BIOL215 Lecture 26 Notes
Synthesis of FACE CO en2ichment 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 CO response
2
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
level:
• 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
•
boreal forests
Impact of CO o2 animals?
• No direct effect on consumers
• There is evidence of indirect effect when looking at herbivores (leaf miner density). When there
was an elevated CO , 2he 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 CO condi2ions, 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 (P /In.
Impact of CO on climate/global change and how climate change is influencing ecology:
2
• A changing global environment
What's changing?
•
• Ecological responses to climate change:
• Phenology
• Range
• Community Composition
• Ecosystem function
The concern at the moment is the rate of temperature change in current society
The connection between CO and 2emperature on Earth is a strong relationship. An increase in CO in 2
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 The average pattern of weather (climate) over the long term is changing. The long term average
weather of a region includes typical weather patterns, the frequency and intensity of storms, cold
spells, and heat waves
Climate is changing - temperature increased by 0.6 degrees Celsius
during the 20th century
• Predicted to alter the hydrological cycle, and thus ocean-
atmosphere interaction: Global consequences
• Areas of the globe where evaporation will be more intense,
precipitation will be more intense. In fact, the pattern of
precipitation on land and on sea is likely to change because of
this change in temperature
• Most of the water that evaporates evaporate from the ocean
Global change and global systems:
• the El Nino/Southern Oscillation (ENSO) is a large-scale
atmospheric and ocean phenomenon that influences ecological
systems on a global scale - responsible for climate variability
around the g
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