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.

6 Aug 2024

Tools and Technical Guidelines for Delineating the Extent of Tidal Waters: Proof of Concept

Abstract: The delineation of shorelines in tidally influenced waters, as well as the inland extent of tidal influence of those waters, is often used to define the extent of federal and/or state jurisdictional boundaries, including the US Army Corps of Engineers’ (USACE) limits of jurisdiction under the Rivers and Harbors Act of 1899 (RHA) and Section 404 of the Clean Water Act. At present, USACE and other practitioners use a variety of field observations and desktop-based data sets, tools, and techniques to identify and delineate the lateral and longitudinal extent of USACE’s jurisdiction under the RHA for tidally influenced waters. Tidal waters, and thus federal jurisdiction under the RHA, “end where the rise and fall of the water surface can no longer be practically measured in a predictable rhythm.” However, the technical standards, definitions, and data to delineate tidal extent are also lacking. The uncertainty and ambiguity in what constitute tidal extent increases litigation risk and decreases repeatability and technical defensibility of USACE decisions. Nationally applicable technical guidance and rapid tools and techniques are needed to increase defensibility and consistency across all coastal USACE districts while also accelerating USACE Regulatory decision-making.

25 Jul 2024

Regeneration Dynamics of Bottomland Hardwood Sites Following Prolonged Growing-Season Inundation

Abstract: The spring flood of the Mississippi River and backwater areas in 2019 resulted in large-scale flooding and was the longest-lasting flood event since the Great Flood of 1927. This flood event provided a rare opportunity to establish permanent plots in batture and backwater habitats to evaluate forest-stand dynamics following prolonged flooding. In this study, we evaluated postflooding conditions of forest overstory, midstory, and regeneration by establishing permanent plots at four locations subjected to varying amounts of flooding within the Mississippi River batture and the Yazoo–Mississippi Delta backwater region. Our results highlight oak regeneration success following the 2019 flood event as well as the utility and need to establish and monitor permanent plots to increase our understanding of floodplain forest dynamics in regions experiencing prolonged riverine flooding during the growing season.

21 May 2024

Engineering With Nature: An Atlas, Volume 3

Abstract: Engineering With Nature: An Atlas, Volume 3 showcases EWN principles and practices “in action” through 58 projects from around the world. These exemplary projects demonstrate what it means to partner with nature to deliver engineering solutions with triple-win benefits. The collection of projects included were developed and constructed by a large number of government, private sector, nongovernmental organizations, and other organizations. Through the use of photographs and narrative descriptions, the EWN Atlas was developed to inspire interested readers and practitioners with the potential to engineer with nature.

22 Jan 2024

Framework Development for Rapid Assessment and Economic Valuation of Feral Swine Damage to Wetland Terrain: A Pilot Study at US Army Corps of Engineers–Somerville Lake, Texas

Abstract: The increased spread and presence of feral swine on sensitive natural resources landscapes like wetlands has become a considerable concern on lands managed by the US Army Corps of Engineers. In August 2021 a pilot study was carried out at Somerville Lake, Texas, as the first step in a three-year research plan to develop an ecological-economic framework for feral swine damage assessments (FSDA) and valuation. The study sought to quantify and value soil disturbance caused by feral swine trampling, rooting, and wallowing on wetland soils. The primary objective—to develop and test a rapid FSDA prototype—was achieved and represents an important first step to creating a quick and user-friendly damage-assessment framework that also estimates the economic value of the damage observed. With continued testing and development, this rapid FSDA protocol will be of use to all who manage feral swine impacts on landscapes with wetland ecosystems, and findings from this information will be of use for scientifically informed cost-benefit analysis and management decision-making.

3 Jan 2024

Using an Object-Based Machine Learning Ensemble Approach to Upscale Evapotranspiration Measured from Eddy Covariance Towers in a Subtropical Wetland

Abstract: Accurate prediction of evapotranspiration (ET) in wetlands is critical for understanding the coupling effects of water, carbon, and energy cycles in terrestrial ecosystems. Multiple years of eddy covariance (EC) tower ET measurements at five representative wetland ecosystems in the subtropical Big Cypress National Preserve (BCNP), Florida (USA) provide a unique opportunity to assess the performance of the Moderate Resolution Imaging Spectroradiometer (MODIS) ET operational product MOD16A2 and upscale tower measured ET to generate local/regional wetland ET maps. We developed an object-based machine learning ensemble approach to evaluate and map wetland ET by linking tower measured ET with key predictors from MODIS products and meteorological variables. The results showed MOD16A2 had poor performance in characterizing ET patterns and was unsatisfactory for estimating ET over four wetland communities where Nash-Sutcliffe model Efficiency (NSE) was less than 0.5. In contrast, the site-specific machine learning ensemble model had a high predictive power with a NSE larger than 0.75 across all EC sites. We mapped the ET rate for two distinctive seasons and quantified the prediction diversity to identify regions easier or more challenging to estimate from model-based analyses. An integration of MODIS products and other datasets through the machine learning upscaling paradigm is a promising tool for local wetland ET mapping to guide regional water resource management.

26 Jun 2023

Antecedent Precipitation Tool (APT) Version 2.0: Technical and User Guide

Purpose: 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 assess the presence of drought conditions and the approximate dates of the wet and dry seasons for a given location. This document constitutes an update to Antecedent Precipitation Tool (APT) Version 1.0: Technical and User Guide (Gutenson and Deters 2022).

6 Apr 2023

Eelgrass Functions, Services, and Considerations for Compensatory Mitigation

Abstract: Coastal-marine eelgrass habitat is a critical resource within New England and throughout the world. Eelgrass habitat provides functions and services including providing structure, biogeochemical cycling, erosion reduction, habitation provision, and water quality improvement. Declines in eelgrass distribution are often due to anthropogenic processes impacting temperature and water quality. Declines in distribution and abundance highlight the importance of protecting the existing eelgrass, improving environmental conditions allowing for ecosystem restoration, and identifying viable in-kind and out-of-kind compensatory mitigation measures. Considering the limited availability of New England sites for in-kind compensatory mitigation, additional approaches for out-of-kind compensatory mitigation should be considered. These include (1) creation of alternative plant or kelp habitat, (2) using a multi-pronged, multi-habitat and structure approach, (3) contributing to the development of water quality improvement initiatives to encourage current eelgrass bed expansion over time, (4) reduce physical impacts to eelgrass habitat, (5) and identifying locations for future eelgrass habitat suitability based on climate predictions and investing to create future compensatory mitigation habitat in these locations.