Felling Site Research Articles

Assessment of Compliance with PEFC Forest Certification Indicators with Remote Sensing

The majority of Finnish forests (95%) are certified by the Programme for the Endorsement of Forest Certification (PEFC). It is a worldwide leading forest certification scheme. The aim of this study is to analyze the Finnish National Standard of PEFC certification and identify the indicators that can be reliably estimated with remote sensing (RS) techniques. The retrieved data are further verified with a chosen geographical information system (GIS) application. The rapid increase in certified areas globally has created a certain level of mistrust that makes the evaluation by certification bodies (CB) questionable. Firstly, the area of the field audit is limited, and the verification results are based on sampling techniques. Secondly, the evaluation of the indicators of sustainable forest management (SFM) is based on auditor expertise and thus is prone to bias. Thirdly, the actual condition of large forest stands in Eastern and Northern Finland are not easy to determine and verify. Thus, PEFC certification in Finland, in particular, faces numerous challenges in regard to the quality of field assessment due to the intensive forest management model with a high number of annual felling sites. At the same time, small scale and scattered harvesting sites are difficult to assess. Our proposed approach combined with remote assessment reliably verified 18% of the standard and could substantially reduce the costs associated with field audits in Finland. The results from our verification analysis are spatially explicit and geographically referenced and can be published in open access portals for interested parties. Moreover, it provides improved transparency in field assessments for the PEFC certification. The novel approach proposed here requires further investigation at larger scales (e.g., national level).

Changes in the ecological diversity of the forest population of ground beetles (Coleoptera, Carabidae) after deforestation and during the initial period of reforestation

The ecological structure of ground beetles was studied. Its dynamics during the migration of ground beetles from one habitat to another as a result of severe ecological disturbances caused by tree felling and subsequent reforestation was considered. Some regularities in the formation and development of a ground beetle community in the early stage of secondary succession at the felling site were determined. Further trends were revealed using the simplest indices of diversity, species, abundance, distribution, and dominance of species. The species richness of ground beetles at the site one year after felling increased from 28 to 41 species. It decreased to 36 species in four years. According to the ecological preference, the basis of the complex of ground beetles at the forest site before felling was formed by spring-breeding species. Four years after felling, the proportion of forest species decreased (from 73.4 to 65.7%) and the significance of forestmarsh and meadow-field species increased. The proportion of summer- and autumn-breeding species also increased. The species and quantitative composition of ground beetles at the site during the first year after felling was mostly determined by neighboring forests. As reforestation proceeded, a separate biocenosis developed at the felling site and the influence of the forests became lower. The proportion of summer- and autumnbreeding species increased. The species and quantitative composition of ground beetles at the felling site was mostly determined by the neighboring forest during the first year. A separate biocenosis developed at the felling site in the following years, and the influence exercised by the forest diminished.

A Comparative Study of Carbon Stock Changes from Different Logging Techniques in Ulu Jelai Forest Reserve, Kuala Lipis, Pahang


 
 
 Conventional logging practices are often highly destructive to forest ecosystems. Heavy machinery can compact the soil and destroy vegetation. Previous research by others have demonstrated that environmental damage can be minimized through the use of site- sensitive harvesting techniques. Forest harvesting in the inland forest in Malaysia is generally carried out by a combination of crawler tractor and winch lorry, which we defined as the current logging technique. Under the current logging technique, crawler tractors are used to skid logs from felling sites to skid trails and winch lorries continue the transportation to the roadside landings. In the early nineties, a Low Impact Logging (LIL) practice using an improved logging system was carried out in some forest areas in Peninsular Malaysia. The technology, called logfisher was mainly deployed to retrieve logs from rocky and deep, narrow ravine which was deemed uneconomical, difficult and dangerous for the crawler tractor to operate. In certain logging areas in Pahang, a combination of crawler tractor and logfisher is being used which we defined in this study as LIL. The study focuses on quantifying the carbon stock changes from the different logging techniques in Lipis, Pahang. Based on preliminary results, the LIL technique showed less carbon loss if the carbon stocks before and after logging were compared. This study indicates that different logging techniques results in different impact on the total residual forest carbon stocks. The introduction of LIL systems and practices have indeed reduced the logging damage and improved stand conditions. Improvement to the current practice, enhance the productivity of the residual stand and reduce forest degradation in terms of carbon stocks as well as other ecological co-benefits.
 
