Using Discussion to Promote Learning in Undergraduate Biology

Summary and Comments from Workshop 40: “Looks Who\u27s Talking! Using Discussion as an Effective Learning Tool” presented at the 100th Ecological Society of America Meetin

Sustaining Wetlands to Mitigate Disasters and Protect People

Hurricanes, flooding, droughts. Weather‐related disasters are dominating news cycles and causing widespread destruction, most recently with Typhoon Mangkhut and Hurricane Florence. The US had the most catastrophic hurricane season on record in 2017, with hundreds of billions of dollars in estimated damages. California is experiencing unprecedented tragedies from widespread wildfires and increased vulnerability to storms. Disasters that were once uncommon appear to be the new norm globally, and evidence suggests the frequency and impacts of extreme events will increase further with climate change

Exploring connections among nature, biodiversity, ecosystem services, and human health and well-being: Opportunities to enhance health and biodiversity conservation

AbstractWe are at a key juncture in history where biodiversity loss is occurring daily and accelerating in the face of population growth, climate change, and rampant development. Simultaneously, we are just beginning to appreciate the wealth of human health benefits that stem from experiencing nature and biodiversity. Here we assessed the state of knowledge on relationships between human health and nature and biodiversity, and prepared a comprehensive listing of reported health effects. We found strong evidence linking biodiversity with production of ecosystem services and between nature exposure and human health, but many of these studies were limited in rigor and often only correlative. Much less information is available to link biodiversity and health. However, some robust studies indicate that exposure to microbial biodiversity can improve health, specifically in reducing certain allergic and respiratory diseases. Overall, much more research is needed on mechanisms of causation. Also needed are a re-envisioning of land-use planning that places human well-being at the center and a new coalition of ecologists, health and social scientists and planners to conduct research and develop policies that promote human interaction with nature and biodiversity. Improvements in these areas should enhance human health and ecosystem, community, as well as human resilience

Uncertainty in United States coastal wetland greenhouse gas inventorying

© The Author(s), 2018. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Environmental Research Letters 13 (2018): 115005, doi:10.1088/1748-9326/aae157.Coastal wetlands store carbon dioxide (CO2) and emit CO2 and methane (CH4) making them an important part of greenhouse gas (GHG) inventorying. In the contiguous United States (CONUS), a coastal wetland inventory was recently calculated by combining maps of wetland type and change with soil, biomass, and CH4 flux data from a literature review. We assess uncertainty in this developing carbon monitoring system to quantify confidence in the inventory process itself and to prioritize future research. We provide a value-added analysis by defining types and scales of uncertainty for assumptions, burial and emissions datasets, and wetland maps, simulating 10 000 iterations of a simplified version of the inventory, and performing a sensitivity analysis. Coastal wetlands were likely a source of net-CO2-equivalent (CO2e) emissions from 2006–2011. Although stable estuarine wetlands were likely a CO2e sink, this effect was counteracted by catastrophic soil losses in the Gulf Coast, and CH4 emissions from tidal freshwater wetlands. The direction and magnitude of total CONUS CO2e flux were most sensitive to uncertainty in emissions and burial data, and assumptions about how to calculate the inventory. Critical data uncertainties included CH4 emissions for stable freshwater wetlands and carbon burial rates for all coastal wetlands. Critical assumptions included the average depth of soil affected by erosion events, the method used to convert CH4 fluxes to CO2e, and the fraction of carbon lost to the atmosphere following an erosion event. The inventory was relatively insensitive to mapping uncertainties. Future versions could be improved by collecting additional data, especially the depth affected by loss events, and by better mapping salinity and inundation gradients relevant to key GHG fluxes. Social Media Abstract: US coastal wetlands were a recent and uncertain source of greenhouse gasses because of CH4 and erosion.Financial support was provided primarily by NASA Carbon Monitoring Systems (NNH14AY67I) and the USGS Land Carbon Program, with additional support from The Smithsonian Institution, The Coastal Carbon Research Coordination Network (DEB-1655622), and NOAA Grant: NA16NMF4630103

