Biomass For Bioenergy Production Research Articles

New Eco-Cements Made with Marabou Weed Biomass Ash

Biomass ash is currently attracting the attention of science and industry as an inexhaustible eco-friendly alternative to pozzolans traditionally used in commercial cement manufacture (fly ash, silica fume, natural/calcined pozzolan). This paper explores a new line of research into Marabou weed ash (MA), an alternative to better-known conventional agro-industry waste materials (rice husk, bagasse cane, bamboo, forest waste, etc.) produced in Cuba from an invasive plant harvested as biomass for bioenergy production. The study entailed full characterization of MA using a variety of instrumental techniques, analysis of pozzolanic reactivity in the pozzolan/lime system, and, finally its influence on the physical and mechanical properties of binary pastes and mortars containing 10% and 20% MA replacement content. The results indicate that MA has a very low acid oxide content and a high loss on ignition (30%) and K2O content (6.9%), which produces medium–low pozzolanic activity. Despite an observed increase in the blended mortars’ total and capillary water absorption capacity and electrical resistivity and a loss in mechanical strength approximately equivalent to the replacement percentage, the 10% and 20% MA blended cements meet the regulatory chemical, physical, and mechanical requirements specified. Marabou weed ash is therefore a viable future supplementary cementitious material.

Roadside vegetated filter strips to simultaneously lower stormwater pollution loadings and improve economics of biorefinery feedstocks

Roadside vegetated filters strips (VFSs) reduce roadway runoff pollution by intercepting stormwater and reducing pollutant loads. VFS maintenance and operating costs can be reduced by designing the VFSs to serve as sites for production of marketable biomass. This biomass can provide feedstock for the emerging bioeconomy producing renewable fuels and biobased chemicals and products. Economic evaluation is needed to quantify the benefit of combining VFS with bioenergy biomass production. This evaluation requires a place-based approach to quantify availability of land, transportation costs, and benefits to sensitive habitats. We evaluated roadside land, within the state right-of-way, in Western Washington, to determine the total area available for implementing VFSs. These data were then used to estimate the volume and cost, of biomass produced on the filter strips, and the resultant reduction in pollutants emitted through highway runoff. The analysis showed that up to 5600 ha were available for roadside VFSs that would be within transportation distance of the theoretical biorefinery location. This space could produce up to 97 dry Gg per year of poplar biomass. The resulting reduction in biorefinery feedstock cost was up to $24 per dry Mg compared to biomass from dedicated tree farms. The results showed that combining roadside poplar with traditional dedicated poplar feedstocks can reduce the feedstock cost of the biorefinery from $76 to $67 per Mg for a biorefinery processing 150 Gg biomass per year. Environmental impact analysis showed that within the study area half of urban roadways and one-third of rural roadways in highly sensitive aquatic areas were amenable to VFS. Construction of VFS in these amenable areas would reduce total loadings to sensitive aquatic areas in urban areas by 26% for TSS, copper, and zinc, and by 10% for phosphorus, and nitrogen and by 21% for lead. The impact for rural sensitive areas was even greater where the VFS had potential to reduce total loadings to sensitive aquatic areas by 38% for TSS, copper, and zinc, by 15% for phosphorus and nitrogen, and by 31% for lead. This research showed an approach combining geographic information system (GIS) mapping and economic analysis to document simultaneous evaluation of cost and environmental benefits when considering use of non-traditional land for bioenergy crop production.

Heterogeneous Catalysis for Sustainable Energy

AbstractThe dominance of fossil fuels in the energy sector is associated with greenhouse-gas emission and release of atmospheric pollutants. Biomass-based energy generation is considered a potential alternative for replacement of fossil fuels, and it has been used as a sustainable source of heat and power for a long time. Biomass as a feedstock can be used for the synthesis of different energy products. Catalysts play a significant role in various conversion routes and affect the yield of major products. Researchers have mainly focused on starchy feedstock, lignocellulosic biomass, and triglyceride containing biomass for bioenergy production. Catalytic reactions for biomass feedstock mainly involve deoxygenation, hydrolysis, hydrogenation, dehydrogenation, and oxidation etc. This review provides an overview of catalytic reactions for the conversion of different classes of biomass feedstock for biofuel production. The primary aim of this review is to summarize catalytic strategies for conversion of lignocellulosic biomass into value-added products.

