In species rich ecosystems, disturbance promotes biodiversity by facilitating the establishment of rare taxa. However, intensive disturbance events may alter community composition and ecosystem function if communities are re-established by non-native species. The Mobile-Tensaw Delta (MTD) is a unique mosaic of diverse habitats that are subject to frequent disturbance events, including hurricanes, flooding, land transformations, and increasing invasive species establishment. To understand the role of disturbance in promoting biodiversity in the MTD and recovery following a disturbance event, we established a disturbance experiment across two habitat types at Jacinto Port Forever Wild Tract (Saraland, AL). We established a series of 1 x 1 m2 paired plots at 2 sites (a mesic mixed-hardwood-pine forest and a hydric bottomland forest) and rototilled one of the pairs by random selection. Prior to rototilling, we performed floristic surveys and collected soil samples to implement a full Before-After-Control-Impact experimental design. Plant and soil community recovery was monitored at 3 and 6 months post disturbance and will continue every 3 months for the next year. Our preliminary results suggest that disturbance may facilitate the establishment of non-native plants like Phyllanthus urinaria, which was more prevalent in our physically-disturbed plots after 3 months. By investigating the potential shifts in plant community structure and resilience, we aim to contribute to the understanding of both long and short-term physical disturbance in deltaic systems, and the efficacy of current conservation practices.

Eddy covariance is of great use to several regulatory and commercial applications, related to environmental and water management, industrial monitoring, agricultural production, and other areas where directly measured energy, water vapor or gas exchanges, emissions and budgets are of interest. Major flux measurement networks exist to provide global synthesis, which allows interpretation of one particular site in the context of world-wide observations. Automated and semi-automated technical tools are now also available to expand the use of automated flux stations, individually and as a part of cross shared flux networks, into modelling and remote sensing with global coverage and local resolution. In this project, we aim to design a network of eddy covariance towers throughout the Mobile-Tensaw Delta in order to understand the responses of different terrestrial ecosystems on releasing/absorbing water to and from the atmosphere and emitting/absorbing carbon to and from the atmosphere. The idea is to set up towers over hardwood evergreen forests, wetlands, marshes and also agricultural areas in the surroundings. These towers, together with remote sensing (satellite) data and modeling we will be able to investigate, e.g., how different ecosystems in the Delta are behaving, both spatially and temporally, in terms of acting a sink or source of carbon.

Tidal marshes provide numerous ecosystem services, including blue carbon (C) storage, but they are also highly vulnerable to degradation and loss from sea-level rise, development, and other anthropogenic impacts. Restoration and creation projects are increasingly used to recover tidal wetland habitat, but it is unclear how effective these projects are at restoring ecosystem functions. To assess the efficacy of restoration projects along the Mississippi-Alabama Gulf Coast, we quantified soil organic matter (SOM) and carbon (C) content in 12 restored marshes of different ages (7-34 yr) and compared them to vegetated and unvegetated areas in nearby reference marshes. We found that vegetated reference marshes consistently stored more SOM and C than restored sites, regardless of marsh age or soil depth. Across restored marshes, we found that SOM and C in the upper 5 cm increased with time since restoration, while SOM and C in deeper soil increments (5-10, 10-15, 15-20 cm) were similar, regardless of age. A comparison among different types of restored marshes (e.g., living shorelines, large-scale beneficial use, mitigation via habitat conversion) revealed that mitigation sites, which were also the oldest, stored more SOM and C than other restored sites. Despite observed lags in C storage recovery, these restored sites are on a trajectory of recovery and are likely outperforming unvegetated areas at nearby reference sites. Consequently, tidal marsh restoration appears to be an effective strategy to recover ecosystem services, including those that help marshes mitigate the effects of climate change.

Natural capital stocks are the durable physical or biological elements of nature that persist through time to contribute to current or future economic production. In October of 2022 the White House Office of Science and Technology introduced a national strategy to develop statistics for environmental decision making and proposed creating a system of natural capital accounting and associated environmental-economic statistics. While restoration ecologists have used multiple measures for determining the success of restoration projects, it is important that the measures proposed represent an accurate accounting of environmental capital stocks and flows produced by the project. Understanding how projects increase biological productivity and increase habitat services is an important step for providing data for the environmental-economic linkages. We have demonstrated natural capital increases for several environmental restoration projects in Alabama and Louisiana which show natural capital benefit: cost ratios of 4:1 and higher. The use of both calibrated ecological models and habitat and resource equivalency analysis increases the robustness of natural capital estimates. We present examples of natural capital increases for both living shoreline and marsh creation projects which show significant increases in net-natural capital benefits and illustrate the methods used to provide meaningful quantitative measures.