Energy dynamics and bioenergy production of Populus deltoides G-3 Marsh plantation in eastern India

The energy content of stems, branches, roots and litter was determined using an oxygen bomb calorimeter, and these data were used to estimate energy storage, net energy fixation and energy transfer within poplar (Populus deltoides G-3 Marsh) plantations of two ages at the Research Farm of Rajendra Agricultural University, Pusa, Bihar, India. Energy fixation, storage and energy released and exit from the 7-year-old plantation were 1.69, 2.11 and 1.53 times that of the 5-year-old plantation. The net energy fixation was 243.08 GJ ha^?1 year^?1 in 5-year-old and 410.57 GJ ha^?1 year^?1 in 7-year-old plantation. The energy conservation efficiency in the 7-year-old plantation was higher (1.51%) than that of the 5-year-old plantation (0.89%). The 5-year-old plantation showed lower energy accumulation ratio (2.02) resulting from less energy accumulation in components of poplar tree and greater annual turnover in terms of litter fall. The energy stored in the above-ground tree components from 2131.87 ha (5-year old) and 1002.88 ha (7-year old) or in the above-ground net annual production from 3924.15 ha (5-year old) and 2386.37 ha (7-year old) of poplar plantations is sufficient to operate a 5 MW generating station for 1 year. Above-ground biomass and net production from 1 ha of 5-year-old and 7-year-old poplar plantations is sufficient to meet the energy need of an average household in eastern India for 8.5 and 18.0 years and 4.6 and 7.6 years, respectively.     

Poplar plantations for paper and energy in the south of Sweden

Once again Swedish forest industries are supposed to face a new threatening shortage of wood. Therefore, demonstration of new ideas of producing wood for pulp and fuels (heat, ethanol, hydrogen gas, dimethylether, electricity) in the most southern part of Sweden was very welcome. One example of new ideas is that some farmers planted hybrid poplars on abandoned farming land at Sångletorp (33 ha), Johannesholm (15 ha), Kadesjö (11 ha) and Näsbyholm (2 ha) in the southernmost part of Sweden in 1991. Some of these plantations were harvested in 2004, but some are still growing. The harvested wood had been used for pulp and fuel. The results of the harvest and of the plantations that are still growing are analysed here from an economic, ecologic and energy point of view.     

The role of marginal agricultural land-based mulberry planting in biomass energy production

Biomass energy is the main energy source in rural China. The low per capita cropland in China makes it impractical to convert cropland to energy crop cultivation as in other countries; development of energy crops must not compete with food and other cash crops for prime cropland. Mulberry planted on marginal lands like land risers, land boundaries and waste slopelands in Ningnan County of China's southwestern Sichuan Province not only yielded enough leaf biomass to support a production of over 6000 t of cocoons in 2005, but also produced large amounts of woody biomass through annual pruning. Mulberry planted on marginal lands would not be replaced by food or other cash crops if cocoon prices drop. The average annual dry matter biomass of pruned mulberry branches is 1.7 kg/plant, or approximately 17.0–22.5 t/ha, which is high compared to the annual biomass growth of many fast growing trees and perennial herbaceous energy crops. Mulberry prunings exceed household needs for fuelwood because household energy requirements are met with multiple sources. Income from cocoons is the major driving force for the expansion of mulberry planting on marginal land, as lack of incentives has accounted for slow development of firewood in China. Large scale development of marginal land-based planting of mulberry can also help reduce greenhouse gas emissions to the atmosphere, conserve forests and promote biodiversity.     

Estimates of technically available woody biomass feedstock from natural forests and willow biomass crops for two locations in New York State

A Geographic Information System (GIS) was used to estimate the technically available woody biomass from forests and willow biomass crops within a 40 km radius of Syracuse and Tupper Lake, NY. Land cover and land use data were used to identify the available land base and restrictions were applied for slope, parcel size and designated wetlands. Approximately 222,984 oven-dry tonnes (odt) of forest biomass are technically available annually around Syracuse, from 165,848 hectares (ha) of timberland. There are 67,880 ha of agricultural land technically available for growing willow biomass crops, which could produce 38,181 odt yr^?1 if 5% of this land was used and yields were 11.25 odt ha^?1 yr^?1. There are approximately 215,300 odt of forest biomass technically available annually around Tupper Lake from 211,500 ha of timberland. There are 781 ha of technically available agricultural land in this area so willow biomass production would be minimal. While these two areas have different land cover and land use characteristics, both have the potential to produce significant amounts of woody biomass.     

