Ecology

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Ecology

• Dr. Jared Heidinger M.D. Ph.D. Masters of
  Ecology, Doctorate of ecology, undergraduate of
  ecology, know it all of ecology, full of it
  ecology

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• Ecology study of interrelationships b/w living
  organisms and b/w organisms and their abiotic
  environment

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Levels of Organization in Biology

• Ecosphere global ecosystem
• Biosphere global community
• Ecosystem community and environ.
• Community group of populations (same place,
  same time)
• Population same species of organism (same area,
  same time)
• Organism individual living thing

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Continued

• Organ system groups of organs that carry out a
  function (eg. digestive system)
• Organ two or more tissues that work together at
  a function (eg. Kidney)
• Tissue groups of cells with similar structure
  and function (eg. Muscle)
• Cell basic unit of life

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Continued

• Organelle structures within cells
• Molecule group of atoms bonded together
• Atom basic unit of all matter

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Other important definitions

• Species organism which can interbreed and
  produce fertile offspring
• Habitat environment in which a species normally
  lives or the location of a living organism.

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Ecosystems (community and environment)

• Consists of
• biota (living things (eg. organisms from the five
  kingdoms))
• Abiota (non-living things (eg. Soil, water, air,
  weather))

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Interrelationships within ecosystem

• Biota affects biota man eats fish

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• Biota affects abiota animals release gas to
  atmosphere

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• Abiota affects abiota fire destroys nesting
  sites
• Abiota affects abiota water erodes rock

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Pork CHNOPS Pork what???
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Within Ecosystem

• Matter is cycled
• C, H, N, O, P, S
• Molecules cycle between biota and abiota
  (biogeochemical cycles)
• Energy does NOT cycle
• Enters by sun, travels through food chain, leaves
  as heat

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Biogeochemical Cycles

• All chemical elements in living organisms (mainly
  CHNOPS) are
• Part of biogeochemical cycles
• Move through land, water and air

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Continued

• Biogeo. Cycles summarize movements of elements
• Through the biota (via food chains) forming
  complex organic molecules
• Through the abiota forming simpler reusable
  organic forms.

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Continued

• Affected by human activity resulting in
• Ozone depletion
• Green house effect and global warming
• Acid rain
• Algal blooms
• Biomagnification of pesticides

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Nitrogen Cycle
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HUMAN IMPACT SHEET
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Continued
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N2 cycle has 3 phases
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Phase 1

• Nitrogen fixation conversion of atmospheric
  nitrogen (N2) to nitrates (NO3-)
• Often NH3 is formed first
• Mostly done by aerobic bacteria
• Some free-living in soil
• Some symbiotic live in plant roots
• Some industrial fixation for fertilizer

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Phase 1 cont

• Legumes (beans, peas, alfalfa, clover) have
  root nodules that containing N2 fixing bacteria
• Mutualistic relationship both organisms benefit
  (/)
• Increase soil nitrates farmers rotate their
  crops with these plants

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Phase 2

• Nitrification
• Process of changing NH3 to NO2- to NO3-
• Done by bacteria in soil

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Phase 3

• Denitrification conversion of nitrates (NO3-)
  to 2N
• Anaerobic bacteria do this
• Lowers available nitrates for plants
• Plants dont grow as well
• Aerate, plow, dig, anything to get some O2 back
  in soil helps to counteract the plot of the evil,
  evil denitrifying bacteria (not really evil,
  unless you are a gardener)

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Final Thoughts

• Animals get all nitrogen (eg. - found in protein,
  DNA) from plants
• Need nitrogen fixation to survive

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Farming

• Breaks the natural nitrogen cycle by removing all
  of the plant matter at harvest
• Less matter to decompose and replenish nitrogen
• Results in the need to fertilize

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Carbon Cycle

• Often called carbon oxygen cycle
• Interrelated
• Major processes
• Photosynthesis
• Decomposition breakdown of organic matter,
  mostly done by fungi and saprophytic bacteria
• Combustion mostly done by automobiles

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Problems

• Global Warming
• Deforestation causes decline in photosynthesis

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Not the same

• Greenhouse effect is a natural process. Without
  it we could not survive on earth.
• Greenhouse gases (CO2, H2O vapour, CH4 (methane),
  nitrous oxide, CFCs) help to keep heat (infrared
  radiation) close to the earths surface
• Global warming an increase in the earths average
  temperature due to the burning of fossil fuels
  releasing excess amounts of CO2

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• Worst case scenario warming is greatest at
  poles causing melting of ice caps
• Ocean could rise by 100m resulting in flooding of
  coastal regions up to 150km inland
• Change in climate could mess with agriculture as
  well.

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Water Cycle
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Steps

• Evaporation l to g
• Transpiration l to g from plants
• Condensation g to l form clouds
• Transport movement of clouds
• Precipitation rain, sleet, snow, etc.
• Runoff streams, lakes, rivers
• Groundwater aquifers, underground streams

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Problems

• Acid rain
• Toxic waste dumping
• Leaching (chemical compounds seep into
  underground water)
• Deforestation
• runoff increases, minerals run into streams,
  disrupting balance in ion concentrations in water
• Transpiration rates are changed.

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Phosphorous Cycle
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Phosphorous uses in Biota

• Cell membranes (phospholipids)
• Energy storage (ATP)
• Genetic information (DNA, RNA)

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in Abiota

• Phosphate ions (PO43-) combined with other
  elements in rock
• Ions dissolved in water move with water cycle

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Problems

• Eutrophication

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Human Impact Worksheet
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Energy Flow in the Biosphere

• E flows through an ecosystem
• Enters as light, leaves as heat
• Is transferred through the food chain.

