bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of growth prediction errors on the expected losses from forest decisions
Authors: Pietilä Ilona , Kangas Annika , Mäkinen Antti , Mehtätalo Lauri
Published: March 2014

In forest planning, forest inventory information is used for predicting future development of forests under different treatments. Model predictions always include some errors, which can lead to sub-optimal decisions and economic loss. The influence of growth prediction errors on the reliability of projected forest variables and on the treatment propositions have previously been examined in a few studies, but economic losses due to growth prediction errors is an almost unexplored subject. The aim of this study was to examine how the growth prediction errors affected the expected losses caused by incorrect harvest decisions, when the inventory interval increased. The growth models applied in the analysis were stand-level growth models for basal area and dominant height. The focus was entirely on the effects of growth prediction errors, other sources of uncertainty being ignored. The results show that inoptimality losses increased with the inventory interval. Average relative inoptimality loss was 3.3% when the inventory interval was 5 years and 11.6% when it was 60 years. Average absolute inoptimality loss was 230 euro ha when the inventory interval was 5 years and 860 euro ha when it was 60 years. The average inoptimality losses varied between development classes, site classes and main tree species.â1â1
Variations of yield and utilisation of bilberries (Vaccinium myrtillus L.) and cowberries (V. vitis-idaea L.) in Finland
Authors: Turtiainen Marjut , Salo Kauko , Saastamoinen Olli
Published: March 2014

So far, only rough estimates for the utilisation rates of wild berries in Finland have been available. One reason for this is that there has been a lack of empirical-knowledge-based studies concerning total yields of wild berries and their yield variations. This study had three aims: 1) total bilberry and cowberry yields of an average crop year were calibrated for different (abundant and poor) crop years using the inventory data on wild berries collected by the Finnish Forest Research Institute (1997â2008); 2) national utilisation rates of bilberries and cowberries were calculated for three different berry years 1997â1999; and 3) regional utilisation rates of these berry species were calculated for the year 1997. According to calculations, annual bilberry yields in Finland vary from 92 to 312 million kg. For cowberry, the range of variation in total berry yields is from 129 to 386 million kg. It was also found that approximately the same proportion of the total yield of bilberries (i.e. 5â6%) was collected between 1997 and 1999. Utilisation rates of cowberries were also quite constant varying from approximately 8% to nearly 10%. In 1997, bilberries and cowberries were utilised most intensively in the eastern parts of the country and in the Oulu-Kainuu region. The results of this present study describe the situation before the phenomenon of foreign pickers. It can be presumed that commercial wild berry picking by migrant collectors has so far affected both national and regional utilisation rates of wild berries.
Multiple criteria decision analysis with consideration to place-specific values in participatory forest planning
Authors: Nordström Eva-Maria , Eriksson Ljusk , Öhman Karin
Published: March 2014

The combination of multiple criteria decision analysis (MCDA) and participatory planning is an approach that has been applied in complex planning situations where multiple criteria of very different natures are considered, and several stakeholders or social groups are involved. The spatial character of forest planning problems adds further to the complexity, because a large number of forest stands are to be assigned different treatments at different points in time. In addition, experience from participatory forest planning indicates that stakeholders may think about the forest in terms of place-specific values rather than in forest-wide terms. The objective of this study was to present an approach for including place-specific values in MCDA-based participatory forest planning and illustrate the approach by a case study where the objective was to choose a multipurpose forest plan for an area of urban forest in northern Sweden. Stakeholder values were identified in interviews, and maps were used to capture place-specific spatial values. The nonspatial and nonplace-specific spatial values were formulated as criteria and used to build an objective hierarchy describing the decision situation. The place-specific spatial values were included in the creation of a map showing zones of different silvicultural management classes, which was used as the basis for creation of forest plan alternatives in the subsequent process. The approach seemed to work well for capturing place-specific values, and the study indicates that formalized methods for including and evaluating place-specific values in participatory forest planning processes should be developed and tested further.
Saw log recovery and stem quality of birch from thinnings in southern Finland
Authors: Kilpeläinen Harri , Lindblad Jari , Heräjärvi Henrik , Verkasalo Erkki
Published: March 2014

