Forestry Harvesting Research Articles

Two prototypes for medium rotation forestry harvesting

Two prototypes for medium rotation forestry harvesting

Treefall Gap Dynamics in a Tropical Rain Forest in Papua New Guinea

Treefall gaps play important roles in tropical rain-forest ecology. But studies rely increasingly on models, remote sensing, and a few intensively studied research sites, mostly in the neotropics. We studied the basic parameters of gap dynamics (size, causes, and frequency) of treefall gaps in a lower montane primary forest on the southern flank of the central range of Papua New Guinea. We found 40 treefall gaps formed on 10.4 km of transect sampled annually over 3 yr. Mean proportion of forest under new gaps was 0.015/yr. Mean area of treefall gaps ≤1 yr old was 312 m2, and gap area was positively correlated with diameter of the fallen tree. Mostly only large trees (diameter at breast height [DBH] = 53 cm) fell as snapped (n = 23) or uprooted (n = 17), creating both single (n = 34) and multiple (n = 6) treefall gaps. There was no strong directionality in the bearings of treefalls. This study provides some of the first information on gap dynamics in Papua New Guinea, where such data can be used to inform sustainable forestry harvesting practices.

The Human Influence on Productivity in Harvester Operations

It is well-known that machine operators vary in their performance when undertaking mechanized forestry harvesting operations. Nevertheless, the human factor is still largely disregarded in productivity calculations. In the present study, operator performance is evaluated by analysing archived production data collected automatically by computers on-board single grip harvesters driven by 32 operators working in 3,351 stands over a period of three years. The experimental conditions were all approximately the same. The effect of the operators is modelled by a multilinear regression analysis. Seventeen operators were found to have performance levels that differed significantly from the mean model. Together, ‘tree volume’ and ‘operator’ explained 84% of the overall variance. However, since 37.3% of the variance in productivity is explained by the operator, the influence of the operator on productivity is quite large. The minimum and maximum significant mean productivity values for all the operators differed by a factor of 2.2, which reduced to a factor of 1.8 if only data from experienced operators were analysed, although this still demonstrates that the best operators are nearly twice as productive as the worst. The operator, therefore, has an important influence on productivity and should be considered a key factor in productivity models.

Avaliação ambiental do processo de inovação tecnológica na colheita florestal

O objetivo deste trabalho foi avaliar o perfil impactante do processo de inovação tecnológica na colheita florestal. Analisou-se o processo de inovação quando da mudança do subsistema tradicional (Motosserra + Forwarder) para o inovado (Feller Buncher + Clambunk Skidder). Utilizou-se um método consolidado para avaliação de impacto ambiental da inovação tecnológica na agropecuária, que avalia o desempenho ambiental de uma dada metodologia ou tecnologia em relação àquela previamente estabelecida. O método foi adaptado para avaliação de impactos na colheita florestal. Os impactos foram analisados para os indicadores dos meios físico (atmosfera; solo, água); biótico (flora e fauna) e antrópico (emprego; saúde, paisagismo e gestão). Elaboraram-se matrizes para cada indicador, sendo estas ponderadas em relação à escala de ocorrência e fator de importância. Técnicos da área de colheita florestal realizaram o preenchimento das matrizes utilizando coeficientes de alteração previamente definidos. O coeficiente de impacto resultou do produto do coeficiente de alteração pelos fatores de ponderação, sendo avaliado numa escala de -15 a +15. O índice geral de impacto foi determinado para o mesmo padrão de escala. De acordo com a média das três avaliações, dois indicadores apresentaram coeficiente de impacto positivo (saúde e gestão); seis mostraram coeficiente negativo (atmosfera, solo, flora, fauna, emprego e paisagismo) e um manteve-se inalterado (água). O índice geral de impacto mostrou-se positivo (1,29), indicando, no contexto global, condições ambienteis favoráveis quando da adoção do subsistema inovado.

