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BIOL 3240 Plant and Animal Ecology – Energy & Nutrients. Energy Sources. Organisms can be classified by trophic levels. Autotrophs use… ______________: Use CO 2 as carbon source, and sunlight as energy. ______________: Use inorganic molecules as source of carbon and energy.
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BIOL 3240 Plant and Animal Ecology – Energy & Nutrients Energy Sources • Organisms can be classified by trophic levels. • Autotrophs use… • ______________: Use CO2 as carbon source, and sunlight as energy. • ______________: Use inorganic molecules as source of carbon and energy. • Heterotrophs use…
BIOL 3240 Plant and Animal Ecology – Energy & Nutrients Solar - Powered Biosphere • Light propagates through space… • _________: Particle of light bears energy. • ____________(IR) Long-wavelength, low energy. • ____________(UV) Short wavelength, high energy. • _____________________________________(PAR)
BIOL 3240 Plant and Animal Ecology – Energy & Nutrients Photosynthetically Active Radiation
BIOL 3240 Plant and Animal Ecology – Energy & Nutrients Solar - Powered Biosphere • PAR • Quantified as _____________________. • Number of photons striking square meter surface each second. • Chlorophyll absorbs light as photons. • Landscapes, water, and organisms can all change the amount and quality of light reaching an area.
BIOL 3240 Plant and Animal Ecology – Energy & Nutrients Photosynthetic Pathways • Used by… • CO2+ ribulosebisphosphate (5 carbon sugar) = phosphoglyceric acid (3 carbon acid)
BIOL 3240 Plant and Animal Ecology – Energy & Nutrients C3 Photosynthesis
BIOL 3240 Plant and Animal Ecology – Energy & Nutrients Photosynthetic Pathways • Reduce internal CO2 concentrations. • Acids produced during carbon fixation diffuse to specialized cells surrounding _______________.
BIOL 3240 Plant and Animal Ecology – Energy & Nutrients C4 Photosynthesis
BIOL 3240 Plant and Animal Ecology – Energy & Nutrients Photosynthetic Pathways • (Crassulacean Acid Metabolism) • Limited to succulent plants in arid and semi-arid environments.
BIOL 3240 Plant and Animal Ecology – Energy & Nutrients CAM Photosynthesis
BIOL 3240 Plant and Animal Ecology – Energy & Nutrients Using Organic Molecules • Three Feeding Methods of Heterotrophs: • _______________: Feed on plants. • _______________: Feed on animal flesh. • _______________: Feed on non-living organic matter.
BIOL 3240 Plant and Animal Ecology – Energy & Nutrients Chemical Composition and Nutrient Requirements • Five elements make up 93-97% of biomass of plants, animals, fungi and bacteria:
BIOL 3240 Plant and Animal Ecology – Energy & Nutrients Essential Plant Nutrients • Potassium • Calcium • Magnesium • Sulfur • Chlorine • Iron • Manganese • Boron • Zinc • Copper • Molybdenum
BIOL 3240 Plant and Animal Ecology – Energy & Nutrients Herbivores • Substantial nutritional chemistry problems. • Low ... • Must overcome plant physical and chemical defenses. • Physical • Chemical
BIOL 3240 Plant and Animal Ecology – Energy & Nutrients Detritivores • Consume food rich in ___________________, but poor in ______________. • Fresh detritus may still have considerable ________________________ present.
BIOL 3240 Plant and Animal Ecology – Energy & Nutrients Carnivores • Consume … • Cannot choose prey at will. • Prey Defenses:
BIOL 3240 Plant and Animal Ecology – Energy & Nutrients Carnivores • Predators are usually selection agents for refined prey defense. • Usually eliminate more conspicuous members of a population (less adaptive). • Must catch and subdue prey - ________________. • Predator and prey species are engaged in a co-evolutionary race.
BIOL 3240 Plant and Animal Ecology – Energy & Nutrients Using Inorganic Molecules • 1977 - Organisms found living on sea floor. • Near nutrients discharged from volcanic activity through oceanic rift. • Autotrophs depend on chemosynthetic bacteria.
BIOL 3240 Plant and Animal Ecology – Energy & Nutrients Energy Limitation • Limits on potential rate of energy intake by animals have been demonstrated by studying relationship between feeding rate and food availability. • Limits on potential rate of energy intake by plants have been demonstrated by studying response of photosynthetic rate to photon flux density.
BIOL 3240 Plant and Animal Ecology – Energy & Nutrients Photon Flux and Photosynthetic Response Curves • Rate of photosynthesis increases linearly with photon flux density at … , rises more slowly with __________________ , and tends to level off at _________________. • Response curves for different species generally level off at _______________ maximum photosynthesis rates.
BIOL 3240 Plant and Animal Ecology – Energy & Nutrients Food Density and Animal Functional Response • Holling described (3) basic functional responses: • 1. Feeding rate increases linearly as food density increases - levels off at maximum. • 2. Feeding rate rises in proportion to food density.
BIOL 3240 Plant and Animal Ecology – Energy & Nutrients Food Density and Animal Functional Response • 3. Feeding rate increases most rapidly at intermediate densities
BIOL 3240 Plant and Animal Ecology – Energy & Nutrients Optimal Foraging Theory • Assures if energy supplies are limited, organisms cannot simultaneously maximize all life functions. • Must compromise between competing demands for resources.
BIOL 3240 Plant and Animal Ecology – Energy & Nutrients Optimal Foraging in Bluegill Sunfish
BIOL 3240 Plant and Animal Ecology – Energy & Nutrients Optimal Foraging Theory • All other things being equal,more abundant prey yields larger energy return. Must consider energy expended during: • Tend to maximize rate of energy intake.
BIOL 3240 Plant and Animal Ecology – Energy & Nutrients Optimal Foraging By Plants • Limited supplies of energy for allocation to … • Bloom suggested plants adjust allocation in such a manner that all resources are equally limited. • Appear to allocate growth in a manner that increases rate of acquisition of resources in ______________________.
