Download Cycles of Matter

• Matter is constantly recycled
through the biosphere in
biogeochemical cycles
– Hydro cycle moves water
– Carbon cycle moves organic
and inorganic carbon molecules
– Nitrogen cycle moves organic
and inorganic nitrogen
molecules
• Earth is a closed system which
follows the Law of
Conservation of Matter
– Energy is the ONLY part of the
cycle that enters and leaves the
system of Earth
Cycles of Matter
• The Water (hydro) Cycle moves
water between solid, liquid, and
gaseous states.
– Processes:
• Evaporation… liquid water entering
a gaseous state at the surface of a
liquid
• Transpiration… liquid water entering
a gaseous state through openings
(stomata) in leaves of plants
• Condensation… formation of clouds
from gaseous water vapor in the
atmosphere
• Precipitation… transformation of
gaseous water to a solid or liquid
that falls back to Earth
• Runoff, percolation (seepage)…the
movement of liquid water back to
the groundwater system
Water Cycle
Nutrient Cycles Carbon
• The carbon cycle is a biogeochemical
cycle
– Sources of carbon
• Organic… most all organic molecules
• Inorganic… calcium carbonate (CaCO3)
deposits & CO2
– Processes:
• Photosynthesis… fixes CO2 into organic
molecules
• Cellular respiration… uses organic
molecules for energy producing CO2
• Decomposition… break down of complex
carbon molecules into simpler forms
– Burial & compression… leads to formation of
coal and oil
• Combustion & igneous activity… converts
organic sources to atmospheric CO2
• Absorption… CO2
• that enters lakes and oceans may become
concentrated into mineral deposits
•
Nutrient Cycles
Nitrogen is an important element in DNA
– Nitrogen &
and every protein molecule in your body
– Phosphorous is essential as it is also part of
DNA and ATP
Phosphorus
– Both Nitrogen and phosphorous cycle
between inorganic and organic sources in
biogeochemical cycles
– Sources of Nitrogen:
• Atmospheric gas (N2), organic molecules,
ammonia (NH3), nitrates (NO3-) , nitrites (NO2-)
and ammonium (NH4+)
– Processes:
• Denitrification… the release of nitrogen gas
from organic molecules through
decomposition
• Nitrogen fixation… the process of changing
ammonia and nitrogen gas to a form useful to
plants (nitrates and nitrites)
– Through bacteria in the soil and on the roots of
certain plants (legumes)
• Assimilation… transformation of inorganic
nitrogen in the soil into organic compounds
• Primary production in an
ecosystem reflects an ecosystems
new dry biomass added per area
per unit time (g/m2/yr)
– Net primary production is limited
by the nutrients available
– Not based on biomass but on
new material
– Ecologist use to describe the
carrying capacity of an ecosystem
• The amount and type of organisms
that can be supported
Primary
Production
• Replacing limiting
nutrients;
– Fertilization
• N, P, K
– Crop rotation
• Adds nutrients back to
soil as different types of
plants utilize nutrients in
different quantities
Limiting
Nutrients
• Process that creates abnormal
algal and cyanobacteria blooms
from sewage and fertilizer runoff
– Can rob a lake ecosystem of
resources due to over utilization
of resources for primary
production
• Decreases aquatic species
– Phosphorus is the limiting
reactant in eutrophication
• Water quality controls and using
phosphate-free detergents are
steps that are helping mediate
this problem
Eutrophication
Drought
• Santa Barbara has estimated that they
will run out of fresh water by 2017!
– The national average for individual water
use is between 60 and 100 gallons per
person per day. Goleta is at 66 gallons per
person per day; Santa Barbara at 86; and
Montecito at 290.
– With California state water at its lowest
allocation in history, the snowpack at 18
percent of its average and reservoirs at
half their normal levels, shortages are
around the corner, according to the
scientists, but people continue to think of
water as a limitless resource.
– In California, agriculture accounts for 80
percent of water use, with the remaining
20 percent going to urban areas.
– Recycling!
• Right now, we’re recycling 10 to 15 percent of
the water in the state — “showers to flowers”
• Making our gardens look more like the
climate that we live in!!!!