The objective of this study was to examine the timber quality of silver birch (Betula pendula Roth) and European white birch (Betula pubescens Ehrh.) trees in the first and second thinnings in southern parts of Finland, from the viewpoint of sawing of small-diameter, short logs, in particular. The average stem volume of birch was 0.140Â m in the first thinning stands and 0.206 m in the second thinning stands. In planted stands, the trees were larger in the first thinnings but slightly smaller in the second thinnings, compared with naturally regenerated pure birch stands or mixed stands of Norway spruce and birch species. Almost 60% of the harvested and 35% of the remaining stems that could provide saw logs were graded as pulpwood for timber quality due to the occurrence of stem defects. The most common stem defects were multiple crooks and middle crooks. Only minor between-stratum differences were detected in the numbers of defects. Depending on the bucking option, the total percentage of saw and plywood logs from the total birch recovery in the thinning of the sample stands varied between 11.7 and 18.2. The recovery of saw logs was clearly higher in the second thinnings, 12â19%, than in the first thinnings, 8â14%. Of the stand types, saw log recovery was the highest in planted birch stands, 12â19%, but lower in naturally regenerated pure birch stands and mixed stands of Norway spruce and birch. The highest share of saw logs was in the second thinning of planted stands, 17â25%. This study shows that the harvesting recoveries of end-use based timber assortments can be estimated in different kinds of thinning birch stands. Based on tree and log dimensions and stem squality, silver birch firstly from plantations and secondly from mixed stands should be the most interesting source of raw material for the saw milling, furniture and interior product sectors.33
Supply chain management applications for forest fuel procurement – cost or benefit?
Authors: Windisch Johannes , Sikanen Lauri , Röser Dominik , Gritten David
Published: March 2014

It is commonly agreed that logistics is very demanding in forest fuel business. Even though logistics and supply chain management (SCM) tools already have found their way into forestry business, for example, in roundwood operations, they are not yet very widespread in the field of forest fuel procurement. The present study investigates if modern supply chain management applications are capable of increasing the profitability of forest fuel procurement operations. Since margins are low, decreasing the provision costs could boost wood-based bioenergy business. The study is based on the investigation of two Finnish forest owners associations (FOA) involved in forest fuel procurement using a modern SCM tool. The investigation is done by cost-benefit analysis (CBA) using the net present value (NPV) methodology to determine the profitability. According to the estimates made by the staff, which are based on data such as work time records and delivery notes from before and after introduction of the new system, in both FOAs, the benefits far outweigh the costs over a considered timespan of ten years. However, the amount of the NPV varied significantly. For FOA1, with an annual chip production of 150 000 loose m3, the NPV is 212 739 euro, while for FOA2, with an annual chip production of 37 000 loose m3, the NPV is 969 841 euro. Even if the NPV of FOA2 seems to be very high, the profitability of SCM tools in forest fuel procurement is clearly demonstrated. Additionally, the results indicate that a considerable cost saving potential in forest fuel procurement is attainable through improving work flows and thus reduce the work input.
Comparison of growth and physiological responses to severe drought between two altitudinal Hippophae rhamnoides populations
Authors: Yang Yongqing , Yao Yinan , Zhang Xuejiang
Published: March 2014

Growth and physiological differences in response to drought were compared between two sea buckthorn (Hippophae rhamnoides L.) populations inhabited in the southeast of the Qinghai-Tibetan Plateau of China. The experimental design included two water regimes (100% and 25% of field capacity) and two populations from the low and high altitude zone. Our experiments were conducted in a naturally lit greenhouse under semi-controlled environmental conditions for a whole growing season in a dry valley (1800 m above the sea level). We found that drought tolerance is highly related to the plant antioxidant capacity and water use efficiency as well as leaf nutrient status in H. rhamnoides. The highland population (HP) experienced a greater inhibition in plant growth and leaf enlargement, lower leaf nitrogen and phosphorus content, lower root nodule biomass and root mass/foliage area ratio, and higher leaf water content loss paralleling with higher enhancement of abscisic acid level in response to drought, as compared with lowland population (LP). Additionally, reduction of leaf lignin content in HP further reduced its drought tolerance. On the contrary, LP showed effective adaptation strategies such as improvement of water economy and maintaining high ascorbic acid content. Therefore, we conclude that LP was more tolerant to drought than HP, and could be selected for reforestation in the dry valleys of upper Minjiang River regions in China.
Effects of training for inexperienced surveyors on data quality of tree diameter and height measurements
Authors: Kitahara Fumiaki , Mizoue Nobuya , Yoshida Shigejiro
Published: March 2014

Due to the large number of sample plots and variables to be measured, inexperienced surveyors are expected to take field measurements in National Forest Inventories (NFIs). However, very little information exists on the data quality that can be expected from inexperienced surveyors given different levels of training. We evaluated the quality of data produced by inexperienced undergraduate students when measuring the most fundamental variables: tree diameter using a diameter tape and height using an ultrasonic Vertex III hypsometer. We found that a single training session on how to use the instruments and how to reduce measurement errors was insufficient for inexperienced surveyors to achieve measurement quality objectives (MQOs). Providing a single feedback of control team measurements significantly improved data quality, except in the measurements of tree height of broad-leaved trees, but additional feedback did not contribute to further improvement. We propose that field training courses for inexperienced surveyors incorporate a one-day exercise with feedback instruction.
Forest habitat loss and fragmentation in Central Poland during the last 100 years
Authors: Mazgajski Tomasz , Zmihorski Michal , Abramowicz Katarzyna
Published: March 2014