Opportunities and spatial hotspots for irrigation expansion in Guatemala to support development goals in the food-energy-water nexus

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.

Species composition of semi‐natural mesic grasslands as a factor influencing the methane yield of plant biomass (Central Europe)

AbstractSemi‐natural lowland and mountain mesic meadows are grasslands rich in species, and their conservation status depends on treatments such as mowing or grazing livestock. In many countries, the condition of grasslands is deteriorating because of their inappropriate use or abandonment. This study aimed to determine the effects of the species composition of plant communities and functional plant groups on the methane yield from biomass harvested from mesic grasslands in the Sudetes Mountains. Biogas potential analysis was performed based on biomass samples collected from Poland and the Czech Republic. The biogas potential was determined in 40 day‐long batch anaerobic digestion tests. The average methane yield obtained from the biomass was 246 ± 16 NL CH4 kg−1 VS, whereas the methane yield per hectare was 870 ± 203 m3 CH4 ha−1. Plant communities comprising different dominant species had no effect on the methane yield but affected the methane yield per hectare. Additionally, the species composition of grasslands with a higher percentage of forbs had lower biomass yield, resulting in lower methane yields per hectare. The continuity of the low‐intensity management of mountain grassland, which can be provided by the utilization of their biomass for bioenergy production, sustains high biodiversity and ensures appropriate meadow conservation.

Bioenergy Crops for Low Warming Targets Require Half of the Present Agricultural Fertilizer Use.

Bioenergy with carbon capture and storage (BECCS) is a key option for removing CO2 from the atmosphere over time to achieve climate mitigation. However, an overlooked impact of BECCS is the amount of nutrients required to sustain the production. Here, we use an observation-driven approach to estimate the future bioenergy biomass production for land-use scenarios maximizing BECCS and the pertaining nutrient requirements. The projected global biomass production during the 21st century is comparable to the CO2 removal target for 2 °C warming scenarios. However, 9-19% of this future production hinges on agrotechnology improvement, which remains uncertain. Additional nutrients from fertilizers, corresponding to 56.8 ± 6.1% of the present-day agricultural fertilizer, will be needed to replenish the nutrients removed in harvested biomass at the end of the century, resulting in additional costs and greenhouse gas emissions. Our study reveals the nutrient challenges associated with BECCS and calls for additional management efforts to grow bioenergy crops in a sustainable way.

Continued obstacles to wood‐based biomass production in the southeastern United States

AbstractInternational demand for wood‐based biomass for bioenergy production is growing, and private forestlands in the southeastern United States have the potential to supply that demand. The southeastern United States (Southeast) is the world's largest exporter of wood pellets for bioenergy, primarily to the United Kingdom (UK) and the European Union (EU). However, wood‐based biomass production accounts for only a small share of total wood removals from private forestlands in the Southeast. There is sufficient wood‐based biomass in the Southeast to support greater production of wood pellets for domestic and international markets without redirecting timber from sawtimber and pulpwood production. In 2018–19, we conducted 39 semi‐structured interviews with private forest landowners, foresters, loggers, and biomass production facility managers in Alabama, Florida, and Georgia to obtain their views on wood‐based biomass production in the Southeast. Although landowners were interested in supplying wood for biomass as a byproduct of timber harvesting, they seldom participated in wood‐based biomass production because of limited and unreliable access to biomass markets. Loggers and production facility managers had not invested in biomass production because they remain skeptical about the financial viability of wood‐based biomass. Continued obstacles to biomass production include: price competition with fossil fuels and conventional wood products; inconsistent domestic government support for biomass production; concerns about meeting the sustainability requirements to export wood‐based biomass to the UK and EU; and the high costs associated with harvesting low‐grade wood for biomass. The barriers to biomass expansion in the southeastern United States remain primarily economic and political rather than biophysical.

