Wetlands components

Our conceptual model divided the BDW lake basin into three land cover types (based on remote sensing data) (i) terrestrial, (ii) wetland, and (iii) lake (Fig. 3). Average annual mass movements for total mercury were calculated using the collected data [86]. Wet precipitation was the only source of mercury inputs considered to the terrestrial system accounting for 184 g (mercury deposited over land. The total outputs from the terrestrial system accounted for 372 g (o- = 36.7 g), of that, 35% (132 g, tr = 0.0 g) was incorporated into vegetation and, 13% (49 g, o-=0.0g) was volatilized from the soil surface. Although we were unable to measure mercury runoff directly, 191 g would be necessary in order to balance the inputs and outputs of the wetland component. 

Rencz AN, O Driscoll NJ, Hall GEM, Peron T, Tehner K, Burgess NM. 2003. Spatial variation and correlations of mercury levels in the terrestrial and aquatic components of a wetland dominated ecosystem Kejimkujik Park, Nova Scotia, Canada. Water Air Soil PoUut 143 271-288. 

There are two industry-specific components of the CWA requirements the NPDES (National Pollutant Discharge Elimination System) permitting and pretreatment programs. Other general CWA requirements, such as those for wetlands and stormwater, may also apply to pulp and paper mills. 

Some time is needed for the constructed wetland to operate smoothly and at the intended low cost level. In particular, the algae and floating aquamats need several years to reach full performance, so that the filter adsorbents are needed during this period. The frequent replacement of these filters adds considerably to the cost. Stand-by of the conventional treatment plant, which is required by the regulators to cope with any unexpected malfunctioning is another cost factor which makes the wetland more expensive in the early years of its operation. The cost breakdown is summarized in Table 2, which also indicates those components which can be significantly reduced over time. 

At whole lake scales, littoral zones are a major component of autochthonous DOM production and important sources of labile organic matter for aquatic bacteria. Of the approximately one billion lakes in the world, the littoral zone accounts for more than 95% of lake surface area in nearly 99.8% of all lakes (Wetzel, 1983 Fig. 3a). The importance of shallow waters is even more marked when the bounds of lakes are expanded to include wetlands. With such an expanded view, the littoral zone and wetlands comprise more than 95% of the area in 99.999% of all lakes (Fig. 3a). Clearly, shallow waters are a dominant feature of lentic ecosystems. 

Bano, N., M. A. Moran, and R. E. Hodson. 1998. Photochemical formation of labile organic matter from two components of dissolved organic carbon in a freshwater wetland. Aquatic Microbial Ecology 16 95-102. 

There are a number of factors which affect the emission rates of biogenic sulfur from wetlands. In a recent study these have been investigated for wetlands in Florida, USA, 157-59) and are summarized in a chapter in this volume (60). These factors are divided into spatial, seasonal, diel and tidal components. In addition, other variables which affect emissions are temperature, insolation, and soil inundation. When these factors are taken into account in estimating emissions, and emission rates are obtained by integrating over the appropriate cycle, the emission estimates are up to two orders of magnitude lower than earlier estimates. However, using these methods results in large uncertainties in the emission estimates, and considerable additional data are required to better refine and extend emission estimates to other environments. 

Yavitt J. B. and Lang G. E. (1990) Methane production in contrasting wetland sites response to organic-chemical components of peat and to sulfate reduction. Geomicrobiol. J. GEJODG 8, 27-46. 

Country Study Area Area km System Components Present River Lake Wetland Key Issues Climate Ecoregion... 

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