2. PHYSICAL ENVIRONMENT
The Physical Environment consists of physical
features that occur naturally on Earth such as
mountains, rivers and forest. Physical
environment can be divided as follows:
The layer of air that surrounds the Earth.
The Earth’s solid land surface.
Water bodies on Earth.
The living things.
7. BIOGEOCHEMICAL CYCLES
In Earth Science, a biogeochemical cycle or substance
turnover or cycling of substances is a pathway by which
a chemical substance moves through both the biotic
(biosphere) and abiotic (lithosphere, atmosphere,
and hydrosphere) components of Earth. A cycle is a series of
change which comes back to the starting point and which can
be repeated. Water, for example, is always recycled through
the water cycle. The water
undergoes evaporation, condensation, and precipitation,
falling back to Earth. Elements, chemical compounds, and
other forms of matter are passed from one organism to
another and from one part of the biosphere to another
through biogeochemical cycles.
8. BIOGEOCHEMICAL CYCLES
The term "biogeochemical" tells us that biological,
geological and chemical factors are all involved. The
circulation of chemical nutrients like carbon, oxygen,
nitrogen, phosphorus, calcium, and water etc.
through the biological and physical world are known
as "biogeochemical cycles". In effect, the element is
recycled, although in some cycles there may be
places (called reservoirs) where the element is
accumulated or held for a long period of time (such
as an ocean or lake for water)
10. There are many biogeochemical cycles that are currently
being studied for the first time as climate change and
human impacts are drastically changing the speed,
intensity, and balance of these relatively unknown
cycles. These newly studied biogeochemical cycles
include
• The Mercury Cycle and
• The Human-caused cycle of atrazine, which may
affect certain species.
Biogeochemical cycles always involve hot equilibrium
states: a balance in the cycling of the element between
compartments. However, overall balance may involve
compartments distributed on a global scale.