Pathways to Coastal Resiliency: The Adaptive Gradients Framework

Current and future climate-related coastal impacts such as catastrophic and repetitive flooding, hurricane intensity, and sea level rise necessitate a new approach to developing and managing coastal infrastructure. Traditional “hard” or “grey” engineering solutions are proving both expensive and inflexible in the face of a rapidly changing coastal environment. Hybrid solutions that incorporate natural, nature-based, structural, and non-structural features may better achieve a broad set of goals such as ecological enhancement, long-term adaptation, and social benefits, but broad consideration and uptake of these approaches has been slow. One barrier to the widespread implementation of hybrid solutions is the lack of a relatively quick but holistic evaluation framework that places these broader environmental and societal goals on equal footing with the more traditional goal of exposure reduction. To respond to this need, the Adaptive Gradients Framework was developed and pilot-tested as a qualitative, flexible, and collaborative process guide for organizations to understand, evaluate, and potentially select more diverse kinds of infrastructural responses. These responses would ideally include natural, nature-based, and regulatory/cultural approaches, as well as hybrid designs combining multiple approaches. It enables rapid expert review of project designs based on eight metrics called “gradients”, which include exposure reduction, cost efficiency, institutional capacity, ecological enhancement, adaptation over time, greenhouse gas reduction, participatory process, and social benefits. The framework was conceptualized and developed in three phases: relevant factors and barriers were collected from practitioners and experts by survey; these factors were ranked by importance and used to develop the initial framework; several case studies were iteratively evaluated using this technique; and the framework was finalized for implementation. The article presents the framework and a pilot test of its application, along with resources that would enable wider application of the framework by practitioners and theorists

Plant Trait Diversity Buffers Variability in Denitrification Potential over Changes in Season and Soil Conditions

BACKGROUND: Denitrification is an important ecosystem service that removes nitrogen (N) from N-polluted watersheds, buffering soil, stream, and river water quality from excess N by returning N to the atmosphere before it reaches lakes or oceans and leads to eutrophication. The denitrification enzyme activity (DEA) assay is widely used for measuring denitrification potential. Because DEA is a function of enzyme levels in soils, most ecologists studying denitrification have assumed that DEA is less sensitive to ambient levels of nitrate (NO(3)(-)) and soil carbon and thus, less variable over time than field measurements. In addition, plant diversity has been shown to have strong effects on microbial communities and belowground processes and could potentially alter the functional capacity of denitrifiers. Here, we examined three questions: (1) Does DEA vary through the growing season? (2) If so, can we predict DEA variability with environmental variables? (3) Does plant functional diversity affect DEA variability? METHODOLOGY/PRINCIPAL FINDINGS: The study site is a restored wetland in North Carolina, US with native wetland herbs planted in monocultures or mixes of four or eight species. We found that denitrification potentials for soils collected in July 2006 were significantly greater than for soils collected in May and late August 2006 (p<0.0001). Similarly, microbial biomass standardized DEA rates were significantly greater in July than May and August (p<0.0001). Of the soil variables measured--soil moisture, organic matter, total inorganic nitrogen, and microbial biomass--none consistently explained the pattern observed in DEA through time. There was no significant relationship between DEA and plant species richness or functional diversity. However, the seasonal variance in microbial biomass standardized DEA rates was significantly inversely related to plant species functional diversity (p<0.01). CONCLUSIONS/SIGNIFICANCE: These findings suggest that higher plant functional diversity may support a more constant level of DEA through time, buffering the ecosystem from changes in season and soil conditions

