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Ecology. Energy and Ecosystem Pyramids. September 27, 2010. FRQ’s are due We will grade… in class Tests were correct, A and B re scanned You may buy back points by ½ for every one. I need full question and answer plus page you found it in the book. Please list answer to Left in the margin
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Ecology Energy and Ecosystem Pyramids
September 27, 2010 • FRQ’s are due • We will grade… in class • Tests were correct, A and B re scanned • You may buy back points by ½ for every one. I need full question and answer plus page you found it in the book. Please list answer to Left in the margin • Begin Chapter 4 Learning Targets • I will be doing a notebook check for 4 not points for activities
THE NATURE OF ECOLOGY • Ecology is a study of connections in nature. • How organisms interact with one another and with their nonliving environment. Figure 3-2
Nonliving and Living Components of Ecosystems • Ecosystems consist of nonliving (abiotic) and living (biotic) components. Figure 3-10
Other animals 281,000 Known species 1,412,000 Insects 751,000 Fungi 69,000 Prokaryotes 4,800 Plants 248,400 Protists 57,700 Fig. 3-3, p. 52
Populations, Communities, and Ecosystems • Members of a species interact in groups called populations. • Populations of different species living and interacting in an area form a community. • A community interacting with its physical environment of matter and energy is an ecosystem.
Biosphere • Atmosphere • Membrane of air around the planet. • Stratosphere • Lower portion contains ozone to filter out most of the sun’s harmful UV radiation. • Hydrosphere • All the earth’s water: liquid, ice, water vapor • Lithosphere • The earth’s crust and upper mantle.
Biosphere Carbon cycle Phosphorus cycle Nitrogen cycle Water cycle Oxygen cycle Heat in the environment Heat Heat Heat Fig. 3-7, p. 55
Solar radiation Energy in = Energy out Reflected by atmosphere (34% ) Radiated by atmosphere as heat (66%) UV radiation Lower Stratosphere (ozone layer) Absorbed by ozone Greenhouse effect Troposphere Visible Light Heat Absorbed by the earth Heat radiated by the earth Fig. 3-8, p. 55
Energy Flow in an Ecosystem: Losing Energy in Food Chains and Webs • In accordance with the 2nd law of thermodynamics, there is a decrease in the amount of energy available to each succeeding organism in a food chain or web.
Productivity of Producers: The Rate Is Crucial • Gross primary production (GPP) • Rate at which an ecosystem’s producers convert solar energy into chemical energy as biomass. Figure 3-20
Net Primary Production (NPP) • NPP = GPP – R • Rate at which producers use photosynthesis to store energy minus the rate at which they use some of this energy through respiration (R). Figure 3-21
Energy Flow in an Ecosystem: Losing Energy in Food Chains and Webs • Ecological efficiency: percentage of useable energy transferred as biomass from one trophic level to the next. Figure 3-19
Heat Heat Tertiary consumers (human) Decomposers Heat 10 Secondary consumers (perch) Heat 100 Primary consumers (zooplankton) 1,000 Heat Producers (phytoplankton) 10,000 Usable energy Available at Each tropic level (in kilocalories) Fig. 3-19, p. 66
The Gaia Hypothesis: Is the Earth Alive? • Some have proposed that the earth’s various forms of life control or at least influence its chemical cycles and other earth-sustaining processes. • The strong Gaia hypothesis: life controls the earth’s life-sustaining processes. • The weak Gaia hypothesis: life influences the earth’s life-sustaining processes.
Geographic Information Systems (GIS) • A GIS organizes, stores, and analyzes complex data collected over broad geographic areas. • Allows the simultaneous overlay of many layers of data. Figure 3-33
Systems Analysis • Ecologists develop mathematical and other models to simulate the behavior of ecosystems. Figure 3-34
