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Background: Wood products continue to store carbon sequestered in forests after harvest and therefore play an important role in the total carbon storage associated with the forest sector. Trade-offs between carbon sequestration/storage in wood product pools and managed forest systems exist, and in order for forest sector carbon modeling to be meaningful, it must link wood product carbon with the specific forest system from which the products originate and have the ability to incorporate in situ and ex situ carbon synchronously over time. Results: This study uses elements of a life cycle assessment approach, tracing carbon from US southern pine timber harvests to emission, to create a decision support tool that practitioners can use to inform policy design around land- and bioproduct-based mitigation strategies. We estimate that wood products from annual loblolly and shortleaf pine timber harvests across the southern US store 29.7 MtC in the year they enter the market, and 11.4 MtC remain stored after 120 years. We estimate fossil fuel emissions from the procurement, transportation, and manufacturing of these wood products to be 43.3 MtCO2e year−1. We found that composite logs, used to manufacture oriented strand board (OSB), were the most efficient log type for storing carbon, storing around 1.8 times as much carbon as saw logs per tonne of log over 120 years. Conclusions: Results from our analysis suggest that adjusting rotation length based on individual site productivity, reducing methane emissions from landfills, and extending the storage of carbon in key products, such as corrugated boxes, through longer lifespans, higher recycling rates, and less landfill decomposition could result in significant carbon gains. Our results also highlight the benefits of high site productivity to store more carbon in both in situ and ex situ pools and suggest that shorter rotations could be used to optimize carbon storage on sites when productivity is high. [ABSTRACT FROM AUTHOR]

A rich fish assemblage that once thrived in the bays of western Lake Erie, and Ohio's glacial pothole lakes, wetlands, and clear prairie streams has changed over the past century. Three species have been extirpated from many of their historic localities, with surviving members reduced to relict populations. Recognizing that conservation efforts for these sensitive species rely on accurate occurrence records, we present results from 2011-2012 surveys of Ohio's glacial lakes and associated habitats for 2 native members of this fish assemblage, Etheostoma exile (Iowa Darter) and Erimyzon sucetta (Lake Chubsucker). We found previously undocumented populations of Lake Chubsuckers in 4 glacial lakes and a previously undocumented population of Iowa Darters; however, comparing our results to surveys completed in the 1980s indicates that both species have been extirpated from many localities. A variety of factors including intensive agricultural practices, urban development, and exotic species are likely the cause of their decline. [ABSTRACT FROM AUTHOR]

Climate change, growing populations, and increasing wealth are increasing demand for food, energy, and water. Additionally, water stress is expected to increase in the future in areas with high rates of seasonality of precipitation, due to increased variability in precipitation. One approach to limiting the impact of climate change on food system productions is through the intensive and extensive expansion of irrigated agriculture. This study develops a hydro-economic model to assess future agriculture production possibilities and the role of irrigation water in the Pacific Slope region of Guatemala, one of the most productive agricultural regions in the country. A range of future scenarios are presented to account for uncertainty around irrigation infrastructure expansion, future crop prices, incentives for production of biomass for bioenergy, and water availability and irrigation demand due to climate change. We find that current surface water irrigation infrastructure increases agricultural output by value in the region by about 5.3% compared to a fully rainfed system. Additionally, we show that with expanded irrigation infrastructure, agricultural output could increase by between 3.4% and 18.4% relative to current levels under current climate conditions, but the value of agricultural production could increase under climate change with projected output from current and expanded irrigation infrastructure resulting in an increase of 1.2–24.8% relative to current irrigation levels. We also present evidence that the marginal benefit from increased irrigation access to smallholder farmers is nearly equal to that received by large-scale industrial agricultural producers. • We defelop a spatially and temporally explicit hydro-economic model to assess alternative irrigation expansion scenarios. • We find that climate change has the potential to shift the location and timing of benefits received from irrigation. • The marginal benefits from irrigation expansion received by small farms are larger than that received by industrial farms. • Climate change has the potential to change the spatial and temporal distribution of irrigation water availability. [ABSTRACT FROM AUTHOR]

Reversing forest losses through restoration, improvement, and conservation is a critical goal for greenhouse gas mitigation. Here, we examine some ecological, demographic, and economic opportunities and constraints on forest-loss mitigation activities. Reduced deforestation and forest degradation could cut global deforestation rates in half by 2030, preserving 1.5 billion to 3 billion metric tons of carbon dioxide-equivalent (tCO2e) emissions yearly. Our new economic modeling for the United States suggests that greenhouse gas payments of up to $50 per tCO2e could reduce greenhouse gas emissions by more than 700 million tCO2e per year through afforestation, forest management, and bioelectricity generation. However, simulated carbon payments also imply the reduction of agricultural land area in the United States by 10% or more, decreasing agricultural exports and raising commodity food prices, imports, and leakage. Using novel transgenic eucalypts as our example, we predict selective breeding and genetic engineering can improve productivity per area, but maximizing productivity and biomass could make maintaining water supply, biodiversity, and other ecosystem services a challenge in a carbon-constrained world. [ABSTRACT FROM AUTHOR]