Nitrogen Application Modifies the Seed and Oil Yields and Fatty Acid Composition of Nicotiana tabacum

Tobacco is traditionally an industrial crop that is used for manufacturing cigarettes. However, due to health concerns and global tobacco control movements, alternative uses of tobacco are urgently needed to support tobacco farmers and vendors. Tobacco is also an oilseed crop with an oil yield ranging from 30% to 40 of its dry weight. However, there is still no information on the effects of nitrogen application on tobacco seed yield and seed oil production. The objective of this study was to evaluate the effects of N fertilization (90, 120, 150, and 180 kg·ha−1 N) on the seed yield, oil content, fatty acid composition, and seed germination characteristics of tobacco plants at two locations. The results showed that applying increasing amounts of N to tobacco plants significantly increased their total seed yields and oil content. Nitrogen application also modified the fatty acid composition of the seed oil, as more unsaturated fatty acids were produced under the increasing N application rate treatments than under the control. Moreover, increasing the N application rate generally significantly increased the yields of individual fatty acids as well. Nevertheless, the increased seed oil content and altered fatty acid composition did not affect seed germination traits, as the seed germination potential and rate showed no obvious change among treatments or the control. The height and size of the tobacco plants also increased with the increasing N application rate, which would be beneficial for increasing biomass production for bioenergy. This study shows for the first time the feasibility of increasing the seed and oil yields and modifying the fatty acid composition of tobacco plants by increasing N addition.

Determinants of the economic viability of mallee eucalypts as a short rotation coppice crop integrated into farming systems of Western Australia

AbstractMallee eucalypts are being developed as a short rotation coppice crop for integration into agricultural systems in the south‐west of Western Australia. These have potential for biomass production for bioenergy, eucalyptus oil and generating carbon credits and to help control the extensive occurrence of dryland salinity. Some 12,000 ha of mallee planting has been undertaken since 1994, mostly in the form of wide‐spaced, narrow belts within the annual agricultural system. Production and market data were used to estimate levelized costs (LC) of mallee biomass production under different harvest regimes across 11 sites from 2006 to 2012. We found LC ranged from AUD40 to AUD257 fresh Mg−1. LC was most strongly determined by mallee production, followed by the crop/pasture rotation decisions of the landholder. Mallee harvest regime had minor impact on LC. Crop and pasture yield loss due to competition from the mallee belts accounted for 38% of costs, harvesting biomass was 32%, opportunity cost of the land occupied by the mallee belts was 16% while establishment and maintenance costs accounted for 14% of the costs. When income from carbon sequestered in mallee root biomass was included, the LC dropped by an average of 11% at the current Australian price of AUD15 Mg−1 CO2 equivalent (CO2e). The income from carbon sequestered in root biomass alone is unlikely to make mallee agroforestry economically viable. Hence, income from harvested biomass in the form of feedstocks for industry or carbon credits is necessary to make mallee agroforestry commercially attractive. LC for unharvested mallee belts ranged from AUD33 to AUD237 Mg−1. Where above‐ and below‐ground biomass is converted to CO2e at AUD15 Mg−1, the LC drops to AUD11–AUD64, with three of 11 sites likely to be profitable. These three sites were characterized by high biomass production with low agricultural gross margins.

Carbon flow through energycane agroecosystems established post‐intensive agriculture

AbstractAs part of an integrated energy and climate system, biomass production for bioenergy based on the tropical perennial C4 grass energycane can both offset fossil fuels and store soil carbon (C). We measured energycane yields, root biomass, soil C pools, and soil C stocks in a 4 year field trial and modeled C flow from plants to soils in the surface layer of no‐till energycane planted after more than a century of intensive sugarcane agriculture. Aboveground yields ranged from 16.7 to 19.0 Mg C/ha over the 4 year trial. Although total C stocks did not significantly differ in the surface layer (approx. 0–20 cm) during the study, C in free and occluded light fractions decreased, whereas C in the mineral‐rich dense fraction increased over 4 years. Belowground system inputs, estimated from measurements and informed by convergence in the final soil fraction model, were set to 2.5 Mg C ha−1 year−1. With this input value, we estimated that surface soils retained photosynthetically fixed C predominantly within the mineral‐associated organic matter pool for a mean and median transit time of 177 and 110 years, respectively. Although we did not model C flow to deep soil layers (approx. 0–100 cm), observed C accumulation (11.4 Mg C ha−1 year−1) and root growth down to 120 cm suggest that soil processes and resulting C sequestration at the surface are likely to persist deeper into the soil profile. Energycane, as a strong candidate for climate change mitigation and land degradation remediation, showed high biomass yields and allocation of resources to roots, with sequestered soil C expected to persist for over a century.

