12 Aug 2021

Quantifying Functional Increases Across a Large-Scale Wetland Restoration Chronosequence

Abstract: Over 300,000 ha of forested wetlands have undergone restoration within the Mississippi Alluvial Valley region. Restored forest successional stage varies, providing opportunities to document wetland functional increases across a large-scale restoration chronosequence using the Hydrogeomorphic (HGM) approach. Results from >600 restored study sites spanning a 25-year chronosequence indicate that: 1) wetland functional assessment variables increased toward reference conditions; 2) restored wetlands generally follow expected recovery trajectories; and 3) wetland functions display significant improvements across the restoration chronosequence. A functional lag between restored areas and mature reference wetlands persists in most instances. However, a subset of restored sites have attained mature reference wetland conditions in areas approaching or exceeding tree diameter and canopy closure thresholds. Study results highlight the importance of site selection and the benefits of evaluating a suite of wetland functions in order to identify appropriate restoration success milestones and design monitoring programs. For example, wetland functions associated with detention of precipitation (a largely physical process) rapidly increased under post restoration conditions, while improvements in wetland habitat functions (associated with forest establishment and maturation) required additional time. As the wetland science community transitions towards larger scale restoration efforts, effectively quantifying restoration functional improvements will become increasingly important.

1 Oct 2020

Evaluating Soil Phosphorus Storage Capacity in Constructed Wetlands: Sampling and Analysis Protocol for Site Selection

Abstract: Soil characteristics determine the capacity of wetlands to sequester phosphorus (P). However, researchers have not yet developed a standard protocol for conducting soil sampling to document the soil phosphorus storage capacity (SPSC) for constructed wetland site selection. In response, the following technical note provides step-by-step instructions for selecting soil sample locations, describing site conditions, conducting soil sampling, and preparing samples for laboratory analysis. This note also includes calculations and interpretation of SPSC.

9 Jul 2020

PUBLICATION NOTICE: Hydrodynamics of a Recently Restored Coastal Wetland: Hamilton Wetlands, California

Abstract: Hamilton Wetlands is a recently restored tidally influenced basin located along the northwest coast of San Pablo Bay, California. Instruments to measure waves, currents, and wind were deployed for a period of up to 2 years shortly after tidal flow was re-introduced to the wetland to examine the sediment and hydrodynamic response. The results indicate that local re-suspension is relatively rare owing to the weak interior tidal currents and the limited fetch within the 3 km long basin. Asymmetries in the acoustic backscatter intensity combined with the much higher flow speeds measured at the entrance suggest a net import of fine sediment. The basin also experiences a distinct seasonal variation that likely contributes to sediment re-distribution. During the summer months, higher wind speeds correlate with turbidity suggesting local re-suspension of fines that are distributed by winds. Overall, the measurements suggest that the sediment dynamics in this shallow water system are controlled by two main factors: (1) net sediment import through the inlet entrance and (2) mixing of interior sediment through a combination of intermittent wind and wave stirring.

27 Jan 2020

PUBLICATION NOTICE: Evaluation of Iron Sulfide Soil Formation Following Coastal Marsh Restoration – Observations from Three Case Studies

 Link: http://dx.doi.org/10.21079/11681/35275 Report Number: ERDC/EL TR-20-1Title: Evaluation of Iron Sulfide Soil Formation Following Coastal Marsh Restoration – Observations from Three Case StudiesBy Jacob F. Berkowitz, and Christine M. VanZomeren Approved for Public Release; Distribution is Unlimited January 2020 Abstract: Wetland restoration