Forested wetland restoration: Development of structure, biomass and carbon storage through tree planting Wes Hudson -- Ph.D. Candidate Dr. Jim Perry -- Advisor 2015 Friends of Dragon Run May 13 – General Meeting Outline • What are wetlands? – Why are they important? • What is ecological restoration? – Why are wetlands restored? • Tree research in restored wetlands • Friends of Dragon Run Historically, what was thought of wetlands? What is a wetland? “Those areas that are inundated or saturated by surface or ground water at a frequency and duration sufficient to support…a prevalence of vegetation typically adapted for life in saturated soil conditions” (33 CFR 328.3(b);1984) 3 parameter approach Hydrology Soil Vegetation Wetland Hydrology • Saturation in the upper 12 inches of the soil column for long periods of time – Water forces air out of the pore spaces in the soil – Anaerobic (low oxygen) conditions • Physical and chemical changes in the soil • Changes vegetation composition • Indicators • Surface water • High water table • Water marks on trees and leaves Hydric Soil • Soils that formed under anaerobic (low oxygen) conditions that have particular physical and chemical characteristics • Indicators – Muck or Peat – Reduced color • Iron when exposed to air will rust • In anaerobic conditions iron will be a grey color Hydrophytic Vegetation • Anaerobic soil conditions lead to a unique assemblage of vegetation with particular adaptations • Hydrophytes are plants that are adapted to wetland conditions • Bald cypress (Taxodium distichum) – Buttressing – Knees (Pneumatophores) • Indicators – More than 50% of dominant vegetation are hydrophytes Types of Wetlands 3.8 million square miles globally 8% of land – Mainly in tropically and boreal regions • Oxbow • Alpine Wetlands • Peatland • Billabong • Pocosin • Bog • Pothole • Bottomland • Rice fields • Delta • Riparian/Riverine • Fen • Salt Marsh • Floodplain • Salt Pan • Lagoon • Slough • Mangrove • Swamp • Marsh – Forested Headwater Wetland • Mire • Tidal freshwater swamp • Mudflat • Vernal pool • Muskeg • Wet meadow Forested Headwater Wetlands • Upper reaches of non- tidal freshwater streams • Stream flow < 5ft3/second • 1st and 2nd order streams • 73% of all stream lengths in U.S. • 43% of the vegetated wetlands in VA Odum, W. E. 1984 Forested Headwater Wetlands • Hydrology: Overland and subsurface flow from uplands • Vegetation: Tree biomass accounts for the majority of living (>96%) and total biomass (>57%) (Rheinhardt et al. 2012) • Species vary by physiographic province, successional stage, hydrologic conditions, soil conditions and site history (fire/logging) • Acer rubrum, Liriodendron tulipifera, Quercus rubra (Rheinhardt et al. 2009) Brinson 1993a Why are forested wetlands important? • Wetland Ecosystem Functions • Wetland Ecosystem Services – Improve water quality – Improve water quality Retain dissolved substances and • Help protect downstream • ecosystems (CB) particulates (Sediments) – Improve air quality • Transform and cycle elements, – Flood protection nutrients and pollutants – Recreational opportunities – Store and moderate discharge of • Bird watching surface and subsurface water • Hunting • Maintain high water tables – Provide timber and animal products • Groundwater recharge – Dissipate of energy • Flood attenuation – Accumulate organic matter (C) • Primary and secondary production • Storage in soil – Maintenance of plant and animal species habitat Loss of Wetlands • Between the 1780’s and 1980’s, 53% of wetlands were lost in the lower 48 states • During the same time period, Virginia lost approximately 42% • Losses were mainly due to drainage or filling activities or permanent flooding – Agriculture – Forestry practices – Reservoirs – Urban/suburban • Most of the wetlands lost in Virginia over the past few decades have been forested wetlands Ecological Restoration • “The process of assisting the recovery of an ecosystem that has been degraded, damaged or destroyed” (SER International Primer on Ecological Restoration 2004) – Applied science – Active engagement and intervention “We abuse land because we see it as a commodity belonging to us. When we see land as a community to which we belong, we may begin to use it with love and respect.” Aldo Leopold Goals of Ecological Restoration Return - Technically and socially feasible - Structure Self Sustaining - Function Connected - Scientifically valid - Services Resilient Why are wetlands restored? “Humans are both the guardians of natural systems and their dependents” (Cairns 1994) • Other ecosystems and species are dependent upon what happens upstream In practice • Re-establishing bird habitat (Ducks Unlimited) • Agricultural easements (state and federal programs) • Compensating for permitted impacts