The Beijing-Tianjin-Hebei (BTH) mega-large urban agglomeration of China (CMUA) has significantly contributed to Chinese socioeconomic development. However, it faces severe shortages in the supply to meet the increasing demand of water, energy, and food resources (WEF). In order to safeguard the resource security of CMUA-BTH and the synergistic development of cities, and to compensate for the lack of dynamic analysis between urban agglomerations and WEF in previous studies. In this study, a coupled CMUA-WEF simulation model is developed based on the system dynamics approach. The model not only studies the three elements of WEF, supply and demand, but also conducts a comparative analysis of the three regions of BTH, and designs a total of four scenarios based on the possibility of future development, so as to facilitate the depiction of the trend of the WEF supply and demand system under different scenarios, and to provide theoretical basis for the government to formulate effective policy. The results show that: (1) Regarding demand, the aggregate demand for energy, food and water in the BTH will increase by about 3–5 times, 3 times, and 2 times, respectively, from 2000 to 2050, among which the total demand for energy will increase most significantly. In contrast, the variation of local resource supply side is small, which leads to the deterioration of resource security. (2) The risk of water shortage is the greatest in resource security, with less than 30% self-sufficiency in water security in all three regions. (3) Scenario analysis for CMUA-BTH indicates that "choking flow" (S3) yields more pronounced effects compared to "open source" (S2), and therefore adhering to the reduction of food waste, promoting energy-saving technologies, and intensifying water-saving measures can effectively reduce the risk of water shortages in the three regions. Optimal resource security in S4 increases Hebei's water pressure by 1.5%, alleviates Beijing's pressure by 7.3%, and the implementation of the Xiongan New Area and the new energy development policy can help realize the synergistic development of BTH and the inter-regional linkage. [ABSTRACT FROM AUTHOR]

Forest carbon offset project implementation costs, comprised of both production and transaction costs, could present an important barrier to private landowner participation in carbon offset markets. These costs likewise represent a largely undocumented component of forest carbon offset potential. Using a custom spreadsheet model and accounting tool, this study examines the implementation costs of different forest offset project types operating in different forest types under different accounting and sampling methodologies. Sensitivity results are summarized concisely through response surface regression analysis to illustrate the relative effect of project-specific variables on total implementation costs. Results suggest that transaction costs may represent a relatively small percentage of total project implementation costs – generally less than 25% of the total. Results also show that carbon accounting methods, specifically the method used to establish project baseline, may be among the most important factors in driving implementation costs on a per-ton-of-carbon-sequestered basis, dramatically increasing variability in both transaction and production costs. This suggests that accounting could be a large driver in the financial viability of forest offset projects, with transaction costs likely being of largest concern to those projects at the margin. [Copyright &y& Elsevier]

Legacies of ancient riverine systems are often manifest in patterns of genetic diversity within aquatic species. The ancient Teays River, a principal drainage of the eastern United States, engaged in several ephemeral connections with neighboring palaeodrainages prior to and during the Pleistocene, when cyclical glacial advance and retreat reconfigured the region's fluvial systems. This study assayed DNA-sequence diversity at one mitochondrial (mtDNA) and three single-copy nuclear DNA (scnDNA) loci from the Tonguetied Minnow (Exoglossum laurae), a species distributed as four disjunct populations, one each within the Upper Great Miami, Upper Allegheny, Upper Genesee, and New rivers. Mitochondrial DNA variation revealed that the New River harbors the highest diversity (h = 0.73) and that the Tonguetied Minnow is composed of two ancient lineages, a Teays River lineage and a Pittsburgh River lineage. Analyses of the scnDNA loci revealed sharing of alleles among populations of E. laurae and between the Tonguetied Minnow and its only congener, the Cutlip Minnow (E. maxillingua), sampled from the Roanoke and Potomac rivers. The probability of interspecific hybridization in the New and Upper Genesee rivers was estimated as 0.16 and 0.34, respectively, but it is likely that some degree of incomplete lineage sorting contributed to these estimates. Probabilities of interspecific hybridization for Cutlip Minnow were 0.62 and 0.65, for the Roanoke and Potomac rivers, respectively, and might reflect ancient hybridization resulting from stream capture events involving these drainages by the Teays River. Management strategies should focus on maintaining the security of the Pittsburgh River lineage in the Upper Great Miami and Upper Allegheny River drainages. Finally, insights into the Tonguetied Minnow's rather convoluted taxonomic history are few, but genetic variation is inconsistent with subspecies status for Tonguetied Minnow in the Upper Great Miami River drainage. [ABSTRACT FROM AUTHOR]