Natural climate solutions for the United States

© The Author(s), 2018. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Science Advances 4 (2018): eaat1869, doi:10.1126/sciadv.aat1869.Limiting climate warming to <2°C requires increased mitigation efforts, including land stewardship, whose potential in the United States is poorly understood. We quantified the potential of natural climate solutions (NCS)—21 conservation, restoration, and improved land management interventions on natural and agricultural lands—to increase carbon storage and avoid greenhouse gas emissions in the United States. We found a maximum potential of 1.2 (0.9 to 1.6) Pg CO2e year−1, the equivalent of 21% of current net annual emissions of the United States. At current carbon market prices (USD 10 per Mg CO2e), 299 Tg CO2e year−1 could be achieved. NCS would also provide air and water filtration, flood control, soil health, wildlife habitat, and climate resilience benefits.This study was made possible by funding from the Doris Duke Charitable Foundation. C.A.W. and H.G. acknowledge financial support from NASA’s Carbon Monitoring System program (NNH14ZDA001N-CMS) under award NNX14AR39G. S.D.B. acknowledges support from the DOE’s Office of Biological and Environmental Research Program under the award DE-SC0014416. J.W.F. acknowledges financial support from the Florida Coastal Everglades Long-Term Ecological Research program under National Science Foundation grant no. DEB-1237517

Social Factors Key to Landscape-Scale Coastal Restoration: Lessons Learned from Three U.S. Case Studies

In the United States, extensive investments have been made to restore the ecological function and services of coastal marine habitats. Despite a growing body of science supporting coastal restoration, few studies have addressed the suite of societally enabling conditions that helped facilitate successful restoration and recovery efforts that occurred at meaningful ecological (i.e., ecosystem) scales, and where restoration efforts were sustained for longer (i.e., several years to decades) periods. Here, we examined three case studies involving large-scale and long-term restoration efforts including the seagrass restoration effort in Tampa Bay, Florida, the oyster restoration effort in the Chesapeake Bay in Maryland and Virginia, and the tidal marsh restoration effort in San Francisco Bay, California. The ecological systems and the specifics of the ecological restoration were not the focus of our study. Rather, we focused on the underlying social and political contexts of each case study and found common themes of the factors of restoration which appear to be important for maintaining support for large-scale restoration efforts. Four critical elements for sustaining public and/or political support for large-scale restoration include: (1) resources should be invested in building public support prior to significant investments into ecological restoration; (2) building political support provides a level of significance to the recovery planning efforts and creates motivation to set and achieve meaningful recovery goals; (3) recovery plans need to be science-based with clear, measurable goals that resonate with the public; and (4) the accountability of progress toward reaching goals needs to be communicated frequently and in a way that the general public comprehends. These conclusions may help other communities move away from repetitive, single, and seemingly unconnected restoration projects towards more large-scale, bigger impact, and coordinated restoration efforts

The Role of Plant Functional Diversity and Soil Amendments in Regulating Plant Biomass and Soil Biogeochemistry in Restored Wetland Ecosystems in the North Carolina Piedmont

