Category: Research article
article id 488, category Research article
Effect of boric acid treatment on mechanical properties of laminated beech veneer lumber. Silva Fennica vol. 37 no. 4 article id 488. https://doi.org/10.14214/sf.488
Laminated veneer lumber (LVL) made from beech wood veneers treated with boric acid by using dipping method was tested for some mechanical properties following different standards. The values for treated LVL varied around the mean values of untreated LVL panels for static bending strength in the grain direction and modulus of elasticity; decreased for compression and splitting strengths, perpendicular to the grain; increased for compression strength parallel to the grain, and for Brinell hardness and pull-out strength of screw, perpendicular to surface.
article id 487, category Research article
Logistic services as a competitive means – segmenting the retail market for softwood lumber. Silva Fennica vol. 37 no. 4 article id 487. https://doi.org/10.14214/sf.487
Softwood lumber has been considered traditionally as commodity. Subsequently brand names and trademarks were of subordinate value and competition was based on price. Recently, retailers have grown substantially and are forcing their suppliers to improve the production and delivery of products. As retailers are getting more diverse and powerful, suppliers are forced to adapt to the retailers’ service requirements. The new situation also brings opportunities for the sawmills to develop their competitive advantage. The retail industry is continuously changing, and in order for sawmills to develop and offer what retailers are asking for, it is necessary that they understand and interpret retailers’ requirements correctly. One way for sawmills to be successful is to develop accurate service elements and to use the service elements as a segmentation base in order to structure their customer base. This study shows that retailers place considerable emphasis on delivery and value-added logistical services. It generates three hypotheses concerning the following potential retail segments; turnover, category, and customer base.
article id 486, category Research article
Comparing simulation methods for modelling the errors of stand inventory data. Silva Fennica vol. 37 no. 4 article id 486. https://doi.org/10.14214/sf.486
Forest management planning requires information about the uncertainty inherent in the available data. Inventory data, including simulated errors, are infrequently utilised in forest planning studies for analysing the effects of uncertainty on planning. Usually the errors in the source material are ignored or not taken into account properly. The aim of this study was to compare different methods for generating errors into the stand-level inventory data and to study the effect of erroneous data on the calculation of specieswise and standwise inventory results. The material of the study consisted of 1842 stands located in northern Finland and 41 stands located in eastern Finland. Stand-level ocular inventory and checking inventory were carried out in all study stands by professional surveyors. In simulation experiments the methods considered for error generation were the 1nn-method, the empirical errors method and the Monte Carlo method with log-normal and multivariate log-normal error distributions. The Monte Carlo method with multivariate error distributions was found to be the most flexible simulation method. This method produced the required variation and relations between the errors of the median basal area tree characteristics. However, if the reference data are extensive the 1nn-method, and in certain conditions also the empirical errors method, offer a useful tool for producing error structures which reflect reality.
article id 485, category Research article
Nature conservation efforts by forest owners – intentions and practice in a Swedish case study. Silva Fennica vol. 37 no. 4 article id 485. https://doi.org/10.14214/sf.485
Before a forest operation Swedish forest owners need to fill in a registration form. Since 1994, when a new Swedish Forestry Act came into force, intended nature conservation measures can also be noted on the form. I evaluate 1) if the self-reported nature conservation intentions displayed any trends from 1995 to 2000, and 2) if the intentions were implemented. All forms from these years, in one municipality, were analysed and the stand structure retention was measured on 40 clear-cuts. The intentions, noted as check-marks on the form, showed an increasing trend during these years. However, the increase may be an artefact of changes the form during the time period. The number of check-marks on the forms and the stand structure items actually present on the 40 clear-cuts showed a positive relation. The clear-cuts with ≤ 3 check-marks on the form had lower amounts of the three most common items, than those with ≥ 4 check-marks. To conclude 1) a true increase in the self-reported intentions of the forest owners could not be established; 2) the intentions were generally followed by associated practices on the clear-cuts; 3) the amounts of stand structures retained were probably not enough to reach the biodiversity goal of the Forestry Act. The registration form could be improved to become less open for interpretation and contain quantified recommendations. Self-reported intentions of the forest owners could then possibly be used as indicators of real structural retention, which could facilitate planning and allow for making predictions about the future forests.
article id 484, category Research article
New, low estimate for carbon stock in global forest vegetation based on inventory data. Silva Fennica vol. 37 no. 4 article id 484. https://doi.org/10.14214/sf.484
Several reports by Intergovernmental Panel on Climate Change (IPCC) have referred to published estimates ranging from 352 to 536 x 109 tons for the global pool of carbon in forest vegetation. However, a rounded estimate of 300 x 109 tons can be derived from the recent Global Forest Resources Assessment 2000 of the FAO, as shown in this paper. By comparing with independent empirical evidence as published in recent scientific literature and by considering sampling principles and the disturbance cycles of large forest regions, it is argued that the new lower estimate is more realistic. A downward correction of the estimate would make an important contribution to balancing the global carbon budget.
