chapter 6 - objectives 1. list the productivity significance of “light.” does it matter if...
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Chapter 6 - Objectives
1. List the productivity significance of “Light.” Does it matter if you’re not a plant?
2. Determine to what extent plants filter light from the heavens
3. Determine to what extent water filters light in the aquatic system
Chapter 6 - Objectives
4. List the adaptive mechanisms plants and animals used in promoting or discouraging energy transfer.
5. Explain diurnal rhythms (Circadian) and how they may effect energy transfer.
Energy (Food)
Basic organism essential elements:
Carbon
Nitrogen
Hydrogen 93%
Oxygen
Phosphorus
Plus a bunch of others - 7%
Energy (Food)
Plus----------
Energy source to build up compounds that can be used for growth
1. Radiant energy (most of the energy)
Photosynthesis
2. Chemical energy (deep sea bacteria)
Chemosynthesis
Fig. 6.2
• Primary Productivity is the production of organic material through photosynthesis.
• Basic Equation:
6 CO2 + 6 H2O = C6H12O6 + O2
Primary Productivity
• Primary Productivity is the production of organic material through photosynthesis.
• Basic Equation:
Light Energy
6 CO2 + 6 H2O = C6H12O6 + O2
Primary Productivity
Light
BUT!!!!
It’s not just quantity,
It’s also quality----
GR -->XR-->UV-->VISIBLE-->IR--->MICRO--->RADIO
shortest----------------------------------------------------->longest
Light
BUT!!!!
It’s not just quantity,
It’s also quality----
GR -->XR-->UV-->VISIBLE-->IR--->MICRO--->RADIO
shortest----------------------------------------------------->longest 250-315Ozone Depletion (UV-B)
Visible Light
Visible spectrum approximations: 400-750 nm
1) Red 750
2) Orange
3) Yellow
4) Green
5) Blue
6) Indigo
7) Violet 400
Visible Light/Adaptations
Visible spectrum approximations
1) Red
2) Orange
3) Yellow
4) Green
5) Blue - - Aquatic Plants use most!!!
6) Indigo
7) Violet
Plant Light - General
The wavelengths used in photosynthesis:
Photosynthetically Active Radiation
PAR
Fig. 6.3
Visible Light/Aquatics
Extinction Coefficient:
Attenuation of light is exponential through the water column. Both intensity and quality can change quickly.
Iz = Ioe-kz
Visible Light/Quality
Angle of Incidence: Altitude of the sun
• Morning/Evening - Longer path through the atmosphere, Blue’s Absorbed, Red’s Prevalent
Plant Light Adaptations
1. Morphological changes e.g., different pigments, different levels of chloroplasts, based on available light
2. Movement of plants to in response to light path - Phototaxis - e.g., Leaves and algae
3. Diurnal duration e.g., function of latitude and season
Animals and Light
Light----Does it matter to animals?
• Not directly for organic production
• But it may affect feeding and behavior
Animals and Light
• Many visual feeders - e.g., walleye
Crepuscular: Of, pertaining to, or resembling
twilight!!!!
Animals and Light
Defense - e.g., schooling of fish during day
Break up school at night!!
Animals and Light
Most mammals are nocturnal
e.g., raccoons, deer, bears
Others: owls
Eye adaptation - More rods than cones (color)
No seein’, No eatin’
Animals and Light
Light - Plants and Animals
Organisms respond to variations in quality and quantity of light - Adaptations in morphology, behavior, physiology, metabolic processes.
The Sun Sets on this Section!
Circadian Rhythms:
• Activities keyed to daylight (darkness)
• Daylight changes over year
• Activities change over the year
• Can trigger physiological processes and metabolic rates e.g., reproduction, flowering, migration, feeding cycles
Energy of organisms (Food)
Photosynthetic - produce food with radiant energy
Heterotrophic - obtain food by eating other organisms
Chemosynthetic - produce food from chemical energy
Energy of plants (Food)
Pho
tosy
nthe
tic
Rat
e
Increasing sunlight (photon flux density)
Isat
Pmax
Fig. 6.19
Functional Response: Three types
1. Type 1 Response
As prey increases the number of prey consumed increases proportionally until predators are satiated.
Energy of Animals
Functional Response: Type 1
Energy of Animals
# Prey Available
# Prey Consumed
Fig. 6.21
Functional Response: Type 1
Energy of Animals
# Prey Available
# Prey Consumed
Satiation
Fig. 6.21
Functional Response: Three types
2. Type 2 Response
As prey increases from low levels, the number of prey consumed increases rapidly. However, as prey density reaches higher levels, further increases in the number of prey consumed is slowed by the amount of time needed to “handle” (kill and eat) the prey
Energy of Animals
Functional Response: Type 2
Energy of Animals
# Prey Available
# Prey Consumed
Fig. 6.21
Functional Response: Three types
3. Type 3 Response
As a previously rare species increases, predators slowly increase their consumption of that prey at first, then rapidly increase their consumption with prey density, until limited by predator satiation or prey handling time
Energy of Animals
Functional Response: Type 3
Energy of Animals
# Prey Available
# Prey Consumed
Fig. 6.21
Food Choice
1. Eat/uptake items that will produce energy for them
Standardneo-tropicalmigrant
GreyDogwood
Herbivores and Carnivores
Optimum Foraging Theory:
Natural selection will favor those individuals within a population that are more effective at acquiring energy----------And, they do this to maximize or minimize some quantity
E.g., Bluegills and size of prey (Fig. 6.24)
Optimum Foraging Theory:
Bluegills
Fig. 6.24
Food Choice
2. Adaptations that allow predator to efficiently obtain nutrients and energy from prey species.
e.g., Herbivores digesting cellulose with the help of bacteria, fungi or protists that live in their digestive tract.
Food Choice
3. Prey species produce defenses that can be formidable.
• Chemicals - toxins and digestion-reducing substances
• Morphological defenses e.g., spines, camouflage, behavior, mimicry, size or number
NO defense is perfect or 100% sure!!!
Fig. 6.14
Fig. 6.16
Bluegills
Bluegills
Done with Chapter 6