Human actions have led to the destruction or degradation of natural habitats in virtually all parts of the Earth. Ecosystem restoration is one method to mitigate the effects of habitat loss. But restoration ecology is a young discipline and there is much left to be learned about how to effectively restore ecosystem functioning. This dissertation examines how soil amendments and planted herbaceous species diversity affect the restoration of ecosystem functions in wetlands, while also testing basic ecological questions that help us understand ecosystem function. Using data from the greenhouse and from the biodiversity and ecosystem function field experiment in Duke Forest, in Durham, NC, I examine how plant trait diversity, average plant traits, and environmental conditions influence nitrogen (N) removal from restored wetlands. Field data collected from a restored wetland in Charlotte, NC, enables me to examine how soil organic amendments influence the development of soil properties, processes, and plant communities. Finally, combining field data from both sites, I compare how soil properties influence denitrification potential in both restored wetlands. One unanswered question in the research relating biodiversity and ecosystem function is whether species diversity or species traits are more important drivers of ecosystem function. The first portion of my dissertation poses several hypotheses about how plant traits, plant trait diversity (calculated as a multivariate measure of plant trait diversity), and environmental conditions are likely to influence two ecosystem functions, biomass N and denitrification potential (DEA), and then examines these hypotheses in a restored wetland in the Piedmont of N.C. Using multiple linear regression, I demonstrate that functional diversity (FD), of traits important for plant growth had no effect on biomass N, but two plant traits, leaf area distribution ratio (LADR) and water use efficiency (WUE), had strong negative effects. Soil inorganic N also had a positive effect. For DEA, FD of traits related to denitrification also did not have a significant effect, but there was evidence of a weak positive effect. Two plant traits had positive effects on DEA, aboveground biomass and aboveground biomass C:N ratio; two traits, belowground biomass C:N ratio and root porosity, had negative effects. Soil inorganic N and soil organic matter also had positive effects on DEA. Results from a Principal Components Analysis (PCA) clustering plant species in trait-space, suggest that <em>Carex</em>, <em>Scirpus</em>, and <em>Juncus</em> species tend to be associated with traits that maximize biomass N, while there is no specific region of trait space or set of species that correspond to high DEA. Instead, there are multiple plant trait combinations that can lead to high DEA. These results suggest that, even though plant diversity (as measured by FD) does not significantly influence biomass N or denitrification, plant trait diversity is important to maintaining multiple ecosystem functions simultaneously. Restored wetlands tend to have lower levels of soil organic matter than natural reference wetlands. Low soil organic matter can limit nutrient cycling as well as plant survival and growth in restored wetlands. In the second portion of my dissertation, I examine how soil compost amendments influence the development of soil properties and processes as well as plant communities at a restored wetland in Charlotte, NC. Using two-way analyses of variance, multiple comparisons of means, and regression, I determine that available N and phosphorus (P) increase with increasing soil organic matter in both the low and high marsh. Total microbial biomass (MB) and microbial activity (measured by denitrification potential (DEA)) also significantly increase with increasing organic matter in both marsh communities, as does soil moisture. Neither total plant biomass (in the low marsh), nor plant species richness (in the high or low marsh) demonstrate any consistent patterns with soil organic matter level in the first three years post-restoration. These results suggest that compost amendments can positively influence some soil properties (i.e. soil available N, P, microbial biomass, and soil moisture) and some ecosystem functions including nutrient cycling (such as denitrification potential), but may have limited early impacts on plant communities. In restoration ecology there is a general assumption that restoring ecosystem structure will also restore ecosystem function. To test this fundamental assumption, I examine whether two restored wetlands demonstrate similar general relationships between soils variables (i.e. do the two systems have similar soil ecosystem structure), and whether the importance of each soil relationship is the same at both systems (i.e. do the two systems demonstrate the same soil function). I use structural equation modeling to both pose hypotheses about how systems function and to test them using field data. I determine that the same model structure of soil relationships is supported by data from these two distinct, yet typical urban restored wetland ecosystems (that is, the two systems have similar soil structure). At both systems higher soil organic matter is the most important predictor of higher DEA; however, most of the other relationships between soils variables are different at each system (that is, the two systems are not functioning in the same way). These results suggest that some fundamental relationships between soil properties and microbial functioning persist even when restored wetlands have very different land-use histories, plant communities, and soil conditions. However, restoring similar soil ecosystem structure does not necessarily lead to the restoration of similar soil function. Ultimately, I hope this research advances our understanding of how ecosystems function and improves future wetland restoration efforts.Dissertatio

Sustaining Wetlands to Mitigate Disasters and Protect People

Hurricanes, flooding, droughts. Weather‐related disasters are dominating news cycles and causing widespread destruction, most recently with Typhoon Mangkhut and Hurricane Florence. The US had the most catastrophic hurricane season on record in 2017, with hundreds of billions of dollars in estimated damages. California is experiencing unprecedented tragedies from widespread wildfires and increased vulnerability to storms. Disasters that were once uncommon appear to be the new norm globally, and evidence suggests the frequency and impacts of extreme events will increase further with climate change