Tyndall, John

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jtyndall@iastate.edu
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Professor
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Organizational Unit
Natural Resource Ecology and Management
The Department of Natural Resource Ecology and Management is dedicated to the understanding, effective management, and sustainable use of our renewable natural resources through the land-grant missions of teaching, research, and extension.
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Publications

Now showing 1 - 10 of 54
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Article

Welcome to the New Frontier: Introducing Extension to the Next Generation of Conservation Planning Tools

2024-11-16 , Bravard, Emma E. , Zimmerman, Emily K. , Tyndall, John , James, David , Natural Resource Ecology and Management

A new frontier of conservation planning capacity utilizing innovative decision support tools has emerged. Extension professionals play an important role in using these new data and tools to achieve conservation and water quality outcomes. Here, we detail the application of two conservation planning tools: Agricultural Conservation Planning Framework (ACPF) and Financial and Nutrient Reduction Tool (FiNRT). Tools like these are increasingly being used to guide conservation efforts in agricultural landscapes; provide information regarding potential resource concern; and offer valuable data about outcomes from best management practice (BMP) placement. Extension professionals’ use of such tools could enhance conservation implementation and outcomes.

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Techno-economic and life cycle analysis of renewable natural gas derived from anaerobic digestion of grassy biomass: A US Corn Belt watershed case study

2024-05-22 , Olafasakin, Olumide , Audia, Ellen M. , Mba-Wright, Mark , Tyndall, John , Schulte Moore, Lisa , Mechanical Engineering , Natural Resource Ecology and Management , Bioeconomy Institute

Restoring native grassland vegetation can substantially improve ecosystem service outcomes from agricultural watersheds, but profitable pathways are needed to incentivize conversion from conventional crops. Given growing demand for renewable energy, using grassy biomass to produce biofuels provides a potential solution. We assessed the techno-economic feasibility and life cycle outcomes of a “grass-to-gas” pathway that includes harvesting grassy (lignocellulosic) biomass for renewable natural gas (RNG) production through anaerobic digestion (AD), expanding on previous research that quantified ecosystem service and landowner financial outcomes of simulated grassland restoration in the Grand River Basin of Iowa and Missouri, United States. We found that the amount of RNG produced through AD of grassy biomass ranged 0.12–45.04 million gigajoules (GJ), and the net present value (NPV) of the RNG ranged −$97 to $422 million, depending on the combination of land use, productivity, and environmental credit scenarios. Positive NPVs are achieved with environmental credits for replacement of synthetic agricultural inputs with digestate and clean fuel production (e.g., USEPA D3 Renewable Identification Number, California Low Carbon Fuel Standard). Producing RNG from grassy biomass emits 15.1 g CO2-eq/MJ, which compares favorably to the fossil natural gas value of 61.1 g CO2-eq/MJ and exceeds the US Environmental Protection Agency's requirement for cellulosic biofuel. Overall, this study demonstrates opportunities and limitations to using grassy biomass from restored grasslands for sustainable RNG production.

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A systematic review of social equity in FEWS analyses

2023-03-22 , Stone, Tiffanie , Dickey, Loulou C. , Summers, Haleigh , Thompson, Janette , Rehmann, Chris , Zimmerman, Emily , Tyndall, John , Natural Resource Ecology and Management , Department of Civil, Construction and Environmental Engineering

Integrating social equity considerations into analyses of the food-energy-water systems nexus (FEWS) could improve understanding of how to meet increasing resource demands without impacting social vulnerabilities. Effective integration requires a robust definition of equity and an enhanced understanding of reliable FEWS analysis methods. By exploring how equity has been incorporated into FEWS research in the United States and countries with similar national development, this systematic literature review builds a knowledge base to address a critical research need. Our objectives were to 1) catalog analysis methods and metrics relevant to assessing FEWS equity at varying scales; 2) characterize current studies and interpret shared themes; and 3) identify opportunities for future research and the advancement of equitable FEWS governance. FEWS equity definitions and metrics were categorized by respective system (food, energy, water, overall nexus) and common governance scales (local, regional, national, global). Two central issues were climate change, which increases FEWS risks for vulnerable populations, and sustainable development, which offers a promising framework for integrating equity and FEWS in policy-making contexts. Social equity in FEWS was integrated into studies through affordability, access, and sociocultural elements. This framework could support researchers and practitioners to include equity in FEWS analysis tools based on study scale, purpose, and resource availability. Research gaps identified during the review included a lack of studies effectively integrating all three systems, a need for publicly available datasets, omission of issues related to energy conversion facilities, and opportunities for integration of environmental justice modalities into FEWS research. This paper synthesized how social equity has previously been incorporated into FEWS and outlines pathways for further consideration of equity within nexus studies. Our findings suggested that continued exploration of connections between FEWS, equity, and policy development across scales could reduce social risks and vulnerabilities associated with these systems.

