•In regenerating forests commercial timber species represent an important proportion of the total tree diversity.•Forests as young as 30 years have stock-harvestable size commercial trees.•The ...significant volume of commercial timber makes mid- to late-secondary forests attractive for management.
The Brazilian Atlantic forest is largely covered by secondary forests, mostly regenerated after the abandonment of patches previously used for shifting cultivation. A characteristic of these secondary forests is the significant timber volume from fast-growing species at ages as young as 30–40 years. In this study, we investigated changes that occur in timber production of secondary forest during the first 50 years of succession. We inventoried 82 plots (10 × 20 m) in a chronosequence ranging from 2 to 50 years since agricultural abandonment in four municipalities located in Santa Catarina State, Southern Brazil. Our results showed that commercial tree species have rapid recovery of richness, basal area and stem volume in naturally regenerating forests. Commercial species represent about 51 percent of tree diversity, with 9 out of 12 dominant species being commercial timber species, with a stem volume up to 155 m3 ha−1. Trees of commercial species with ≥15 cm in diameter are first observed after 20 years of succession, while trees ≥30 cm are found at 30 years of succession, and produce 126 m3 ha−1 of stem volume. We highlight Hyeronima alchorneoides, Miconia cabucu and Miconia cinnamomifolia, as fast-growing dominant species that produce timber quality ≥20 cm in diameter after 20 years of succession, with volume reaching 200 m3 ha−1 before 40 years of succession. We found that secondary forests are dominated by fast-growing and wood-producing species, with a rapid increase in timber stocks in the early stages of succession. These secondary forests are important biodiversity reservoirs in human-pressured landscapes, in addition to providing forest products and other ecosystem services. The management of secondary forests may be an alternative restoration approach that can accelerate the recovery of timber stocks, provide landscape diversity, and add more value to private forests.
•Tree species diversity in forests can lead to higher productivity compared with monospecific stands.•However, little is known about the relationship between diversity and timber quality.•We found no ...significant relationship between tree species richness and timber quality in six major European forest types.•Tree size, crown dimension and stand characteristics are far more important for stem quality development.•High-quality wood production is possible in diverse forests.
Mixed-species forests can have higher productivity, in terms of wood volume, than monospecific forests. In addition, higher tree species richness has been found to positively correlate with multiple ecosystem services and functions. Surprisingly, stem quality as one of the most important factors regarding the economic value of forests has rarely been formally studied in diverse forests. This paper aims at investigating how tree species richness influences stem quality and which factors may drive quality development in these stands. Stem quality, understood here essentially as the suitability of a particular stem for particular end-uses, is influenced by a tree's ability to capture sufficient resources for growth and is influenced by neighbouring trees, e.g. through shading and physical crown interactions. We collected data on crown size, stem form and tree health for over 12,000 trees in 209 study plots in six European regions (Finland, Germany, Poland, Romania, Italy and Spain) within naturally diverse forests to assess the impact of tree species richness on these characteristics. Results showed that quality variability between regions, stands and individual trees was high across species. At the stand level, there was a slight tendency towards lower stem quality with increasing diversity. However, individual trees of high quality were present at all diversity levels and for all target species. Tree species richness could not be confirmed as a primary influence on stem quality at the stand level. Rather, stand and individual tree properties such as structural composition, competition, tree size and crown characteristics were identified as the main factors for stem quality development, even in mixed stands. Many of the factors identified in this study can be directly or indirectly influenced by forest management strategies tailored to produce high-quality timber in mixed-species forests. Our findings suggest that diverse stands are not inferior regarding stem quality, while at the same time being able to provide various other ecosystem services.
•Conversion of conifer plantations to mixed hardwood and conifer forests is important.•The optimal thinning intensity for creating mixed forests remains unclear.•Intensive thinning is a reliable ...method to create mixed forests at the canopy level.•Intensive thinning (67%) produced large trees of both conifers and hardwoods.•Weak thinning (33%) is suitable for producing high-quality conifer timber.
