25 Sep 2025

Considerations and Lessons Learned for Remote Sensing Data Acquisition of Understudied Wetland Vegetation Metrics

Purpose: Traditional field-based methods for monitoring wetland ecosystems are often limited by accessibility and cost, hindering comprehensive assessment of these vital habitats. These wetlands often present challenges for mapping and monitoring due to their size, location, and diverse vegetation types. Therefore, thorough planning and execution are essential for collecting reliable data for analysis and generating meaningful results. To overcome these challenges, we investigated how remote sensing data captured from uncrewed aerial systems (UAS), such as multispectral imagery and lidar, can be effectively used to develop and validate metrics for measuring wetland vegetation characteristics as an alternative to traditional field-based methods.

15 Sep 2025

Standard Operating Procedures for the Design, Construction, and Maintenance of Linear Infrastructure in Fens in Cold Regions

Abstract: In Alaska and across the Arctic and Subarctic, winter conditions can enable the expansion of linear infrastructure across the frozen landscape of fen wetlands. This expands military training opportunities into lowland wet, boggy, mostly impassable terrain. However, there are personnel, civilian, and environmental risks from using fens as travel corridors and drop zones. The effective design, construction, operation, and maintenance of such infrastructure on fens supports the dual mandate of troop training to fulfill the mission and protect the environment. This Technical Report (TR) addresses the risks of the establishment and use of linear infrastructure on the DoD lands in Alaska and in other austere cold environments where the DoD operates. This TR is founded on a review of methods used by US Army Installations, focusing primarily on Fort Wainwright in Interior Alaska. It establishes basic standard operating procedures (SOPs) by drawing on federal agency and international best practices and emerging research in circumpolar regions and beyond. This TR serves as a reference document for military land and infrastructure planners and unit leadership to create and maintain linear infrastructure on fens as environmental challenges evolve and opportunities develop to further the Army mission in high latitude environments.

12 Sep 2025

Quantifying Wild Pig Damage Reduction Using Before-After-Control-Impact Design at USACE Richard K. Yancey, Louisiana

Abstract: The FY23 research presented in this report is year three of a 3-year research plan to develop a user-friendly ecological-economic framework for rapid assessment of wild pig damage to wetlands. Building off research and findings from the FY21 and FY22 efforts conducted at Somerville Lake, Texas, the FY23 research focused on adapting the sampling frame-work to a forested wetland using a more advanced method for the extrapolation of damage to the whole study area, refining the economic valuation approach with machine-learning techniques, and improving the setup of the before-after-control-impact (BACI) study design estimating damage reduction after a targeted control effort. We estimate that the benefits provided by wetlands lost to wild pigs over a 1-year period in the Richard K. Yancey Wildlife Management Area study area was $234,486 (80% confidence interval, $63,155 to $691,220), and the aerial gunning control effort in the treatment plot provided a 243% return on investment in terms of damages avoided to wetlands.

29 Aug 2025

Monitoring of Understudied Wetlands: State of Knowledge

Abstract: Some wetlands can present unique challenges for mapping and monitoring due to their size, location, foliage architecture, and spectral characteristics. For instance, assessing ecological condition and restoration success using traditional remote-sensing systems in forested and ephemeral wetlands is onerous. Therefore, the purpose of this technical note is to evaluate the state of knowledge and technology related to the use of remote sensing in assessing vegetation dynamics in understudied and hard to monitor wetlands. Ultimately, this exercise will identify data gaps and recommend improvements for analyzing and modeling wetland systems and trends, quantifying disturbance impacts, and assist efficiencies of data collection to improve management decisions, which in turn will help in reaching restoration goals.

18 Jul 2025

Antecedent Precipitation Tool (APT) Version 3.0 : Technical and User Guide

Abstract: This document provides an overview of the technical components of the Antecedent Precipitation Tool (APT) and a user’s guide for the APT. The APT is an automation tool that the US Army Corps of Engineers (USACE) developed to facilitate the comparison of antecedent or recent precipitation conditions for a given location to the range of normal precipitation conditions that occurred during the preceding 30 yr.* In addition to providing a standardized methodology to evaluate normal precipitation conditions (precipitation normalcy), the APT queries additional datasets to compute drought condition indices and the approximate dates of the wet and dry seasons for a given location. The latest update to the APT builds upon the precipitation normalcy methodology by generating streamflow normalcy for the United States Geological Survey (USGS) gage and National Oceanic and Atmospheric Administration (NOAA) National Water Model (NWM) simulation results. The update also expands the APT’s analysis domain to include Alaska, Hawaii, Puerto Rico, and the US Virgin Islands.