An economic analysis of hardwood fiber production on dryland irrigated sites in the US Southeast

Although there is renewed interest in intensively managed, short-rotation plantations as a source of hardwood for pulp mills, few have been established in the Southeast. Understanding all the costs associated with these plantations will help determine their feasibility. Using a model developed to summarize all the costs, a break-even analysis was completed to determine the delivered cost for plantations of eastern cottonwood (Populus deltoides Bartr.) from a hypothetical fiber farm in 2003. Using current yield from an experimental fiber farm, short-rotation cottonwood plantations were not cost effective, as delivered cost to a pulp mill averaged 78$ t⁻¹. If yield can be increased by 40% through improvements in genetics and silvicultural practices, delivered cost is reduced to 60$ t⁻¹. Thus, finding this additional yield is key to the cost feasibility of intensively managed, short-rotation hardwood plantations.     

Net carbon dioxide emissions from alternative firewood-production systems in Australia

The use of firewood for domestic heating has the potential to reduce fossil-fuel use and associated CO₂ emissions. The level of possible reductions depends upon the extent to which firewood off-sets the use of fossil fuels, the efficiency with which wood is burnt, and use of fossil fuels for collection and transport of firewood. Plantations grown for firewood also have a cost of emissions associated with their establishment. Applying the FullCAM model and additional calculations, these factors were examined for various management scenarios under three contrasting firewood production systems (native woodland, sustainably managed native forest, and newly established plantations) in low-medium rainfall (600–800 mm) regions of south-eastern Australia. Estimates of carbon dioxide emissions per unit of heat energy produced for all scenarios were lower than for non-renewable energy sources (which generally emit about 0.3–1.0 kg CO₂ kWh⁻¹). Amongst the scenarios, emissions were greatest when wood was periodically collected from dead wood in woodlands (0.11 kg CO₂ kWh⁻¹), and was much lower when obtained from harvest residues and dead wood in native forests (<0.03 kg CO₂ kWh⁻¹). When wood was obtained from plantations established on previously cleared agricultural land, use of firewood led to carbon sequestration equivalent to −0.06 kg CO₂ kWh⁻¹ for firewood obtained from a coppiced plantation, and −0.17 kg CO₂ kWh⁻¹ for firewood collected from thinnings, slash and other residue in a plantation grown for sawlog production. An uncertainty analysis, where inputs and assumptions were varied in relation to a plausible range of management practices, identified the most important influencing factors and an expected range in predicted net amount of CO₂ emitted per unit of heat energy produced from burning firewood.     

Forest resource use pattern in Kedarnath wildlife sanctuary and its fringe areas (a case study from Western Himalaya,India)

The rural population of Himalaya has been strongly dependent on the forest resources for their livelihood for generations. The present study, carried out at three different altitudes of Kedarnath Wildlife Sanctuary (KWLS), explored forest resource-use patterns to understand rural peoples' dependency on the adjacent forests. A total of six forests were selected and the seven dependent villages were surveyed for the study of forest resource use patterns in relation to their socioeconomic status. Average fuelwood and fodder consumption were found to be 2.42 kg/capita/day and 43.96 kg/household/day respectively which was higher than the earlier reported values. Average fuelwood consumption by temporary dhaba (roadside refreshment establishments) owners (52.5 kg/dhaba/day) is much higher than the permanent villagers. Average cultivated land per family was less than 1 ha (0.56 ha). Inaccessibility of the area and deprived socio-economic status of the locals are largely responsible for the total dependency of the local inhabitants on nearby forests for fuelwood, fodder and other life supporting demands. Extensive farming of fuelwood trees on less used, barren land and establishment of fodder banks could be the alternative to bridge the gap between the demand and supply. Active participation of local people is mandatory for the conservation of these forests.     