Diameter Fitting by Least Square Algorithm Based on the Data Acquired with a 2-D Laser Scanner

For improving the working efficiency of the forestry harvester, a laser scanner was used to collect the 2-d scan data of the target living-trees. First of all, the noise of the scanning data are filtered with a extraction algorithm. Furthermore, the diameters of the living-trees are calculated out with the least square algorithm and the curve fitting. The results of the research and experiment show that the extraction algorithm the least square algorithm are accurate; the mean error of the calculation is 4.29 millimetre.

Production of Woody Nursery Crops in Clean Chip Residual Substrate

Abstract Clean chip residual (CCR) is a potential replacement for pine bark (PB) in nursery crop substrates. It is a by-product of in-field forestry harvesting practices and has been shown to produce annual plants and perennials similar in size to plants grown in PB. Studies were conducted in two locations, Auburn, AL, and Poplarville, MS, to evaluate growth of woody ornamentals grown in CCR or PB. Five species were tested; Loropetalum chinensis var. rubrum, Buddleja davidii ‘Black Knight’, Lagerstroemia indica ‘Hopi’, Lagerstroemia × fauriei ‘Natchez’, and Rhododendron indicum ‘Mrs. G.G. Gerbing’. There were few differences in plant growth indices, leaf chlorophyll content, and inflorescence number over the course of the year for all species at both sites. Percent rootball coverage was generally similar among treatments, though those grown in PB had the greatest percent rootball coverage for loropetalum and buddleja (at both sites) and azalea at Auburn. Shoot dry weight of loropetalum and crapemytrle grown in PB at Poplarville was greater than plants grown in CCR.

Saving the Island in the Sky: the plight of the Mount Mulanje cedar Widdringtonia whytei in Malawi

The Endangered Mulanje cedar Widdringtonia whytei, endemic to the Mount Mulanje massif in Malawi, has undergone a drastic decline due to increased fire incidence and illegal logging. Valued for its fine timber, attractive fragrance, and pesticide-resistant sap, the tree has been regarded as highly desirable since its discovery in the late 19th century. Because of its steep slopes and isolated high altitude plateau, Mount Mulanje is also a refuge for a number of other endemic plant species. The first assessment of the Mulanje cedar since 1994 was commissioned by the Mulanje Mountain Conservation Trust to ascertain the species' current extent and status. This study identified an area of 845.3 ha of Mulanje cedar, which represents a loss of 616.7 ha over the previous 15 years. Of the recorded trees 32.27% (37,242 m3) were dead cedars. Therefore, under current Department of Forestry harvest licensing, there remains in theory sufficient dead cedar to last >30 years. At this stage it is imperative that cedar nurseries are established and saplings planted out across the mountain on an annual basis, small cedar clusters are protected to facilitate regeneration, and a strict monitoring programme is followed to prevent the cutting of live cedar.

Exposure to biological fungicides, environmental microorganisms and oils in forestry harvesting

New chemicals have been introduced into forestry harvesting during the past decade. In field experiments five harvesters and their operators were used to study exposure to biological fungicides, biodegradable oils and log colour-coding agents. Respiratory exposure to the biological fungicide Phlebiopsis gigantea, other basidiomycetes, environmental microorganisms and endotoxins was assessed using samples taken from the workers’ breathing zone. Exposure to biological fungicide was also estimated by antibody determinations from serum samples. Dermal exposure to biodegradable oils and biological fungicides was studied using a fluorescent tracer method and digital photography. Dermal exposure to log colour-coding agents was observed visually. The field survey indicated that respiratory and dermal exposure to biological fungicides, log colour-coding agents and hydraulic and chainsaw oils was insignificant during normal harvester operations. Skin contamination may occur during maintenance work such as the sharpening of chains or the handling of hydraulic hoses.