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Food Chain

• Shows flow of energy thorough ecosystem
• DIAGRAM

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Producer
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Consumer

• Eats something
• Primary eats producer
• Secondary eats primary
• Tertiary
• Quaternary not usually more than a quaternary
  consumer

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• Autotroph make own food from abiotic materials
• Photoautotroph use sun
• Chemoautotroph Use heat and chemical compounds
  to make useable energy
• Heterotroph needs something else for energy

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Decomposers

• Use last energy from organic matter that has died
• NOT shown on a food chain
• Trophic level (feeding level) each step in a
  food chain

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Energy Transfer in a Food Chain

• Inefficient some E lost in each step
• Only 10-20 of E passed to next level
• E loss due to
• Some material not eaten
• Some not digested or assimilated
• Heat lost through cellular respiration

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• Therefore, the E available to each trophic level
  is always less than at the previous level
• Results in less organisms at each successive level

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Ecological Pyramids

• Used to show overall E flow
• Numbers can be inaccurate (many insects on one
  tree)
• Biomass
• Energy most accurate, biggest pain to do

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Food Webs

• Show alternative food chains
• Shows complexity of energy flow

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Population Ecology

• Populations are described in terms of
• Size
• Distribution
• Density
• Diversity

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Four main Factors affect Population size

• Natality (birth rate)
• Mortality (death rate)
• Immigration (moving in)
• Emmigration (moving out)

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Estimating Population size

• Mark and recapture method.

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Population Growth
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Represented on growth curves

• DIAGRIZZLE

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Definitions

• Carrying capacity number of organisms an
  ecosystem can support
• Reproductive potential max reprod. Rate under
  ideal conditions

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Elephant - 2 years
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Human - 9 months
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Limiting factors

• Conditions that prevent population growth
• Amount of food
• Space
• Waste
• Competition
• Predation

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Limiting factors cont

• Responsible for establishing the carrying
  capacity
• Determine the distribution of org. in ecosys.
• Plants affected by temp., water, soil pH,
  salinity, mineral nutrients
• Animals affected by temp., water, breeding
  sites, food supply, territory

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Niche

• Total role of an organism in its ecosystem
  including
• Trophic level (food sources)
• Habitat used
• Interactions with biota and abiota

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Competitive Exclusion Principle

• No two species can occupy the same niche
• One always out competes the other.

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Biological Relationships

• Symbiotic organisms living in close association
  with each other
• Mutualism / both benefit (nitrogen fixing
  bacteria and bean plant)
• Commensalism /0 one benefits other unaffected
  (shark and remora)

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• Parasitism /- one benefits other is harmed
  (tapeworm and human)

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Competition

• Intraspecific b/w members of the same species
  (eg food, mates)
• Interspecific b/w members of different species
  (eg. Food, space)

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• Competition creates selection pressures that
  drive evolution forward.
• Competition is reduced by resource partitioning
  (making use of different parts of the ecosystem
  (I.e. niche specialization)

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Succession

• Successive stages of development in an ecosystem
• Begins with pioneer species
• Develops through seral stages
• Ends with a climax community

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Succession continued

• Primary succession occurs in an area where
  organisms have not established themselves already
  
• lichens, moss on rocks exposed by a retreating
  glacier

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• Secondary succession occurs in an area where
  life has already been but has been disturbed
• Forest after a forest fire

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Why Succession Happens

• Organisms at each stage affect the abiotic
  environment, altering the conditions in such a
  way as to allow other species to move in
• Abiotic changes include soil
• development, accumulation of minerals and
  reduced erosion

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Productivity in the Ecosystem

• Gross Production (Gross Primary Productivity gt
  GPP)
• Total amount of light E converted to chemical E
  by the autotrophs of an ecosystem over a given
  period of time

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• some E from gross production is used for
  cellular respiration
• Rest is converted to biomass and is available to
  the next trophic level

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Net Productivity (Net Primary Productivity -gt NPP)

• Gross production minus respiration
• GPP Rs NPP
• net production can be expressed as
• Energy per area per time (J m-2 yr-1)
• Biomass (dry weight) expressed as mass per area
  per time (g m-2 yr-1)

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Biodiversity and Conservation

• Biodiversity number and types of organisms
  present in an area (a.k.a. species richness)
• Wildlife conservation efforts to maintain high
  levels of biodiversity

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Eg) With reference to rainforest why attempt to
conserve biodiversity?

• Ethical concerns responsibility
• Ecological concerns interrelationships between
  species
• Economic concerns medicines, drugs, pool of
  valuable resources
• Aesthetic concerns beauty of the rainforest
  worth saving.

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In-situ vs ex-situ conservation measures

• In-situ keeping organisms in their natural
  habitat
• Eg creating nature reserves (aquatic or
  terrestrial)

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Ex-situ

• Ex-situ conservation efforts outside of their
  original habitat
• Eg. Zoos (captive breeding programs), aquaria,
  seed banks, botanical gardens

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In-situ advantages/disadvantages

• Advantages
• Natural habitat
• Maintains ecological relationships
• Protects from human exploitation

• Disadvantages
• Need large tracts of land
• Must control alien species
• Must restore degraded areas

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Ex-Situ Advantages/Disadvantages

• Advantages
• Breeding ensured even with low population counts
• Animals released where they are lowest in numbers

• Disadvantages
• Animals not in natural habitats
• Doesnt maintain ecological relationships
• Doesnt fix original problem