Estimating carbon supply curves from afforestation of agricultural land in the Northeastern U.S.

The Regional Greenhouse Gas Initiative for the northeastern states of the U.S. allows for terrestrial carbon (C) sequestration offsets generated by afforestation activities only. This paper estimates the maximum potential quantity and associated costs of increasing the storage of carbon by afforestation of existing agricultural land in the 11 states of the Northeast United States. The focus of the work was to describe location, the quantity, and at what cost it would be economically attractive to shift agricultural production to afforestation to increase carbon storage in the region. Widely available data sets were used to (1) identify spatially-explicit areas for lower costs carbon offsets and (2) estimate carbon supply curves related to afforestation of agricultural land over three time periods (10, 20, and 40 years). Carbon accumulation and total carbon offset project costs were estimated at a county scale and combined to identify expected costs per ton of carbon dioxide equivalents (CO₂e). Large variation in estimated costs per ton of CO₂e are driven by varying carbon accumulation potentials and opportunity costs of taking land out of agricultural production, as well as the duration of the project activity. Results show that the lowest cost carbon offset projects will be in certain counties of Maine, Vermont, and New York. Pasture land, with lower opportunity costs, generally presents the opportunity for lower cost carbon offset projects relative to cropland. This analysis estimates that afforestation of pasture land in the northeast will not become economically attractive until the price rises above 10 per metric tonne (MT) CO < sub > 2 < /sub > e and that up to 583 million MT could be economically sequestered if the price were to rise to10 per metric tonne (MT) CO₂e and that up to 583 million MT could be economically sequestered if the price were to rise to 50 per MT CO₂e, based on a 40-year project life. With regard to cropland in the northeast, afforestation does not become economically advantageous for land owners until the price rises above $40 per MT CO₂e. It is estimated that up to 487,000 MT could be sequestered from cropland if the price were to rise to $40 per MT CO₂e. It is estimated that up to 487,000 MT could be sequestered from cropland if the price were to rise to 50 per MT CO₂e, based on a 40-year project life.     

Contributions of green infrastructure to enhancing urban resilience

After briefly reviewing key resilience engineering perspectives and summarising some green infrastructure (GI) tools, we present the contributions that GI can make to enhancing urban resilience and maintaining critical system functionality across complex integrated social–ecological and technical systems. We then examine five key challenges for the effective implementation of GI that include (1) standards; (2) regulation; (3) socio-economic factors; (4) financeability; and (5) innovation. We highlight ways in which these challenges are being dealt with around the world, particularly through the use of approaches that are both context appropriate and socially inclusive. Although progress surmounting these challenges has been made, more needs to be done to ensure that GI approaches are inclusive and appropriate and feature equally alongside more traditional ‘grey’ infrastructure in the future of urban resilience planning. This research was undertaken for the Resilience Shift initiative to shift the approach to resilience in practice for critical infrastructure sectors. The programme aims to help practitioners involved in critical infrastructure to make decisions differently, contributing to a safer and better world.     

Fathead Minnow and Bluegill Sunfish Life‐Stage Responses to 17β‐Estradiol Exposure in Outdoor Mesocosms

Developmental and reproductive effects of 17β‐estradiol (E2) exposure on two generations of fathead minnows and one generation of bluegill sunfish were assessed. Fish were exposed to E2 for six continuous weeks in outdoor mesocosms simulating natural lake environments. First generation fish were exposed while sexually mature. Second generation fathead minnows were exposed either during early development, sexual maturity, or both stages. Multiple endpoints were measured to assess effects of E2 exposure on fecundity and fish health and development. Plasma vitellogenin concentrations were highly variable in all fish. Differences in egg production timing for both species indicate differences in fecundity between females exposed to E2 and controls. First generation fathead minnows exposed to E2 had lower body condition factors and reduced secondary sexual characteristic expression by males. Only a difference in relative liver weight was observed in second generation fathead minnows. First generation bluegill males exposed to E2 had significantly smaller testes compared to controls. Although fish response was highly variable, results indicate that exposure to E2 at environmentally relevant concentrations affect fathead minnow and bluegill sunfish health and development, which may have implications for the health and sustainability of fish populations. Furthermore, exposure timing and environmental factors affect fish response to E2 exposure.     