 

Fuel consumption in the transport of technical broadleaf roundwood in lowland areas

This paper presents the results of an analysis of fuel consumption in the transport of technical roundwood of soft broadleaves from the felling site to a roadside landing using forwarders and tractor assemblies. The research was performed in various operating conditions in the area of FE "Banat" Pancevo. On the basis of the results of the analysis of variance, the data recorded in a variety of conditions were grouped. In addition, the dependence of fuel consumption on the average volume of tour was estimated. The results of the conducted analysis indicate that operating conditions significantly affect fuel consumption of the investigated vehicles. The elements of statistical analysis of the dependence of fuel consumption on the volume of load indicate that an increase in load causes increased fuel consumption per unit of production. Having in mind the results of the analysis of variance, unique norms of fuel consumption were adopted for practical purposes. The highest average consumption (1.21 L/m3) was achieved by a tractor assembly (Same Laser 130 tractor and Imako TP12 trailer with a Loglift 61F hydraulic crane), while significantly lower consumption was achieved by a John Deere 1210E forwarder (1.06 L/m3). In favourable operating conditions, consumption of the forwarder was about 0.9 L/m3.

Variation in indigenous forest resource use in central Guyana.

Sustainable forest conservation strategies should be based on local as well as landscape-scale forest resource use data. Using ecological and sociological techniques, we test the hypotheses that (1) forest resource use differs between ethnic and socioeconomic indigenous groups and (2) that this difference results in differing spatial patterns of resource use, with implications for forest diversity and for conservation planning. In the North Rupununi Guyana, three adjacent indigenous communities (differing in their indigenous/immigrant balance) were recorded using 73 animal and 164 plant species (plus several unidentified ethno-species). Farm sites formed important foci for most forest based activities and ex-farm sites supported similar floristic diversity to surrounding forest. Resource usage differences between communities could be attributed to socio-cultural drivers, e.g. mammal meat consumption and the use of the fruits from the palm tree A. maripa were higher in more traditional households. When extracting household construction timber, lower income groups created small scattered felling sites akin to tree fall gaps whereas higher income groups created larger gaps. Lower income (indigenous) households tended to clear larger but more contained sites for farming while mixed or non-Amerindian household tended to clear smaller but more widely dispersed farm sites. These variations resulted in different patterns of forest disturbance originating from agriculture and timber extraction.

Light microscopic analysis of Tectona grandis L.f. wood inoculated with Irpex lacteus and Phanerochaete chrysosporium

Felling of immature teak (Tectona grandis L.f.) trees or delay in transport of wood logs from felling sites provide platform to microbial attack. Among them, white rot fungi are central driving force that degrades wood and causes severe economic loss. In contrast, Phanerochaete chrysosporium and Irpex lacteus are more extensively studied for their ability to degrade synthetic dyes and poly-aromatic compounds. Therefore, in the present study, both the fungi collected from the Gujarat forest were utilised for in vitro decay test to assess their potential in lignin degradation, extent of cell wall damage and pattern of wood decay in sound blocks of teak. In the early stage of fungal inoculation, there was a negligible amount of weight loss; after 1 month it became rapid and highest weight loss (30.05 % by P. chrysosporium and 27.97 % by I. lacteus) was observed at the end of 120 days. Mycelial invasion occurred through vessels, from vessels to axial and ray parenchyma and subsequently into xylem fibres. Both the strains showed selective delignification and the first symptom of degradation was defibration, separation of rays, and formation of boreholes on ray cell walls at an advanced stage. Xylem fibres and parenchyma cells lost their integrity and collapsed completely. Among all the cell types, parenchyma cells and fibres were more vulnerable to fungal attack, while vessels were resistant to the activity of lignolytic enzymes.

The impact of climate change on the technical accessibility of forests in the Tikhvin District of the Leningrad Region of Russia

Large forest areas in Russia are accessible for wood harvest only during the ground-frost season with stable snow cover. Currently, in the Leningrad Region, 80% of the actual annual fellings are carried out in winter. The general aim of the study was to develop a simple method to predict the impact of climate change on production of industrial and energy wood. The Tikhvin District of the Leningrad Region of Russia was selected as a study area. The average duration of the winter felling season was predicted for decades in the period 2008–2098 using the daily temperature trend in the period 1949–2008 derived from regional meteorological data and extrapolated out to 2098. The average duration of the winter felling season is predicted to decrease by 3–4 days per decade. Forests which can be cut only in winter were identified using geographic information technologies and a set of criteria. Annually, 209,000 m3 of industrial and energy wood can be cut in these forests. The supply of energy wood is less vulnerable to the reduction of winter felling season compared to the production of industrial wood because summer felling sites can provide enough energy wood to satisfy the current demand. In the future, the most harmful impact of climate change on the technical accessibility of wood in the study area will be the increasing occurrence of extreme, short winters.

