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Forests fluxes

Deposition. The products of the various chemical and physical reactions in the atmosphere are eventually returned to the earth s surface. Usually, a useful distinction is made here between wet and dry deposition. Wet deposition, ie, rainout and washout, includes the flux of all those components that are carried to the earth s surface by rain or snow, that is, those dissolved and particulate substances contained in rain or snow. Dry deposition is the flux of particles and gases, especially SO2, FINO, and NFl, to the receptor surface during the absence of rain or snow. Deposition can also occur through fog, aerosols and droplets which can be deposited on trees, plants, or the ground. With forests, approximately half of the deposition of SO(, NH+,andH+ occurs as dry deposition. [Pg.213]

Figure 2. The carbon dynamics of a primary forest prior to and following deforestation and slash burning. Arrows represent the relative magnitude of C flux. In the primary forest (represented by the large box at the top of the figure), the C pool is in a dynamic equilibrium with inputs approximately equalling exports. With deforestation and fire, the balance is altered with exports far exceeding imports. Figure 2. The carbon dynamics of a primary forest prior to and following deforestation and slash burning. Arrows represent the relative magnitude of C flux. In the primary forest (represented by the large box at the top of the figure), the C pool is in a dynamic equilibrium with inputs approximately equalling exports. With deforestation and fire, the balance is altered with exports far exceeding imports.
The maximum temperature and duration of heating during fires are important variables that influence the soil nutrient status, as well as the survival of residual vegetation following fire (Table III). Deforestation results in the presence of large quantities of wood debris in close proximity to the soil surface. Fires in this scenario result in soil temperatures and magnitudes of heat flux far in excess of those which occur in fires in uncut forests (Shea, R. W. Oregon State University, unpublished data). [Pg.435]

Stidson RT, CA Dickey, JN Cape, KV Heal, MR Heal (2004) Fluxes and reservoirs of trichloroacetic acid at a forest and moorland catchment. Environ Sci Technol 38 1639-1647. [Pg.47]

Frescholtz 2002). Although ongoing and new planned field and laboratory studies are designed to further test this hypothesis, we feel that it is warranted at this time to develop a pilot-scale network of aimual ecosystem fluxes of THg in TF and LF as indicators of total atmospheric deposition. These fluxes can then be compared with measured wet plus modeled diy deposition based on both inferential and regional-scale models to develop independent estimates of total atmospheric deposition for forested catchments. We also believe that this approach could eventually be applied to a national network, such as the MDN. Although this method is best aimed at forested sites, ongoing research will address methods appropriate for other ecosystems. [Pg.35]

Lee Y-H, Borg GCh, Iverfeldt A, Hultbeig H. 1994. Fluxes and turnover of methyhnercury mercury pools in forest soils. In Watras CJ, Fluckabee JW, editors. Mercury pollution, integration and synthesis. Boca Raton (FL) Lewis Pubhshers, CRC Press, Inc. [Pg.44]

Munthe J, Hultberg H. 2004. Mercury and methylmercury in nm-off from a forested catchment — concentrations, fluxes and their response to manipulations. Water Air Soil Pollut Focus 4 607-618. [Pg.45]

St. Louis VL, Rudd JW, Kelly CA, Hall BD, Rolfhus KR, Scott KJ, Lindberg SE, Dong W. 2001. The importance of the forest canopy to fluxes of methyl mercury and total mercury to boreal ecosystems. Environ Sci Technol 35 3089-3098. [Pg.45]

Schwesig D, Matzner E. 2000. Pools and fluxes of mercury and methylmercury in two forested catchments in Germany. Sci Total Environ 260 213-223. [Pg.45]

Dixon R, Brown S, Houghton R, Solomon A, Trexier M, Wisniewski J. Carbon pools and flux of global forest ecosystems. Science, 1994. 263(14) pp. 185-190. [Pg.78]

Fosberg, M. A. Heat and Water Vapor Flux in Conifer Forest Litter and Duff. U.S. Forest Service, Research Pap. RM-152 Fort Collins, Co, 1975. [Pg.448]

Friedland, A.J. and A.H. Johnson. 1985. Lead distribution and fluxes in a high-elevation forest in northern Vermont. Jour. Environ. Qual. 14 332-336. [Pg.330]

