Biomass For Bioenergy Research Articles

Dedicated biomass crops can enhance biodiversity in the arable landscape.

Suggestions that novel, non‐food, dedicated biomass crops used to produce bioenergy may provide opportunities to diversify and reinstate biodiversity in intensively managed farmland have not yet been fully tested at the landscape scale. Using two of the largest, currently available landscape‐scale biodiversity data sets from arable and biomass bioenergy crops, we take a taxonomic and functional trait approach to quantify and contrast the consequences for biodiversity indicators of adopting dedicated biomass crops on land previously cultivated under annual, rotational arable cropping. The abundance and community compositions of biodiversity indicators in fields of break and cereal crops changed when planted with the dedicated biomass crops, miscanthus and short rotation coppiced (SRC) willow. Weed biomass was consistently greater in the two dedicated biomass crops than in cereals, and invertebrate abundance was similarly consistently higher than in break crops. Using canonical variates analysis, we identified distinct plant and invertebrate taxa and trait‐based communities in miscanthus and SRC willows, whereas break and cereal crops tended to form a single, composite community. Seedbanks were shown to reflect the longer term effects of crop management. Our study suggests that miscanthus and SRC willows, and the management associated with perennial cropping, would support significant amounts of biodiversity when compared with annual arable crops. We recommend the strategic planting of these perennial, dedicated biomass crops in arable farmland to increase landscape heterogeneity and enhance ecosystem function, and simultaneously work towards striking a balance between energy and food security.

Efficient method for rapid multiplication of clean and healthy willow clones via in vitro propagation with broad genotype applicability

Willow is a versatile crop with considerable potential as a source of renewable biomass for bioenergy. Although breeding new varieties takes less time compared with some other tree species, producing new willow varieties is still a slow, labour-intensive process, partly because clonally propagating the results of each cross is a bottleneck early in the breeding scheme. In this paper, we describe a facile, rapid method for the in vitro culture of a wide range of willow genotypes. We have developed a combination of media and methods for efficient tissue-culture propagation to rapidly multiply individual plants and simultaneously produce clean, stock germplasm applicable to a wide range of willow genotypes that can be phytosanitary tested to demonstrate their disease-free status. The micropropagation method described could generate in the order of 5000 viable, transplantable clones from a single plant in just 24 weeks and was used to produce phytosanitary tested breeding material for export to overcome restriction on the international transport of woody cuttings. This method could represent a valuable biotechnology adjunct to willow breeding programmes and could accommodate early selection via molecular or biochemical markers.

Cellulosic ethanol production: Landscape scale net carbon strongly affected by forest decision making

In producing cellulosic ethanol as a renewable biofuel from forest biomass, a tradeoff exists between the displacement of fossil fuel carbon (C) emissions by biofuels and the high rates of C storage in aggrading forest stands. To assess this tradeoff, the landscape area affected by feedstock harvest must be considered, which depends on numerous factors including forest productivity, the amount of forest in a fragmented landscape, and the willingness of forest landowners to sell timber as a bioenergy feedstock. We studied landscape scale net C balance by combining these considerations in a new, basic simulation model, CEBRAM, and applying it to a hypothetical landscape of short-rotation aspen forests in northern Michigan, USA. The model was parameterized for forest species, growth and ecosystem C storage, as well as landscape spatial patterns of forest cover in this region. To understand and parameterize forest owner decision making we surveyed 505 nonindustrial private forest (NIPF) owners in Michigan. Survey results indicated that 47% of these NIPF owners would willingly harvest forest biomass for bioenergy. Model results showed that at this rate the net C balance was 0.024 kg/m2 for a cellulosic ethanol system without considering land use over a 40 year time horizon. When C storage in aggrading, nonparticipating NIPF land was included, net C balance was 1.09 kg/m2 over 40 years. In this region, greater overall C gains can be realized through aspen forest aggradation than through the displacement of gasoline by cellulosic ethanol produced from forest biomass.