Bat community response to intensification of biomass production for bioenergy across the southeastern United States.

Human demand for food, fiber, and space is accelerating the rate of change of land cover and land use. Much of the world now consists of a matrix of natural forests, managed forests, agricultural cropland, and urbanized plots. Expansion of domestic energy production efforts in the United States is one driver predicted to influence future land-use and land management practices across large spatial scales. Favorable growing conditions make the southeastern United States an ideal location for producing a large portion of the country's renewable bioenergy. We investigated patterns of bat occurrence in two bioenergy feedstocks commonly grown in this region (corn, Zea mays, and pine, Pinus taeda and P. elliottii). We also evaluated potential impacts of the three major pathways of woody biomass extraction (residue removal following clearcut harvest, short-rotation energy plantations, and mid-rotation forest thinning) to bat occurrence through a priori land-use contrasts. We acoustically sampled bat vocalizations at 84 sites in the Southeastern Plains and Southern Coastal Plains of the southeastern United States across three years. We found that mid-rotation thinning resulted in positive effects on bat occurrence, and potential conversion of unmanaged (reference) forest to managed forest for timber and/or bioenergy harvest resulted in negative effects on bat occurrence when effects were averaged across all species. The effects of short-rotation energy plantations, removal of logging residues from plantation clearcuts, and corn were equivocal for all bat species examined. Our results suggest that accelerated production of biomass for energy production through either corn or intensively managed pine forests is not likely to have an adverse effect on bat communities, so long as existing older unmanaged forests are not converted to managed bioenergy or timber plantations. Beyond bioenergy crop production, mid-rotation thinning of even-aged pine stands intended for timber production, increases to the duration of plantation rotations to promote older forest stands, arranging forest stands and crop fields to maximize edge habitat, and maintaining unmanaged forests could benefit bat communities by augmenting roosting and foraging opportunities.

Insights of Molecular Mechanism of Xylem Development in Five Black Poplar Cultivars.

Black poplar (Populus deltoides, P. nigra, and their hybrids) is the main poplar cultivars in China. It offers interesting options of large-scale biomass production for bioenergy due to its rapid growth and high yield. Poplar wood properties were associated with chemical components and physical structures during wood formation. In this study, five poplar cultivars, P. euramericana ‘Zhonglin46’ (Pe1), P. euramericana ‘Guariento’ (Pe2), P. nigra ‘N179’ (Pn1), P. deltoides ‘Danhong’ (Pd1), and P. deltoides ‘Nanyang’ (Pd2), were used to explore the molecular mechanism of xylem development. We analyzed the structural differences of developing xylem in the five cultivars and profiled the transcriptome-wide gene expression patterns through RNA sequencing. The cross sections of the developing xylem showed that the cell wall thickness of developed fiber in Pd1 was thickest and the number of xylem vessels of Pn1 was the least. A total of 10,331 differentially expressed genes were identified among 10 pairwise comparisons of the five cultivars, most of them were related to programmed cell death and secondary cell wall thickening. K-means cluster analysis and Gene Ontology enrichment analysis showed that the genes highly expressed in Pd1 were related to nucleotide decomposition, metabolic process, transferase, and microtubule cytoskeleton; whereas the genes highly expressed in Pn1 were involved in cell wall macromolecule decomposition and polysaccharide binding processes. Based on a weighted gene co-expression network analysis, a large number of candidate regulators for xylem development were identified. And their potential regulatory roles to cell wall biosynthesis genes were validated by a transient overexpression system. This study provides a set of promising candidate regulators for genetic engineering to improve feedstock and enhance biofuel conversion in the bioenergy crop Populus.

