ALEXANDRIA, VA. A thin veneer of weathered rock and organic matter has had a
profound influence on the Earth's history. Soils have helped change the gases
of the atmosphere, altered the chemistry of ground water, and nourished life on
this planet. In the June issue of GEOTIMES,
soil scientists discuss strategies
to improve their discipline -- a science governed by uncertainty and complex
interactions.
In his article "Soil Science: Interdisciplinary by Necessity," Fred Miller argues
that meeting societal demands will require an integrated effort by physicists,
chemists, mineralogists, biologists, engineers, and other scientists.
Interdisciplinary cooperation can develop models for sustainable ecosystem
management and provide sound information for making decisions that affect public
safety.
Predicting the behavior of water and chemicals in soils is an inexact science,
too often used without regard to its inherent limitations. R.J. Wagenet's
article, "Simulation Modeling: Predicting the Dynamics of a Soil's Unsaturated
Zone," looks at the modeling techniques used to understand the region where water
resides in partially-saturated soil pores. Spatial variability, pore size
distribution, and the difficulty of collecting field data confound and challenge
models and model users.
"We have long recognized that soil varies continuously rather than abruptly in
most landscapes, yet models provide a rigid and discrete view of soil," explains
Kevin McSweeney and John Norman in their article, "Soil Landscape Modeling:
Issues of Scale." Models are helpful in refining basic understanding but are not
useful for predicting changes occurring over a continuum of scale. New
techniques such as digital terrain modeling and voxels (a 3-dimensional pixel)
may improve spatial representation and provide models that help us make better
use of the land.
In "Paleosols: Record and Engine of Past Global Change," Gregory Retallack shows
how ancient soils provide clues about the atmospheric composition over the past
3.5 billion years. They recorded and fueled changes in levels of oxygen and
carbon dioxide as plants and animals struggled for domination. "...Earth may have
teetered from icehouse to greenhouse as first plants, then animals, gained the
upper hand."
Coming in July ... GEOTIMES looks at wetlands -- vital but vanishing natural
systems that keep surface water clean, control flooding, recharge groundwater,
and provide homes to countless plant and animal species. Scientists examine
efforts to slow the loss of wetlands in the United States and the tropics and
look at the underlying geology of these ecosystems where land and water meet.