Agricultural biogas plants in Poland: Investment process,economical and environmental aspects,biogas potential

The formal and legal requirements as well as the support system for building agricultural biogas plants in Poland have been presented. There are currently 24 agricultural biogas plants operating in Poland. The fermentation substrates are slurry, food waste and maize silage. It is most often mesophilic fermentation. Produced biogas is combusted in cogeneration and thus obtained electrical and thermal energy is used for the biogas plant's own needs and sold. The support system for biogas plants' operation in Poland is based on a system of certificates. In this system it is cost-effective to use waste for fermentation whilst it is not cost-effective for a biogas plant to run on maize silage. It has been calculated that in Poland the theoretical annual biogas potential for cattle slurry is 3646 million m³, for pig slurry it is 2581 million m³, for poultry manure it is 717 million m³, from maize after seed harvest it is 1044 million m³, from municipal waste biofraction it is 100 million m³ of biogas.     

Solar electricity prospects in Oman using GIS-based solar radiation maps

This paper discusses solar power prospects in Oman. First, the geographic and topographic information about Oman are presented. The methodology of producing solar radiation maps using GIS tools is then discussed. The results obtained show very high potential of solar radiation over all the lands of Oman during the whole year. A slope analysis has allowed calculating the yearly electricity generation potential for different Concentrated Solar Power (CSP) technologies such as the parabolic trough, parabolic dish, tower, and concentrated PV. For instance if only 10% of the land of Oman with a slope less than 1% is considered an exploitable land for the parabolic trough CSP technology, then the total calculated potential of yearly electricity generation would be about 7.6 million GWh, which is many multiples of (680 times) the current generation supply in Oman which was about 11,189 GWh in 2007.     

The feasibility and implications for conventional liquid fossil fuel of the Indonesian biofuel target in 2025

This paper identifies conventional liquid fossil fuels that can be replaced or blended with biofuel and quantifies the biofuels required to meet the Indonesian biofuel target of at least 5% of the total primary energy mix in 2025. The analysis was conducted using the Long range Energy Alternatives Planning (LEAP) system with an energy elasticity of 1 and maximum allowable biofuel blending ratios according to the current best practices. The results show that the target could be achieved with the maximum blending alternative based on constant energy demand growth of 6%. The target requires a total contribution from biofuel of about 8–27 GL in 2025 depending on blending ratios. In energy terms, these are equivalent to 232–782 PJ or about 40–135 million barrels crude oil, which constitute roughly around 3.3–11.0% of the estimated liquid fossil fuel oil annual consumption in that year. The results imply that it may have detrimental environmental impact, as it requires 5.2 million ha of palm oil and sugar cane plantations. On the positive side, achieving the target offers potential new employment opportunities of about 3.4 million jobs, particularly in the agricultural sector relevant to liquid biofuel production.     

Wood production potential in poplar plantations in Sweden

Shortage of oil, large variations in exports from Russia of wood to Europe, plenty of abandoned agriculture land, new ideas about a more intensive silviculture; these circumstances are driving forces in Sweden for planting fast-growing poplar and hybrid aspen clones on suitable land. The advantage of such trees is that the wood can be used for both energy (heat, biofuels, electricity), paper and for construction. Poplar clones bred in the USA and Belgium, and older hybrid aspen clones from Sweden, together with new poplar clones collected and selected for Swedish conditions from British Columbia, Canada, were planted during the 1990s in south and central Sweden. The stem diameters and heights of the trees have been measured during the last 10 years and the woody biomass production above ground has been calculated. MAI for all the plantations is 10–31 m³ or 3–10 ton DM per hectare with the highest annual woody production of 45 m³ or 15 ton DM per hectare in some years in a very dense plantation in the most southern part of Sweden. All the plantations have been fenced for at least the first ten years. The damage has been caused by stem canker, insects, leaf rust and by moose after removal of the fences. The possibilities for the use of poplar plantations as energy forest and vegetation filters are discussed.     

