Hydrologic Gradients and Topsoil Additions Affect Soil Properties of Virginia Created Wetlands

Abstract

and retain nutrients (Mitsch and Gosselink, 2000). Without suitable soil properties, CWs may never functionally As the role of soil properties in the development of created wetreplace the natural wetlands that were destroyed. lands (CWs) has not received adequate attention in regulatory or scientific communities, this study was conducted to evaluate the devel-As soils of natural wetlands have been exposed to opment of soil properties in 11 CWs in Virginia ranging from 4 to 16 wetland processes for periods of decades, centuries, or yr since creation. Six of the 11 sites received at least 15 cm of topsoil even millennia, it is unfair to expect CWs that have (TS) while the other five sites received no topsoil (No TS). Cores been exposed to wetland processes for only a few years collected from wet, intermediate, and dry positions at each site were to immediately exhibit soil properties that are characteranalyzed for moisture, bulk density (D b), soil organic matter (SOM), istic of natural wetlands. Thus, for this study, comparitexture, water-holding capacity (WHC), P sorption index (PSI), and sons of CWs to natural wetlands were omitted, as this microbial biomass C (MBC). Both positions along the hydrologic gradiresearch was conducted to evaluate the development of ent and topsoil status were hypothesized to be significant factors in soil properties in 11 Virginia Department of Transportaexplaining the variability of the measured soil properties. Soil moisture tion (VDOT) CWs ranging in age from 4 to 16 yr since decreased significantly while D b increased significantly from wet to dry zones. Moisture, WHC, and PSI were all significantly elevated in construction. In the period from 1980 to 1996, VDOT certain zones of TS compared with No TS sites. Soil organic matter constructed more than 105 non-tidal CWs (Whittecar had significant Spearman correlations with all other measured soil and Daniels, 1999). The focus of this study was on CWs properties, revealing that this parameter was an important indictor in the Coastal Plain, as this is the location of the majority of soil quality. In addition, sites with high mean moisture, SOM, and of wetland impacts in Virginia (Whittecar and Daniels, PSI values all received TS; conversely, the site with the lowest mean 1999). The investigation was limited to non-tidal formoisture and SOM content did not receive TS. Thus, amending CW ested CWs for two main reasons: (i) non-tidal CWs have soils with TS appeared to be an effective strategy for increasing soil been studied much less than their tidal counterparts; moisture, WHC, and PSI. Whenever possible, practices such as TS and (ii) natural non-tidal forested wetlands have been or organic amendments should be employed, especially if wetland shown to perform important nutrient transformation creation involves excavation into subsoils with low SOM and high D b. and retention functions (Walbridge and Struthers, 1993; Axt and Walbridge, 1999; Verhoeven et al., 2001). As few CW sites are assessed beyond what is needed to S ection 404 of th...

Variabilité spatiale des réserves de nutriments dans les humus et les sols d’un massif forestier (Fougères, France)

“…A lower stock variability by level was observed in the Alocrisols-Neoluvisols compared with the Colluviosols-Fluviosols (Fig. 3) and confirmed the high spatial variability of soil properties in these locations [12,23,30,41].…”

The Effects of Organic Matter Amendments on Greenhouse Gas Emissions from a Mitigation Wetland in Virginia’s Coastal Plain

“…Many studies have advocated for the amendment of created wetlands with OM in the form of salvaged topsoil or compost to help them achieve reference functionality (Stauffer and Brooks 1997;Whittecar and Daniels 1999;Bruland and Richardson 2004). Indeed, studies have found that moderate loading of compost OM into a created wetland increase woody plant development (Bailey et al 2007) and soil functions, such as microbial decomposition and increased denitrification enzyme activity (Bruland and Richardson 2009;Sutton-Grier et al 2009).…”

A cost-effective method for reducing soil disturbance-induced errors in static chamber measurement of wetland methane emissions

“…Site history is complex, with one unsuccessful restoration attempt for this formerly forested wetland being followed by an experimental addition of organic matter amendments to improve tree growth. For more detail on site characteristics, see Bruland and Richardson (2004), Bergschneider (2005), and Bailey et al (2007).…”