Biogeochemical Dynamics

Biogeochemical dynamics refers to interactions between the biological, geological, and chemical components of the Earth's environment. These dynamics are influenced by interactions between organisms and their physical surroundings, including soils, sediments, rocks, water, and air. Biogeochemistry, the study of biological controls on the chemistry of the environment (air, water, and soil) and the geochemical regulation of ecosystems, is a central focus in the study of ecosystems, and is vital to the study of our Earth.

• The Odyssey of the Atom ...

[The atom] had marked time in the limestone ledge since the Paleozoic seas covered the land. Time, to an atom
locked in a rock, does not pass.
The break came when a bur-oak root nosed down a crack and began prying and sucking. In the flash of a century
the rock decayed, and [the atom] was pulled out and up into the world of living things. [The atom] helped build
a flower, which became an acorn, which fattened a deer, which fed an Indian, all in a single year. . . . .
When the Indian took his leave of the prairie, [the atom] moldered briefly underground, only to embark on a second
trip through the blood stream of the land. . . . .
All routines come to an end. This one ended with a prairie fire, which reduced the prairie plants to smoke, gas, and
ashes. . . . .
Between each of his excursions through the biota, [the atom] lay in the soil and was carried by the rains, inch by
inch, downhill [and eventually to the sea]. . . . .
For every atom lost to the sea, the prairie pulls another out of the decaying rocks.

Excerpted from "A Sand County Almanac" by Aldo Leopold, 1949

Biogeochemistry

Biogeochemistry is the study of biological controls on the chemistry of the environment (air, water, and soil) and the geochemical regulation of ecosystems. Biogeochemistry is a central focus in the study of ecosystems and is vital to the study of the Earth. Although the term was first used more than 50 years ago, the roots of this discipline can be traced back to the earliest development of natural sciences, before biology, geology, and chemistry became separate disciplines. Today, the study of biogeochemistry integrates research and assessment across these three disciplines.
Biogeochemistry is central to understanding changes such as:

• global changes in the cycling of atmospheric greenhouse gases, including carbon dioxide, methane, and nitrogen compounds
• loss of biological diversity from accelerated cycling of elements, especially in association with changes in land use
• forest die-back from increased deposition of nutrients and acids from the atmosphere
• degradation of water quality from increased inputs of nutrients
• acidification of streams and lakes from atmospheric deposition

Carbon Cycle and Ecosystems

NASA's Earth Sciences Division has built its Research and Analysis activity around a suite of six interdisciplinary science focus areas. The mission of the ORNL DAAC for Biogeochemical Dynamics falls within the Carbon Cycle and Ecosystems focus area, which addresses:

• the distribution and cycling of carbon among the active terrestrial, oceanic, and atmospheric reservoirs
• ecosystems as they are affected by human activity, as they change due to their own intrinsic biogeochemical dynamics, and as they respond to climatic variations and, in turn, affect climate.

The Carbon Cycle and Ecosystems focus area was designed to address a specific set of questions regarding how the earth is changing, the primary causes of those changes, the Earth's response to natural and human-induced change, the consequences to life, and our ability to predict them. Research activities strive to provide data and information to answer the following questions:

1. How are global ecosystems changing?
2. What changes are occurring in the global land cover and land use, and what are their causes?
3. How do ecosystems, land cover, and biogeochemical cycles respond to and affect global environmental change?
4. What are the consequences of land cover and land use change for human societies and the sustainability of ecosystems?
5. How will Carbon cycle dynamics and terrestrial and marine ecosystems change in the future?