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Financial Analysis of Converting Rural Lawns to Pollinator Habitat in the Corn Belt

2021-06-01 , Bradbury, Steven , Janke, Adam , Tyndall, John , Natural Resource Ecology and Management , Department of Entomology , Pollinator Working Group

Conservation efforts in rural landscapes seek to improve the multifunctional nature of land uses for people and the biotic communities that support them. In these environments, existing turfgrass lawns mowed routinely through the summer present an opportunity where changes in management from intensively managed monocultures to diverse native perennial vegetation can stack environmental benefits by improving soil health, water quality, and wildlife habitat. Conversion of lawns to pollinator habitat can help achieve continental goals of reversing declines in high-profile species such as the monarch butterfly Danaus plexippus and native bees. Here, we examine the financial implications for landowners and managers considering conversion of lawns to pollinator habitat in rural landscapes. We examined financial factors over a 10-y management horizon in three unique scenarios with a range of expenses: self-maintenance of lawns, contracted maintenance of lawns, and establishment and management of pollinator habitat. Our analyses indicate conversion to pollinator habitat was appreciably less expensive ($54–$167·acre−1·y−1) than continued self-care ($637–$1,007·acre−1·y−1) or contracted care ($326–$1,034·acre−1·y−1) of lawns over a 10-y period. These results establish the financial benefits for landowners or land managers considering an alternative management paradigm of existing lawns. These financial benefits complement existing literature, demonstrating multiple ecological benefits of diverse native perennial vegetation.

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Mapping barriers to food, energy, and water systems equity in the United States

2024-11-08 , Summers, Haleigh N. , Stone, Tiffanie F. , Dickey, Loulou C. , Rehmann, Chris , Zimmerman, Emily K. , Tyndall, John , Liu, Lu , Natural Resource Ecology and Management , Department of Civil, Construction and Environmental Engineering

Barriers to affordable, accessible, high-quality food, energy, and water systems (FEWS) harm social equity. Connections within and across FEWS suggest that co-occurring barriers to equity can compound vulnerability. We hypothesized that barriers to FEW resources are strongly associated with geographic location, both within and across FEWS, as they rely heavily on localized sociopolitical and natural environments. This study explored the geographic relationships between FEWS barriers and social equity through a spatial analysis of census tracts within the United States. Cluster analyses showed that all FEWS barriers had a positive spatial autocorrelation (Moran's I = 0.12–0.94), with energy barriers being the most spatially clustered and affordability barriers being the least spatially clustered. In 54 % of census tracts, we observed the co-occurrence of low barriers to water quality and access. Barriers to FEWS affordability almost always co-occurred in parallel (e.g., high barriers to affordability in one system co-occurred with high barriers to affordability in another system). Finally, we developed a spatial index of the barriers to FEWS equity to determine vulnerability at the census tract scale, which had a positive spatial autocorrelation (Moran's I = 0.41). Clusters and intersections of FEWS equity barriers suggest that resources are interconnected, resulting in additional challenges for people living in these areas. The maps of barriers to equity in FEWS are useful tools that could help stakeholders (e.g., federal agencies, city planners, utilities) distribute FEWS resources fairly and begin engagement with communities about FEWS barriers in their local context.