Nutritional value of hybrid Rumex patientia L. x Rumex tianschanicus A.Los (Rumex OK 2) in different periods

Article Details: Received: 2018-07-31 | Accepted: 2018-10-18 | Available online: 2018-10-31 https://doi.org/10.15414/afz.2018.21.04.197-200 The aim of this study was to determine the nutritive value of hybrid Rumex patientia L. x Rumex tianschanicus A.Los (Rumex OK 2). Rumex OK 2 can be considered as a technical or energetic plant for renewable production of biomass or as a feed as source of nutrients for animals. In this study two harvestings were planned, firs cut was realised in June (growth from March to June) and second cut was realised in November (growth from July to November). Samples of Rumex OK 2 plants were collected in the 20 th day of the month in March to June and in September to November. Concentration of nutrients were detected according to Regulation no. 2145/2004-100. Fresh Rumex OK 2 samples from March 7.42%, April 8.71% and September 4.89% had very low concentration of dry matter (DM). On the other hand samples from March, April, September and October had high concentration of crude protein in range from 31.42 to 24.54% of DM. From start of growth in spring to time of firs cut in June increased both concentration of dry matter from 7.42 to 56.62% and concentration of crude fibre from 14.86 to 47.38% of DM. Concentration of fat in Rumex OK 2 is low and similar to that of maize plant or alfalfa, whereas concentration of nitrogen free extract in Rumex OK 2 plant is similar only to alfalfa. Results of this article bring compact view over nutritional characteristic of Rumex OK 2, which can be according to gained results about nutritional value used as a source of nutrients in animal nutrition, or as a source of renewable biomass for bioenergy production. Keywords: Rumex OK 2, months, nutrients, fiber complex References BOCKHOLT, R. and KANNEWURF, B. (2001) Rumex obtusifolius in peatbog at Mecklenburg-Vorpommern (widening, forage quality, ensilability, force out by extensiveness). In 45. Jahrestagung AGF, 23.–25. 8. 2001, Gumpenstein, pp. 49–51. (in German). DERRICK, R.W. et al. (1993) Intake, by sheep, and digestibility of chickweed, dandelion, dock, ribwort and spurrey, compared with perennial ryegrass. The Journal of Agricultural Science, vol. 120, no. 1, pp. 51–61. Doi: https://doi.org/10.1017/S0021859600073585 GALIK, B. et al. (2016) Nutritional characteristics of feeds. Nitra: Slovak University of Agriculture in Nitra (in Slovak). HEJDUK, S. and DOLEŽAL, P. (2004) Nutritive value of broadleaved dock (Rumex obtusifolius L.) and its effect on the quality of grass silages. Czech Journal of Animal Science, vol. 49, no. 4, pp. 144–450. Available from: http://www.agriculturejournals.cz/publicFiles/53197.pdf HRIC, P. et al. (2018) The changes of the assimilation pigments content of turf Festuca spp. leaves after application of different nutrition forms. Acta Fytotechnica et Zootechnica, vol. 21, no. 1, pp. 6–10. Doi: https://doi.org/10.15414/afz.2018.21.01.06-10 JURACEK, M. et al. (2012) Nutritional value and ensilability if maize hybrids. Nitra: Slovak University of Agriculture in Nitra (in Slovak). JURACEK, M. et al. (2011) Laboratory protocols. In GALIK et al. (2011) Biotechnology and animal food quality – Part II. Animal food quality. Nitra: Slovak University of Agriculture in Nitra, pp. 122–133. KOVAR, P. et al. (2017) The influence of various dose of nitrogen on botanical composition of turfs on the basis of drought-tolerant fescues cultivated under conditions without irrigation. In Journal of Central European Agriculture, vol. 18, no. 2, pp. 494–514. Doi: https://doi.org//10.5513/JCEA01/18.2.1922 PETŘIKOVA, V. (2012) Forage plant – Rumex OK 2. [Online]. Retrieved 2018-07-31 from: https://biom.cz/cz/odborneclanky/krmna-plodina-rumex-ok-2 (in Czech). PETRIKOVIC, P. et al. (2000) Nutritional value of feeds. Nitra: VUŽV (in Slovak). RAKHMETOV, D. (2018) Non-traditional plant species for bioenergetics. Nitra: Slovak University of Agriculture in Nitra, 103 p. Doi: https://doi.org/10.15414/2018.fe-9788055218557 (in Russian). REGULATION of the Ministry of Agriculture of the Slovak republic no. 2145/2004-100 about sampling of feeds, laboratory testing and evaluation of feeds. ROLINEC, M. et al. (2018a) Energy content of hybrid Rumex patientia L. × Rumex tianschanicus A.Los. (Rumex OK 2) samples from autumn months. Acta Fytotechnica et Zootechnica, vol. 21, no. 1, pp. 20–23. Doi: https://doi.org/10.15414/afz.2018.21.01.20-23 ROLINEC, M. et al. (2018b) Energy content of hybrid Rumex patientia L. × Rumex tianschanicus A.Los (Rumex OK 2) samples from spring months and June. Acta Fytotechnica et Zootechnica, vol. 21, no. 2, pp. 60–62. Doi: https://doi.org/10.15414/afz.2018.21.02.60-62 SIMKO, M. et al. (2010) Saccharides in ruminants nutrition. Nitra: Slovak University of Agriculture in Nitra (in Slovak) TRINACTÝ, J. (2013) Evaluation of feeds for dairy cows. Pohořelice: AgroDigest (in Czech). USŤAK, S. (2007) Cultivation and use of fodder sorrel in condition of Czech Republic. Prague: Crop Research Institute. Available from: http://www.vurv.cz/files/Publications/ISBN978- 80-87011-26-3.pdf (in Czech).