Biomass accumulation in rapidly growing loblolly pine and sweetgum

Loblolly pine (Pinus taeda) and sweetgum (Liquidambar styraciflua) trees, growing in International Paper Company's study of intensive management on marginal agricultural land near Bainbridge GA, were destructively sampled at the end of the sixth growing season. All trees were single family blocks of genetically superior trees planted 2.5 m apart on sub-soiled rows 3.6 m apart and grown with complete competition control. Management treatments were: control, irrigation, irrigation plus fertilization, and irrigation plus fertilization plus pest control. Tree measures were basal diameter, DBH, height of live crown, diameter at base of live crown, and total height. Twenty trees of each species were destructively sampled. Stems were sectioned at 1 m intervals, stem diameter determined at each end and sections were weighed green. Branches were removed and height, basal diameter, and length were measured on each branch. Branches were separated into foliated and unfoliated segments and weighed green. A stem disk and branch from each meter were returned to the lab to determine dry weight: green weight ratio. Foliated limb: foliage ratios were also determined from sub-sampled branches. Intensive culture resulted in larger growth differences for sweetgum (most intensive treatment 9.5 m tall, 13.1 cm DBH; control trees 5.0 m tall, 6.3 cm DBH) than in pine (most intensive treatment 10.3 m tall, 17.7 cm DBH; control, 7.6 m tall, 13.4 cm DBH). The pipe model of tree development explained dimensions of the upper 5 m of crown with leaf biomass highly correlated to branch basal area (r² from 0.697 to 0.947). There was a constant ratio of leaf biomass to branch basal area (50 gm/cm² for pine, 30 gm/cm² for sweetgum). We also found a constant ratio of bole basal area to cumulative branch basal area throughout the crowns. Rapidly growing pines produced about 49 Mg ha⁻¹ of stem biomass, 11 Mg ha⁻¹ of dead branch biomass, and 17 Mg ha⁻¹ of unfoliated branch biomass at the end of six years.     

Optimization of bioenergy yield from cultivated land in Denmark

A cost minimization model for supply of starch, oil, sugar, grassy and woody biomass for bioenergy in Denmark was developed using linear programming. The model includes biomass supply from annual crops on arable land, short rotation forestry (willow) and plantation forestry. Crop area distributions were simulated using cost data for year 2005. Five scenarios with different constraints, e.g. on food and feed supply and on nitrogen balance were considered focusing on: a) constraints as the year 2005, b) landscape aesthetics and biodiversity c) groundwater protection, d) maintaining current food and feed production, or e) on site carbon sequestration. In addition, two oil price levels were considered. The crop area distributions differed between scenarios and were affected by changing fossil oil prices up to index 300 (using 55$ per barrel in 2005 as index = 100). The bioenergy supply (district heating, electric power, biogas, RME or bioethanol) varied between 56 PJ in the “2005” scenario at oil index 100 and 158 PJ at oil index 300 in the groundwater scenario. Our simple model demonstrates the effect of prioritizing multiple uses of land resources for food, feed or bioenergy, while maintaining a low nitrogen load to the environment. In conclusion, even after drastic landuse changes the bioenergy supply as final energy will not exceed 184 PJ annually (including 26 PJ processed biowaste sources) by far lower than the annual domestic total energy consumption ranging between 800 and 850 PJ yr^?1.     

Wood fuel supply,costs and home consumption in Lithuania

This paper examines the possibilities of increasing the use of wood from private forests in Lithuania for bioenergy purposes. Potential wood fuel supply and consumption were investigated using a literature review and analysis of statistical data. Costs of wood chips production were calculated applying economic simulation. The analysis showed that 0.6 Mm³ (1.2 TWh) of firewood is produced and about 0.3 Mm³ (0.6 TWh) of forest logging residues could be used annually for fuel in private forests. The available volume will increase in coming decades. In total, Lithuanian households had increased wood fuel consumption by five times during 10 years and exceeded 2.3 Mm³ (4.6 TWh) in 2003. Firewood production for home consumption is one of the most important forest owners’ objectives.The cost of forest chips varied from 19 to 36 euro m⁻³ in pre-commercial thinnings and from 20 to 28 euro m⁻³ in final thinnings. The lack of specific policies supporting the use of natural resources is causing a lack of incentive to increase the use of local fuels.     

Above-ground biomass production and allometric relations of Eucalyptus globulus Labill. coppice plantations along a chronosequence in the central highlands of Ethiopia