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The influence of prairie strips sown in midwestern corn and soybean fields on sediment discharge throughout the year

2024-03 , Stephenson, Jessica A. , Liebman, Matt , Niemi, Jarad , Cruse, Richard , Tyndall, John , Witte, Chris , James, Dave , Helmers, Matthew , Natural Resource Ecology and Management , Department of Agronomy , Statistics (CALS) , Department of Agricultural and Biosystems Engineering (CALS)

Many crop fields in the United States Corn Belt continue to erode at rates in excess of soil regeneration leading to sediment being transported from farms to adjacent surface water and degrading wildlife habitat. To reduce or eliminate sediment loss, vegetative filter strips can be established perpendicular to the hillslope and at the edge-of-field to intercept and filter surface runoff transporting sediment. The filter strips can be planted with native prairie vegetation to filter sediment out of runoff as well as establishing high quality habitat. A long-term study at Neal Smith Wildlife Refuge Farm in central Iowa found that with as little as 10% of a field converted to prairie filter strips, sediment discharge from fields could be reduced up to 95%. To improve our understanding of prairie filter strips and erosion processes over a broader range of landscapes, this study was conducted at six farm sites throughout Iowa. Following a paired treatment approach, each farm site was broken into two different subcatchments; one subcatchment was fully cropped (control) while the other had a portion of the field sown with native prairie vegetation. Each subcatchment had an H-flume installed to sample runoff water and determine the total suspended sediment (TSS) load and a rain gauge to monitor rainfall amount, frequency, and duration. Between 2016 and 2021, subcatchments with prairie strips median TSS load was 89.5% lower (95% CI: 69.2% to 96.4%; p<0.001) than the control subcatchments. In fields when corn was planted, the subcatchments with prairie strips had significantly lower TSS discharged, with a median TSS load 97.6% less (95% CI, 92.1% to 99.3%, p<0.001) compared to the control subcatchments. The TSS loads were significantly influenced by the amount of rainfall (p<0.001) despite the treatment. To investigate effects of seasonality and rainfall amount, the dataset was parsed out based on the growing season of the dominant cropping system. There was no prairie strip effect during the primary growing months (PGS (May to August); however, outside of the primary growing months (OPGS) (March to April and September to November) the prairie strip subcatchments median TSS load was 96.1% less (95% CI, 82.5% to 99.1%, p<0.001) than the controls. The significant interaction of crop planted with the prairie strip treatment and the differences between PGS and OPGS suggest that prairie strips have the capacity to reduce sediment leaving a field when they are the most vulnerable to effects of splash erosion (i.e., low ground cover and higher rainfall amount). Climate change models predict that areas like Iowa will continue to trend towards higher frequency and intensity rain events, so the compounded benefits of prairie planted in cropped fields could promote biodiverse landscapes that increase resilience to predicted effects from climate change during parts of the year when the land is more susceptible to erosion.

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Technical Report

Learning About Ecosystem Services with PEWI: Student Reflections

2022-10 , Magala, Richard , Tyndall, John , Schulte Moore, Lisa , Natural Resource Ecology and Management

People in Ecosystem/Watershed Integration (PEWI; https://www.nrem.iastate.edu/pewi/) is an online teaching and learning tool designed to help students learn the relationships between land management, land cover, watershed hydrology, and ecosystem outcomes (Chennault et al., 2020; Anderson et al., 2020). PEWI features a 2,383 ha (6,000 acres) virtual watershed based on real-world locations. PEWI is both a simulation and game-based learning tool. As a game, PEWI is designed with goal orientation, constraints, feedback mechanisms, and gameplay features, as described in Becker (2021). The gameplay design is technically passive — the stu-dent plays with the computer, which provides feedback during and at the end of the play. The tool lets users discover causal relationships between ecosystem service outcomes and allows participants to assume roles and decision-making responsibilities. As a computer model that allows students to test out their hypotheses related to land use, PEWI qualifies as a simulation tool (Gredler, 1996; O'Neil et al., 2005).

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Article

Economic evaluation of barriers to minimize reservoir sport fish escapement

2024-06-05 , Lewis, Madeline C. , Tyndall, John , Dodd, Ben , Weber, Michael , Natural Resource Ecology and Management