Efecto de herbicidas pre-emergentes sobre la siembra directa de semillas pregerminadas de Gmelina arborea Roxb. y Gliricidia sepium (Jacq.) Kunth ex Walp. para el establecimiento de plantaciones dendroenergéticas

This study addresses the need to find preemergence herbicides for the direct sowing of seeds of forest species dedicated to the establishment of energy plantations. Twelve different preemergence herbicides were evaluated on the direct sowing of two forest species with great potential for biomass production for bioenergy. One of the limiting aspects of the plantations energy is the high cost of establishment by concept of acquisition of plants, so we looked for the best options for direct sowing of pregerminated seeds of Gmelina arborea (Melina) and Gliricidia sepium (Black Madero), and offer an alternative in lowering costs. The experiment was carried out in a greenhouse (ITCR, Cartago), for 10 weeks, analyzing each species separately. A randomized complete block experimental design was used. The seeds were subjected to the best pre germination treatment and sown in pots, they were immediately atomized by the different pre-emergent herbicides following the protocol described in the methodology. At the end of the experiment it was determined that pre-emergent herbicides with the active ingredient of Linuron and Oxyfluorfen can be used in the direct sowing of Melina, as they did not cause damage to plant yields, in addition to obtaining most of the parameters with statistically superior results. In the case of black Madero the pre-emergent Linuron obtained the best results, concluding that it can be useful for use in direct sowing. The pre-emergent herbicide with the active ingredient of Pendimethalin obtained the lowest yield results in almost all the parameters analyzed; For both species it produced the total death of the weeds before week 7.

