Ecosystems and Energy Chapter 3

What is Ecology? Ecology- Ecology- the study of systems that include interactions among organisms and between organisms and their abiotic environment. the study of systems that include interactions among organisms and between organisms and their abiotic environment. Biotic Biotic Abiotic Abiotic

Energy Energy- the capacity or ability to do work Energy- the capacity or ability to do work Potential energy vs. kinetic energy Potential energy vs. kinetic energy 1. First Law of Thermodynamics 1. First Law of Thermodynamics Energy can’t be created or destroyed (but it can change forms) Energy can’t be created or destroyed (but it can change forms) 2. Second Law of Thermodynamics 2. Second Law of Thermodynamics when energy is converted some of it is degraded into heat that disperses into the environment. when energy is converted some of it is degraded into heat that disperses into the environment.

Heat and kinetic energy converted Potential energy Kinetic energy

Photosynthesis Light energy from the sun in captured and converted into chemical energy Light energy from the sun in captured and converted into chemical energy Who uses this? Who uses this? autotrophs autotrophs

Respiration C 6 H 12 O 6 + O 2 → CO 2 + H 2 O + energy C 6 H 12 O 6 + O 2 → CO 2 + H 2 O + energy Makes the chemical energy stored in glucose and other food molecules available to the cell for work (moving, growing, etc.) Makes the chemical energy stored in glucose and other food molecules available to the cell for work (moving, growing, etc.)

Life without the Sun Chemosynthesis- Chemosynthesis-

Flow of Energy Through Ecosystems Producers- autotrophs Producers- autotrophs Consumers-heterotrophs Consumers-heterotrophs Primary consumers Primary consumers Secondary consumers Secondary consumers Tertiary consumers Tertiary consumers detritivores detritivores decomposers decomposers

Flow of Energy Food Chain- energy from food passes from organism to organism in a sequence Food Chain- energy from food passes from organism to organism in a sequence Trophic levels- each level or link in a food chain/foodweb Trophic levels- each level or link in a food chain/foodweb Food Web- more realistic model of flow of energy and materials through an ecosystem Food Web- more realistic model of flow of energy and materials through an ecosystem Human Impact Human Impact

Ecological Pyramids Ecological Ecological Numbers Numbers Biomass Biomass Energy Energy

The transfer between trophic levels is <20% The transfer between trophic levels is <20% Why? Why?

How can more people be supported on Earth when there is a limited supply of resources? Human Population Growth It depends on what they are eating…

Productivity Gross primary productivity (GPP)- Gross primary productivity (GPP)- This is the amount of light energy that is converted into chemical energy This is the amount of light energy that is converted into chemical energy Net primary productivity (NPP)- GPP minus the energy used by the primary producers for respiration. Net primary productivity (NPP)- GPP minus the energy used by the primary producers for respiration.

Human Impact Southern Hemisphere and whale hunting Southern Hemisphere and whale hunting Ozone Ozone Global warming Global warming

Practice Fox eats – rabbit and mice Fox eats – rabbit and mice Rabbit eats- grass Rabbit eats- grass Mouse eats- grass and grasshopper Mouse eats- grass and grasshopper Grasshopper eats- grass Grasshopper eats- grass Golden eagle- eats rabbit, snake, and fox Golden eagle- eats rabbit, snake, and fox Snake eats- mice Snake eats- mice Barn owl- eats mice Barn owl- eats mice Humans eat- rabbit Humans eat- rabbit Draw a food web and identify the consumers and producers. ID the primary, secondary, and tertiary consumers Draw a food web and identify the consumers and producers. ID the primary, secondary, and tertiary consumers