BIOL 1020 and BIOL 1021 - Lecture 21
- Ecosystem Ecology -
Assigned Readings in Textbook:
Chapter 47 (section 47.5) – Ecosystems (pages 1036 to 1039)
Chapter 48 (section 48.1) – The Physical Basis of Climate (pages 1046 to 1049) – omit this section
Chapter 48 (section 48.2) – Biomes (pages 1049 to 1060)
Chapter 48 (section 48.3) – Global Ecology: Cycling Bioessential Elements (pages 1060 to 1064)
Chapter 48 (section 48.4) – Global Biodiversity (pages 1066 to 1068) – omit this section
Use the following wireframe outline to make notes on the content presented in Lecture 21
Refer to Chapter 47 and Chapter 48 in your textbook and the Chapter 47 and 48 resources on
LaunchPad to supplement your notes and aid in studying this material
1. What is an ecosystem?
Biological community of interacting organisms and their physical environment
2. What is the focus of studies of ecosystems?
Study of communities of organisms and the physical environment they occupy
• Physical and biological components of an ecosystem are linked by the processes that
(1) cycle nutrients within the system
(2) transfer energy through the system
3. How do ecosystems function?
Ecosystems involve biotic and abiotic interactions
Energy from the sun flows in one direction
- energy entering ecosystem is processed and transformed
Matter is recycled within ecosystem
- results in outputs (e.g. heat, water flow, waste products)
1
, (a) how is matter cycled through biological communities?
Species interactions result in food chains or webs that re-cycle carbon and other elements
within ecosystems
(through photosynthesis, chemosynthesis, cellular respiration and decomposition)
Most important biological interactions within communities - predation and herbivory
These interactions are antagonisms within community ecology but are major links in the
carbon / nutrient cycles
Ultimately ecosystem function depends on the autotrophs form complex energy-rich
organic molecules by reduction of carbon dioxide from the environment:
(1) photoautotrophs – use photosynthesis
(2) chemoautotrophs – use chemosynthesis
Materials cycle in communities through various trophic levels
From primary producers to consumers to decomposers
4. How does energy flow through ecosystems?
Species interactions form trophic pyramids that transfer energy through ecosystems -
flows through ecosystems
Energy does not cycle within ecosystem
New energy must continually be harvested from environment to sustain the community
Energy is harvested through photosynthesis (using sunlight) or through
chemosynthesis (using chemical energy from earth’s core – reduced metal compounds)
Some energy stored in chemical bonds of organic molecules
(e.g. carbohydrates) by producers
Relatively small amounts of energy transferred from one trophic level to the next
trophic level based on allocation
2
- Ecosystem Ecology -
Assigned Readings in Textbook:
Chapter 47 (section 47.5) – Ecosystems (pages 1036 to 1039)
Chapter 48 (section 48.1) – The Physical Basis of Climate (pages 1046 to 1049) – omit this section
Chapter 48 (section 48.2) – Biomes (pages 1049 to 1060)
Chapter 48 (section 48.3) – Global Ecology: Cycling Bioessential Elements (pages 1060 to 1064)
Chapter 48 (section 48.4) – Global Biodiversity (pages 1066 to 1068) – omit this section
Use the following wireframe outline to make notes on the content presented in Lecture 21
Refer to Chapter 47 and Chapter 48 in your textbook and the Chapter 47 and 48 resources on
LaunchPad to supplement your notes and aid in studying this material
1. What is an ecosystem?
Biological community of interacting organisms and their physical environment
2. What is the focus of studies of ecosystems?
Study of communities of organisms and the physical environment they occupy
• Physical and biological components of an ecosystem are linked by the processes that
(1) cycle nutrients within the system
(2) transfer energy through the system
3. How do ecosystems function?
Ecosystems involve biotic and abiotic interactions
Energy from the sun flows in one direction
- energy entering ecosystem is processed and transformed
Matter is recycled within ecosystem
- results in outputs (e.g. heat, water flow, waste products)
1
, (a) how is matter cycled through biological communities?
Species interactions result in food chains or webs that re-cycle carbon and other elements
within ecosystems
(through photosynthesis, chemosynthesis, cellular respiration and decomposition)
Most important biological interactions within communities - predation and herbivory
These interactions are antagonisms within community ecology but are major links in the
carbon / nutrient cycles
Ultimately ecosystem function depends on the autotrophs form complex energy-rich
organic molecules by reduction of carbon dioxide from the environment:
(1) photoautotrophs – use photosynthesis
(2) chemoautotrophs – use chemosynthesis
Materials cycle in communities through various trophic levels
From primary producers to consumers to decomposers
4. How does energy flow through ecosystems?
Species interactions form trophic pyramids that transfer energy through ecosystems -
flows through ecosystems
Energy does not cycle within ecosystem
New energy must continually be harvested from environment to sustain the community
Energy is harvested through photosynthesis (using sunlight) or through
chemosynthesis (using chemical energy from earth’s core – reduced metal compounds)
Some energy stored in chemical bonds of organic molecules
(e.g. carbohydrates) by producers
Relatively small amounts of energy transferred from one trophic level to the next
trophic level based on allocation
2