The climate effect of increased forest bioenergy use in Sweden: evaluation at different spatial and temporal scales

Bioenergy from boreal forests managed for productive purposes (e.g., pulp, timber) is commonly held to offer attractive options for climate change mitigation. However, this view has been challenged in recent years. Carbon balances, cumulative radiative forcing, and average global temperature change have been calculated for a variety of bioenergy management regimes in Swedish forests, and the results support the view that an increased use of forest biomass for energy in Sweden can contribute to climate change mitigation, although methodological (e.g., spatial scales) and parameter value choices influence the results significantly. We show that the climate effect of forest‐based bioenergy depends on the forest ecosystems and management, including biomass extraction for bioenergy and other products, and how this management changes in response to anticipated market demands; and on the energy system effects, which determine the fossil carbon displacement and other greenhouse gas (GHG) mitigation effects of using forest biomass for bioenergy and other purposes. The public and private sectors are advised to consider information from comprehensive analyses that provide insights about energy and forest systems in the context of evolving forest product markets, alternative policy options, and energy technology pathways in their decision‐making processes. WIREs Energy Environ 2016, 5:351–369. doi: 10.1002/wene.178This article is categorized under: Bioenergy > Climate and Environment

Assessing Sustainable Bioenergy Feedstock Production Potential by Integrated Geospatial Analysis of Land Use and Land Quality

Development of viable bioenergy economies will require large increases in biomass feedstock production. Improved methods are needed to quantify production potential based on land availability, land suitability, biomass yield, and cost. We developed such a method and applied it throughout New York State. While maintaining existing forest and agricultural production, we quantified additional sustainable biomass production potential using geospatial and yield modeling that integrates remotely sensed and survey data for land cover, soil type, climate patterns, and crop yields and then applied multiple sustainability constraints. Nearly 680,000 ha with varying quality was found to be available and suitable for new biomass production. Predicted yields ranged from 7.8 to 18.3 Mg/ha for short-rotation willow and 6.9–16.3 Mg/ha for perennial grasses for a total production potential of 8.2 Tg/year. Increased forest harvest could produce an additional 4.3 Tg/year of hardwood and 1.6 Tg/year of softwood. In total, an additional 14.2 Tg/year of biomass for bioenergy could be produced while maintaining existing agricultural and forest production. This new biomass, before processing, would contain energy equivalent to 7.4 % of 2012 New York energy use (3.4 % if converted to ethanol).

Comparing bioenergy production sites in the Southeastern US regarding ecosystem service supply and demand.

Biomass for bioenergy is debated for its potential synergies or tradeoffs with other provisioning and regulating ecosystem services (ESS). This biomass may originate from different production systems and may be purposefully grown or obtained from residues. Increased concerns globally about the sustainable production of biomass for bioenergy has resulted in numerous certification schemes focusing on best management practices, mostly operating at the plot/field scale. In this study, we compare the ESS of two watersheds in the southeastern US. We show the ESS tradeoffs and synergies of plantation forestry, i.e., pine poles, and agricultural production, i.e., wheat straw and corn stover, with the counterfactual natural or semi-natural forest in both watersheds. The plantation forestry showed less distinct tradeoffs than did corn and wheat production, i.e., for carbon storage, P and sediment retention, groundwater recharge, and biodiversity. Using indicators of landscape composition and configuration, we showed that landscape planning can affect the overall ESS supply and can partly determine if locally set environmental thresholds are being met. Indicators on landscape composition, configuration and naturalness explained more than 30% of the variation in ESS supply. Landscape elements such as largely connected forest patches or more complex agricultural patches, e.g., mosaics with shrub and grassland patches, may enhance ESS supply in both of the bioenergy production systems. If tradeoffs between biomass production and other ESS are not addressed by landscape planning, it may be reasonable to include rules in certification schemes that require, e.g., the connectivity of natural or semi-natural forest patches in plantation forestry or semi-natural landscape elements in agricultural production systems. Integrating indicators on landscape configuration and composition into certification schemes is particularly relevant considering that certification schemes are governance tools used to ensure comparable sustainability standards for biomass produced in countries with variable or absent legal frameworks for landscape planning.

