Pollutants have water vapour adhered to it = man made clouds. Clouds hold HEAT in. So no clouds = colder. After 9/11, shut down jet traffic in USA for three days. Scientists able to observe during that 3 day period, there was about 1*C change over the 3 days. This change over a long period = climate change… can impact ecosystems.
intergovernmental panel on climate change Different countries put their data together Study how changes in temperature affect our planet Raise in temperature affect arctic ecosystems more than ecosystems closer to equator. Impact on the species that have evolved to live in cold temperatures.
1ºC change over next 100 years All coral becomes bleached. Coral made up of two things = a coral (essentially an animal) + algae (plant, lives mutualistic with them) Coral will extrude (force out) the algae, so can’t use photosynthetic process of algae = bleached. Increase temperature = warmer.. Affect 10% of world’s ecosystems. - Affect arctic ecosystems more. - Species can’t evolve quickly enough to adapt to the change in climate = impacted by that.
2ºC change over next 100 years
3ºC change over next 100 years 1/2 of nature reserves unable to meet conservation objectives Manmade change… Environment impacted by humans.
Primary change Due to human intervention or natural agents
PRIMARY CHANGE Manmade change: Introduction of exotic/alien-species Noxious species, e.g. rabbits, cane toads. Page 510. Manmade change: Overharvesting of a biological resource (e.g. fishing too much, hunting of animals) page 517. Natural change agents: Bushfires. Page 528. Obligate seeder plants (seeds survive and germinate after fires) Vegetative reproducer plants (regrow through means of (epicormic)buds located under bark or in underground stems/rhizomes) Fire is important agent of change in some Australian ecosystems (e.g. page 531 “fire for parrots”)
Primary succession: ecosystem must rebuild after being completely destroyed (including the soil) Main feature of primary ecological succession = soil formation. - Rock exposed of receding glacier New land formed by volcanic explosions Mosses and lichens (spore bearing plants) = pioneer organisms … Lichens secret toxins into rocks = break down into soil Wearing down of rocks by weather/water = form soil When mosses and lichens die = biomass degrades into soil Secondary succession: ecosystem must rebuild with the soil still intact. e.g. small bushfire… doesn’t have to go through process of soil formation… No pioneer organisms because there are already organisms in and around soil. Process of succession stops when a stable community becomes established. Stable community = climax community.
Frequency of change: Changes in ecosystems may occur regularly, sporadically, or due to one-off events. (1) Identify a change agent that acts on an ecosystem as follows: Regularly, sporadically (irregularly), or as a one-of event. (2) Give an example of change in an ecosystem that is due to: a. human intervention… b. a naturally-occurring agent of change. - Invasive exotic species cause negative effects in ecosystems. - Over-harvesting of a biological resources can cause populations to crash. - Fire is an important agent of change in some Australian ecosystems.
BIOLOGY Chapter 16: Changes In Ecosystems
Changes in ecosystems
Chapter 16 (Page 500)
Harm to Coral Reef
0.5ºC over next 100 years
and Arctic Ecosystems
All coral reefs bleached
1ºC over next 100 years
10% of global ecosystems transformed
Mass mortality in coral reefs
2ºC over next 100 years
1/6 of global ecosystems transformed
1/4 species committed to extinction
1/2 of nature reserves unable
to meet conservation objectives
3ºC over next 100 years
1/5 of global ecosystems transformed
1/3 species committed to extinction
Primary changes in ecosystems
may produce a cascade of
secondary changes that may not
become apparent immediately.
What are the primary and secondary changes in the:
Temperature change example?
Frequency of change
Regular and predictable events (e.g. tides and seasons)
Sporadic (irregular) events (e.g. floods)
One-off events, planned or unpredictable (e.g. oil spill)
Examples of changes?
Activity! (20 minutes)
Split into 3 teams of 5-6 people. Each team will be given a
scenario with primary change.
TASK: Create a strategic plan to restore the ecosystem
back to it's original state.
In the plan you have to highlight :
What is the primary change and how has it impacted
the ecosystem and the organisms that live there?
Identify the secondary changes that may occur.
Can the damage be reversed? If so, how can the
balance of the ecosystem be restored?
UN Meeting on Climate Change
Can the ecosystem be
Succession in ecosystems: The
natural replacement over time of
one community by another
community with different
Primary succession Secondary succession
Primary changes and secondary changes
Frequency of change?
Can damage of an ecosystem be reversed/restored?
Primary succession vs. Secondary succession
Invasive species Over-harvesting Fire = important
Invasive species + over-harvesting
Goats on trees found in
Like to eat the fruit of
the argan tree, which is
similar to an olive
The argan tree slowly
disappearing due to
over-harvesting for the
tree's wood and
overgrazing by goats.
The world’s 10 worst invasive species:
Invasive species specialist group: http://www.issg.org/
Invasive species database: