Terrestrial component

The Table of Contents for this collection will facilitate this discussion. Notice that the papers are grouped into the categories of Atmospheric, Aquatic and Terrestrial Components, Global Carbon Cycle and Climate Change, and Global Environmental Science Education. The reader may want to consider the various chemical species studied in each paper. Next, the reader may wish to group the papers by whether they address the source or the receptor, the transport or transformation processes for the chemical species. Finally, the reader needs to establish the time scales and the spatial resolution used. 

The Terrestrial Component. These papers illustrate the application of temporal, spatial, and domain connectivity. Chemicals associated with people, food eaten by people, insects, and other organisms that compete with people for food, and other biomass must be identified. Since most of these chemical groups are terrestrial, spatial boundaries such as urban, biome, regional, and global are used. From a system perspective, these boundaries exclude water and air and require that they be placed in the "rest of the system" category. This type of boundary introduces the assumption that food, competitors for food, or any chemical that is discharged to or harvested from the air or water is ignored or assumed to be external to the system studied. 

Keegan, W.F. and DeNiro, M.J. 1988 Stable carbon- and nitrogen- isotope ratios of bone collagen used to study coral-reef and terrestrial components of prehistoric Bahamian diet. American Antiquity 53 320-336. 

Schoeninger, M.J., DeNiro, M.J. and Tauber, H. 1983 Stable nitrogen isotope ratios of bone collagen reflect marine and terrestrial components of prehistoric human diet. Science 220 1381-1383. 

Rare earth abundance patterns, particularly of the clay fraction, may also help determine the origin of the terrestrial components. Rare earth patterns in clay fractions of sediments tend to inherit the patterns of the rocks from which they originated [24]. In figure 2 are shown several samples of the rare earth abundance patterns of nitric-acid-insoluble residues from the Danish boundary layer and the limestones above and below. Such patterns along with the other chemical data may indicate the... 

These results strongly imply that a portion of the Hg inputs to the sediments in these lakes comes from their watersheds, and that the magnitude of this terrestrial component increases with catchment size. However, the relative increase in Hg accumulation from preindustrial rates is nearly constant among sites (Table II). The ratio of modern to background accumulation ranges from 3.2 to 4.9. This uniformity indicates that the change in Hg inputs since preindustrial times has been regionally similar for rural or remote areas of the upper Midwest. 

Menzie, C.A., Burmaster, D.E., Freshman, J.S., Callahan, C.A. (1992) Assessment of methods for estimating ecological risk in the terrestrial component A case study at the Baird and McGuire Supefund site in Holbrook, Massachusetts. Environ. Toxicol. Chem. 11, 245-260. 

Meyers-Schulte, K.J., and Hedges, J.I. (1986) Molecular evidence for terrestrial component of organic matter dissolved in ocean water. Nature 321, 61-63. 

In the past few years, application of improved measurements and models suggests a robust partitioning of CO, emissions from fossil fuel consumption and land use about one-third remains in the atmosphere, one-third is reassimilated by land surfaces, and one-third is absorbed by the oceans (Keeling el ah, 1996). The terrestrial component of the sink has special political interest, because it is that part of the global carbon which can most directly be managed. If we were able to change the large fluxes of assimilation and respiration, as they were summarized by Schimel... 

Damon PE, Sonett CP (1991) Solar and terrestrial components of the atmospheric " C variation spectmm. In The Sun in Time. Sonett CP, Giampapa MS, Matthews MS (eds) Univ. Arizona Press, Tucson, p 360-388... 

The value of the sterol fraction (— 24.88%o, Table 1) and the presence of the C29 sterol, (3-sitosterol in dominant amounts relative to other sterols, would imply terrestrial contribution to the organic carbon (Huang and Meinschein, 1976 Venkatesan et al, 1987). This value is also within the range of determined by Pearson et al. (2000) for sterols such as cholesterol, 27 and C28 and many other sterols from the surface sediments of Santa Barbara (SBB, 0-1 cm) and SM basins (0-5.5 cm). They did not find any depletion in the C29 sterols as would be expected from a significant terrigenous inputs and concluded that these sediments do not contain a quantitatively significant terrestrial component. Similar conclusion may not be applicable to our sample which comes from a much deeper horizon than their study. 

The terrestrial component of the dust particles embedded in the ice consists of volcanic ash, finegrained dust derived from soil on the continents, carbon particles released by forest fires, biogenic particles (e.g., the skeletons of diatoms, seeds, and pollen grains), aerosol particles of atmospheric origin, including sea-spray particles that nucleate snow flakes (Section 17.10). In addition, the uppermost layer of snow and fim that was deposited after the start of the Industrial Revolution (i.e., post ad 1850) contains anthropogenic detritus such as flakes of metal, paint, and plastics, fly-ash particles and other combustion products, fibers (composed of wood, cotton, and synthetics), industrial contaminants (e.g., lead), and radioactive nuchdes released by the testing of nuclear weapons and by the operation of nuclear reactors (Faure et al. 1997). 

Initially, effects to freshwater systems attributed, at least in part, to acid deposition were reported from Sweden, Norway and Canada. Now, however, effects are reported for both freshwater and terrestrial components of ecosystems in a large number of nations. Acid deposition may be considered an additional stress factor for terrestrial systems. Materials of technical, economic and cultural importance are also at risk from acid deposition. The immediate importance of these problems tends to indicate that the phenomenon of acid deposition is of recent origin, however, the subject has a relatively long history. As early as 1852 R. A. Smith collected and analysed rainwater in north west England, neologised the term acid rain and described its effects upon terrestrial ecosystems and materials. At this time, sulphur was the major pollutant and the effects of acid deposition were most clearly experienced at the meso scale. 

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