Justice in sustainability indicators and indexes

At least since the Brundtland Report, technical assessments of what can be sustained and values about what is desirable to sustain, for whom, and for how long have been intertwined. This intersection is particularly evident in the assumption that justice among people living today and between present and future generations is a key part of sustainability. In official international policy documents and academic studies of sustainability, this justice may include the equitable distribution of environmental benefits and burdens, distributive justice, or the ability of people to meaningfully contribute to decisions that affect their lives, participatory justice. Yet, the process of developing indicators and indexes to track movement toward or away from sustainability has been dominated by technical, economic, and environmental assessments. This raises questions about whether or not indexes align with and thus will monitor and encourage progress toward sustainability in a technically possible and desirable way. To begin to answer this question, this paper identifies definitions of justice used in sustainability discourse and evaluates the degree to which sustainability indicators and indexes align with these concepts. The 2010 Environmental Performance Index, Eurostat's Sustainable Development Indicators, and a group of local indicators and indexes are examined. It is found that the indicators embody various aspects of justice, though they are still significantly limited by the available data, especially as they generally cannot monitor inequities between subpopulations and have a limited capacity to monitor progress toward participatory justice.     

Testing hypotheses in evolutionary ecology with imperfect detection: capture-recapture structural equation modeling

Studying evolutionary mechanisms in natural populations often requires testing multifactorial scenarios of causality involving direct and indirect relationships among individual and environmental variables. It is also essential to account for the imperfect detection of individuals to provide unbiased demographic parameter estimates. To cope with these issues, we developed a new approach combining structural equation models with capture-recapture models (CR-SEM) that allows the investigation of competing hypotheses about individual and environmental variability observed in demographic parameters. We employ Markov chain Monte Carlo sampling in a Bayesian framework to (1) estimate model parameters, (2) implement a model selection procedure to evaluate competing hypotheses about causal mechanisms, and (3) assess the fit of models to data using posterior predictive checks. We illustrate the value of our approach using two case studies on wild bird populations. We first show that CR-SEM can be useful to quantify the action of selection on a set of phenotypic traits with an analysis of selection gradients on morphological traits in Common Blackbirds (Turdus merula). In a second case study on Blue Tits (Cyanistes caeruleus), we illustrate the use of CR-SEM to study evolutionary trade-offs in the wild, while accounting for varying environmental conditions.     

Occurrence and public perception of jellyfish along the German Baltic coastline

Jellyfish accumulations are often problematic for tourism and fisheries both along European coastlines and overseas. They damage the reputation of several seaside resorts and cause serious economic losses. On the German Baltic coast, jellyfish accumulations are well known, too. Besides population increase due to anthropogenic effects, normal hydrodynamic processes are notable key factors when it comes to jellyfish accumulations. Along German Baltic coastlines, moon jellyfish (Aurelia aurita) occur most frequently but also stinging lion??s mane jellyfish (Cyanea capillata) appear regularly, however not as abundant. The objectives of our study were a) to screen when, where, how many and which jellyfish species occur on German Baltic coasts, b) to find the causes for jellyfish accumulations and c) to evaluate how beach visitors perceive native medusae and whether information can influence their perception. Different methods where combined: systematic jellyfish observations in cooperation with lifeguards, investigations of jellyfish abundance in shallow water zones, and interviews with beach visitors. Our results suggest that jellyfish occurrence along the German Baltic coast correlates with offshore wind or shore-parallel wind, which cause upwelling events. In contrast, there is no evidence that frequency of jellyfish occurrence was dependent on water temperature in summer. In regard to tourism, we found that beach visitors who received information about jellyfish stated to feel significantly less bothered by medusae. Overall, this article addresses different methods to learn more about jellyfish accumulations and it shows information strategies in terms of improved beach management.     

Parasite transmission in complex communities: predators and alternative hosts alter pathogenic infections in amphibians

While often studied in isolation, host-parasite interactions are typically embedded within complex communities. Other community members, including predators and alternative hosts, can therefore alter parasite transmission (e.g., the dilution effect), yet few studies have experimentally evaluated more than one such mechanism. Here, we used data from natural wetlands to design experiments investigating how alternative hosts and predators of parasites mediate trematode (Ribeiroia ondatrae) infection in a focal amphibian host (Pseudacris regilla). In short-term predation bioassays involving mollusks, zooplankton, fish, larval insects, or newts, four of seven tested species removed 62-93% of infectious stages. In transmission experiments, damselfly nymphs (predators) and newt larvae (alternative hosts) reduced infection in P. regilla tadpoles by -50%, whereas mosquitofish (potential predators and alternative hosts) did not significantly influence transmission. Additional bioassays indicated that predators consumed parasites even in the presence of alternative prey. In natural wetlands, newts had similar infection intensities as P. regilla, suggesting that they commonly function as alternative hosts despite their unpalatability to downstream hosts, whereas mosquitofish had substantially lower infection intensities and are unlikely to function as hosts. These results underscore the importance of studying host-parasite interactions in complex communities and of broadly linking research on predation, biodiversity loss, and infectious diseases.