ecosystem services ch 2.4. ecosystem services def: benefits experienced by organisms, including...
TRANSCRIPT
Ecosystem ServicesEcosystem Services
Def: benefits experienced by organisms, including humans, that are provided by sustainable ecosystems– Natural result of all activities in biosphere
Cycling of nutrientsPollination of cropsBalance of growth/decompositionContribution of beauty
Let’s examine a forest…Let’s examine a forest…
How does it influence local climate?– Canopy traps humidity, keeps
cool What role do tree roots
play?– Reduce erosion
How many organisms do you see? How many are there?– Provide shelter and protection
from predation
DesertificationDesertification
Trees extract massive quantities of water from soil
On hot days, a lot of water escapes through the stomata, adding water vapour to the atmosphere– This reduces temperature, forms rain clouds
Did you know more than ½ the moisture above tropical forests comes from trees?
DesertificationDesertification
When forested areas are cleared, local precipitation drops– The climate gets hotter and drier leading to
desertification (change of non-desert land into a desert)
Can also occur from climate change, over-farming, and
excessive water use
Watersheds and ErosionWatersheds and Erosion
A watershed is an area of land over which run-off drains into a body of water
Trees benefit watersheds– How??
Watersheds and ErosionWatersheds and Erosion
Soil (without trees) cannot retain water as well as forested areas– Erosion increases
ErosionErosion Rock and soil are loosened from Earth's surface at
one location and moved to another - Natural – Wind and water break rock and soil into smaller pieces,
and loosen them from the earth's surface.
Changes landscape:– Wears down mountains– Fills in valleys– Rivers appear and disappear
Usually a slow and gradual process that occurs over thousands or millions of years. – Can be sped up by such human activities as farming and
mining.
Another ecosystem serviceAnother ecosystem service
Cross-pollination: when pollen is Cross-pollination: when pollen is transferred from one flower to a transferred from one flower to a different flowerdifferent flower
Most plants rely on animals, insects Most plants rely on animals, insects to move pollen between flowersto move pollen between flowers– Bees, beetles and bats are the busiest Bees, beetles and bats are the busiest
pollinators!pollinators!
Cross-pollinationCross-pollination
What abiotic factor could also help cross-What abiotic factor could also help cross-pollinate?pollinate?– The windThe wind
Did you know…?Did you know…?
……that cross-pollination by insects that cross-pollination by insects contributes to 1/3 of world food contributes to 1/3 of world food productionproduction– Holy cripes!Holy cripes!– $250 B per year$250 B per year
HomeworkHomework
Read “Case Study” on p 72-73 What is colony collapse disorder? What 2 parasites are named as being
potential factors in the decline of bees?
How does pesticide use affect bees? How could your cell phone affect a
poor bee?