The process of habitat fragmentation consists of two components â habitat loss and fragmentation per se. Both are thought to be among the most important threats to biodiversity. However, the biological consequences of this process such as species occurrence, abundance, or genetic structure of population are driven by current, as well as previous, landscape configurations. Therefore, historical analyses of habitat distribution are of great importance in explaining the current species distribution. In our analysis, we describe the forest fragmentation process for an area of 178 km in the northern part of Mazowsze region of central Poland. Topographical maps from the years 1890, 1957 and 1989 were used. Over the 100-year period, forest coverage in this area changed from 17% to 5.6%, the number of patches increased from 19 to 42, while the area of the forest interior decreased from 1933 ha to 371 ha. The two components of fragmentation were clearly separated in time. Habitat loss occurred mainly during the first period (1890â1957) and fragmentation per se in the second (1957â1989). Moreover, we recorded that only 47.7% of all the currently (in 1989) afforested areas constitute sites where forests previously occurred (in 1890 and 1957). For forest dwelling organisms characterized by low dispersal abilities, the effective forest coverage seems to be a half of the real forest area in the studied landscape. New afforestations should be planned especially to increase those patches which contain ancient forest, where various plants and animals sensitive to fragmentation may have survived.2
Ophiostomatoid fungi transported by Ips sexdentatus (Coleoptera; Scolytidae) in Pinus pinaster in NW Spain
Authors: Bueno Alberto , Diez Julio , Fernández Mercedes
Published: March 2014

Ips sexdentatus (Coleoptera; Scolytidae) is one of the main vectors of ophiostomatoid blue stain fungi that can cause mortality of healthy conifers. For this reason, our objective was to identify the fungal species carried by this bark beetle in Maritime pine (Pinus pinaster) in north-western Spain. We collected insects from naturally infected pines placed them on malt extract agar (MEA) and left to walk freely on culture plates. Plant tissues (phloem and xylem) from adult pines were cultivated in moist chambers and also on MEA. At the same time, we inoculated pine logs with living insects in the laboratory. Four ophiostomatoid fungi appeared: Ophiostoma ips, Ophiostoma brunneo-ciliatum, Ceratocystiopsis minuta and Ophiostoma sp., as well as Graphium and Sporothrix imperfect stages. Moreover there were seven saprophytic species: Penicillium sp., Trichoderma sp., Verticillium sp., Mucor sp., Aspergillus niger, Gliocladium viride and Scopulariopsis brevicaulis, and the pathogenic Ophiostoma ips. The fructification percentage of the ophiostomatoid species was low, however; its imperfect stage Sporothrix/Hyalorhinocladiella produced high quantity of conidiophores.
Effect of soil preparation method on economic result of Norway spruce regeneration chain
Authors: Uotila Karri , Rantala Juho , Saksa Timo , Harstela Pertti
Published: March 2014

Economic result of forest regeneration chains, based either on spot mounding or on disc trenching and planting of Norway spruce (Picea abies [L.] Karst.) seedlings, were clarified and compared to each other. First, effects of soil preparation method on early development of Norway spruce stands were measured from field experiments. Second, the effects of soil preparation method on stand level management programs were modelled. The modelling was based on growth simulation and investment calculations. The soil preparation methods substantially affected early development of a stand. The density of the removed trees in early cleaning was 56% higher on the disc-trenched area compared to the spot-mounded area. The difference was especially high (120%), close by (< 25 cm) the remained spruce seedlings. There was also a difference between the methods in the growth of crop spruces; at biological age of 8 years, the mean height of spruce was 110 cm on the spot-mounded area and 68 cm on the disc-trenched area. The differences led to divergent management programs between the areas. The disc-trenched area needed three young stand management operations whereas two was enough at the spot-mounded area. Although disc trenching is a less expensive method than spot mounding, the total management costs were higher in disc trenching than in spot mounding. Furthermore, incomes from the first commercial thinning were higher when regeneration based on spot mounding. At the interest rate of 3%, the investment in spot mounding had 329 EUR ha higher net present value than the investment in disc trenching.â1
Effects of Melampyrum extracts on the growth of axenic cultures of Cronartium flaccidum and Peridermium pini
Authors: Kaitera Juha , Nuorteva Heikki
Published: March 2014

For 3â6 months, mycelial colonies cultured from 5 isolates of each of two pine stem rusts (Cronartium flaccidum and Peridermium pini) were grown on nutrient-rich agar supplemented with Melampyrum extracts. Non-autoclaved extracts of M. pratense significantly reduced the growth of P. pini. The growth of C. flaccidum isolates was slightly stimulated after the second month of incubation but after that was inhibited during incubation months 4â6. We observed considerable variation in colony growth, a significant component of which was explained by incubation time, isolate, growth medium and their interaction. Rust species (C. flaccidum or P. pini) was not an important factor in growth variation. While sterilized extracts of M. pratense, M. sylvaticum and M. nemorosum did not significantly affect growth, colonies of C. flaccidum were slightly stimulated, whereas colonies of P. pini were slightly inhibited. Generally, isolates of P. pini grew better and showed a slower rate of degeneration than C. flaccidum on all media.
Non-destructive estimation of sapwood and heartwood width in Scots pine (Pinus sylvestris L.)
Authors: Bieker Dirk , Rust Steffen
Published: March 2014

