1. The scope of biogeochemistry
Biogeochemistry is a relatively new discipline that integrates knowledge primarily from biology (ecology), geology and chemistry. The core of biogeochemistry deals with cycling of biologically active elements.
(1) Biogeochemistry is the chemistry of the surface of the Earth. (WH Schlesinger 1997)
(2) Biogeochemistry deals with control of the concentrations and cycling of elements in and above the earth’s crust by the synthesis, death and decomposition of organisms, most of which capture their energy from the sun. (Eville Goham 1991).
Biogeochemical processes are imbedded in the atmosphere, the lithosphere and the hydrosphere
Special attentions are often paid to crucial mechanisms such as:
Interdependence
Thresholds
Scales and scaling
Stoichiometry
2. Thermodynamics
The first law
The second law
3. Earth as a biogeochemical system
The Biosphere governed by the two laws of thermodynamics
Steady-state assumption
Connectedness
Everything cycles
4. Cycles in biogeochemistry
Why use cycles?
What can we learn from these cycles?
5. Gaia
Remains as a controversial hypothesis
6. Human enterprise and biogeochemistry (See Schlesinger’s article)
Globalization/technological advances
Impacts on the Planet Earth
Sustainability/long-term wellbeing
Major conceptual advances in biogeochemistry — a chronology (Gorham 1991)
In the long series of conceptual advances involved in the development of biogeochemistry, the following are among those of greatest significance:
1. the nature of the hydrologic cycle (Halley 1687);
2. the role of carbonic acid in rock and soil weathering (Cavendish 1767;Thaer 1810;Davy 1813);
3. the interactive roles of plants and animals in gaseous metabolism on a global scale (Priestley 1772);
4. the role of solar radiation in driving such gaseous metabolism (Ingenhousz 1779);
5. the unification of theories of plant nutrition (de Saussure 1804);
6. the wholly inorganic nutrition of green plants (de Saussure 1804; Sprengel 1839; Liebig 1840);
7. the role of microbes in organic decomposition (Schwann 1837; Cagniard-Latour 1838);
8. the global significance of the biogeochemical cycles of carbon and nitrogen powered by solar energy (Dumas 1841; Dumas & Boussingault 1844);
9. the recognition that the primitive atmosphere was anaerobic, and that the gradual evolution of plants, accompanied by the locking tip of their residues as fossilized carbon, was responsible for an atmosphere rich in oxygen (Spencer 1844; Koene 1856);
10. the major role of microbial decomposers in biogeochemical cycles (Cohn 1872);
11. the recognition of the qualitative equality of the biosphere with the lithosphere, hydrosphere and atmosphere (Suess 1875; Vernadsky 1924, 1926);
12. the involvement of specific micro-organisms in the cycles of elements such as nitrogen, sulfur, and iron (Winogradsky 1887—1894; and others);
13. the fitness of the environment for living organisms (Henderson 1913);
14. the plausible origin of life through prebiotic synthesis of organic molecules in a primitive reducing environment and their consumption initially by heterotrophic organisms (Oparin 1924; Haldane 1929; Miller 1953);
15. the large-scale regulation of biogeochemical cycles in general by the biota (Vernadsky 1924, 1926; Redfield 1934, 1958) and
16. the view of humanity as a major geological agent (Vernadsky 1945; Hanya & Akiyanna 1987).
The list above is about people in the past. Here are three well-known biogeochemists in the US who are actively doing their research as we speak:
Gene E. Likens:
https://www.caryinstitute.org/science/scientific-staff/our-scientists/dr-gene-e-likens
Peter M. Vitousek:
http://www.stanford.edu/group/Vitousek/
William H. Schlesinger:
https://www.caryinstitute.org/science/scientific-staff/our-scientists/dr-william-h-schlesinger
Biogeochemistry has come of age in the 1980’s with the founding of two major scientific journals devoted to the new discipline, Biogeochemistry in 1985 and Global Biogeochemical Cycles in 1987.
Several key technological and methodological advances in the late 1900’s have moved the discipline to its present stage. Among these technological contributions, new analytical capabilities for measuring trace substances (e.g., GC, HPLC, IRGA) and isotope abundance (mass spectrometry), space technology (remote sensing, GIS), and computing power are widely recognized as significant.