Ensuring Soil Quality and Function in Wetland Creation and

Restoration Efforts W. Lee Daniels

and many more from many places!

http://www.landrehab.org Eric Stein, Principal Scientist, Southern California Coastal Water Research Project Jeremy Sueltenfuss, Colorado State University, Department of Forest and Rangeland Stewardship W. Lee Daniels, Thomas B. Hutcheson Professor of Environmental Soil Science at Virginia Tech Matt Schweisberg, Principal, Wetland Strategies and Solutions, LLC

Hydric Soils and Wetland Creation • The definition of a hydric soil is: a soil that formed under

conditions of saturation, flooding or ponding long enough during the growing season to develop anaerobic conditions in the upper part. https://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/use/hydric/?cid=nrcs142p2_053961

• Presumably, hydric soils are developing in wetland creation and restoration sites and are providing or supplementing numerous functions, including: – N removal via denitrification and plant uptake – P removal via sedimentation, plant uptake, etc. – C sequestration via net OM accumulation – Habitat provision for wetland flora, fauna, microbes, etc. – This necessarily involve driving soil redox low enough to favor wetland

obligates, etc. vs. upland species that want to invade.

https://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/use/hydric/?cid=nrcs142p2_053961https://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/use/hydric/?cid=nrcs142p2_053961

High OM wetland soil at Sandy Bottom Nature Park in Hampton, VA.

The A horizon here is over 30 cm thick. The annual hydroperiod of this soil fluctuates approximately 1.5 m!

This is a mineral flat landscape.

High O.M, friable, loamy; with B.D. < 1.3 in all A and B horizons.

Native hydric soil (Roanoke series) in a Carolina Bay (closed depression) landform. Very high clay, dense in Btg, and acidic.

Not all hydric soils are “pretty”!

Spartina sp. tidal marsh vegetation on sound behind barrier island in Maryland.

Sulfidic peaty soil in a tidal marsh (Sulfihemists).

Considerable and detailed work on tidal marsh soils has been done by Rabenhorst, Fanning, Stolt and others at the Universities of Maryland and Rhode Island.

Charles City Wetland (CCW); first built in 1997 & 1998 via excavation of upland landform; modified by VDOT several times thereafter.

Surface soil at CCW in 2002 after preliminary “remediation efforts”

Note massive structure in surface breaking to firm plates at about 20 cm.

This directly limits rooting, litter to soil incorporation, subsoil microbial biomass, and therefore redox process and associated development of features!

Common Limitations in Created / Restored Wetland Soils

• Compaction, compaction, compaction! • Lower soil OM levels than natural sites/soils • Lack of microtopography • Degraded soil structure/permeability/rooting • Higher soil temps when young, leading to

higher C loss rates • Often dissimilar in basic chemical and

physical properties than native soils due to cut/fill processes during contstruction

High OM wetland soil at Sandy Bottom Nature Park in Hampton. The A horizon here is over 30 cm thick. The annual hydroperiod of this soil fluctuates approximately 1.5 m!

This is a mineral flat landscape.

High O.M, friable, loamy, and B.D. < 1.3 A and B horizons.

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Shows that the two levels being measured are clearly “connected”. Note falling head with depth; indicative of GW recharge locally. Data from DesPres & Whittecar and DesPres M.S. thesis.

Sandy Bottom Wetland Sandy Bottom Wetland

Rich Whittecar (hydrogeology), Jim Perry (ecology) and WLD on a cool day at Sandy Bottom. I can’t express enough how valuable it is to have other disciplines involved with site assessments.

Sandy Bottom Constructed Wetland

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Same site x dates; nested piezometers in created wetland portion.

Focus Area of Related VT Projects Sponsored by Piedmont Wetlands Research Program/WSSI. All in N. Virginia Triassic

Cedar Run 3 and 4 Wetlands > 1000 ha created wetlands in region in Triassic geology

WSSI = Wetland Studies and Solutions Inc.

Created Wetland

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Hydroperiod in Cedar Run 3 created wetland. Red values are field measurements during ponded periods. 2013 MS thesis by N. Troyer.

Local landform at Cedar Run 4 location #2. Soils are an intimate mixture of the somewhat poorly drained Rowland Soil Series (Fine-loamy, mixed, superactive, mesic Fluvaquentic Dystrudepts) and the poorly drained Bowmansville Soil Series (Fine-loamy, mixed, active, nonacid, mesic Fluventic Endoaquepts). Note: Local depressions were not sampled.

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Water Budgeting is Critical! One option is Wetbud, which is a design tool for

wetland creation

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Site for Charles City Wetland (CCW) OM Loading rate experiment, first built in 1997 & 1998; modified by VDOT several times thereafter. How do we determine “soil success’?

Effects of Compost amendment on pedogenesis after 3 years

0 Mg/ha rate; Relict redox only 56 Mg/ha (25 T/ac; < 2.5% OM)

Long term effect of original compost loading (112 Mg/ha – 50 T/ac) at CCW dry experiment – Summer 2015.

WWB Earle

Richmond

Weanack/199 Wetland

Experimental area graded and flagged. Note uniform brown and oxidized sediment colors across the site.

Experimental area after hummock installation and application of topsoil. Picture shot 3 hours after

adjacent high tide.

Distinct redox concentrations and depletions (F3; depleted matrix) formed in replaced upland topsoil within three years. Also note distinct band of concentrations at topsoil/sand contact.

Photo from 2009 of high compost addition treatment vs. original soil from berm. Soils in the creation site were evaluated for color and were similar.

Image of control plot soil (sand; fertilizer only) taken 11/8/15 – 10 years old. Note significant accumulation of OM in surface and low chroma below. Detailed study by Emily Ott (PhD student) & John Galbraith is ongoing.

Bald cypress in pit (left) vs. mound (right). Note other woody stems invading.

Avoid sulfidic materials at all costs! Mattaponi Wetland; bare ground in rear was pH 3.1 as is the wetland floor when it dries down in the summer. Around 25% of VDOT Coastal Plain sites hit sulfidic materials which will then require high liming rates, etc.

So, how do I determine “hydric soil success”? • Learn how to accurately and completely describe soil

morphology, particularly redox features!

• Carefully describe soil morphology (a) before any site disturbance and then (b) immediately after final creation/restoration. Quantify/count redox feature abundance; don’t simply place them into classes (e.g. few vs. many).

• At a pre-determined interval (e.g. 1, 3 and 5 yr?), conduct follow-up soil descriptions on “mini-pits” excavated to 30 cm+ and carefully quantify color, redox feature abundance, etc.

• If the soil is “moving in the right direction”, you should be able to detect and quantify (a) development of lower overall chroma and (b) increased redox concentrations, pore linings, or other features.

Ensuring Soil Quality and Function in Wetland Creation and Restoration Efforts�Hydric Soils and Wetland CreationSlide Number 3Slide Number 4Slide Number 5Slide Number 6Slide Number 7Slide Number 8Common Limitations in Created / Restored Wetland Soils Slide Number 10Slide Number 11Sandy Bottom WetlandSlide Number 13Focus Area of Related VT Projects Sponsored by Piedmont Wetlands Research Program/WSSI. All in N. Virginia Triassic Slide Number 15Slide Number 16Slide Number 17Slide Number 18Slide Number 19Effects of Compost amendment on pedogenesis after 3 yearsSlide Number 21Slide Number 22Slide Number 23Slide Number 24Slide Number 25Slide Number 26Slide Number 27Slide Number 28Slide Number 29So, how do I determine “hydric soil success”?