Accurate estimates of the water conducting sapwood area are necessary to scale sapflow measurements to tree and stand level transpiration. We tested a non-destructive method, electric resistivity tomography (ERT), to estimate the area of conductive sapwood in 9 Pinus sylvestris L. trees in lower Saxony, Germany. Tomograms were compared to cross-sections stained with benzidine after harvesting. All tomograms displayed a distinct pattern of low resistivity at the stem perimeter and high resistivity in the stem centre with a steep increase in resistivity in between, assumed to indicate the transition from sapwood to heartwood. The tomograms showed a sapwood width 2 cm smaller than the staining method. This indicates that staining methods overestimate the amount of active sapwood because when heartwood is formed, moisture content decreases before extractive contents reach levels visible by staining. The ERT method is a new powerful method for the non-destructive estimation of sapwood and heartwood width.
Assessing national compliance with international forest policy processes – the role of subjective judgments
Authors: Lindstad Berit , Solberg Birger
Published: March 2014

Several international policy processes with sustainable forest management (SFM) as a common goal have emerged during the past two decades. Based on an empirical study from Norway, this paper analyses the role of subjective judgments in assessing national compliance with three international forest policy processes, and the implications for determination of the effects of these processes. The Expanded Programme of Work on Forest Biological Diversity, the Ministerial Conference on the Protection of Forests in Europe and the United Nations Forum on Forests, including its predecessors, collectively provide more than 600 recommendations for SFM. While it is nothing new that SFM encompasses value questions, this paper is a systematic review of where in a process of assessing national compliance the role of judgments is most profound. The paper shows that the multiple objectives of the forest recommendations, references to national circumstances and provisions for stakeholder involvement lead to differing opinions about the degree of conformity between international recommendations and national situation, i.e. compliance. These differing opinions mean different prospects for the international processes to have effects, because only implementation, or active responses to international recommendations, constitutes effects. The roles of judgments and values are recommended topics for further investigation. Factors influencing how compliance is assessed, and consequently the degree to which implementation is deemed necessary, require specific attention. Due consideration to substantive and methodological choices in determining national changes and in separation of other sources of influence will provide a better basis for informed discussion of compliance with and effects of international forest-related policy processes.
Democratic legitimacy of the forest sector and nature conservation decision-making in Finnish print media discussion
Authors: Rantala Tapio
Published: March 2014

The study explores perceived democratic legitimacy of forest-related decision-making processes in the Finnish print media discourse. The data consists of the readersâ letters in four journals (n = 530), and the comments given during the preparation of the Finnish National Forest Program (n = 140). The objective is to identify the patterns of democratic legitimacy and respective performance evaluations of actual decision-making processes. The patterns can be classified as support for: (A) democracy and other forms of government, (B) different forms of participation, and (C) principles of democracy. The principles can be further classified into 1) core regime, 2) input, 3) throughput, and 4) output principles. Democratic legitimacy was found to be an important source of legitimacy in the public discussion since democratic patterns were found in more than half of the texts. The most common core legitimacy principles included freedom of speech, good national and international standing, forerunnership, and legality at national and international level. The central principles related to input legitimacy included popular sovereignty, a voice for the people, popular participation, openness, presenting alternatives, and urgency. The consensus and majority rules were found to be the most prominent throughput principles. Democratic output legitimacy included accountability, responsibility, cooperation, commitment, responsiveness, the possibility to appeal, credibility, comprehensiveness, and understandability. The findings suggest that among the writers of readersâ letters there is less contestation regarding the principles of democratic legitimacy but there are significant disagreements concerning the performance of decision-making processes. The negative performance evaluations were two times more frequent than the positive evaluations.
New paradigm for saving the world’s forests?
Authors: Katila Pia , Katila Marko
Published: March 2014

Book review: Douglas, J. and Simula, M. 2010. The Future of the Worldâs Forests. Ideas vs Ideologies. World Forests, volume 7. Springer. 211p.
Research method and improvement of log rotation in sawmills
Authors: Tulokas Tomi , Tannous Jawdat
Published: March 2014

