Author ORCID Identifier

https://orcid.org/0000-0002-2824-7262

Semester

Fall

Date of Graduation

2022

Document Type

Thesis

Degree Type

MS

College

Davis College of Agriculture, Natural Resources and Design

Department

Division of Forestry and Natural Resources

Committee Chair

James T Anderson

Committee Co-Chair

Christopher Rota

Committee Member

Christopher Rota

Committee Member

Walter Veselka

Abstract

Wetland ecosystem spatial extent and integrity have declined due to conversion to anthropogenic land uses. Wetland mitigation offsets the impact on wetlands encountered during development by restoring a previously degraded wetland or creating new wetlands. This activity creates an ecosystem service market where wetland impacts (debits) are offset by wetland restoration/creation (credits). Mitigation aims to replace functions provided by aquatic resources lost during development. Post-restoration monitoring criteria known as performance standards are used to evaluate and verify restored wetland functionality and regulate mitigation credit release. Therefore, performance standards are vital in ascertaining wetland restoration techniques and mitigation processes. In Chapter 1, I discuss considerations and perspectives of performance standards as a bridge between the management and ecological environments of wetland mitigation. In Chapter 2, I explore performance standards as part of the management environment. I evaluate differences among state performance standard strategies. While federal legislation is the primary driver for wetland mitigation, federal and state agencies regulate and oversee wetland mitigation programs. Using a mixed-method approach, I investigate the extent of state involvement in the performance standard determination process. In addition, I explore how performance standards differ among states. Using data from semi-structured interviews with state agency personnel and online database reviews, I rank states based on the inclusion of performance standard criteria in legislation: none (18), some (18), moderate (7), extensive (7). Through interviews, I discovered guidance documents play a prominent role in decision-making, with 35 states referencing guidance documents during this research study. I classified documents by authorship: state only (18) and federal and state (17). Next, I further classified guidance documents by type: general guidance (25), study/technical report (6), and template (4). In addition, I describe performance standards by type (abiotic, biotic, and administrative). Performance standard criteria were often ecological and abiotic (P = 0.3) and relied heavily on vegetative criteria. Collaboration and negotiation between agencies, legislation, and guidance documents influence performance standard determination. In Chapter 3, I investigate woody vegetation development post-restoration and discuss the potential of using woody vegetation as a performance standard. I conduct field sampling at 40 restored wetlands that vary in the time since restoration from 1 to 29 years. I assess woody vegetation community metrics and stem diameter sizes along the chronosequence gradient and among three West Virginian ecoregions. I tallied 15,785 individuals from 60 species and 25 families during growing season sampling in 2021. I found native species richness declined as wetland site age increased (P = 0.042). Oppositely, I discovered that stem area at groundline (SAG), a basal area metric, increased with wetland age (P < 0.001). However, linear regression model assumptions were not met. I fit a transformed model that shows log(SAG) increases with wetland age (R2 = 0.31, P < 0.001). Every year after restoration, the absolute log(SAG) increases by 0.110 when considering both volunteer and planted woody vegetation. All sites, regardless of age, were dominated by small-diameter stems, with only the frequency of stems ≥ 9.1 cm increasing with wetland age (P = 0.008). In addition, I investigated differences in woody vegetation sampling results between growing (May – September) and dormant (November – December) seasons. There were no differences in species richness, stem density, or SAG between the two sampling seasons, suggesting that woody vegetation sampling can occur regardless of the season. My results demonstrate woody vegetation may take two decades to develop post-restoration. In conclusion, this research investigates performance standards from two perspectives. Chapter 2 presents performance standards as a synthesis of expectations from regulatory stakeholders. Chapter 3 indicates that diverse ecological conditions exist in restored wetlands, differing from management expectations which assume predictable ecological development post-restoration. Overall, wetland regulators and managers should consider this balanced perspective when implementing performance standards as measures of wetland development.

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