Bryce J. Stokes

U.S. Billion-ton Update: Biomass Supply for a Bioenergy and Bioproducts Industry

The Report, Biomass as Feedstock for a Bioenergy and Bioproducts Industry: The Technical Feasibility of a Billion-Ton Annual Supply (generally referred to as the Billion-Ton Study or 2005 BTS), was an estimate of “potential” biomass within the contiguous United States based on numerous assumptions about current and future inventory and production capacity, availability, and technology. In the 2005 BTS, a strategic analysis was undertaken to determine if U.S. agriculture and forest resources have the capability to potentially produce at least one billion dry tons of biomass annually, in a sustainable manner—enough to displace approximately 30% of the country’s present petroleum consumption. To ensure reasonable confidence in the study results, an effort was made to use relatively conservative assumptions. However, for both agriculture and forestry, the resource potential was not restricted by price. That is, all identified biomass was potentially available, even though some potential feedstock would more than likely be too expensive to actually be economically available. In addition to updating the 2005 study, this report attempts to address a number of its shortcomings

A strategic assessment of forest biomass and fuel reduction treatments in Western States

In the 15 western states there are at least 28 million acres of forest that could benefit from some type of mechanical treatment to reduce hazardous fuel loading. It is estimated that about 60 percent of this area could be operationally accessible for treatment with a total biomass treatment volume of 345 million bone dry tons (bdt). Two-thirds of this forest area is on public lands. Most of the volume is in trees 6 inches diameter and greater that have conventional utilization opportunities. Transportation cost and distance to markets, however, may preclude actual recovery. Treatment costs are increased by the need to treat large numbers of low-volume stems less than 4 inches in diameter. Gross costs can range from

The transportation of fuelwood from forest to facility

35 to over

Harvesting small trees and forest residues

1000 per acre depending on type of operation, terrain, and number of trees to be treated. Some areas will likely be prohibitively expensive to treat, although cost estimates presented here may be high because they are based on the use of conventional timber harvesting systems applied to small diameter treatments. Implementation of any significant fuel reduction effort will generate large volumes of biomass and require the development of additional workforce and operations capacity in western forests.

Production of short-rotation woody crops grown with a range of nutrient and water availability: establishment report and first-year responses.

Abstract Secondary transportation from the forest to the utilisation facility is the simplest of the handling phases in transferring fuelwood from its point-of-origin to ultimate processing point, both in its objectives and application. In spite of this simplicity secondary transport is typically responsible for between 20 and 40% of the delivered fuel cost. Truck transportation is in an advanced state of development as the technology employed comes from a very large scale industry that dominates the transport of industrial products in most developed countries. To achieve a full payload within maximum allowable load dimension restrictions the material transported must have a minimum bulk density of about 250 to 280 kg/m 3 . While conventional forest products generally exceed this limit, fuelwood in an unprocessed form may have a bulk density of only 120 to 150 kg/m 3 . To offset this problem fuelwood material can be compacted before loading, or compacted in the trailer, but, more frequently, it is comminuted before transport. Processing of fuelwood to a chip allows the use of standard transport systems designed for the transport of wood chips for the pulp sector. Major technological gains to improve the transport efficiencies of fuelwood are unlikely in the immediate future. The most important improvements are likely to come from efforts to improve carrying efficiencies in pulp chip transport because of the much greater volume and value of this material carried annually. Any developments will be rapidly adopted by those engaged in fuelwood chip transport.

Evaluation of erosion control techniques on forest roads

Eight countries collaborated and shared technical information on the harvesting of small trees and forest residues in a three year program. Proceedings and reports from workshops and reviews are summarized in a review of activities and harvesting systems of the participating countries. Four databases were developed for harvesting and transportation of these materials.