Log rotation studies were performed at 14 Finnish sawmills during the years 2003â2005. In the investigation of automatic log rotation, the materialized degree of log rotation for each log was calculated from photos captured from a digital video recording. Rotation errors (D) for individual logs and again the accuracy of the automatic log rotator was determined from optimized angle values of the log measuring system and materialized angle values calculated from the still photos. The accuracy of the log rotation varied considerably between sawmills. The rotation error average of the automatic log rotation varied from â23.6Â° to +11.4Â°. This means that in some cases the logs were under-rotated and in some they were over-rotated, on an average. Standard deviation of the rotation error (s) of the automatic rotator varied from 4.4Â° to 22.9Â°. The results of the simulation indicated that the performance of the log rotation system can be improved by adjusting the log rotator control. In addition to the zero degree error on an average rotation (or near to zero), the corrected values have a significantly smaller standard deviation of the rotation error, and the number of correct rotations was significantly higher compared to the situation before the adjusted rotation commands. At Sawmill 1, standard deviation of the rotation error was reduced by 40.9% from 14.9 degrees to 8.8 degrees. At the same time the number of correct rotations (â10Â°â¤ D â¤ +10Â°) increased 4.0 fold from 20.1% to 79.4%. At Sawmill 2, standard deviation of the rotation error was reduced by 23.8% from 10.5 degrees to 8.0 degrees. At this sawmill, the rate of accepted rotations increased 1.9 fold from 42.6% to 81.0%. According to previous research, 2.5Â° decrease in standard deviation of the rotation error (from 10.5 to 8.0Â°) in square sawing means about 0.5% increase in value yield. For example with 10 million Ã annual sales of sawn timber this means 50 000 Ã extra profit.
Dynamic response of herbaceous vegetation to gap opening in a Central European beech stand
Authors: Kelemen Kristóf , Mihók Barbara , Gálhidy László , Standovár Tibor
Published: March 2014

Herbaceous ground vegetation in artificially-created gaps was studied in a managed beech (Fagus sylvatica L.) forest over a period of eight years in Northern Hungary, Central Europe. These gaps were being used as an alternative to the regular shelterwood system to create uneven-aged stands. The effects of gap size (15 and 40 m diameter) and canopy openness on herbaceous species colonization and persistence were assessed in a systematic grid of 5 5 m. Overall, herbaceous cover was low before gap creation, increased soon afterwards, and continued to rise over time. The number of herb species increased in the gaps and, to a lesser extent, in adjacent areas under the remaining tree canopy. Colonization of gaps was rapid and there was substantial turnover of species i.e. various species disappeared from the gaps over time whilst others colonized. Species with both long-term persistent seed banks and long distance dispersal abilities were the most successful types colonizing gaps. Six species occurred preferentially in large gaps, while only one species was found to prefer small gaps. Species present before gap creation survived in both gap sizes. Smaller gaps with a diameter of half the height of canopy trees also tended to remain free of common weed species, whereas large cover of Rubus fruticosus L. and Calamagrostis epigejos (L.) Roth could hamper natural regeneration in larger gaps. For the successful regeneration of beech we recommend the use of small gaps complemented by few large gaps.
The suitability of leaf-off airborne laser scanning data in an area-based forest inventory of coniferous and deciduous trees
Authors: Villikka Maria , Packalén Petteri , Maltamo Matti
Published: March 2014

This study examined the suitability of airborne laser scanner (ALS) data collected under leaf-off conditions in a forest inventory, in which deciduous and coniferous trees need to be separated. All analyses were carried out with leaf-on and leaf-off ALS data collected from the same study area. Additionally, aerial photographs were utilized in the Nearest Neighbor (NN) imputations. An area-based approach was used in this study. Regression estimates of plot volume were more accurate in the case of leaf-off than leaf-on data. In addition, regression models were more accurate in coniferous plots than in deciduous plots. The results of applying leaf-on models with leaf-off data, and vice versa, indicate that leaf-on and leaf-off data should not be combined since this causes serious bias. The total volume and volume by coniferous and deciduous trees was estimated by the NN imputation. In terms of total volume, leaf-off data provided more accurate estimates than leaf-on data. In addition, leaf-off data discriminated between coniferous and deciduous trees, even without the use of aerial photographs. Accurate results were also obtained when leaf-off ALS data were used to classify sample plots into deciduous and coniferous dominated plots. The results indicate that the area-based method and ALS data collected under leaf-off conditions are suitable for forest inventory in which deciduous and coniferous trees need to be distinguished.
Analysing the agreement between an Airborne Laser Scanning based forest inventory and a control inventory – a case study in the state owned forests in Finland
Authors: Wallenius Tarja , Laamanen Risto , Peuhkurinen Jussi , Mehtätalo Lauri , Kangas Annika
Published: March 2014

Airborne laser scanning based forest inventories have recently shown to produce accurate results. However, the accuracy varies according to the test area and used methodology and therefore, an unambiguous and practical quality assessment will be needed as a part of each inventory project. In this study, the accuracy of an ALS inventory was evaluated with a field sampling based control inventory. The agreement between the ALS inventory and the control inventory was analysed with four methods: 1) root mean square error (RMSE) and bias, 2) scatter plots with 95% confidence intervals, 3) Bland-Altman plots and 4) tolerance limits within Bland-Altman plots. Each method has its own special features which have to be taken into account when the agreement is analysed. The pre-defined requirements of the ALS inventory were achieved. A simplified control inventory approach with a slightly narrower focus is proposed to be used in the future. The Bland-Altman plots with the tolerance limits are proposed to be used in quality assessments of operational ALS inventories. Further studies to improve the efficiency of quality assessment are needed.
Firm capabilities in the Finnish forest cluster: comparisons based on self-organizing map
Authors: Järvinen Joonas , Linnakangas Jaakko
Published: March 2014