Waste of Felling and On-Site Production of Teak Squarewood of the Community Forest

Major suppliers of teak wood for the raw material of furniture industry in Indonesia are Perum Perhutani, community forests, and private forests. Community teak forest management produce roundwood or squarewood, in which squarewood is produced on the felling site by the use of chainsaw after felling and bucking activities. Utilization of teak wood from community forest has been practiced for decades, however information on the extent of utilization and the quantity of wood waste have not been published to a greater extent. The present research was intended to determine and analyze the extent of utilization and teak wood waste produced from felling and bucking, and on-site squarewood production of community forests. Quantification of wood waste from felling and bucking was based on the whole tree method, while that of squarewood production was based on the percentage of yield. It was found that the quantity of teak felling and bucking wood waste in community forest was reaching 28% of felled wood volume that consisted of branch and twig (46.15%), upper trunk (30.77%), short cut off (15.38%), and stumps (7.69%). The largest part of the wood waste of teak felling and bucking satisfied the requirement as raw material of wood working industry according to Indonesian National Standard. On-site production of squarewood increased the quantity of wood waste in the forests (in the form of slabs and sawdust).

Comparative study on the structure of Cedrus deodara (Roxb. Ex Lambert.) G. Don forest in silvicultural felling and non-felling sites of Chakrata Forest Division

Vegetation composition, species diversity, Shannon-Wiener Index and regeneration behaviour of tree species in silviculturally managed felling and non-felling sites of the Deodar (Cedrus deodara (Roxb.ex Lambert.) G. Don forest of the Chakrata Forest Division, Uttarakhand, India was analysed. Plant density (plants ha-1) was higher in felling sites (350 ha-1) than the non felling sites (300 ha-1). Total basal cover (TBA, cm2 100 m-2) was also found higher in felling sites (7375) than non-felling site (3949). The diversity index and species richness were higher for shrubs and herbs at felling site. Dominant species (Cedrus deodara) has shown good regeneration potential as evidenced by the presence higher sapling and seedlings in felling site. Canopy opening by felling operation created the route for the invasion of the new shrub and herb species and regeneration of dominant tree species at felling site.

Leaching of wood ash products aimed for spreading in forest floors – Influence of method and L/S ratio

Use of biofuels in the form of logging residues is increasing in the European countries. This intensive forestry, where entire trees are removed from the felling sites, may contribute to a negative nutrient balance in the forest soil. Recycling of ash from the combustion of clean wood fuel, sometimes in combination with limestone or additives/binders, back into the forest soil could maintain the soil nutrient reservoir intact. Before spreading ash, it is important to determine its contents and, particularly, its decomposition pattern using reliable laboratory leaching tests. In this study, mineralogy and the leaching of Na, Ca, K, Mg, Mn, Al, Cu, Fe, P, and Zn from wood ash pellets and granules, produced both from green liquor sludge and fly ash, are examined by XRD and by subjecting these substances to three different laboratory leaching tests: upflow percolation (CEN/TS 14405), batch leaching (SS-EN12457), and a new Swedish leaching test using a magnetic stirrer. Mineral phases such as quartz, ettringite, calcite, gehlenite, and aphtitalite were identified in the ash granules and in the ash/green liquor sludge granules, by means of XRD. Six additional minerals were detected in the granules of ash only, and another six in the ash/green liquor sludge granules. At L/S 2, the batch leaching test resulted in the highest amounts of elements leached and the upflow percolation test the lowest. At L/S 10, both the batch leaching test and the upflow percolation test resulted in high amounts of elements leached. The batch leaching test at L/S 10 complies quite well with the percolation test and could be suitable for ash/green liquor sludge granule evaluation in daily practice. The magnetic stirrer test seems to underestimate the release potential of elements from granules. The batch test is simple to perform, and has the ability to dissolve 70-80% of the elements with the highest mobility from the materials under study.