Selection harvests in Amazonian rainforests: long-term impacts on soil properties

Coleman, M.D., et. al. 2003. Production of Short-Rotation Woody Crops Grown with a Range of Nutrient and Water Availability: Establishment Report and First-Year Responses. Report. USDA Forest Service, Savannah River, Aiken, SC. 26 pp. Abstract: Many researchers have studied the productivity potential of intensively managed forest plantations. However, we need to learn more about the effects of fundamental growth processes on forest productivity; especially the influence of aboveground and belowground resource acquisition and allocation. This report presents installation, establishment, and first-year results of four tree species (two cottonwood clones, sycamore, sweetgum, and loblolly pine) grown with fertilizer and irrigation treatments. At this early stage of development, irrigation and fertilization were additive only in cottonwood clone ST66 and sweetgum. Leaf area development was directly related to stem growth, but root production was not always consistent with shoot responses, suggesting that allocation of resources varies among treatments. We will evaluate the consequences of these early responses on resource availability in subsequent growing seasons. This information will be used to: (1) optimize fiber and bioenergy production; (2) understand carbon sequestration; and (3) develop innovative applications such as phytoremediation; municipal, industrial, and agricultural wastes management; and protection of soil, air, and water resources.

Mechanisation of short rotation forestry

The cutslope and fillslope on a newly constructed forest road on the Talladega National Forest near Heflin, Alabama were treated with three erosion control techniques: wood excelsior erosion mat, native grass species, and exotic grass species. Bare soil plots were used as the experimental controls. Total sediment yield was measured during the period 21 September 1995 to 18 March 1996. A randomized complete block design was used to evaluate treatment methods on the basis of sediment yield and runoff volume. No significant difference in sediment yield was found from the fillslope among the treatments. However, on the cutslope significant differences were detected among all treatments. The erosion mat treatment was most effective in mitigating erosion losses with a 98% reduction in cutslope sediment yield and 88% reduction in fillslope sediment yield.

Improved harvesting systems for wet sites

Abstract Surface soil properties were compared among disturbance classes associated with a single-tree selection harvest study installed in 1979 in the Brazilian Amazon. Response variables included pH, total N, total organic C, extractable P, exchangeable K, Ca, Mg, and bulk density. In general, concentrations of all elements displayed residual effects 16 years after harvests with N, P, K, and C being inversely related to disturbance intensity while Ca and Mg levels as well as pH were directly related. Elemental contents exhibited fewer residual effects except in the cases of Ca and Mg contents which generally increased with disturbance intensity. Higher intensity disturbance classes were associated with increased bulk density. Soil impacts apparent after 16 years suggest a combination of direct effects of harvests (e.g. as in the case of bulk density) combined with indirect influences of the ecophysiology of the Cecropia sp. which dominate disturbed areas.

Field trials of a short-rotation biomass feller buncher and selected harvesting systems

This paper is split into two distinct parts since it addresses two very different crops grown in North America and Europe. In North America short rotation forestry is being developed principally to generate a feedstock for the wood pulping industry and is typically single stem hardwood plantations grown for 6–10 years before harvest. In Europe by contrast, coppiced willow plantations are being grown as an energy crop and harvested on a 3–4 year cycle. In North America, the industry is being driven by the large pulp producing companies; plantations are designed to fit the local conditions and specialist mechanisation is generally not being used. Rather, the companies are using standard agricultural or forestry practices for planting and husbandry and using the crews which already exist to harvest the crop. This paper describes the type of plantations which are being used and the mechanisation which is being applied. In Europe, the coppice crops are grown commercially in Sweden and will shortly be planted on a commercial scale in the UK. In Sweden, the resulting wood fuel is fed into the many wood fired district heating plants and combined heat and power plants. In the UK, the majority of new planting will be used to fire power generation plants working on the gasification principle. Three plants have been given contracts to generate electricity under a premium price scheme and this could result in the planting of 8,000 ha of coppice. Sweden has lead the development of mechanisation for the crop and two harvesters are now considered to be commercial; they are based on existing machines for harvesting forage and sugar cane. Planters are also at the commercial stage of development and machines for weed control have been tested. This paper covers the machinery developments and discusses issues relevant to the mechanisation of the crop such as: whether to harvest as chips or as whole shoots (sticks), the impact of soil compaction, weed control and plantation layout.