This paper examines the capability portfolios of Finnish forest cluster firms in 1998â2008. In particular, the focus is on what kind of capabilities the firms in the cluster have developed, whether the firms have developed such capabilities consistently, and whether they have developed similar capability portfolios. Further, a particular focus is on the links between innovativeness and other identified capabilities. We approach the topic with an exploratory quantitative analysis of the annual reports of 11 large firms in the cluster by using computerized content analysis and a self-organizing map as the main research methods. Based on the content analysis and earlier literature, we first identify fifteen capabilities, and then build capability portfolios for the firms on the basis of the results of the self-organizing map. At the firm level, the results reveal both similarities and differences in the capability portfolios of the forest cluster firms. Similarly, we identify both continuity and change in the development of the portfolios. At the cluster level, the focus is on innovativeness capability and its relationship with other capabilities. The results suggest that especially being strategic, market-oriented, and monitoring the external environment are positively related with innovativeness; in contrast, a focus on finance and change seems to suppress innovativeness.
The restorative imperative: challenges, objectives and approaches to restoring naturalness in forests
Authors: Burton Philip , Macdonald S.
Published: March 2014

Many of the worldâs forests are not primeval; forest restoration aims to reverse alterations caused by human use. Forest restoration (including reforestation and forest rehabilitation) is widely researched and practiced around the globe. A review of recent literature reveals some common themes concerning forest restoration motivations and methods. In some parts of the world, forest restoration aims mainly to re-establish trees required for timber or fuelwood; such work emphasizes the propagation, establishment and growth of trees, and equates with the traditional discipline of silviculture. Elsewhere, a recent focus on biocentric values adopts the goal of supporting full complements of indigenous trees and other species. Such ecosystem-based restoration approaches consider natural templates and a wide array of attributes and processes, but there remains an emphasis on trees and plant species composition. Efforts to restore natural processes such as nutrient cycling, succession, and natural disturbances seem limited, except for the use of fire, which has seen widespread adoption in some regions. The inherent challenges in restoring ânaturalnessâ include high temporal and spatial heterogeneity in forest conditions and natural disturbances, the long history of human influence on forests in many regions of the world, and uncertainty about future climate and disturbance regimes. Although fixed templates may be inappropriate, we still have a reasonably clear idea of the incremental steps required to make forests more natural. Because most locations can support many alternative configurations of natural vegetation, the restoration of forest naturalness necessarily involves the setting of priorities and strategic directions in the context of human values and objectives, as informed by our best understanding of ecosystem structure and function now and in the future.
Temporal variability of deadwood volume and quality in boreal old-growth forests
Authors: Aakala Tuomas
Published: March 2014

Reference deadwood volumes from natural forests for forest management and restoration are often derived from one-time measurements or from repeated measurements over short time-scales. Such an approach often assumes an equilibrium state between tree mortality and decomposition, which is questionable in many boreal forest ecosystems due to the occurrence of allogenic disturbances. Using a simulation model based on empirical estimates of tree mortality, disturbance chronologies and models of wood decay class dynamics, this study aimed at characterizing variability in the volume and quality of deadwood for the past 200 years. The variability of deadwood volumes in old-growth forests, arising from differences in disturbance regimes and differing decay rates, was exemplified in two areas of Picea abies-dominated forests in northern Europe. The results imply that with stable deadwood input and slow decay rates the deadwood volume may be in an equilibrium state. On the contrary, if moderate-severity disturbances occur such a state seems improbable. Both study areas displayed continuity in deadwood availability, although temporary paucity in the early decay classes with shortest residence times was also observed. The results stress the importance of understanding the dynamic nature of deadwood in old-growth forests, instead of the traditional view of deadwood as a static ecosystem component.
Relationships between wood-inhabiting fungal species richness and habitat variables in old-growth forest stands in the Pallas-Yllästunturi National Park, northern boreal Finland
Authors: Ylläsjärvi Inari , Berglund Håkan , Kuuluvainen Timo
Published: March 2014

Indicators for biodiversity are needed for efficient prioritization of forests selected for conservation. We analyzed the relationships between 86 wood-inhabiting fungal (polypore) species richness and 35 habitat variables in 81 northern boreal old-growth forest stands in Finland. Species richness and the number of red-listed species were analyzed separately using generalized linear models. Most species were infrequent in the studied landscape and no species was encountered in all stands. The species richness increased with 1) the volume of coarse woody debris (CWD), 2) the mean DBH of CWD and 3) the basal area of living trees. The number of red-listed species increased along the same gradients, but the effect of basal area was not significant. Polypore species richness was significantly lower on western slopes than on flat topography. On average, species richness was higher on northern and eastern slopes than on western and southern slopes. The results suggest that a combination of habitat variables used as indicators may be useful in selecting forest stands to be set aside for polypore species conservation.
Old-forest species: the importance of specific substrata vs. stand continuity in the case of calicioid fungi
Authors: Lõhmus Asko , Lõhmus Piret
Published: March 2014

