On the economics of optimal timber production in boreal Scots pine stands

2013 ◽  
Vol 43 (8) ◽  
pp. 719-730 ◽  
Author(s):  
Olli Tahvonen ◽  
Sampo Pihlainen ◽  
Sami Niinimäki
Keyword(s):  
Interest Rates ◽  
Scots Pine ◽  
Rotation Period ◽  
Stand Density ◽  
Optimization Methods ◽  
Growth Conditions ◽  
Maximum Sustainable Yield ◽  
Pattern Search ◽  
Stand Management ◽  
Volume Yield

This study analyzes the optimal management of Scots pine (Pinus sylvestris L.) stands by applying recent developments in numerical optimization methods and forest production ecology. Our approach integrates a process-based, stand-level growth model and a detailed economic description of stand management. The variables optimized include the initial stand density, the number, timing, type, and intensity of thinnings, and the rotation period. A generalized pattern search is used to maximize the present value of net timber revenue over an infinite time horizon. The model adopts quality pricing, which takes branch size and quality into account, to differentiate among five different timber assortments. The analysis also covers five different site types. The results demonstrate the necessity of optimizing all of the management variables simultaneously. Given a low interest rate, optimized thinning significantly increases the rotation period, volume yield, and economic outcome. At higher interest rates, optimal rotation may be shortest under the least fertile growth conditions. The inclusion of a detailed price structure reveals that previous results concerning sensitivity to timber price and the relationship between maximum sustainable yield and economic solutions do not hold true in models that provide a more realistic description of forest management.

scholarly journals Long-Term Effect of Lophodermium Needle Cast on The Growth of Scots Pine and Implications for Financial Outcomes

Forests ◽  
2020 ◽  
Vol 11 (7) ◽  
pp. 718 ◽  
Author(s):  
Āris Jansons ◽  
Pauls Zeltiņš ◽  
Jānis Donis ◽  
Una Neimane
Keyword(s):  
Scots Pine ◽  
Stand Density ◽  
Resistance Breeding ◽  
Financial Loss ◽  
Management Scenarios ◽  
Early Management ◽  
Needle Cast ◽  
Stand Management ◽  
Negative Effect

In Northern Europe, climate change may facilitate the prevalence of Scots pine, yet also promote the spread of pathogens attacking this species. A common biotic risk for Scots pine in nurseries and young stands is Lophodermium needle cast, primarily caused by Lophodermium seditiosum, which negatively affects the survival and growth of saplings. Reduced tree growth has been observed several years after damage by Lophodermium needle cast. However, for decision-making in protection or resistance breeding, an estimate of financial loss is important. Thus, the study aimed to assess the long-term influence of Lophodermium needle cast on the growth and financial value of Scots pine stands. The effect of needle cast damage during the sixth growing season on growth at the age of 17 years was evaluated in a control-crossed Scots pine progeny trial, and the results indicated a significantly negative effect on the height and diameter of the trees. A significant family effect also existed on the severity of the needle cast damage. Long-term simulations indicated that severely damaged Scots pines had a reduced equivalent annual annuity (EAA) of almost 100% at the final harvest. More intensive early management to reduce stand density could partly compensate for losses caused by needle cast. A higher EAA for the most resistant group of trees regardless of the stand management scenarios suggests an economically justified potential for improved resistance. Strong negative (−0.62 to −0.70) correlations of height and survival with the proportion of severely affected trees at the family mean level implies that resistant genotypes can be selected along with improved growth in progeny trials, which are affected by needle cast.