Fuel quality changes during seasonal storage of compacted logging residues and young trees

Abstract Forest fuel procurement creates logistical problems, as large stocks are accumulated along the supply chain. The purpose of this study was to examine fuel quality (moisture content, ash content and calorific value) of compacted young trees (mainly downy birch) and both uncompacted and compacted logging residues (LR) (mainly Norway spruce). The materials were examined before and after storage, with and without cover, and effects of handling were considered. Dry matter losses from compacted LR during storage and handling were determined. Fuel quality and mass were determined before and after storage and handling. The moisture content of LR dropped to 28.6% when stored in small piles after fuel adapted logging at the clear felling site for 3 weeks in May. Drying continued after compaction into cylindrical bales (length 3.4 m, diameter 0.7 m) and during storage in windrows (9 and 12 months), the moisture content falling to 18.2–20.7% for the covered and 18.8–24.9% for the uncovered material. The windrow of loose LR remoistened to 40.8% (by snow contamination) resulted in a 6% lower net calorific value as received, compared to cylindrical bales. Ash contents were in the range 1.6–2.2% for LR and 1.0–1.2% for young trees. Dry matter losses ranged from 8.4% to 18.1% on compacted LR. Remoistening during the winter is higher for loose than for compacted LR. Early summer in northern Sweden provides favourable conditions for drying forest fuels.

Fuelwood Comparison with Other Kinds of Fuel

A part of Latvia’s forest resources, namely, branches, stumps, small stump top ends, firewood, slabs, sawdust, etc. remains unutilised both in the felling sites and woodworking plants. All this can be successfully utilised for production of heat energy, thereby replacing a part of the imported natural gas, coal and liquid fuel. To assess the utilisation of a definite type of primary energy, not only its accessibility and costs, but also calorific value should be known. The rational utilisation of energy resources in Latvia is urgent, since less than 30% from the consumption is obtained in this country. Thus, in 2000, the Latvia’s energy balance showed the total consumption of different types of primary energy resources to be 159 145 TJ (T = 1012). Utilising firewood, woodworking waste and chips, 34 250 TJ of energy was produced, or 21.5 % from the total primary energy consumed in Latvia. In the present study, fuel wood is compared with other types of fuel. If the equivalent value of one ton of coal (tce) is 29.308 MJ/kg, then the calorific value of natural gas and dry wood is 1.507 and 0.644, respectively. If 18.883 MJ of heat is obtained from 1 kg of oven dry wood, then 1.3 kg of wood with the relative moisture (Wr) content 20% and about 2.0 kg of freshly cut wood are necessary. To replace 1 ton of sawdust pellets or granules, 2.44 steres of birch firewood with the moisture content Wr = 20% or 2.63 steres with Wr = 40% are necessary. The above-mentioned amount of pellets or granules can be replaced by 3.47 steres of spruce firewood with Wr = 20% or 3.76 steres with Wr = 40%. The production of 1 kWh of heat from natural gas yields 0.224 kg of carbon dioxide, but in the case of fully combusted wood, from 0.35 to 0.4 kg of carbon dioxide.

The Impact of Wood Ash and Green Liquor Dregs Application on Ca, Cu, Zn and Cd Contents in Bark and Wood of Norway Spruce

To counteract nutrient depletion and acidification of forest soils, recycling of waste products from the forest industry has been suggested. Spreading of these waste products will probably change the concentration and availability of Ca and heavy metals in forest soils and thereby the contents of these metals in trees. This field study aimed at examining the influence of pellets of wood ash (ash) or a mixture of wood ash and green liquor dregs (ash+GLD) on the contents of Ca, Cd, Cu and Zn in wood and bark of Norway spruce [Picea abies (L.) Karst.]. The waste products were spread in an amount of 3000 kg ha−1 in 1996 at a felling site in Sweden and in 1999 and 2002 young spruce trees, planted in 1995, were collected and wood and bark were analysed for Ca, Cd, Cu and Zn with AAS. Changes in the metal content of wood and bark of young spruce trees were found 3 and 6 years after spreading pellets of ash or ash+GLD compared with the control. The effect of the treatments on the metal contents of bark and wood differed and was larger after 3 years than after 6 years. Treatment with ash+GLD tended to have less effect on the metal contents of bark and wood than treatment with only ash. An increase in the contents of Cu and Zn in bark or wood, compared with the control, was only found for the ash treatment and only 3 years after application. Both the ash and ash+GLD treatment decreased the Cd content of the wood and/or bark after 3 years, and after 6 years it still was, or tended to be, lower than the control.