Appropriate conservation management of old-forest species depends on the causes of their old-forest affinity, which, however, are insufficiently known. Calicioid fungi are often considered old-forest dependent because of their special requirements for microhabitat, microclimate, and stand continuity for at least two tree generations. We demonstrate that, for several methodological or interpretational problems, published studies do not provide unequivocal evidence for such mechanisms and even for old-forest dependency of calicioids in general. We then analyse a large Estonian dataset (ca. 2300 records of 32 species) representing various management types and site types to answer whether old forests have more calicioid species, and any specific species, than could be expected for the substratum availability observed. Although old growth had more species and records than mature managed stands or cutover sites, those substratum types that occurred at roughly similar abundances also hosted comparable numbers of species in different management types. The characteristic substrata adding extra species to old growth were snags and root-plates of treefall mounds; wood surfaces in general comprised more than half of all calicioid records. Although substratum abundance did not fully explain the species-richness contrast between old growth and mature stands, additional evidence suggested that the unexplained variance is rather due to small-scale habitat characteristics than stand-scale continuity or microclimate. Finally, we review the evidence for old-forest affinity of calicioid species and distinguish a set of threatened species. We conclude that the availability of specific substrata is the main limiting factor for calicioid fungi in forests, and its quantitative and stochastic nature explains the large random and region-specific variation in the published lists of âold-forest speciesâ.
Density and height structure of seedlings in subalpine spruce forests of Central Europe: logs vs. stumps as a favourable substrate
Authors: Bace Radek , Svoboda Miroslav , Janda Pavel
Published: March 2014

Decaying logs and stumps provide an important seedling substrate in natural subalpine forests. However, only stumps present such a role in managed forests. The aim of this study was to assess the differences in the process of seedling colonization between logs and stumps. The study was carried out in the Czech Republic, in two old-growth subalpine spruce forests located in the Bohemian Forest and Ash Mts., dominated by Athyrium distentifolium Opiz and Vaccinium myrtillus L. undergrowth, respectively. Norway spruce (Picea abies (L.) Karst.) regeneration growing on logs, stumps and non-coarse woody debris (CWD) microsites was surveyed. Regeneration (height 0â2.0 m) densities exceeded 5000 individuals per ha on both sites. The average density of P. abies regeneration per square meter of substrate was 0.3-5.7-19.6 and 0.5-3.8-11.0 on non-CWD microsites, logs and stumps, located in A. distentifolium and V. myrtillus undergrowth, respectively. Stumps and non-CWD microsites dominated by V. myrtillus, supported a higher proportion of taller seedlings per plot compared to the small seedlings growing on logs and non-CWD dominated by A. distentifolium ground-cover. The disproportion in regeneration densities between the stumps and the original logs decreased with increasing stages of decay. The tallest regeneration growing on stumps (root-soil plates) was significantly older than that growing on the logs (stems). Based on these two latter findings, the stumps appeared to provide suitable seedling substrates several years earlier than the logs did. Therefore, we conclude that the stumps play a more important role (relative to their covered area, 21â28 m ha) in terms of suitable microsites for regeneration, than the logs do.2â1
Nontrivial solutions for singular semilinear elliptic equations on the Heisenberg group
Authors: Tyagi Jagmohan
Published: March 2014

In this article, we prove the existence of nontrivial weak solutions to the singular boundary value problem

-

Δ

ℍ

n

u
=
μ

g
(
ξ
)
u

(
|
z
|

4

+

t
2

)

1
2

+
λ
f

(
ξ
,
u
)

$-\Delta _{{\mathbb {H}}^{n}} u= \mu \frac{g(\xi ) u}{(|z|^{4}+ t^{2} )^{\frac{1}{2} }} +\lambda f(\xi , u)$

in Ω,

u
=
0

$ u =0$

on

∂
Ω

$\partial \Omega $

on the Heisenberg group. We employ Bonanno's three critical point theorem to obtain the existence of weak solutions.
Demand for Life Insurance in Malaysia: An Ethnic Comparison Using Household Expenditure Survey Data
Authors: Tan Andrew K. G. , Yen Steven T. , Hasan Abdul Rahman , Muhamed Kamarudin
Published: March 2014

This study examines the socio-demographic determinants of household expenditures on life insurance in Malaysia. Cragg’s two-part regression model is applied to data of 20,313 sample households from the 2009–2010 Malaysian Household Expenditure Survey to examine the determinants of purchase decisions and expenditure level for life insurance. Results of marginal effects, segmented by ethnicity, suggest that while socio-demographic factors are important determinants of life insurance demand, the effects vary across ethnic groups in Malaysia. For instance, wealth and education levels are associated with purchase likelihoods and amount of life insurance premiums purchased across ethnic groups. However, household size, regional location, urbanicity, and occupation type are associated with life insurance demand within certain ethnic groups only. Based on these results, several observations are noted vis-à-vis the life insurance market in Malaysia.
Character rigidity for special linear groups
Authors: Peterson Jesse , Thom Andreas
Published: March 2014

In this paper we study characters on special linear groups

SL
n

⁢

(
R
)