Life‐Cycle Assessment of Mineral and Rapeseed Oil in Mobile Hydraulic Systems

SummaryThe use of rapeseed oil in mobile hydraulic systems has become more widespread over recent years. This is because of concern about the environment in which the systems work and the perceived benefit of using such fluids. This article examines the major segments of the life cycle of mineral and rapeseed oil as used in mobile hydraulic systems, with case studies of a forestry harvester and a road sweeper. It shows that the systems running on rapeseed oil are not necessarily better for the environment. Many of the environmental issues examined in the study were affected more negatively by the use of rapeseed oil than mineral oil. The main exception to this was greenhouse gas emissions, which are consistently higher for systems using mineral oil because of the use of fossil resources.This study examines the production of the machinery, the oils, and their use throughout the machines' lives. The poor environmental performance of the rapeseed oil is due mainly to its poor performance in the field. This is because it does not respond as well to high pressure and temperature as mineral oil, causing it to need more frequent replacement during use. This, in turn, influences the definition of the functional unit used in the life‐cycle assessment that was conducted. Also, the rapeseed oil has more corrosive qualities than the mineral oil, and more hydraulic components need replacing during the life of a machine running on rapeseed oil than one running on mineral oil.

Helmet design to facilitate thermoneutrality during forest harvesting

The purpose of this investigation was to evaluate the ventilatory characteristics of vented and non-vented helmets for use in forestry harvesting operations. A ventilation index developed by Birnbaum and Crockford (1978) was used to determine the ventilation capacity of twelve helmets varying in design and presence, location, and dimension of vents. Helmets with top vents had higher ventilation indices than non-vented, side and side/top-vented helmets. Ten physically fit men participated in a maximal oxygen consumption test and four trials wearing a non-vented, round-side-vented, round-top-vented or rectangulartop-vented helmet. Trials simulated typical summer environmental conditions (28°C, 80% rh) and physiological work loads (40% V O 2 max) experienced during forest harvesting in New Zealand. The temperature and humidity under the helmet was typically lowest when the helmet with the largest vented area (288 mm 2) in the crown was worn, although physiological responses (temperatures at the tympanum, ear and scalp; humidity at the centre of the helmet) of the participants to wearing the helmets differed significantly during some rest periods only. Top-vented helmets (in this experiment measured 288 mm 2) should be worn to minimize temperature and humidity of the head during forest harvesting operations.

Compactación del suelo durante la cosecha forestal: evolución de las propiedades físicas

Se realizaron ensayos en campo con el objeto de evaluar los efectos y la persistencia de la compactación inducida por diferentes intensidades de tránsito durante la cosecha forestal en una población de álamos (Populus sp.). Se trabajó con un tractor de tracción simple de 73,5 kW y un acoplado, con una masa de 4,2 Mg y 2,7 Mg, respectivamente. Se establecieron 3 tratamientos de tránsito: 1, 5 y 10 pasajes sobre una misma senda, contrastados con un testigo sin tránsito. Luego de cada tratamiento, y 3 años después de realizados los mismos, se efectuaron determinaciones de penetrometría, densidad aparente y humedad gravimétrica. Hubo incrementos significativos de resistencia a la penetración para los tratamientos con tránsito, alcanzando el de mayor intensidad valores entre el 76 y el 16 % en los primeros 40 cm de profundidad. La densidad aparente tuvo una tendencia similar limitada a una menor profundidad. Luego de 3 años, los efectos persistían a nivel subsuperficial, para el índice de cono en los sectores tránsitados con respecto a los no transitados, encontrándose diferencias significativas para el tratamiento de 10 pasajes respecto al de 1 pasaje hasta 50 cm. Aún con cargas por eje de 3 Mg, el incremento de la intensidad de tránsito induce compactación a nivel subsuperficial que persiste en el tiempo.