The Burning Question: Does Forest Bioenergy Reduce Carbon Emissions? A Review of Common Misconceptions about Forest Carbon Accounting

Critical errors exist in some methodologies applied to evaluate the effects of using forest biomass for bioenergy on atmospheric greenhouse gas emissions. The most common error is failing to consider the fate of forest carbon stocks in the absence of demand for bioenergy. Without this demand, forests will either continue to grow or will be harvested for other wood products. Our goal is to illustrate why correct accounting requires that the difference in stored forest carbon between harvest and no-harvest scenarios be accounted for when forest biomass is used for bioenergy. Among the flawed methodologies evaluated in this review, we address the rationale for accounting for the fate of forest carbon in the absence of demand for bioenergy for forests harvested on a sustained yield basis. We also discuss why the same accounting principles apply to individual stands and forest landscapes.

Economic and Life-Cycle Analysis of Forest Carbon Sequestration and Wood-Based Bioenergy Offsets in the Central Hardwood Forest Region of United States

This study investigates the combined impact of carbon and bioenergy markets on upland oak dominated mixed hardwood forests in the Central Hardwood Forest Region (CHFR) of the United States. A modification of the Hartman model was used for the economic analysis of carbon sequestration and using wood-based biomass for bioenergy. A life-cycle assessment was used to determine the amount of carbon sequestered due to stand growth and emitted during harvesting and decay of wood products. Two scenarios were taken, one where additionality of carbon is considered and the other where it is not. Sensitivity analysis was done with the range of carbon and bioenergy prices. The results show that net carbon payments have more impact on land expectation value (LEV) when additionality is not considered; in contrast, bioenergy payments have more impact on LEV when additionality is considered. Carbon and bioenergy prices also influenced the amount of stand level supply of forest products and carbon in both scenarios. In general, sawtimber, wood bioenergy, and carbon supply increased with an increase in carbon prices, whereas, pulpwood supply decreased. With few exceptions at higher carbon prices, bioenergy supply decreased with the increase in wood bioenergy prices, showing a backward bending supply curve in both scenarios.

Biomass harvest of invasive Typha promotes plant diversity in a Great Lakes coastal wetland

Ecological and financial constraints limit restoration efforts, preventing the achievement of desired ecological outcomes. Harvesting invasive plant biomass for bioenergy has the potential to reduce feedback mechanisms that sustain invasion, while alleviating financial limitations. Typha × glauca is a highly productive invasive wetland plant that reduces plant diversity, alters ecological functioning, its impacts increase with time, and is a suitable feedstock for bioenergy. We sought to determine ecological effects of Typha utilization for bioenergy in a Great Lakes coastal wetland by testing plant community responses to harvest‐restoration treatments in stands of 2 age classes and assessing community resilience through a seed bank study. Belowground harvesting increased light penetration, diversity, and richness and decreased Typha dominance and biomass in both years post‐treatment. Aboveground harvesting increased light and reduced Typha biomass in post‐year 1 and in post‐year 2, increased diversity and richness and decreased Typha dominance. Seed bank analysis revealed that young stands (<20 years) had greater diversity, richness, seedling density, and floristic quality than old stands (>30 years). In the field, stand‐age did not affect diversity or Typha dominance, but old stands had greater Typha biomass and slightly higher richness following harvest. Harvesting Typha achieved at least 2 desirable ecological outcomes: reducing Typha dominance and increasing native plant diversity. Younger stands had greater potential for native recovery, indicated by more diverse seed banks. In similar degraded wetlands, a single harvest of Typha biomass would likely result in significant biodiversity and habitat improvements, with the potential to double plant species richness.

Linking state-and-transition simulation and timber supply models for forest biomass production scenarios

