BIOL 215 Lecture Notes - Great Salt Lake, Trophic Cascade, Tropical Eastern Pacific
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BIOL215 Lecture 26 Notes
Synthesis of FACE CO2 enrichment experiments have shown that the plant community responds quite
differently than plants in greenhouses. When you have more realism to the real world, the effects are
more muted to CO2 response
Locating the missing carbon sink is not in the tropical lands. While NPP does increase in tropical lands,
deforestation and respiration by decomposers offsets that increase in NPP so that NEP is negative in
terms of carbon balance.
Two hypothesis of NEP in Northern lands is sequestering a fairly large amount of carbon at ecosystem
• Agricultural lands that were previously used and were abandoned are now re-growing resulting in
succession and growth of biomass in plants
• All the nitrogen being released through human activity is fertilizing the land in temperate and
Impact of CO2 on animals?
• No direct effect on consumers
• There is evidence of indirect effect when looking at herbivores (leaf miner density). When there
was an elevated CO2, the plants respond to it but due to an unbalance of high C:N, the plant will
have poor nutritional quality
• Herbivores that feed on the plant tissue that's been grown under the high CO2 conditions, have
very low conversion efficiency. The total consumption therefore increases slightly to compensate
the poor food quality. Even so, the herbivores are not able to make much secondary production
because the C:N ratio is too high or in other words, the leaf material is not of high quality to allow
for high rates of secondary production
• Conversion efficiency is production divided by ingestion (Pn/I).
Impact of CO2 on climate/global change and how climate change is influencing ecology:
• A changing global environment
• What's changing?
• Ecological responses to climate change:
• Community Composition
• Ecosystem function
The concern at the moment is the rate of temperature change in current society
The connection between CO2 and temperature on Earth is a strong relationship. An increase in CO2 in
the atmosphere is a concern of enhancing the Greenhouse effect and warming the planet
From an ecosystem level observing the map of Europe's warmest autumn in 500 years, the removal of
ice in the Arctic will change the dynamic of the Arctic ecosystem not to mention animal life that
requires ice for hunting and survival
We need to be able to distinguish between variability and change
Climate is what you expect (long term average), weather is what you get
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