Objective: Barriers can be an effective method for reducing escapement of reservoir sport fish; however, whether the financial benefits of a barrier outweigh the costs of a barrier is unknown. We sought to quantify the costs and benefits associated with constructing barriers to reduce fish escapement while explicitly accounting for variability and uncertainty.
Methods: We developed a framework using simulation modeling and discounted cash flow techniques to quantify the costs and benefits of barrier construction on Brushy Creek Lake, Iowa, where a barrier was constructed in 2020 to reduce escapement of stocked Walleye Sander vitreus and Muskellunge Esox masquinongy. We then incorporated this framework into an interactive Shiny application to enable cost–benefit evaluations across a wide range of barrier types, system types, species, and escapement rates.
Result: The present value of the parallel-bar barrier on Brushy Creek Lake, Iowa, over 10 years was US$69,576 (range = $64,484–$73,976), whereas the present value of escaped fish was $316,416 ($253,459–$378,823), indicating a net benefit of $246,840 ($188,975–$304,847) associated with barrier construction. The benefit–cost ratio of barrier construction was 4.55 after 10 years, indicating that for every $1 in present value spent on barrier construction, we saved $4.55 by preventing fish escapement. There was a 99% probability of a positive mean net benefit of the barrier after 3 years.
Conclusion: Our results indicate that barriers can be a cost-effective option to minimize fish escapement, and barrier costs are more predictable compared with the cost of escapement. Quantifying the value of escaped fish and barrier construction on an economic scale enables the use of formal decision-making tools to address complicated and multifaceted issues associated with reservoir fisheries management.

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Report

Responses to Outstanding Stakeholder Questions: Supplemental Document to 2023 Grass2Gas Iowa, Pennsylvania, and National Workshop Proceedings

2024 , Stagner, Forrest , Akingbasote, Mary Tutuola , Ciolkosz, Dan , Cook, Vivian , Costello, Chris , Helbing, Mike , Karsten, Heather , Kelly, DeWaunis , Korkut, Ekrem , Lazarus, William , Mba-Wright, Mark , Montabon, Frank , Morris, Chris , Rahic, Elmin , Richard, Tom , Santos, Lucas de Lima Casseres dos , Schulte, Abbie , Sigdel, Sailesh , Stephenson, Jessica , Tyndall, Dan , Tyndall, John , Wild, Katie , Schulte Moore, Lisa , Consortium for Cultivating Human And Naturally reGenerative Enterprises (C-CHANGE)

In 2023, the Grass2Gas project held a series of workshops to engage with stakeholders, provide insight into what the project has been learning, and to elicit feedback from stakeholders, including what questions they had about the project that had not been answered yet. The G2G team compiled a list of outstanding questions from these workshops and set to work providing the best and most current answers available. The questions cover a wide range of topics, but stakeholders were particularly interested in how adding grass to digesters affects the economics and incentives of anaerobic digestion, what the G2G scenario would look like in practice, and what the environmental benefits of G2G would be. The questions and their responses are listed in this report.

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The Agricultural Conservation Planning Framework Financial and Nutrient Reduction Tool: A planning tool for cost effective conservation

2022-04-11 , Bravard, Emma E. , Zimmerman, Emily , Tyndall, John , James, David , Natural Resource Ecology and Management , Iowa Nutrient Research Center

We have developed an add-on tool for use with the Agricultural Conservation Planning Framework (ACPF) that features a multistate financial analysis and field-scale nitrogen (N) reduction tool for use when analyzing different ACPF conservation scenarios. Financial and expected field-scale N loss data are used to calculate total long-term cost and cost effectiveness of various conservation plans. Unique to the ACPF Financial and Nutrient Reduction Tool is the ability to identify individual treatment areas for each practice evaluated, allowing users to create combinatorial conservation planning scenarios drawing from multiple ACPF-identified conservation practices. Financial data account for direct long-term annualized costs for best management practice (BMP) installation and management in Iowa and Minnesota. Opportunity costs of BMPs that retire cropland are spatially determined according to weighted-average crop productivity indices and land rent relationships. The tool quantifies the N requirements for each field, based on 6-yr land-use data, and evaluates the proportion of N likely to be lost from the field as nitrate load via leaching. Financial analyses that can be accomplished by using the ACPF are illustrated in case study watershed scenarios in Iowa and Minnesota. In Iowa, featured scenarios range from 26 to 31% reduction in total nitrate, for a total cost between US$0.580 million and $2.3 million per year, respectively. In Minnesota, example scenarios range from 28 to 51% total nitrate reduction, for total costs of $1.7 million to $2.1 million per year. Tradeoffs in BMP selection related to N reduction outcome and cost are also demonstrated.