We linked state-and-transition simulation models (STSMs) with an economics-based timber supply model to examine landscape dynamics in North Carolina through 2050 for three scenarios of forest biomass production. Forest biomass could be an important source of renewable energy in the future, but there is currently much uncertainty about how biomass production would impact landscapes. In the southeastern US, if forests become important sources of biomass for bioenergy, we expect increased land-use change and forest management. STSMs are ideal for simulating these landscape changes, but the amounts of change will depend on drivers such as timber prices and demand for forest land, which are best captured with forest economic models. We first developed state-and-transition model pathways in the ST-Sim software platform for 49 vegetation and land-use types that incorporated each expected type of landscape change. Next, for the three biomass production scenarios, the SubRegional Timber Supply Model (SRTS) was used to determine the annual areas of thinning and harvest in five broad forest types, as well as annual areas converted among those forest types, agricultural, and urban lands. The SRTS output was used to define area targets for STSMs in ST-Sim under two scenarios of biomass production and one baseline, business-as-usual scenario. We show that ST-Sim output matched SRTS targets in most cases. Landscape dynamics results indicate that, compared with the baseline scenario, forest biomass production leads to more forest and, specifically, more intensively managed forest on the landscape by 2050. Thus, the STSMs, informed by forest economics models, provide important information about potential landscape effects of bioenergy production.

Evaluation of damage caused by Ectinogonia buquetti (Coleoptera: Buprestidae) in dendroenergetic plantations of Eucalyptus camaldulensis

In a trial established to produce biomass for bioenergy from Eucalyptus camaldulensis Dehnh, ring-debarking in branches and stems caused by Ectinogoniabuquet...

Effects of Grassland Biomass Harvest on Nesting Pheasants and Ducks

Grasslands enrolled in conservation programs provide important habitat for nesting game birds and waterfowl, but conservation grasslands have been targeted as a source of biomass for bioenergy and this could impact nesting birds. We studied the effects of biomass harvest on nest success and density using 109 blue-winged teal (Anas discors), mallard (Anas platyrhynchos), and ring-necked pheasant (Phasianus colchicus) nests found in southwestern Minnesota during 2009 (pretreatment) and 2010 (posttreatment). Grassland biomass was harvested in late autumn of 2009 with production-scale machinery. Harvest treatments included controls (0% biomass removal), partial harvest (50 or 75% biomass removal), and full harvest (100% biomass removal) from 8 ha plots. Nest success averaged 31% and was not influenced by biomass harvest. Daily survival rates were greater for nests located closer to wetlands. Estimated total nest density (0.42 nests ha−1; corrected for survivorship) was similar across harvest treatments, but within-plot analysis revealed nest density was greater in unharvested refuge regions. Estimated nest density was positively correlated with vegetation height and the spatial extent of wetlands surrounding each plot. Harvesting relatively small-scale patches of conservation grasslands in late autumn does not appear to be detrimental to nesting ducks and pheasants the following spring, but managers should consider leaving unharvested refuges near wetlands when harvesting large continuous tracts.

The use of an acetoacetyl-CoA synthase in place of a β-ketothiolase enhances poly-3-hydroxybutyrate production in sugarcane mesophyll cells.

Engineering the production of polyhydroxyalkanoates (PHAs) into high biomass bioenergy crops has the potential to provide a sustainable supply of bioplastics and energy from a single plant feedstock. One of the major challenges in engineering C4 plants for the production of poly[(R)-3-hydroxybutyrate] (PHB) is the significantly lower level of polymer produced in the chloroplasts of mesophyll (M) cells compared to bundle sheath (BS) cells, thereby limiting the full PHB yield-potential of the plant. In this study, we provide evidence that the access to substrate for PHB synthesis may limit polymer production in M chloroplasts. Production of PHB in M cells of sugarcane is significantly increased by replacing β-ketothiolase, the first enzyme in the bacterial PHA pathway, with acetoacetyl-CoA synthase. This novel pathway enabled the production of PHB reaching an average of 6.3% of the dry weight of total leaf biomass, with levels ranging from 3.6 to 11.8% of the dry weight (DW) of individual leaves. These yields are more than twice the level reported in PHB-producing sugarcane containing the β-ketothiolase and illustrate the importance of producing polymer in mesophyll plastids to maximize yield. The molecular weight of the polymer produced was greater than 2×10(6) Da. These results are a major step forward in engineering a high biomass C4 grass for the commercial production of PHB.

Characterization of novel Sorghum brown midrib mutants from an EMS-mutagenized population.

