Transcript 4 Cycling of Matter

Cycling of Matter
Recap:
 Environment: all abiotic and biotic factors
that exist on Earth as well as their interactions
 Abiotic: non-living factors
 Biotic: living factors
 Biodiversity: # of diff. organisms in an area
-increase biodiversity, increase healthy,
sustainable envmt
 Parts of an ecosystem can be organized as
follows:
spp  pop’n  community  ecosytem  biome
What Sustains Life on Earth?
 Solar energy, the
cycling of matter,
and gravity sustain
the earth’s life.
Two Secrets of Survival: Energy Flow and Matter
Recycle
 An ecosystem survives
by a combination of
energy flow and matter
recycling.
Key Terms
 Organic substances: contain atoms of C, H, and many times O, N
(e.g.) proteins, sugars, fats (generally associated with living things)
 Inorganic substances: matter does not contain a combination of C
and H atoms (e.g.) nylon, carbon dioxide (non-living forms)
organic
consumption
decay
inorganic
 Decay: organic materials die, and then decomposers break them down
and recycle nutrients back to the earth
 Decomposers: (mushrooms, bread mold, bacteria, fungi) break down
organic matter into small inorganic molecules
MATTER CYCLING IN ECOSYSTEMS
 Nutrient Cycles: Global Recycling
 Cycles recycle nutrients through the earth’s air, land, water, and
living organisms.
 Nutrients are the elements and compounds that organisms need
to live, grow, and reproduce.
 Cycles move these substances through air, water, soil, rock and
living organisms.
Cycles:
Reservoirs & Pathways
Atmosphere
Biosphere
Hydrosphere
Lithosphere
The Water Cycle
 Water is moved throughout the entire hydrosphere.
 It moves in a cycle, which means it has no beginning or end.
 Key terms:
evaporation – water droplets changing from a liquid to a gas
condensation – water droplets changing from a gas to a liquid
precipitation – water falling from the atmosphere
transpiration – plants release water into atmosphere via their leaves
seepage – water that flows into large underground lakes
Condensation
Rain clouds
TranspirationEvaporation
Transpiration
Precipitation
to land
from plants
Precipitation
Runof
f
Precipitation
Evaporation
Evaporation
Surface runoff from land
from ocean Precipitation
(rapid)
to ocean
Surface
runoff
(rapid)
Infiltration
and
Percolation
Groundwater movement (slow)
Ocean storage
Effects of Human Activities
on Water Cycle
 We alter the water cycle by:
 Withdrawing large amounts of freshwater.
 Clearing vegetation and eroding soils.
 Polluting surface and underground water.
 Contributing to climate change.
Carbon Cycle
Atmosphere
Biosphere
Hydrosphere
Lithosphere
C cycles between living and non-living forms
Inorganic (non-living)
CO2 in atmosphere
(carbon dioxide)
C in rocks
C dissolved in oceans
Photosynthesis
Respiration
Organic (in living
things)
Sugar (C6H12O6)
Fats, Proteins, DNA
Carbon Cycle: Reservoirs
Atmosphere
1x
(= 7.3x1017 grams
carbon)
Biosphere
3x
55x
35,000x
Hydrosphere
Lithosphere
Carbon Cycle
Atmosphere
Respiration& Decay
Photosynthesis
Biosphere
Hydrosphere
Lithosphere
Carbon Cycle
Atmosphere
Respiration& Decay
Photosynthesis
Biosphere
Dissolution
Exsolution
Weathering
& Volcanism
Burial &
Lithification
Hydrosphere
Lithosphere
Photosynthesis
Burial &
Lithification
Human
Impacts
Carbon Cycle
Atmosphere
Deforestation:
Decrease Photosynthesis
Increase Respiration
Biosphere
Net Effect:
Increase in Carbon
in Atmosphere
Hydrosphere
Burning fossil fuels:
Increased combustion
Lithosphere
Carbon Cycle
 Carbon is vital for life but
is not abundant
 Enters biological cycles
through photosynthesis to
produce organic forms of
carbon
 Carbon is moved back into
the inorganic form
through cellular
respiration (which is the
opposite of photosynthesis)
Photosynthesis
Chlorophyll
Carbon dioxide + water→ sugar + oxygen
+ ENERGY
CO2 + H2O + Energy → C6H12O6 + O2
Respiration
Mitochondria
Sugar + oxygen → carbon dioxide + water
+ ENERGY
C6H12O6 + O2 → CO2 + H2O + Energy
Combustion
 Makes carbon dioxide from… organic matter
Effects of Human Activities
on Carbon Cycle
 We alter the carbon
cycle by adding excess
CO2 to the atmosphere
through:




Burning fossil fuels.
Digging up fossil fuels/
coal.
Clearing vegetation faster
than it is replaced.
Breathing out also releases
carbon dioxide!
Another Nutrient
THE NITROGEN CYCLE
Nitrogen Cycle
 Essential for manufacturing proteins and DNA
 Although 80% of atmosphere is molecular nitrogen,
it is unreactive and cannot be used directly
 Nitrogen fixation converts nitrogen to ammonia or
nitrate
 Nitrates are the usable form of nitrogen (plants use
this)
Nitrogen Cycle
Atmosphere
Denitification:
bacteria
Nitrogen fixation:
• bacteria
• lightning
Biosphere
Absorption
Waste &
Decomposition
Erosion
Hydrosphere
Lithosphere
Nitrogen-Fixing
Bacteria in Root
Nodules
Human
Impacts
Nitrogen Cycle
Atmosphere
Biosphere
Net Effect:
Increase in Nitrogen
in water & soil
Nitrogen fixation:
• industrial (fertilizer)
• combustion
Increased Erosion
Hydrosphere
Lithosphere
Effects of Human Activities
on the Nitrogen Cycle
 We alter the nitrogen cycle by:
 Adding gases that contribute to acid rain.
 Adding nitrous oxide to the atmosphere through farming
practices which can warm the atmosphere and deplete ozone.
 Contaminating ground water from nitrate ions in inorganic
fertilizers.
 Releasing nitrogen into the troposphere through deforestation.
Effects of Human Activities
on the Nitrogen Cycle
 Human activities
such as production of
fertilizers now fix
more nitrogen than
all natural sources
combined.
Figure 3-30
Textbook Practice Questions
P 27 #1-4, P29 #1-4