ecology review 1
TRANSCRIPT
Ecology Review
The branch of Biology that describes relationships between organisms and the environments in which they live
Principles
• The law of conservation of matter:
• Matter can be changed from one form to another
• but it cannot be created or destroyed
1st law of energy
• Energy cannot be created or destroyed but can be converted from one form to another– Radiant energy – sun– Chemical energy – photosynthesis– Kinetic energy – animal movement– Thermal energy – creating heat
2nd law of energy
• Every time energy is converted from one form to another, energy is lost in the form of heat
Energy Cycle
• The fundamental source of energy in almost all ecosystems is radiant energy from the sun
• energy and organic matter are passed along an ecosystem's food chain.
• Organisms are classified based upon the number of energy transfers through a food web
Primary Production
• Photoautotrophic production of organic matter represents the first energy transfer in ecosystems
2nd Trophic Level
• Consumption of a plant by a herbivore is the second energy transfer,
• Herbivores occupy the second trophic level,
• also known as secondary production.
Consumers
• Consumer organisms that are one, two, or three transfers from autotrophs are classified as primary, secondary, and tertiary consumers.
Energy Loss
• Moving through a food web, energy is lost during each transfer as heat, as described by the second law of thermodynamics.
Energy Loss
• Consequently, the total number of energy transfers rarely exceeds four or five;
• with energy loss during each transfer, little energy is available to support organisms at the highest levels of a food web.