Transcript CYCLING IN THE ECOSYSTEM

CYCLING IN THE ECOSYSTEM
18.4
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
1. WATER CYCLE
1. WATER CYCLE
•
Evaporation: water vapor enters the atmosphere
1. WATER CYCLE
Evaporation: water vapor enters the atmosphere
• Transpiration: evaporation of water through the
leaves of plants
•
1. WATER CYCLE
•
Precipitation: water vapor that leaves the
atmosphere (rain and snow)
2. Oxygen Cycle
 Plants release O2 as a waste product during
photosynthesis
oxygen
photosynthesis
respiration
carbon
dioxide
2. Oxygen Cycle
 Plants release O2 as a waste product during
photosynthesis
 Humans and other organisms take in O2 and release
it as CO2
oxygen
photosynthesis
respiration
carbon
dioxide
3. CARBON CYCLE
3. CARBON CYCLE
 Photosynthesis: converting light energy into
organic compounds (C6H12O6)
3. CARBON CYCLE
 Cellular respiration: breaking down organic
compounds to release energy
 (C6H12O6  CO2 + H2O + ATP)
3. CARBON CYCLE
 Combustion: burning of fossil fuels for energy
releases CO2
4. NITROGEN CYCLE
• 70% of atmosphere is nitrogen, but it is not in a ready to
use form
•N2 needs to converted into NH3 (ammonia)
4. NITROGEN CYCLE
 Bacteria and decomposers play major role.
 Takes place mostly below ground.
4. NITROGEN CYCLE
 Plant takes in N from soil
 Herbivore eats plant and gets N
 Organism dies and N is released by bacteria
and decomposer in soil for Plant