For managers of conifer plantations, conversion to mixed hardwood and conifer forests is an important management goal. However, the extent to which thinning intensity affects stand volume and timber quantity and quality remains unclear. We investigated the growth of conifer and hardwood trees over 14 years (at 5 and 9 years after the first and second thinning operations, respectively) under unthinned (Control), 33% thinned (Weak), and 67% thinned (Intensive) treatments in a Cryptomeria japonica plantation. The diameter growth of both conifers and hardwoods, stand volume of hardwoods, and relative increment of stand volume of conifers increased with greater thinning intensity in the order of Control < Weak < Intensive, whereas the reverse was observed for the stand volume of conifers, dead conifer trees, and total yield of stand volume (i.e., gross production). These results suggest that intensive thinning can create large conifers and hardwoods, but reduces gross production. Mean annual tree ring width (ATRW), consistency of ATRW value, and mean crown ratio increased with increasing thinning intensity in the order of Control < Weak < Intensive, while height-to-diameter ratio (i.e., slenderness) showed the opposite trend. These findings suggest that timber quality (e.g., wood density, stiffness, visual grading) was better under Weak than under Intensive thinning. However, the production of large conifer timbers with homogeneous ATRW may offset reductions in quality. This study suggests that intensive thinning is a reliable method for rapidly creating mixed hardwood–conifer forests at the canopy level and producing large timbers of both conifer and hardwood species, whereas weak thinning is suitable for producing high-quality conifer timbers and maintaining net primary production, although repeated thinning is necessary.
•Developed a mathematical model to manage the wood market interactions in the post-hurricane timber market.•Maximizing the total profit of the landowners and the mills in the post-hurricane timber ...market.•Developed two decomposition methods to speed up the solution process.•A case study is developed to visualize and validate the modeling results.
Among other factors, the softwood industry is disrupted by a large number of hurricanes that landfall in the southern U.S. Lack of efficient tools to manage the wood market interactions in the post-hurricane situation increases timber salvage loss drastically. In this study, we propose a bi-level mixed-integer linear programming model that captures important features such as the hurricane’s degree, quality of damaged timbers, price-related issues, optimizes different critical decisions (e.g., purchasing, storage, and transportation decisions) of a post-hurricane damaged timber management problem. The overall goal is to provide an efficient decision-making tool for planning and recovering damaged timber to maximize its monetary value and mitigate its negative ecological impacts. Due to the complexity associated with solving the proposed model, we developed two exact solution methods, namely, the enhanced Benders decomposition and the Benders-based branch-and-cut algorithms, to efficiently solve the model in a reasonable timeframe. We use 15 coastal counties in southeast Mississippi to visualize and validate the algorithms’ performance. Key managerial insights are drawn on the sensitivity of a number of critical parameters, such as selling/purchasing prices offered by the landowners/mills, quality-level, and deterioration rate of the damaged timbers on their economic recovery following a natural catastrophe.
The Resistograph has emerged as efficient non-destructive evaluation method, because it allows the fast assessment of mechanical resistance, density and other wood properties. The aim of the present ...study is to assess the influence of wood density and anatomy on resistance to resistographi drilling. Twenty trees of Eucalyptus grandis x Eucalyptus urophylla hybrids, at the age group of 6 years, whose chest height discs (CHD) were removed and subjected to diametrical strip drilling, were herein assessed. The critical locations of amplitude radius were selected after the visual analysis of the resistogram; it was done to remove samples for the anatomical analysis and density carried out to determine several moisture contents. Resistance to drill increased due to increased wood density. Person’s correlation between resistance to drill and basic density reached 0.67; density in hygroscopic moisture was 0.65. There was moderate correlation between fiber wall amplitude and thickness (r=0.65). Cell wall thickness, fiber length and lumen diameter were the main anatomical features contributing to higher resistance to resistograph drilling.
