Chapter 3 Ecosystems: How They Work

Matter Matter Anything that has Anything that has Made of atoms of elements → molecules and compounds Made of atoms of elements → molecules and compounds ______ molecules have carbon-carbon bonds or carbon-hydrogen bonds (can be synthesized) ______ molecules have carbon-carbon bonds or carbon-hydrogen bonds (can be synthesized) ______ molecules are not from living things ______ molecules are not from living things

Matter (cont) Law or Conservation of Mass: Law or Conservation of Mass:

Energy The ability to move matter The ability to move matter Kinds: Kinds: ____: Energy of motion or action ____: Energy of motion or action ____: Stored energy ____: Stored energy ____: stored energy in the form of chemicals & fuels ____: stored energy in the form of chemicals & fuels Measured: Measured: ____ (c) – heat required to raise 1 gram of water one degree Celsius ____ (c) – heat required to raise 1 gram of water one degree Celsius ____ (C): food calories ____ (C): food calories

Forms of Energy

Energy Laws 1 st Law of Thermodynamics (law of conservation of energy): 1 st Law of Thermodynamics (law of conservation of energy): 2 nd Law of Thermodynamics: In any energy conversion, some of the usable energy is always lost: 2 nd Law of Thermodynamics: In any energy conversion, some of the usable energy is always lost: Example: Chemical reaction of Respiration Example: Chemical reaction of Respiration

Matter and Energy Changes in Organisms and Ecosystems Producers: Producers: Kinetic energy of light is converted to high potential energy in the form of carbon bonds. Kinetic energy of light is converted to high potential energy in the form of carbon bonds. The original energy is always there (sun) to drive this mechanism. The original energy is always there (sun) to drive this mechanism.

Matter and Energy (cont) Consumers Consumers Respiration releases high potential energy of glucose bonds into low potential energy of CO2 and energy loss by body heat. Respiration releases high potential energy of glucose bonds into low potential energy of CO2 and energy loss by body heat. Fate of Food Fate of Food ____% is oxidized for energy. ____% is oxidized for energy. ____% is converted to the body tissues of the consumer. ____% is converted to the body tissues of the consumer. Some of the ____% is passed through-fecal waste. Some of the ____% is passed through-fecal waste.

Detritus Feeders and Decomposers Digest ____ and use as energy source Digest ____ and use as energy source Sometimes respiration occurs in the absence of oxygen: _______ Sometimes respiration occurs in the absence of oxygen: _______

Principles of Ecosystem Function Energy Flow: Most energy is from the sun for producers. The actual production of crops at any one time on Earth is know as the standing crop biomass. Most energy is from the sun for producers. The actual production of crops at any one time on Earth is know as the standing crop biomass. Productivity of different ecosystems depends on different biotic and abiotic factors (see p 67). Productivity of different ecosystems depends on different biotic and abiotic factors (see p 67). Energy moves through the trophic levels. Energy moves through the trophic levels.

Energy Flow (cont) Energy Efficiency Only a small fraction of energy flows from one trophic level to the next. Only a small fraction of energy flows from one trophic level to the next. Often the majority of energy ends up and flows through the detritus food web. Often the majority of energy ends up and flows through the detritus food web. Ecosystems do not use energy at a rate that is faster than that which is available from the sun. Ecosystems do not use energy at a rate that is faster than that which is available from the sun. Humans are consuming fossil fuels at a rate faster than they can be produced. Humans are consuming fossil fuels at a rate faster than they can be produced.

Energy Flows, Nutrients Cycle

Nutrient Cycles Keeping in mind the law of Conservation of Matter: the molecules in an organism can eventually be found in another. Keeping in mind the law of Conservation of Matter: the molecules in an organism can eventually be found in another.

Carbon Cycle Carbon Cycle Changing the location of this element is the primary issue in global warming, from fossil fuels to the atmosphere.

Phosphorus Cycle Phosphorus Cycle Changing the location of this element is one of the primary reasons for the increased nutrient load in aquatic ecosystems, from concentrated waste and deposits in soil to its release in water.

Nitrogen Cycle Nitrogen Cycle Changing the location of this element also increases the nutrient load in aquatic ecosystems. Changing the location of this element also increases the nutrient load in aquatic ecosystems.

Sulfur Cycle

2 Principles of Ecosystem Sustainability 1. Ecosystems 2. Ecosystems

Implications for Humans ____ are excellent models for Humans ____ are excellent models for Humans Non-sustainable actions by humans affect the nutrient cycles: Non-sustainable actions by humans affect the nutrient cycles: N H E C F