Maximizing pollinator diversity in willow biomass plantings: A comparison between willow sexes and among pedigrees

Shrub willow has potential to be a substantial source of renewable biomass for production of bioenergy, biofuels, and bioproducts. At the same time, scientists and land managers are increasingly challenged to achieve multiple ecosystem functions in bioenergy plantings. Due to willow's early-season bloom period, a time when natural forage for bees can be limited, biomass plantings offer a potential benefit of floral resources for pollinators, some of which are known to be experiencing recent declines. To assess which willow cultivars and sex may provide the most benefit to pollinators, we conducted a common-garden experiment (Northeast U.S.) comparing bee (Hymenoptera: Anthophila) visitation among seven pedigrees and both sexes of short rotation coppice willow. We quantified abundance, richness, diversity, evenness, and species composition in plots planted with each pedigree and sex. Over seven sampling dates, we found an abundant and diverse bee assemblage comprised of 4675 individuals representing >56 species, at least 10 of which are rare or in decline in the northeastern United States. Willow sex was an important factor in bee visitation differences, with male willows supporting 39% greater abundance, 20% greater richness, and 9% greater diversity of bee visitors. Greater bee richness and diversity on male willows was due to an abundance-driven accumulation of species, as determined via rarefaction. Ordination analyses indicated composition of bee species assemblages differed among both willow pedigree and sex. Thus, our findings suggest male willow of varying pedigrees may be optimal for strategic plantings intended to meet bioenergy goals while also benefiting pollinators.

Annotated Bibliography of the Global Literature on the Secondary Transportation of Raw and Comminuted Forest Products (2000–2015)

Secondary transportation of raw and comminuted forest products is a major component in forest harvesting operations in terms of economics, public perception, and safety. Consequently, there is a substantial amount of literature on this topic. The existing literature has dealt with many of the technical aspects of transportation with a majority of them focusing on improving supply chain issues; however, there are only few specific to secondary transportation issues in general. This annotated bibliography will help practitioners, researchers, and stakeholders gain a better understanding of the existing literature from 2000 to 2015. To this end, we began by classifying the selected literature into six themes: cost, roads and routes, trucking, efficiency and safety, other modes of transportation, and supply chain and optimization. Woody biomass for bioenergy production was the most researched forest product with respect to transportation. About one-third of the articles were presented in the context of supply chain modeling and optimization. More than half of the studies originated from Europe while the United States had the most publications for any given country. Most articles (16) were published in 2013. Biomass and Bioenergy published the highest number of articles (29) during the timeframe.

Energy analysis of poplar production for bioenergy in Sweden

Poplar (Populus spp.) species are currently not widely grown in Sweden but offer interesting options for future large-scale biomass production for bioenergy. This study assesses the average annual net energy yield and the ratio between the gross energy yield and the total primary energy input for well-managed current commercial poplar production systems in Sweden, with and without fertilization with mineral nitrogen (N). The two systems perform similarly, mainly because the yield response to fertilization is estimated to be small. The average annual net energy yields with and without fertilization are estimated at 190 and 179 GJ ha−1 yr−1, respectively. The corresponding energy ratios are 32 and 34, i.e., the total primary energy inputs correspond to only ca. 3% of the gross energy yield, in both cases. Therefore, improving the net energy yield by increasing the harvest level may be considered the most important objective from an energy performance point of view. To do this, more research is needed in order to develop poplar clones that are better adapted to the Swedish climate and identify in which situations poplar responds well to fertilization. At the same time, by reducing the energy inputs associated with the most fuel-intensive activities (wood-chip transportation, chipping, harvesting, forwarding, and stump lifting), greenhouse gas emissions can be reduced. The results should be interpreted with caution since several parameters, especially the yield response to fertilization and fuel consumption rates, are associated with considerable uncertainties.

Effect of Increasing Salinity on Development of Giant Reed (Arundo donax) from Rhizome and Culms.

Arundo donax (giant reed) has great potential for bioenergy biomass production in constructed wetlands. Large scale use of A. donax in constructed wetlands will require the use of either established plants sourced from nurseries, or the use of cuttings or rhizomes and stems from mother plants derived from nurseries or wild stands. The results of this study suggest that cuttings and rhizomes are not sensitive to salinity up to an EC ~ 4500 µScm- 1. Plants used to establish a constructed wetland should have stems of at least 300mm length, with well established roots. Moreover, culms will emerge from small pieces of stems with viable nodes regardless of salinity, albeit the fresher the water the less likely salinity will subsequently affect the emerging shoot. From a practical perspective, this suggests that wetlands can be planted with giant reed using horizontally laid stems. Unless using plants pre-stressed to a salinity matching that of the wastewater to be treated, giant reed should be established using reasonable quality water (EC < 1000 µS cm- 1) until the plants are of a reasonable size, e.g. > 500mm in height, after which undiluted wastewater can be used.

