dead organism, leaves,
  etc. undigested faecal matter excreted waste
  products from metabolism). Bacteria carry out
  final breakdown to its original inorganic
  constituents
• Nutrient recycling
• consider the nutrients from the product of
  photosynthesis

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Energy Flows in Ecosystem

• Energy Source
• main basis for the differentiation of organisms
• Autotroph
• an organism that obtains its cell carbon from an
  inorganic source (CO2, HCO3-) its energy from
  the sun
• Heterotroph
• an organism that obtains both its cell carbon
  its energy from organic matter
• Chemotroph
• an organism that obtains its energy from the
  oxidation of simple inorganic compounds such as
  FeS H2S, its cell carbon from inorganic /or
  organic matter. Chemotrophs are relatively
  insignificant in the energy relations of an
  ecosystem, but play a significant role in the
  movement of mineral nutrients in the ecosystems

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Food Chain Trophic Levels

• Trophic levels
• are levels of nourishment
• A plant that obtains its energy directly from the
  sun (autotrophs) occupies the 1st trophic level.
  
• An organism that consumes the tissue of an
  autotroph (herbivore) occupies the 2nd trophic
  level.
• An organism w/c eats the organism that had eaten
  autotrophs (carnivore) occupies the 3rd trophic
  level.

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Food Chain Trophic Levels

• Producers
• organisms that are able to make new, complex,
  organic material from the atoms in their
  environment
• Consumers
• consumes the organic matter to provide themselves
  w/ energy the organic molecules necessary to
  provide themselves w/ energy the organic
  molecules necessary to build their own bodies
• Primary consumers or herbivores
• Secondary consumers or carnivores
• Omnivores w/ mixed diets

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Trophic Levels
Each time energy moves to a new trophic level,
approximately 90 of the useful energy is lost.
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Food Chains Trophic Levels

• Food chain
• the passage of energy from one trophic level to
  the next as a result or organism consuming
  another an idealized pattern of flow of energy
  in a natural ecosystem in the classical food
  chain, plants are eaten only by primary
  consumers, primary consumers are eaten only be
  secondary consumers, and so on.

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Food Web

• Food Web
• results when several food chains overlap

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INTRODUCTION TO ENVIRONMENTAL SCIENCE

• ? environmental science ? environmental
  interrelationship ? environmental issues ?
  interactions environment and organisms ? kinds
  of organism interactions ? laws of ecology ?
  energy flow in ecosystems ? biogeochemical cycles
  ?