Environmental Engineering Reference
In-Depth Information
FIGURE 1.6
Atmospheric deposition of
nitrogen and sulfur for the year 2000 to
Mount Desert Island study area of Acadia
National Park, Maine (ACAD). Deposition
estimates are based on a GIS-based empiri-
cal model. (From Weathers et al. 2006.)
Deposition in ACAD,
2000 (kg.ha
-1
.yr
-1
)
Sulfur
5.5-9.2
9.2-12.9
12.9-16.6
16.6-20.3
20.3-24.9
Nitrogen
3.0-5.0
5.0-7.0
7.0-9.0
9.0-11.0
11.0-13.5
N
01
2 km
important precursors to the modern idea of the ecosystem included Karl M¨bius' (1877)
use of the term biocoenosis to refer to the biotic community associated with oyster beds;
Stephen Forbes' (1887) essay on “The Lake as a Microcosm,” which explored the myriad
of ecological interactions that existed within a bounded area (a lake) to produce a single
system; and K. Friedericks' (1930) use of the idea of holocoens (
Jax 1998
). Although
Vernadsky's ideas perhaps were closest to modern ideas of the ecosystem, they were not
widely influential outside of the former USSR, and none of the other early concepts really
captured the idea that organisms and their abiotic environment could be integrated into a
single system.
In 1935, Tansley brought all of these ideas together by writing, “The fundamental con-
cept appropriate to the biome [i.e., all living organisms] considered together with all
the effective inorganic factors of its environment is the ecosystem.” He further stated: “It is
the systems so formed which, from the point of view of the ecologist, are the basic units of
nature on the face of the earth.” Tansley's definition finally explicitly recognized the close
interactivity (indeed the inseparability) of living and nonliving entities sharing the same
physical space, and is remarkably similar to the definition of ecosystem that many ecolo-
gists use 75 years later. Just a few years after Tansley's paper appeared (1942), Raymond
Lindeman, a young American ecologist, published a paper laying out a conceptual
framework that defined trophic levels and allowed the analysis of energy flow through