Eucalyptus plantations are extensively managed for wood production in the central highlands of Ethiopia. Nevertheless, little is known about their biomass (dry matter) production, partitioning and dynamics over time. Data from 10 different Eucalyptus globulus stands, with a plantation age ranging from 11 to 60 years and with a coppice-shoot age ranging from 1 to 9 years were collected and analyzed. Above-ground tree biomass of 7–10 sampled trees per stand was determined destructively. Dry weights of tree components (W_c; leaves, twigs, branches, stembark, and stemwood) and total above-ground biomass (W_a) were estimated as a function of diameter above stump (D), tree height (H) and a combination of these. The best fits were obtained, using combinations of D and H. When only one explanatory variable was used, D performed better than H. Total above-ground biomass was linearly related to coppice-shoot age. In contrast a negative relation was observed between the above-ground biomass production and total plantation age (number of cutting cycles). Total above-ground biomass increased from 11 t ha^?1 at a stand age of 1 year to 153 t ha^?1 at 9 years. The highest dry weight was allocated to stemwood and decreased in the following order: stemwood > leaves > stembark > twigs > branches. The equations developed in this study to estimate biomass components can be applied to other Eucalyptus plantations under the assumption that the populations being studied are similar with regard to density and tree size to those for which the relationships were developed.     

Biomass production in the Central Great Plains USA under various coppice regimes

This paper presents the results of numerous short-rotation coppicing studies with nine fast-growing hardwood tree species grown in the central plains states of the United States. The objective was to compare biomass production of various tree species planted at different densities, coppiced at several intervals, and the longevity of succeeding harvests. Survival, growth, and yield were evaluated. Plant spacing ranged from 0.3×0.3 m to 2.6×2.6 m. Above-ground dormant-season coppice weight and survival on small research plots with one- to five-year coppice cutting cycles were determined. Annual yield of 4–17 oven-dry weight Mg ha⁻¹ for black locust, boxelder, catalpa, cottonwood, honey locust, silver maple, and Siberian elm resulted after several cuts. Survival of cottonwood was about 12% over a 20-year period. Stump sprouting was prolific in silver maple (6.1 per tree); nearly twice as many as the other species compared. Multiple harvests are feasible for many of the broadleafed species evaluated in this study. Survival decreases dramatically at the very close (less than 1 m) spacings. Tonnage remains high for cutting cycles of one, two, or five years. At least three harvests appear feasible. Considering high establishment costs along with survival results conventional spacing distances of about 2 m is suggested for high biomass production especially if plantation longevity of 10 or more years is desired.     

Car dieselization: A solution to China's energy security?

Recently, there is a renewed interest in car dieselization in China to address the challenge of oil security. We developed an econometric model to estimate the vehicle fuels and crude oil demands. The results indicate that if the average travel distance of cars is maintained at the level of 2010–16,000 km/yr, and if the distillation products mix of the refineries remains unchanged, China's crude oil demand in 2020 will reach 1060 million tonnes (Mt), which also results in an excess supply of 107 Mt of diesel. A new balance of diesel supply and demand can be reached and crude oil demand can be significantly reduced to 840 Mt by improving the production ratio between diesel and gasoline on the supply side and promoting passenger vehicle dieselization on the demand side. The crude oil demand will be reduced to 810 Mt in 2020, if the vehicle travel distance gradually drops to 12,000 km/yr. If so, dieselization will provide a rather limited added value—only 6% further oil saving by 2020. Dieselization is not a silver bullet but it depends on a series of key factors: growth rate of gross domestic products (GDP), vehicle sales, and vehicle annual travel distance.     

Short-rotation forestry of birch,maple, poplar and willow in Flanders (Belgium) I—Biomass production after 4 years of tree growth

During the last three decades, oil crises, agricultural surpluses and global climate change enhanced the interest in short-rotation forestry (SRF). In this study, the biomass production of birch (Betula pendula Roth), maple (Acer pseudoplatanus L.—Tintigny), poplar (Populus trichocarpa × deltoides—Hoogvorst) and willow (Salix viminalis—Orm) growing under a short-rotation (SR) management system were compared after a 4 years period. The plantation was established on former agricultural land. The sandy soil had a mean pH of 4.5 and a mean carbon content of 1.0%. Survival rates after 4 years were 75.8%, 96.8%, 86.3% and 97.6% for birch, maple, poplar and willow, respectively. The mean actual annual biomass production for these four species amounted to 2.6, 1.2, 3.5 and 3.4 t DM ha⁻¹ yr⁻¹, respectively. The large variation in biomass production at the different plots of the plantation could not be explained by the measured soil parameters. Biomass production results found here were in the lower range of values reported in literature. However, in contrast to most other studies, no weed control, fertilisation or irrigation was applied in this experiment. As marginal agricultural soils are suboptimal for the growth of poplar and willow, birch can be considered as a very interesting alternative for the establishment of SR plantations in Flanders.