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Plantation forests are established, and expanding, to satisfy increasing global demand for timber products. Shifting societal values, such as safety, productivity, environmental, quality and social are influencing the plantation forestry sector. This is primarily driven through an ever increasing world population, which in turn influences the way nations view the value systems by which they live. More people require more resources—also forest products. Also, the availability of information is influencing the pace of technological development. These changes could result in a difference in the management of plantations that could affect the forest engineering systems of the future. This review aimed to summarize the current status of plantation forests; summarize future developments and possible scenarios in forest plantation management for the various products; and assess whether these developments in a plantation environment could affect the harvesting systems used. Factors influencing the form of plantations include the type and nature of the plantation owner; the change in demand for different and new forest products; climate change factors, including the use of biomass for energy, carbon sequestration and trading; ecosystem services and other products and services; and sustainability certification of forest management. The impact and influence of these factors were summarised into a series of key drivers that will influence the technology used in harvesting machines, as well as the choice of harvesting machines, systems and methods. These drivers were the effect of variations in tree size, the expansion of plantation areas onto more difficult terrain, diversity in plantation design, increased attention towards site impacts and the increased use of biomass for energy. Specific information is provided regarding how the harvesting systems could be affected. [ABSTRACT FROM AUTHOR]

A cereal grain harvesting system is introduced that combines existing technologies in a unique way to improve cereal grain harvest performance, increase profitability, and efficiently collect biomass. The harvesting system is comprised of three machines: one to reap grain, harvest biomass, and size crop residue for no-till seeding; a second to thresh and winnow the grain; and a third to separate the grain by quality for added value. This study describes the new harvesting system and the development of one of the system's major components: the reaper/flail harvester. The reaper/flail harvester consists of a mobile power unit, a stripper header to harvest the crop, and a flail to chop the standing residue into small pieces. A prototype harvester was fabricated and tested to determine system design criteria and performance characteristics in terms of machine power requirements, quantity of biomass collected, and bulk density of the material harvested. Trials were conducted in seven wheat (Triticum aestivum L.) fields in Oregon during 2005 and 2006 that ranged in yield from 3.3 to 6.4 t ha-1. Harvester performance was evaluated at various travel speeds, straw chop heights, and with different types of wheat. Flail power requirements were highly linearly correlated with quantity and rate of biomass chopped (R² = 0.91). The maximum reaping power requirement was 2. 7 kW m-1, only slightly higher than the no-load power requirement of 1.9 kW m-1. Power requirements for reaping, conveying, and flailing ranged from a low of 5.0 to a high of 13.5 kW m-1 depending on travel speed, crop yield, biomass concentration, and chop height. Values were linearly correlated with the combined grain, chaff, and biomass feed rate (t h-1) with an R² of 0.88. Total machine power requirements for a harvester with a 7.3 m header would be about 175 kW, including 75 kW for propulsion, losses, and reserve. Chaff yield in the grain/chaff (graff) mixture harvested exceeded 2 t ha-1 in six of the seven trials. With chaff valued at $23 t-1, collecting 2 t ha-1 of chaff would increase farm revenues by $46 ha-1. Realistic graff densities of awned wheat were less than 1/11 that of clean grain, and new, efficient material handling systems would need to be developed to have harvesting capacities comparable to that of a conventional combine-based system. Awnless wheat had graff densities that averaged about 1/5 that of clean grain. Equipment is commercially available to handle this volume of material and have harvesting field capacities comparable to that of a conventional combine-based system. [ABSTRACT FROM AUTHOR]

To utilize timber and forest biomass resources for bioenergy, technically feasible and economically viable timber and forest biomass resources should be estimated accurately considering their long-term availability. This study focuses on five prefectures, namely, Aomori, Iwate, Miyagi, Akita, and Yamagata, and considers trade between these prefectures. The annual availability of timber and forest biomass resources, such as small-diameter or defect stem logs, rather than logging residues in Japan was estimated as supply potential from profitable forests where expected revenues surpassed all costs, from planting to final harvest. As a result, the supply potential and annual availability of timber were estimated at 11,388,960 m3/year and 1,631,624 m3/year, whereas those of forest biomass resources were estimated at 2,277,792 m3/year and 326,325 m3/year, respectively. Therefore, the rate of annual availability to supply potential was 14.3%. Since timber production and wood chip usage from thinned woods and logging residues in 2018 were 4,667,000 m3/year and 889,600 m3/year, the rates of annual availability for timber and forest biomass resources to those values were 35.0% and 36.7%, respectively. Furthermore, the demand was estimated at 951,740 m3/year from 100,000 m3/year with a generation capacity of 5 MW. The rate of forest biomass resource availability to demand was 34.2%. A thinning subsidy was provided for operational site areas larger than 5 ha in Japan. The rates from subcompartments and aggregated forests with a thinning subsidy increased to 91.4% and 190.3%, respectively. Thus, the estimated availability from aggregated forests with a thinning subsidy met the demand sufficiently in this region. [ABSTRACT FROM AUTHOR]