Reducing lignin concentration in lignocellulosic biomass can increase forage digestibility for ruminant livestock and saccharification yields of biomass for bioenergy. In sorghum (Sorghum bicolor (L.) Moench) and several other C4 grasses, brown midrib (bmr) mutants have been shown to reduce lignin concentration. Putative bmr mutants isolated from an EMS-mutagenized population were characterized and classified based on their leaf midrib phenotype and allelism tests with the previously described sorghum bmr mutants bmr2, bmr6, and bmr12. These tests resulted in the identification of additional alleles of bmr2, bmr6, and bmr12, and, in addition, six bmr mutants were identified that were not allelic to these previously described loci. Further allelism testing among these six bmr mutants showed that they represented four novel bmr loci. Based on this study, the number of bmr loci uncovered in sorghum has doubled. The impact of these lines on agronomic traits and lignocellulosic composition was assessed in a 2-yr field study. Overall, most of the identified bmr lines showed reduced lignin concentration of their biomass relative to wild-type (WT). Effects of the six new bmr mutants on enzymatic saccharification of lignocellulosic materials were determined, but the amount of glucose released from the stover was similar to WT in all cases. Like bmr2, bmr6, and bmr12, these mutants may affect monolignol biosynthesis and may be useful for bioenergy and forage improvement when stacked together or in combination with the three previously described bmr alleles.

Sustainability Criteria and Indicators for the Bio-Based Economy in Europe: State of Discussion and Way Forward

There is a strong interest in the EU to promote the bioeconomy sector within the EU 2020 strategy. It is thus necessary to assure a sound sustainability framework. This paper reviews international and European sustainability initiatives mainly for biomass for bioenergy. The basic and advanced sustainability indicators are identified and described with particular attention to those points without agreement between stakeholders. Based on the state of the discussion, some suggestions to enhance the sustainable development of the bioeconomy sector are proposed.

Soil and crop management and biomass removal effects on soil organic matter content in Hungary

Greater use of biomass for bioenergy has increased the need to evaluate above ground biomass removal (BR) effects on soil quality components, especially soil organic matter (SOM). A multifactor, 40 year fi eld experiment was conducted in Kompolt, Hungary on a carbonate-free, slightly acidic chernozem brown forest soil (USDA: Ustolls) with the objective of determining the effect of different management systems with concurrent removal of the above ground biomass on the SOM content of the 0-320 mm layer. A multifactor experiment composed of treatments involving different crop rotation (CR), beef manure application, mineral fertiliser application, above ground BR (vs. biomass incorporation, BI) and lucerne management options for different rotations are the basis of this study. CR had no signifi cant effect on SOM content. Management options that included a four year lucerne stand produced signifi cantly higher SOM content in fi ve out of six fertiliser and biomass management combinations. Continuous manure applications and manure + NPK fertiliser resulted in a signifi cantly greater SOM content than management options that minimised or eliminated fertiliser or manure additions. SOM content for different soil amendments and biomass treatments ranked: BR < NPK + BR < BI < manure + BR = NPK + manure + BR with SOM contents of 2.75 < 2.82 < 2.87 < 2.92 per cent (w/w) respectively. Manure had the most profound effect because its signifi cance was most consistent across a range of management combinations and years. The results suggest that agricultural management systems that include lucerne and manure application have the potential to sustain SOM content with concurrent above ground BR in continental climates on Ustolls with near level topography.

Soil and crop management and biomass removal effects on soil organic matter content in Hungary

Greater use of biomass for bioenergy has increased the need to evaluate above ground biomass removal (BR) effects on soil quality components, especially soil organic matter (SOM). A multifactor, 40 year fi eld experiment was conducted in Kompolt, Hungary on a carbonate-free, slightly acidic chernozem brown forest soil (USDA: Ustolls) with the objective of determining the effect of different management systems with concurrent removal of the above ground biomass on the SOM content of the 0-320 mm layer. A multifactor experiment composed of treatments involving different crop rotation (CR), beef manure application, mineral fertiliser application, above ground BR (vs. biomass incorporation, BI) and lucerne management options for different rotations are the basis of this study. CR had no signifi cant effect on SOM content. Management options that included a four year lucerne stand produced signifi cantly higher SOM content in fi ve out of six fertiliser and biomass management combinations. Continuous manure applications and manure + NPK fertiliser resulted in a signifi cantly greater SOM content than management options that minimised or eliminated fertiliser or manure additions. SOM content for different soil amendments and biomass treatments ranked: BR < NPK + BR < BI < manure + BR = NPK + manure + BR with SOM contents of 2.75 < 2.82 < 2.87 < 2.92 per cent (w/w) respectively. Manure had the most profound effect because its signifi cance was most consistent across a range of management combinations and years. The results suggest that agricultural management systems that include lucerne and manure application have the potential to sustain SOM content with concurrent above ground BR in continental climates on Ustolls with near level topography.