${\mathrm{SL}_{n}(R)}$

, where R is either an infinite field or the localization of an order in a number field.
We give several applications to the theory of measure-preserving actions, operator-algebraic superrigidity, and almost homomorphisms.
The twisted Kähler–Ricci flow
Authors: Collins Tristan C. , Székelyhidi Gábor
Published: March 2014

In this paper we study a generalization of the Kähler–Ricci flow,
in which the Ricci form is twisted by a closed, non-negative

(
1
,
1
)

$(1,1)$

-form. We show that when a twisted Kähler–Einstein metric
exists, then this twisted flow converges exponentially. This
generalizes a result of Perelman on the convergence of
the Kähler–Ricci flow, and it builds on work of Tian–Zhu.
Generating sequences of PSL(2,p)
Authors: Nachman Benjamin
Published: March 2014

Julius Whiston and Jan Saxl [J. Algebra 258 (2002), 651–657] showed that the size of an irredundant generating set of the group G = PSL(2,p) is at most four and computed the size m(G) of a maximal set for many primes. We will extend this result to a larger class of primes, with the surprising result that, when p ¬≡ ±1 mod 10, m(G) = 3 except for the special case p = 7. In addition, we will determine which orders of elements in irredundant generating sets of PSL(2,p) with lengths less than or equal to four are possible in most cases. We also give some remarks about the behavior of PSL(2,p) with respect to the replacement property for groups.
Influence of tire-cord layers and arrangement direction on the physical properties of polyester tire cord reinforced with chloroprene rubber composite materials
Authors: Tsai Peir-An , Wu Jyh-Horng
Published: March 2014

Polyester tire cord is used as reinforcement for making chloroprene rubber (CR) composite materials. This study investigated the influences of polyester tire-cord layers and arrangement direction on the mechanical properties of CR composite materials. The experimental results indicate that the optimal temperature and heating time for CR vulcanization are 170°C and 35 min, respectively. This processing condition enabled CR to achieve rapid vulcanization and exhibit optimal mechanical properties. The hardness and compression stiffness of the CR composites increased with increasing tire-cord layers. This phenomenon reduced the occurrence of creep under long-term loading but increased the compression set. In addition, when the arrangement direction of the tire cord and the stretching direction of CR were perpendicular, crack formation and growth easily developed, which reduced the bending-fatigue resistance of CR.
Antioxidant modification of C/C composites by in situ hydrothermally synthesized 4ZnO·B2O3·H2O
Authors: Yang Liu-Qing , Huang Jian-Feng , Li He-Jun , Cao Li-Yun , Fei Jie , Ouyang Hai-Bo , Wu Jian-Peng , Hao Wei
Published: March 2014

Antioxidant modification of carbon/carbon (C/C) composites by
Investigation of the joining characteristics of Al-B4C composites manufactured by friction welding
Authors: Orhan Ayhan
Published: March 2014

In this study, metal matrix composite materials consisting of 99% pure Al powder as the matrix and 99% pure B
Role of RET genetic variants in MEN2-associated pheochromocytoma
Authors: Siqueira Débora Rodrigues , Ceolin Lucieli , Ferreira Carla Vaz , Romitti Mírian , Maia Silvana Cavalcante , Maciel Léa Maria Zanini , Maia Ana Luiza
Published: March 2014

Background: RET polymorphisms have been involved in the clinical presentation and prognosis of multiple endocrine neoplasia type 2 (MEN2)-associated medullary thyroid carcinoma.

Objective

To investigate the effect of RET variants on the penetrance of pheochromocytoma (PHEO) in MEN2 patients. Methods: The RET variants L769L, S836S, and G691S/S904S were evaluated in a cohort of 153 MEN2 patients attending a tertiary teaching hospital. A comparison of RET variant frequencies between patients with and without PHEO was performed. Kaplan–Meier curves and Cox regression analysis were used to estimate the effect of RET variants on the age-dependent penetrance.

Results

A total of 48 (31.4%) patients presented with MEN2-associated PHEOs. The mean age at diagnosis was 35.5±13.4 years, 60.4% of patients were women, and 92.8% had RET mutations at codon 634. The frequencies of RET polymorphisms were as follows: 20.1% L769L, 4.75% S836S, and 17.3% S904S/G691S. We did not observe any association between the frequencies of L769L, S836S, or S904S/G691S variants and PHEO development (all P>0.05). However, individuals carrying two RET polymorphic alleles had an increased estimated risk of PHEO (2.63; 95% CI, 1.4–5.0; P=0.004) and were younger at diagnosis when compared with those with one or no polymorphism (29.6±6.3 and 39.3±14.4 years respectively; P=0.006). Accordingly, additional analysis using Cox proportional hazard models demonstrated that the presence of two RET variants was associated with an increased risk for early PHEO development (hazard ratio, 5.99 (95% CI, 2.24–16.03); P<0.001).

Conclusions

RET polymorphic alleles have an additive effect on the estimated risk of age-related PHEO penetrance in MEN2 patients.