Effects of Clearfell Harvesting on Lucanid Beetles (Coleoptera: Lucanidae) in Wet and Dry Sclerophyll Forests in Tasmania

The effects of commercial forestry harvest and regeneration practices (clearfelling and slash-burning) on the lucanid fauna of the wet sclerophyll forests of southern Tasmania and the dry sclerophyll forests of eastern Tasmania were examined using pitfall catches. Lucanids are saproxylic beetles, dependent on dead, moribund and decaying wood. Samples taken from old-growth forest and from a chronosequence of sites regenerating after logging, in each forest type, were used to compare the species richness and abundance of the lucanid assemblages. In both forest types, species richness and abundance was highest in the youngest regeneration sites (1–3 year), reflecting the species richness of the original and adjacent unlogged forest, lowest in the older (20–25 year) sites, and variable in the old-growth sites. TWINSPAN cluster analysis showed no clear distinction between regeneration and old-growth forest. The post-harvest slash and stump residue provided an important refugium and initial habitat, but our research indicates that some species may not maintain populations in the long term. Our results suggest that most species of lucanids will find a continuous supply of suitable habitat only in old-growth forests; and such species may become less common as clearfell harvesting leads to a replacement of heterogeneous old-growth forest with single-aged monospecific stands. Continuity of supply of wood in all decay stages, the maintenance of sufficient source areas, and biological connectivity between old-growth stands to enable dispersal, are all likely to be essential to maintain lucanid beetle community integrity. If similar principles apply to other saproxylic species of invertebrate, then clearfelling and slash-burning may cause a gradual extinction of an important element of the forest biota.

Safe Drinking Water and its Acquisition: Rural Women's Participation in Water Management in Maharashtra, India

The present study was on the participation of women in 10 villages which had a perennial problem of adequate and safe drinking water. These remote villages are situated in the arid region of Vidarbha in the state of Maharashtra,India. The endeavour to have safe and sufficient drinking water helped the women in fighting not only against poverty but also oppression, exploitation and human rights violation. Discussion and dialogue with men and women of the rural communities were the main methods used for data collection. The participatory research helped the women to realize that they too could be equal to men and advocates of rural sustainable development. The street plays and protests organized by the women and the consistent struggle for water created strong community awareness. The search for safe drinking water and water management by women had an all-pervading effect in all villages. The women also initiated programmes for social forestry and rain water harvesting to protect the environment. For the first time in the recent history of these villages, there was sufficient safe drinking water in seven villages during the summer months of 1997.

Modelling the long-term impacts of atmospheric pollution deposition and repeated forestry cycles on stream water chemistry for a holm oak forest in northeastern Spain

Estimates based on the MAGIC model of the long-term effects on stream water quality of forest management cycles as well as of atmospheric pollutant inputs for a holm oak catchment in northeastern Spain, show that despite high pollutant sulphur inputs as well as substantial base cation loss from the catchment owing to forest harvesting, stream water has not deteriorated in any major way. Acidification of the catchment will continue, to a limited degree, unless either sulphur deposition is reduced by more than 60% or forest harvesting schemes are terminated. The detrimental changes in water quality owing to acid deposition and forestry harvesting practice in other parts of Europe are not observed in this region, because of high base inputs from the atmosphere and high base cation weathering rates within the catchment.

The energy forestry production systems

When growing and using energy forests a long chain of steps is taken: choice of site, site characterization, amelioration, choice of plant material and spacing, land preparation, planting, management, harvest and handling, transport, conversion, production of hot water and electricity. The economics of energy forestry must be improved to make the whole concept viable. Although the economics need strengthening, it has been agreed that energy forestry is one of the most promising alternatives to cereal crops on farm land. There are two main ways to improve the economics: to increase production of stemwood per area and time, and to lower the costs of production. Good achievements along these routes have been reached over the last three years. Improving each step in growing is being achieved gradually. Lowering the costs is a more stepwise process, for example as was the case when a modified maize harvester proved to work surprisingly well as an energy forestry harvester. Introductary work done during the three-year period indicates that expert systems or decision support systems may play an important role to share and use the knowledge on energy forestry production systems. For immediate use, a handbook on how to grow short rotation forests has been made published.