Yield and Nitrogen Removal of Bioenergy Grasses as Influenced by Nitrogen Rate and Harvest Management in the Coastal Plain Region of North Carolina

The agronomic performances of giant miscanthus (Miscanthus x giganteus) and switchgrass (Panicum virgatum L.) grown as bioenergy grasses are still unclear in North Carolina, due to a relatively short period of introduction. The objectives of the study were to compare the biomass yield and annual N removal of perennial bioenergy grasses and the commonly grown coastal bermudagrass [Cynodon dactylon (L.) Pers.], and to determine the optimum N rates and harvest practices for switchgrass and miscanthus. A 4-year field trial of the grasses under five annual harvest frequencies (May/Oct, June/Oct, July/Oct, Aug/Oct, and October only) and five annual N rates (0, 67,134, 202, and 268 kg N ha−1) was established at a research farm in Eastern North Carolina in 2011. Across harvest treatments and N rates, greatest biomass was achieved in the second growth year for both miscanthus (19.0 Mg ha−1) and switchgrass (15.9 Mg ha−1). Grasses demonstrated no N response until the second or the third year after crop establishment. Miscanthus reached a yield plateau with a N rate of 134 kg ha−1 since achieving plant maturity in 2013, whereas switchgrass demonstrated an increasing fertilizer N response from 134 kg N ha−1 in the third growth year (2014) to 268 kg N ha−1 in the fourth growth year (2015). The two-cut harvest system is not recommended for bioenergy biomass production in this region because it does not improve biomass yield and increased N removal leads to additional costs.

Bioenergy production on marginal land in Canada: Potential, economic feasibility, and greenhouse gas emissions impacts

Growing energy crops such as perennial grasses and trees on marginal land offers the possibility of reducing the competition with food crops for land resources. Identifying the productivity, economic feasibility and greenhouse gas (GHG) emissions impact is the premise of our study on using marginal land for bioenergy production in Canada. The area of marginal land available was identified by intersecting national maps of land suitability and land cover. The costs and potential returns of growing energy crops on marginal land were then analyzed, and the GHG emissions were evaluated using a GHG emissions model. The results indicated that approximately 9.48 million ha of potentially useable marginal land was available in Canada. The land cover of the available marginal land consists of grassland (68.2%) and shrubland (31.8%). If the available marginal land was completely utilized, the biomass production would be 23.7 million tonnes of switchgrass or 51.2 million tonnes of hybrid poplar. The production of biofuel from these biomass sources would be 5.69 and 11.26 billion L, equivalent to 14.0% and 27.7% of the total transportation gasoline consumption in Canada in 2014, for switchgrass and poplar, respectively. On the marginal land, the average production cost was estimated to be approximately 68.2 CAD $/t (173.8 CAD $/ha) for switchgrass, and 26.2 CAD $/t (140.2 CAD $/ha) for coppiced hybrid poplar. The production of biomass showed a positive net return on marginal land in Ontario (eastern Canada), with a biomass price of 99 CAD $/t and 35 CAD $/t for switchgrass and coppiced hybrid poplar, respectively. When the biomass price is less than 101 CAD $/t, growing switchgrass in the provinces of Alberta and Saskatchewan, where 69% of Canada’s marginal land is located, was not considered economically attractive. By replacing fossil fuel, the maximum potential switchgrass production on marginal land would reduce GHG emissions by 29.49 million t CO2-eq/yr. However, when considering the economic aspect of production, the potential reduction of 6.1 million tonnes CO2/yr from planting poplar is more viable. Further analysis of the broader economic value of the current use of marginal land (primarily livestock grazing) and the impacts on biodiversity, soil quality, and water resources is needed to completely assess the practicality of a widespread increase in biomass production for bioenergy on Canada’s marginal land.