Tree mineral nutrition is deteriorating in Europe.

The response of forest ecosystems to increased atmospheric CO2 is constrained by nutrient availability. It is thus crucial to account for nutrient limitation when studying the forest response to climate change. The objectives of this study were to describe the nutritional status of the main European tree species, to identify growth-limiting nutrients and to assess changes in tree nutrition during the past two decades. We analysed the foliar nutrition data collected during 1992-2009 on the intensive forest monitoring plots of the ICP Forests programme. Of the 22 significant temporal trends that were observed in foliar nutrient concentrations, 20 were decreasing and two were increasing. Some of these trends were alarming, among which the foliar P concentration in F. sylvatica, Q. Petraea and P. sylvestris that significantly deteriorated during 1992-2009. In Q. Petraea and P. sylvestris, the decrease in foliar P concentration was more pronounced on plots with low foliar P status, meaning that trees with latent P deficiency could become deficient in the near future. Increased tree productivity, possibly resulting from high N deposition and from the global increase in atmospheric CO2, has led to higher nutrient demand by trees. As the soil nutrient supply was not always sufficient to meet the demands of faster growing trees, this could partly explain the deterioration of tree mineral nutrition. The results suggest that when evaluating forest carbon storage capacity and when planning to reduce CO2 emissions by increasing use of wood biomass for bioenergy, it is crucial that nutrient limitations for forest growth are considered.

Forest biomass for bioenergy: opportunities and constraints for a good governance. A case study from Italy

Interest in the use of biomass for energy has increased significantly in the last few years. The latest report by the Intergovernmental Panel on Climate Change highlights the influence mankind has had on the climate: an unprecedented increase in GHG levels in the last 800,000 years and a rise of 40% in CO 2 concentrations since pre-industrial times. The challenge now is to find energy alternatives, and in this context, one important option is bioenergy, one of the most important energy sources of the future. In light of this, the goal of this paper was to assess the sustainable potential of woodfuel resources in Italy using WISDOM methodology. WISDOM, developed by the FAO, has been applied in many countries around the world. From this study, at national level, household consumption was at 19.3 Mt in 2003 (average value), while the potential supply of woody biomass (productivity) was 24.9 Mt (average value), with a surplus of almost 6 million tons between household consumption and productivity. This study represents an advance in knowledge of the biomass potential for energy use in Italy, and, as such, is subject to possible future improvement. Forest bioenergy development creates good opportunities to mobilize the production potential of European forests, and to contribute to a more climate-friendly, bio-based economy.

Modeling Population Dynamics and Woody Biomass in Alaska Coastal Forest

Alaska coastal forest, 6.2 million ha in size, has been managed in the past mainly through clearcutting. Declining harvest and dwindling commercial forest resources over the past 2 decades have led to increased interest in management of young-growth stands and utilization of woody biomass for bioenergy. However, existing models to support these new management systems are very limited in number and value. This study presents a density-dependent, size-specific, and species-specific matrix growth model for forest in coastal Alaska. This model enables short- and long-term predictions of stand basal area, volume, and biomass in a simple and accurate way and facilitates understanding of the ecological and economic effects of forest management alternatives. Components of forest growth were estimated from tree- and stand-level attributes from repeated measurements of 544 Forest Inventory and Analysis permanent sample plots located throughout coastal Alaska with a wide range of stand conditions. The model was tested on 293 postsample validation plots and found to have significantly higher accuracy than the Forest Vegetation Simulator, the only growth model available for the region. Analysis of residuals revealed no spatial autocorrelation, which indicates that this model is able to adequately account for the effects of physiographic factors and other differences between southeast and southcentral Alaska.