In forest ecosystems these symbols stand for CL(M) is critical load of a heavy metal (g ha-1 a-1) Mu is metal net uptake in wood biomass under critical loads conditions (g ha-1 a 1) Mle(crit) is critical leaching flux of metal with drainage water (from the uppermost 10 cm soil layer) (g ha-1 a-1). [Pg.84]

The values of output metal fluxes mentioned above vary as a function of spatial distributed parameters including climate, soil and forest-type data. As a basis for computing critical loads, an overlay of three maps was made ... [Pg.85]

Soil-related data (HM and BC content in soil parent materials) were included in calculations to account the values of HM weathering. Also we considered the influence of soil types on forest biomass productivity. Runoff data (at scale 0.5 x 0.50 were directly used to get input data on drainage water fluxes, Qie. Forest-type-related data (wood biomass growth and HM content in wood biomass) inserted into our database were subdivided depending on either coniferous, deciduous or mixed forests. [Pg.86]

Since nitrogen is a nutrient, which limits the productivity of almost all Boreal and Sub-Boreal Forest ecosystems, its biogeochemical cycling is relatively well understood at present. The major N transformations and fluxes are shown in Figure 3. [Pg.139]

Figure 3. The general nitrogen model for illustrating the bio geochemical cycling in Forest ecosystems. Explanations for the fluxes 1, ammonia volatilization 2, forest fertilization 3, N2-fixation 4, denitrification 5, nitrate respiration 6, nitrification 7, immobilization 8, mineralization 9, assimilatory and dissimilatory nitrate reduction to ammonium 10, leaching 11, plant uptake 12, deposition N input 13, residue composition, exudation 14, soil erosion 15, ammonium fixation and release by clay minerals 16, biomass combustion 17, forest harvesting 18, litterfall (Bashkin, 2002). Figure 3. The general nitrogen model for illustrating the bio geochemical cycling in Forest ecosystems. Explanations for the fluxes 1, ammonia volatilization 2, forest fertilization 3, N2-fixation 4, denitrification 5, nitrate respiration 6, nitrification 7, immobilization 8, mineralization 9, assimilatory and dissimilatory nitrate reduction to ammonium 10, leaching 11, plant uptake 12, deposition N input 13, residue composition, exudation 14, soil erosion 15, ammonium fixation and release by clay minerals 16, biomass combustion 17, forest harvesting 18, litterfall (Bashkin, 2002).
The data of Table 3 provide a general characteristic of trace element fluxes in Boreal and Sub-Boreal Forest ecosystems. [Pg.145]

Table 2. Averaged fluxes and pools of biological cycling in Forest ecosystems (after Rodin and Bazilevich, 1965 Dobrovolsky, 1994). Table 2. Averaged fluxes and pools of biological cycling in Forest ecosystems (after Rodin and Bazilevich, 1965 Dobrovolsky, 1994).
Fluxes and pools Northern Taiga Spruce Forest Southern Taiga Spruce Forest Sub-Boreal Oak Forest Southern Taiga Sphagnum Swamp... [Pg.146]

The averaged fluxes and sinks of trace metals in biogeochemical turnover in Spruce Forest ecosystems are shown in Table 5. [Pg.148]

Box 2. Biogeochemical fluxes of elements in Oak Forest ecosystem (after Jakucs, 1985)... [Pg.155]

Table 9. The bio geochemical fluxes and pools in the Oak Forest ecosystem of Central Europe. Table 9. The bio geochemical fluxes and pools in the Oak Forest ecosystem of Central Europe.

See other pages where Forests fluxes is mentioned: [Pg.215]    [Pg.215]    [Pg.18]    [Pg.366]    [Pg.392]    [Pg.406]    [Pg.14]    [Pg.27]    [Pg.32]    [Pg.33]    [Pg.33]    [Pg.37]    [Pg.38]    [Pg.44]    [Pg.72]    [Pg.586]    [Pg.348]    [Pg.267]    [Pg.269]    [Pg.481]    [Pg.35]    [Pg.90]    [Pg.140]    [Pg.146]   
See also in sourсe #XX -- [ Pg.78 ]




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Forest soil, metal flux

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