Development strategies for privately owned forestry in the mountainous region of Sweden

Forestry in Sweden as well as in other European countries is characterised by intense and increasing international competition resulting in decreasing roundwood prices in real terms. This is especially the situation in the mountainous region of Sweden with long transportation distances between the felling site and the processing industries located at the coast. The question arises whether forestry must be run more extensively than at present to achieve the optimal rate of silvicultural activities compared with the amount of timber cut. With this in mind, optimising economic analyses have been performed at the stand level as well as at the level of forest estates. Results of the analyses reveal that more intensive thinning (more frequent operations) and shorter rotation periods would increase profit and offset continuously decreasing roundwood prices. Intensive pre-commercial thinning (cleaning) is especially important for profitability of the subsequent thinnings and the final cut. The large number of cuts during the rotation will increase logging costs. However, this will be more than offset by the increasing production of economically matured dimensions of timber, an effect that will be still more pronounced when using new harvesting technology. Moreover, frequent high thinning operations (thinning ‘from above’ or removal of dominant trees) will result in more dense wood close to the pith, more evenly distributed year rings, and fewer and smaller knots in the lower part of the stem — in other words more valuable roundwood which will justify high transportation costs. Several biological and technical aspects of these treatment programs are discussed in the paper.

Does climber cutting reduce felling damage in southern Cameroon?

In the lowland rain forest in southern Cameroon, an experiment was set-up to test whether pre-felling climber cutting could reduce logging damage. The abundance of lianas in the forest and their resprouting capacity after cutting was assessed. Logging damage was considered as tree mortality and tree damage in the felling gaps and the sizes of the created gaps after felling. Lianas were very abundant: on average nearly 5000 individuals (at breast height) of which over 100 large ones (≥5 cm DBH) per ha. Some 70% of monitored lianas had died 22 months after cutting. Resprouting capacity was high but variable among species. Felling gapsizes (average 550 m 2 per felled tree), tree mortality (12 trees per felled tree) and damage (20 trees per felled tree) were not significantly affected by pre-felling climber cutting. A minority of the damage was severe. Smaller trees were most prune to destruction and severe damage. The results show that pre-felling climber cutting has no significant effect on resulting gapsizes, tree mortality and damage levels. We conclude that climber cutting before a logging operation does not contribute to damage reductions at the felling sites in African moist forests where the logging intensity is extremely low. The average harvest level in the study area was one tree or about 13 m 3 ha −1. We suggest that climber cutting should be applied on a tree-by-tree basis only, and after a careful judgement of the tree’s liana load.

Forest damage caused by selection logging of mahogany ( Swietenia macrophylla) in northern Belize

We assessed the damage caused by selection logging of mahogany in a tropical forest in northern Belize and compared it with damage reported in other Neotropical logging and disturbance studies. We mapped skid roads and tree felling sites, and assessed soil compaction, loss of canopy cover, damage to saplings and trees, seedling survival and seedling height growth. Logging had been conducted using hand crews with chain saws and cable skidders. Logging directly affected 11.9 ha (12.9%) of the 92.3 ha logging area. Canopy cover decreased the most at logging gaps, and soils were most compacted on skid roads. Soil compaction was much greater on roads where more than one tree had been skidded. For the whole logged area, canopy cover declined 2% and compacted soils covered 3.8% of the area. Seedling height growth was unaffected by soil compaction, but seedling survival was less on compacted sites. About 50% of the trees and about 15% of the saplings were damaged in gaps and along skid roads. However, only 4.8% of the trees and 1.9% of the saplings were damaged for the logged area as a whole. The most common kinds of damage included scraped bark, snapped tops, and run-over stems. Although this logging operation had relatively low impacts compared with other logging operations in the Neotropics, it may not be silviculturally sustainable because its disturbance may be insufficient to promote adequate mahogany regeneration.

Uso de hidrófobos en la fabricación de tableros de partículas con residuos de cosecha forestal

SUMMARY The technical feasibility and the effect of a hydrophobic substance on particleboards made with the logging residues of Olivillo, and Pino insigne wood was studied. The manufacturing of the boards used residues from a 13 year old radiata pine tried with an average diameter of 14 cm and a height of 20.3 m., and for the Olivillo boards residue from a felling site of Roble-Laurel-Lingue, with average diameters of 25.8 cm and 100 to 150 years of age was used. Twenty-four boards, of a single layer, 11 mm. thick and with density of 600 kg/m 3 , were made from each of the two species considered. Ureaformaldehyde was the adhesive used with a binder factor of 9% b.o.d.w. The hydrophobic substance used, was a parafine emulsion which was applied at five different concentrations b.o.d.w. of the particles, the lowest being 0.5% and the heighest being 2.5 %. By including hydrophobic substances into the boards, their physical properties improve notably. However, the hydrophobe produced a slight decrease in the recorded mechanical resistance of the boards, particulary those of traction, which was not, however, significant. With a level of up to 1.5% of parafine emulsion added to the boards, adequate physico-mechanical properties were attained which also reached the values established by the corresponding norms.