Biogeochemical Cycles
Biogeochemistry is the scientific discipline that involves the study of the chemical, physical, geological, and biological
processes and reactions that govern the composition of the natural environment. In particular, biogeochemistry is the
study of the cycles of chemical elements, such as carbon, nitrogen, phosphorus, potassium, and oxygen and their
interactions with and incorporation into living things transported through earth scale biological systems in space
through time. The field focuses on chemical cycles which are either driven by or have an impact on biological activity.
Through this activity we will continue to evaluate the composition of the schoolyard habitat and evaluate the general
health of this ecosystem. We will test the schoolyard soil for Nitrogen, Phosphorus, and Potassium and the pond water
for Nitrogen, Phosphorus, and Dissolved Oxygen.
Research:
How it Enters the
Sphere
Element
How it Exits the
Sphere
Organismal Use
Nitrogen
Geosphere
(Soil)
Phosphorus
Potassium
Nitrogen
Hydrosphere
(Water)
Phosphorus
Dissolved Oxygen
Procedure:
1. Collect material (soil or water) from the appropriate habitat with the collection jar.
2. Follow directions on each individual kit to determine the quantity of each element present in the appropriate habitat.
Data:
Geosphere Tests
Nitrogen
Phosphorus
Hydrosphere Tests
Potassium
Nitrogen
Phosphorus
Dissolved
Oxygen
Trial 1
Trial 2
Trial 3
Average
Rating
Questions:
1. Describe a human activity which negatively alters the biogeochemical cycle for nitrogen and phosphorus.
2. Describe the elemental composition of the atmosphere.
3. Design a test to measure carbon levels in the geosphere, hydrosphere, and atmosphere.
4. Describe a human activity which would improve the biogeochemical cycle for any of the elements tested.