Primary

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Primary Secondary Productivity
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Definitions

• Autotrophy - organisms that use CO2 as their
  carbon source
• Photosynthesis
• Chemosynthesis
• Heterotrophy organisms that use organic C as
  their carbon source

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Primary Production - Photosynthesis

• General Reaction
• 2 AH2 CO2 ? (HCOH) 2A H2O
• AH2 can be
• O
• H2O CH3-C-OH (acetate)
• H2S CH3-CH2-OH (ethyl alcohol)

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Green Plant Phototrophes

• General
• 2 H2O CO2 ? (HCOH) O2 H2O
• Balanced
• 12 H2O 6 CO2 ? C6H12O6 6 H2O 6 O2

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Bacterial Phototrophes

• Green and Purple Sulfur Bacteria
• 2 H2S CO2 ? (HCOH) 2 S H2O
• Purple non-sulfur bacteria
• 2 organics CO2 ? (HCOH) oxidized
• organics H2O

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Phototrophic Pigments

• Chlorophylls a, b, c
• Only Chl-a can use electrons to produce chemical
  energy in photosynthesis
• Chl-b and Chl-c absorb light and pass the
  electrons to Chl-a ? accessory pigments
• Algae and some bacteria have chlorophyll

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• Carotenoids
• Accessory pigments to Chl-a
• Also can provide protection from harmful light ?
  photoprotective agents
• Having different pigments allows algae to take
  advantage of wavelengths at different depths ?
  chromatic adaptation

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Types of Primary Producers

• Lakes
• Plantonic
• Aerobic
• Green algae
• Blue-green algae
• Diatoms
• Anaerobic
• Green sulfur bacteria
• Purple sulfur bacteria
• Purple non-sulfur bacteria

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• Vascular Plants
• Rooted
• Pondweed (Potamogeton)
• Quilwort (Isoetes)
• Floating
• Water hyacinth (Eichhornia)
• Aufwuches attached algae, periphyton, and
  associated biota on rocks, sticks, non-living
  substrata

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• Mosses
• Ex Willow moss (Fontinalis) and stonewort
  (Chara)
• Benthic Algae
• Greens
• Diatoms

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• Streams
• Rooted plants
• Ex watercress (Rorippa nasturtium-aquaticum)
• Attached algae
• Ex Blanket weed (Cladophora)

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Methods of Measuring PPR

• Pigments
• Change in Chl-a concentration per unit of time
• O2 changes
• Measures community metabolism
• Light and dark bottles method for lakes
• Dark canopy for streams

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• CO2 Depletion
• Photosynthesis uses CO2
• Measure CO2 concentrations with IR analyzer
• pH change
• Photosynthesis raises pH
• Shift of bicarbonate to carbonate

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• 14-C isotope
• C12 available C14 available
• C12 assimilated C14 assimilated
• C12 assimilated X (unknown)
• C12 available total CO2, HCO2, CO3
• C14 available counts per second (added)
• C14 assimilated GiegerMuller or Scintillation
• counts corrected for counting efficiency

Isotope effect
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• Change in nutrient concentrations
• Loss of P or N due to plant uptake

Primary productivity measurements are DIFFERENT
than standing crop measurements, i.e. rate vs.
concentration
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Secondary Production

• Net production
• Gross production

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• Basic production equation
• P Bf Bi Be
• P production over a given time interval
• Bf biomass at the end of the time interval
• Bi biomass at the beginning of the time
  interval
• Be biomass eliminated during the interval
• Biomass weight of organisms/unit area (volume)
• of individuals average weight of an
  individual

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Some Terminology

• Cohort
• Recruitment
• Voltinism

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Direct Methods for Measuring Secondary Production

• Production of animals without continuous
  recruitment, i.e. distinct cohorts can be
  recognized
• Two population parameters must be known
• Quantitative estimates of abundance
• Growth rate of individuals in the cohort

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• Removal summation method
• Plot numbers (survivorship) and growth on a time
  scale

of individuals
Time
Be Change in over a time period avg. weight
of an individual during that period P Sum of
all Be for all time periods in a cohorts life
span
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• Allen curve

of individuals
Weight of average individual
P of one cohort area under the curve
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• Hynes-Hamilton
• Measures community secondary production
• Developed for use with stream invertebrates
• Ref
• Hynes and Coleman. 1968. Limnology and
  Oceanography. 13569-573.
• Hamilton. 1969. Limnology and Oceanography.
  14771-782.

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• Some problems with these methods
• Cohorts are not always easily distinguishable
  through their entire life
• Negative mortality
• Significant fraction of the total production
  estimate is due to a few large individuals which
  are often the most difficult to sample
• Migration
• Cohorts do not start simultaneously, usually
  staggered

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• Production of animals with continuous recruitment
• Methods require prior knowledge of growth rate
  and developmental time
• Best used on animals with distinct developmental
  stages, e.g. copepods

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• ProductionAverage biomass (PB ratios)
• Generally range between 2.5 5
• Estimates population turnover time, i.e. how long
  it takes a given biomass to produce an equivalent
  amount of biomass
• Ex
• if PB 4, the turnover time 3 months, i.e.
  population would double in 3 months if there was
  no mortality