Download Basic Ecology I

Basic Ecology II
• Cycling of chemical Elements in
Ecosystems
• Biological and geological processes
• Hydrologic cycle
• Nitrogen cycle
• Phosphorous cycle
• Carbon cycle
• Human Impacts of nutrient cycles
What is an ecosystem?
• Ecosystem =
• Community + abiotic
component
• Energy Flow
• Chemical cycling
• No discrete boundaries
Types of Ecosystems
Biological and geological
processes
• Weathering and
erosion
• Decomposition
• Reservoirs of
nutrients
• Recycling within the
ecosystem to
minimize loss of
nutrients
Biogeochemical cycle
Hydrologic cycle
Distribution of Water
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97% of water is in oceans
2% in glaciers & ice caps
0.001% in atmosphere
60% of precipitation evaporates
Distribution of water is problem
Nitrogen cycle
Phosphorous cycle
Sulfur Cycle
Carbon cycle
• Most carbon in
sediments and
sedimentary rock
• Carbon enters biota
through
photosynthesis and
loss through
respiration
• Missing carbon sink
Carbon cycle
Carbon cycle: aquatic system
Human Impacts of nutrient cycles
• Hubbard Brook Watershed Study
• Long term ecological research
Logging
Human Impact
Impact of Salmon on Ecosystems
Summary
• Biogeochemical cycles in which elements are
moved
• Biogeochemical cycles are composed of
reservoirs and pathways. Fluxes between
compartments can be measured.
• Some elements cycle quickly such as those with
a gaseous phase.
• Some cycles are internal with an ecosystem
• Ecosystems can lose nutrients and be deposited
elsewhere.
• Humans can have an impact on nutrient cycling.