under CWA Restoration Outcome • Wetland restoration is not always successful – Tree establishment is difficult in forested wetland restoration Goals of Forested Wetland Restoration - Restore ecosystem structure, - Self sustaining and resilient functions and services - Connected to adjacent habitats Time Hydrology Vegetation Planted Tree Site Prep Previous Land Use Biodiversity Soil Climate Success Colonization Stochastic Events Time Species Selection Arrangement Timing of Planting Stochastic Events Site Conditions Planting Method Initial Seedling Morphology and Physiology Nursery Location Pesticides Cost Irrigation Seed source Propagation Fertilization Pruning Age Stocktype Photoperiod Method TheDescription goal of my that research can refer is to to determine several production how these techniquesfactors influence reaching these goalsNot ofstandardized replacing lost across ecosystem nurseries structure, function and services - Containerized (size) vs. non-contanerized (bare root) - Age (size) Current Research • When colonization is not sufficient trees are planted into restored forested wetlands • Wetland restoration practitioners are interested in which species and stocktype will survive and return lost ecosystem structure and functions • Designed a large scale field experiment to investigate this question Seven Species Three Stocktypes Variety of soil conditions Bare Root (BR) Betula nigra (River Birch) Hydrology (Cells) Ambient (Ideal) Saturated Liquidambar styraciflua (Sweetgum) Flooded Soil texture Platanus occidentalis (Sycamore) Tubeling (TB) Sand Silt Clay Salix nigra (Black willow) Soil nutrients Carbon (OM) Quercus bicolor (Swamp white oak) Nitrogen Phosphorus Quercus palustris (Pin oak) Quercus phellos (Willow oak) 1 Gallon Container Tree Morphological Measurements Height Measured 3x/year Survival Canopy Diameter Diameter at Breast Height (DBH) (convert to area) 1.4 m (4’7”) Basal Diameter (convert to area) Summer 2010 – Year 2 August 2011 – Year 3 August 2011 - Year 3 April 2013 - Year 5 April 2013 – Year 5 August 2013 – Year 5 Summer 2013 - Year 5 FallFall 2013 2013 – Year 5 Survival & Morphology Results GAL > BR = TB (Across all cells) SAT>AMB>>FLD Pri > Sec (Flooded) Pri = Sec (Amb and Sat) GAL > BR = TB (Fld) GAL >= BR (Amb & Sat) AMB>SAT>FLD GAL > BR = TB (Sat & Fld) GAL >= BR (Amb) AMB>SAT>FLD Survival & Morphology Summary • Survival – GAL > BR = TB (Across all cells) – Pri > Sec (Flooded) – Pri = Sec (Ambient and Saturated) – Saturated > Ambient >> Flooded • Height – GAL > BR = TB (Flooded) – GAL >= BR (Ambient and Saturated) – Pri > Sec (Across all cells) – Ambient > Saturated > Flooded Biomass (Dry plant material) 346 Trees Removed Winter 2011/12 – Year 3 221 Trees Removed 2013/14 – Year 4 103 Subsamples Relate basal diameter to dry biomass Power law equation Biomass = A * basal diameterB A = Intercept B = Scaling coefficient (exponent) 40 35 30 25 20 15 10 5 0 0 1 2 3 4 5 6 Standard Error of Primary Successional Species a a STERR b b STERR the Regression Betula nigra 0.0316777 0.0048558 2.4419198 0.0665102 0.6673714 Liquidambar styraciflua 0.0317770 0.0100781 2.7512410 0.1492996 0.9083254 Platanus occidentalis 0.0275311 0.0027393 2.7888479 0.0494827 0.5223591 Salix nigra 0.0290348 0.0074763 2.5190495 0.0988290 0.9108000 Secondary Successional Species Quercus bicolor 0.0472973 0.0072147 2.7351962 0.1134003 0.5710256 Quercus palustris 0.0472934 0.0041728 2.5024261 0.1331602 1.0157480 Quercus phellos 0.0554955 0.0069351 2.4554801 0.1719241 1.8912760 • From this relationship between BD and biomass we determined the biomass of all trees after 6 years 20,077 kg 9,035 kg 196 kg 44,262 lb 19,919 lb 432 lb GAL=TUB=BR PRI > SEC AMB > SAT > FLD Biomass Results • 73,432 lb dry shoot and root biomass • ~34,293 lb carbon stored after 6 years – Equivalent carbon emissions of 15 cars over 1 year • 12,000 miles/year, 25.5 mpg • PRI>SEC (Ambient and Saturated) – Returning ecosystem function • AMB>SAT>FLD • GAL=BR=TUB Conclusions • Best stocktypes depends on goals and environmental condition – GAL better survival and growth but is more expensive – Plant more BR in less stressful conditions • Eventually have same biomass • Primary species > Secondary species – Faster Growth (more habitat provided) – More carbon storage (important ecosystem function) • Accurately predict biomass from basal diameter – Will use relationship to calculate carbon sequestration rates • Citizen scientists provide accurate results Over six years ~200 students, Master Naturalists, Master Gardeners, FODR, Boy Scouts, Girl Scouts, family members, and friends have helped collect data Friends of Dragon Run • Field Visit • Jan 21, 2015 • Teta Kain, Davis Rhodes, John Jensen, Jed Dolan Paddle Trip – April 13th 2015 My Thoughts • Little