The purpose of this paper is to demonstrate the properties of glued laminated beams made in diverse configurations of timber quality classes, reinforced using a new technique that is cheaper and easy ...to apply. The aim of the experimental investigations was to enhance reinforcement effectiveness and rigidity of glued laminated beams. The tests consisted of four-point bending of large-scale specimens reinforced with basalt fibres (BFRP). The tests were meant to obtain images of failure, the load-displacement relation and load carrying capacity of basalt fibres depending on the reinforcement ratio. The tests, which concerned low and average quality timber beams, were conducted in a few stages. The aim of the study was to popularize and increase the use of low-quality timber harvested from reafforested areas for structural applications. In the study, theoretical and numerical analysis was carried out for reinforced and unreinforced elements in various configurations of wood quality classes. The aim was to compare the results with the findings of experimental tests. Based on the tests, it was found that the load carrying capacity of beams reinforced with basalt fibre was higher by, respectively, 13% and 20% than that of reference beams, while their rigidity improved by, respectively, 9.99% and 17.13%. The experimental tests confirmed that basalt fibres are an effective structural reinforcement of structural timber with reduced mechanical properties.
One of the goals of the European Union’s agroforestry plans is to alleviate the shortage of timber in Europe caused by the growing demand for hardwoods and the declining import of tropical timber. ...The study shows which tree species can be considered in agroforestry systems in Europe, and which of them can be used as raw material for the wood industry and what quality of wood can be produced in agroforestry systems. Since 2005, the European Union has been officially encouraging farmers to plant the crops in an agroforestry system and parallel try to produce trunks for high quality timber. By analysing the current economic developments of the European Union, especially Horizon 2020, our study provides an overview of what can be expected by the participants of the agroforestry sector and the related primary wood industry in the European Union now and in the future. In addition to the distribution analysis, indices describing projects have also been created. Rank correlation was used to examine the relationship between them. Possible decision mechanisms were also outlined using a custom-built expert software system.
High quality North American hardwood lumber and veneer is increasingly exported and used worldwide. A large portion of the timber resource utilized in the production of these products is contained ...within the northern region of the eastern United States. The cubic volume of this resource has increased by 15% since 2000, with most of this increase occurring in trees greater than 43.2 cm diameter at breast height. Although the volume of high-quality timber is likely at its highest level in over 100 years, 60% of the increase in the volume between 2008 and 2017 was in sawtimber-size (27.9 cm and larger) trees of low quality. Region wide, the species group “other white oaks” had the largest increase in high-quality volume. The largest increases in low-quality volume were for the soft maple and “other red oaks” species groups. While the volume of poletimber (12.7 to 27.7 cm) growing stock decreased between 2008 and 2017, the volume of cull poletimber-size trees increased more than 50%. These trends indicate a future decline in timber quality. Research is needed to determine the cause of these declines and how they may be reversed. One question that should be examined is the role of natural mortality and damage versus human disturbance on timber quality.
The purpose of this study was to apply an intermittent drying schedule developed from a conventional kiln to a solar kiln. Implementing this experiment could help better understand the oscillation of ...the temperature inside a solar kiln and timber quality during drying progress. The theoretical recharge and discharge curves were used to predict the temperature inside the solar kiln using experimental data obtained previously using a solar kiln. The surface and internal checks were measured using ImageJ freeware, and the development of the Moisture Content (MC) profile was assessed by coring and slicing method for the Eucalyptus delegatensis boards during drying. The results showed that the recharge and discharge model can predict the temperature with less than 2 °C error from the experimental data in the solar kiln. The total drying time to 12% MC was 87 days for the solar kiln. The drying rate was equivalent to the conventional kiln decreasing at an average rate of 0.2% per day. The surface check formation was found when the MC gradient between the core and the case of the board was greater than 42% at 9 days of drying in the solar kiln and conventional laboratory kiln. The applied drying schedule used in the solar kiln was successful and offered similar drying time. However, the oscillation of temperature in the intermittent drying will require further improvement to get closer conditions in a solar kiln.
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