11 Jun 2025

A Bellwether for Microplastic in Wetland Catchments in the Great Lakes Region

Abstract: This study is intended as a bellwether for the occurrence of microplastics (MPs) in Great Lakes wetlands. In 2020, sediment, surface water, and atmospheric deposition samples were collected from wetland catchments in or near five National Wildlife Refuges (NWRs) in the Great Lakes region: Horicon-WI, Seney-MI, Shiawassee-MI, Ottawa- OH, and Montezuma-NY. Sediment and surface water samples were taken from river, stream, and canal inflows and outflows to and from wetland areas. Atmospheric deposition samples were collected in carboys placed near established rain gauges. These sample sites were chosen as indicators of MP deposition into and out of the region’s wetland systems. MPs were extracted from each sample, enumerated, and categorized by particle morphology and polymer type. Average MP particle abundances in the sediment and surface water samples ranged from 344 to 538 particles kg⁻¹ (dry weight) and 2–68 particles m⁻³, respectively. Atmospheric MP deposition ranged from 5.8 to 22.6 particles m⁻² d⁻¹. Fibers were the most abundant MP particle type found in each sample type (sediment, surface water, and atmospheric deposition), followed by fragments. These results suggest that input and retention of MPs are pervasive in the Great Lakes region and surrounding wetland areas.

6 May 2025

Technical Recommendations for the Identification and Management of Potential Acid Sulfate Soils in an Ecological Restoration Context

Abstract: Restoration projects are being implemented to address natural and anthropogenic threats to coastal wetlands, including increased inundation and historic land use alterations. The US Army Corps of Engineers (USACE) and other organizations introduce dredged sediments into coastal environments to increase elevation and stabilize marsh platforms. However, some dredged sediments either contain iron sulfide compounds (i.e., iron monosulfide [FeS] and pyrite [FeS₂]) or form them after application. Under aerobic conditions, FeS and FeS₂ can rapidly oxidize, which generates acidity that can dramatically lower the soil pH, impacts plant establishment, and threatens the success of wetland restoration projects. Recommendations are needed to properly manage iron sulfide containing materials through project design, screening, monitoring, and adaptive management. Tools and techniques exist to evaluate dredged sediments for the presence of FeS and FeS₂ prior to and following marsh sediment applications, and project design and construction approaches can minimize associated acidification risks. This report provides a framework for properly identifying and managing sediments containing iron sulfide minerals during wetland restoration projects. These technical recommendations provide dredged sediment beneficial use practitioners a decision support tool for the successful management of iron sulfide containing dredged sediments to increase the ecological function and sustainability of coastal wetlands.

3 Apr 2025

Advancing a Framework for Rapid Assessment and Economic Valuation of Wild Pig Damage to Wetland Terrain: Year Two of Research at US Army Corps of Engineers Somerville Lake, Texas

Abstract: Wild pigs significantly impact wetlands, yet a standardized method for quantifying and valuing this damage is lacking. This research aims to develop a user-friendly ecological-economic framework for rapid assessment of wild pig damage on wetlands, building on a pilot study conducted at Lake Somerville, Texas, in FY21. The FY22 project advanced methods to value the lost benefits provided by wetlands due to wild pigs and identified methods to adapt and refine the framework for broader application. Additionally, a 65% reduction in wild pig population was achieved by Texas Wildlife Services personnel through helicopter gunning at two treatment sites, which is estimated to have prevented further damage to wetlands.

21 Jan 2025

Engineering With Nature: Natural Infrastructure for Mission Readiness at U.S. Navy and Marine Corps Installations

Abstract: This book illustrates some of the current challenges and hazards experienced by military installations, and the content highlights activities at eight U.S. Navy and Marine Corps military installations to achieve increased resilience through natural infrastructure.

2 Jan 2025

Assessing the Validity and Accuracy of Wetland Indicator Status Ratings for Eight Species in Alaska Subregions

Abstract: Preexisting ecological information and plant species occurrence data were used to determine the accuracy and validity of the present regional and subregional wetland indicator status ratings for eight species: Andromeda polifolia, Arctous rubra, Carex canescens, Rhododendron tomentosum, Rubus arcticus, Salix arctica, Salix pulchra, and Viola palustris. Technical documentation was developed to either (1) support the current National Wetland Plant List (NWPL) subregion boundaries and wetland indicator status ratings for the NWPL Alaska Region or (2) support a proposed change to the subregions or wetland indicator status ratings for the NWPL Alaska Region, for inclusion into the next NWPL update. The project developed repeatable, quantitative methods for assignment of wetland indicator status rating. Analyses included multiple correspondence analysis (MCA), analysis of similarities (ANOSIM), nonmetric multidimensional scaling (NMDS), and principal component analysis (PCA). Prevalence index (PI) was used as a numeric approximation of wetland status for comparing observations across subregions. A pilot study on S. pulchra data evaluated regional assignments by machine learning and assessed the feasibility of correlation network analysis and Louvain clustering for wetland indicator status rating assignment as dictated by co-occurring species. The methods developed for this Alaska-specific study may be applied to any future regional or subregional updates to the NWPL.