article id 483, category Research article
Addition of stabilized wood ashes to Swedish coniferous stands on mineral soils - effects on stem growth and needle nutrient concentrations. Silva Fennica vol. 37 no. 4 article id 483. https://doi.org/10.14214/sf.483
Increasing use of forest fuels for energy production is generating increasing quantities of wood ash. A common understanding is that this ash should be spread in forests to counteract soil acidification and potential future nutrient deficiencies, and thus help sustain long-term forest productivity. A series of seven field experiments was established in Sweden in 1988–1995 to study the stem growth and needle nutrient concentrations of 30–60-year-old Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) Karst.) stands on mineral soil after additions of wood ash in different doses or a combination of wood ash and N. The results showed that the most pronounced growth responses occurred when N was added, either alone or in combination with wood ash. The stem growth responses to additions of wood ash without N were small and variable, and not statistically significant at any of the studied experimental sites. However, there were indications that the addition of wood ash may increase stem-wood growth on fertile sites and decrease it on less fertile sites. In the short term, the addition of wood ash tended to increase the needle nutrient concentrations of most analyzed elements, except for N, but this could not be correlated to responses in stem growth.
article id 482, category Research article
Reproductive biology of Faidherbia albida (Del.) A. Chev. Silva Fennica vol. 37 no. 4 article id 482. https://doi.org/10.14214/sf.482
Phenology, flowering and fructification were studied in 5 natural populations of Faidherbia albida in a semi-arid zone in Senegal. In this species, the inflorescence acts as the reproductive unit; the basal flowers, opening first, have a low rate of fertilisation; the maximum rate of fertilisation (65%) was obtained in the apical flowers. Stigmatic receptivity, tested by esterasic reaction, was maximal immediately after anthesis. Stigmata of F. albida can bear simultaneously 2 or 3 polyads. Controlled pollination revealed that allogamy is the dominant reproductive system (ISI = 0.2) in natural populations of F. albida. Intra-specific variability in selfing (ISI ranging from 0 to 0.54) was also observed. Despite of the complete reproductive mechanism during flowering, only a small number of ripe pods (1.25%) is produced, and an average of 70% of the ovules per carpel are fertilized.
article id 481, category Research article
Relationship between empty seed and genetic factors in European beech (Fagus sylvatica L.). Silva Fennica vol. 37 no. 4 article id 481. https://doi.org/10.14214/sf.481
The relationship between percentage of empty seed (Pes) and genetic factors was explored in an isolated stand of European beech (Fagus sylvatica L.). Nine allozyme loci (GOT-B, IDH-A, LAP-A, MDH-B, MDH-C, MNR-A, 6-PGDH-A, PGI-B and PGM-A) were used to estimate genetic factors. Pes ranged from 4.8% to 40.9% for seed samples of 91 trees within the stand and showed an approximate normal distribution. The average Pes was 21.4% and the repeatability of Pes was 43.4%. The multilocus estimate for outcrossing rate (tm) based on seed samples of 30 trees within the stand was 1.015 (SE = 0.011) and the mean single locus estimate was slightly higher at 1.061 (SE = 0.026). No evidence of biparental inbreeding was found. Weak positive correlation between Pes and maximum selfing rate as well as and significant negative correlation between Pes and multilocus outcrossing rate indicated that self-fertilization may be explained as one of the important causes of empty seeds in beech.
Category: Review article
article id 489, category Review article
U.S. landowner behavior, land use and land cover changes, and climate change mitigation. Silva Fennica vol. 37 no. 4 article id 489. https://doi.org/10.14214/sf.489
Landowner behavior is a major determinant of land use and land cover changes, an important consideration for policy analysts concerned with global change. Study of landowner behavior aids in designing more effective incentives for inducing land use and land cover changes to help mitigate climate change by reducing net greenhouse gas emissions. Afforestation, deforestation, reforestation, and timber harvest are the most frequent land management practices that influence forest carbon stocks and flux. Research studies provide estimates of how private landowners respond to market signals and government programs and how they alter land management. For example, landowners have tended to retain subsidized afforested stands well beyond program life in the United States, suggesting that similar programs for climate change mitigation could result in high rates of retention. At the same time, policy makers need to be aware that unintended consequences of policies can lead to significantly different outcomes than envisioned, including leakage possibilities.