Download CYCLING IN THE ECOSYSTEM

STARTER:
 Describe one way human
activity affects either the water
cycle, carbon cycle, or the
nitrogen cycle.
Setting up your notes
(Use 8x14 paper)
The Water Cycle (pg. 371)
The Carbon Cycle (pg. 372) The Nitrogen Cycle (pg. 373)
The Nitrogen Cycle (pg. 373)
The Carbon Cycle (pg. 372)
The Water Cycle (pg. 371)
Setting up your notes
CYCLING IN THE
ECOSYSTEM
Foldable-Notes
pp. 371-374
DEFINITIONS
Ecosystem: an environment
where the living (biotic) and
non-living (abiotic) things affect
one another
Biogeochemical process:
circulation of substances
through living organisms and
the environment
WATER CYCLE (pg. 371)
WATER CYCLE (pg. 371)
 Evaporation:
water vapor
enters the
atmosphere
WATER CYCLE (pg. 371)
 Transpiration:
evaporation
of water
through the
leaves of
plants
WATER CYCLE (pg. 371)
 Precipitation:
water vapor
that leaves the
atmosphere
 Ex: Rain,
Snow, Sleet,
Hail
WATER CYCLE (pg. 371)
 Human
Effects/Influences:
 Building cities
prevents water
from reaching
groundwater stores
(increases runoff)
 Pollutants in air mix
with water vapor
to create acid rain
CARBON CYCLE (pg. 372)
CARBON CYCLE (pg. 372)
Photosynthesis:
converting light
energy into
glucose (C6H12O6)
 CO2 + H2O  C6H12O6
CARBON CYCLE (pg. 372)
Cellular
respiration:
breaks down
sugar to release
energy and CO2
is released into
atmosphere
 (C6H12O6  CO2 + H2O + ATP)
CARBON CYCLE (pg. 372)
Combustion:
burning of fossil
fuels for energy
releases CO2
CARBON CYCLE (pg. 372)
 Human Effects/Influences:
 Deforestation reduces amount of
producers that can perform
photosynthesis
NITROGEN CYCLE (pg. 373)
NITROGEN CYCLE (pg. 373)
Nitrogen (N) is an essential
component of DNA, RNA,
and proteins, the building
blocks of life.
70% of atmosphere is
nitrogen, but it is not in a
ready-to-use form (triple
bond too hard to break)
NITROGEN CYCLE (pg. 373)
N2 gas must first be converted into
a useable form such as ammonium
(NH4+) or nitrate (NO3-).
Nitrogen Fixation (N2 --> NH3 or NH4+)
NITROGEN CYCLE (pg. 373)
 Nitrogen fixation (biological): bacteria
convert nitrogen gas (N2) to usable
form, NH3 (ammonia)
NITROGEN CYCLE (pg. 373)
Nitrogen fixation (environmental): Highenergy natural events which break the
bond N2
Examples: lightning, forest fires, hot
lava flows
NITROGEN CYCLE (pg. 373)
Ammonification: decomposers break
down wastes (urine, feces, death) to
NH3
NITROGEN CYCLE (pg. 373)
 Nitrification: bacteria convert NH3 to
nitrates (NO3-) i.e. like fertilizers
NITROGEN CYCLE (pg. 373)
 Assimilation: plants absorb nitrate to
make amino acids (enters food chain!)
NITROGEN CYCLE (pg. 373)
Denitrification: bacteria return
nitrogen to atmosphere (NO3-  N2)
NITROGEN CYCLE (pg. 373)
 Human Effects/Influences:
FERTILIZERS!
Extra nitrogen fertilizer can
runoff, where it contaminates
surface water or infiltrates into
ground water.
 In drinking water, excess
nitrogen can lead to cancer in
humans and respiratory distress
in infants.
NITROGEN CYCLE (pg. 373)
 Human Effects/Influences:
 In surface waters, extra nitrogen can lead to
nutrient over-enrichment
 This leads to
fish-kills,
harmful algal blooms,
and species shifts in
aquatic and land
ecosystems.