The economics of timber and bioenergy production and carbon storage in Scots pine stands

2014 ◽  
Vol 44 (9) ◽  
pp. 1091-1102 ◽  
Author(s):  
Sampo Pihlainen ◽  
Olli Tahvonen ◽  
Sami Niinimäki
Keyword(s):  
Carbon Storage ◽  
Scots Pine ◽  
National Level ◽  
Stand Density ◽  
Pattern Search ◽  
Forest Growth ◽  
Positive Contribution ◽  
Bioenergy Production ◽  
Rotation Length ◽  
Dead Trees

We optimize timber and bioenergy production combined with carbon storage in Scots pine (Pinus sylvestris L.) stands, using an ecological-economic model. Forest growth is specified with a highly detailed process-based growth specification, and optimization is based on an efficient generalized pattern search algorithm. The optimized variables are rotation length, initial stand density, and the number, intensity, timing, and type of thinnings. The carbon pool includes all aboveground biomass (including dead trees) and timber products. The analysis includes the comparison of different carbon subsidy systems. The results are presented for the most relevant site types and thermal zones in Finland. Carbon storage increases the optimal rotation length, number of thinnings, and initial density at all forest sites. Carbon storage effects on stand density and harvests are strongest at poor sites. Timber output increases with carbon price. High natural mortality in our results implies notable carbon storage in dead trees and a positive contribution to biodiversity. The stand-level analysis is extended to a cost-efficient national-level carbon storage plan.

Postfire black spruce establishment in subarctic and boreal Quebec

1989 ◽  
Vol 19 (12) ◽  
pp. 1571-1580 ◽  
Author(s):  
Luc Sirois ◽  
Serge Payette
Keyword(s):  
Black Spruce ◽  
Rotation Period ◽  
Stand Density ◽  
Growth Conditions ◽  
Fire Disturbance ◽  
Northern Forest ◽  
Postfire Regeneration ◽  
Short Period ◽  
The 1950S ◽  
Age Range

Forest regeneration in areas burned during the 1950s in northern Quebec was studied along topographic and climatic gradients, from the northern Boreal Forest to the northern Forest–Tundra. Regenerated plant communities are mostly dominated by Cladinamitis in well-drained uplands and by hygrophilous shrub species in moister lowlands. The age structure of 23 stands, as they were immediately before and about 30 years after the 1950s fires, was used to analyze the patterns of establishment and development of black spruce (Piceamariana (Mill.) B.S.P.) populations associated with fire disturbance. Postfire black spruce establishment was active during the first 20 years of vegetation recovery, then it decreased rapidly. Three older populations originating from 1936 and 1922 fires showed a rapid postfire tree establishment, whereas a long delay of recolonization was observed in the 1906 fire. Along the topographical gradient, postfire regeneration was more rapid in hill sites, whereas spruce recruitment was more abundant in lowland sites. Along a northward latitudinal gradient, prefire populations showed an increasing trend in age range, mean age, and mean age of youngest individuals. This gradient coincided also with an increasing fire rotation period from south to north. The proportion of stunted individuals in postfire populations was often more important than in prefire populations on the same sites, suggesting more rigorous growth conditions associated with forest removal. Because most black spruce seedling establishment is occurring during a short period in this area, it is suggested that stand density is determined by regeneration conditions, including seed input and seedbed quality, soon after the fire. Therefore, comparisons between prefire and 30-year-old postfire populations can be used as an index to evaluate fire impact on stand density.

scholarly journals A Financial Assessment of Windstorm Risks for Scots Pine Stands in Hemiboreal Forests

Forests ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 566 ◽  
Author(s):  
Janis Donis ◽  
Renate Saleniece ◽  
Oskars Krisans ◽  
Edgars Dubrovskis ◽  
Mara Kitenberga ◽  
...  
Keyword(s):  
Interest Rates ◽  
Scots Pine ◽  
Rotation Period ◽  
Site Index ◽  
Wind Damage ◽  
Planting Density ◽  
Stand Age ◽  
Salvage Logging ◽  
Commercial Thinning ◽  
The Impact

Windstorms are a significant disturbance in northern European Scots pine forests. Mechanistic models for assessment of their impact have been developed. The aim of our study was to assess the impact of windstorms on the financial value of Scots pine (Pinus sylvestris L.) stands. Wind damage probability in stands with certain dimensions (linked to age and site index) and the reduced value retrieved from salvage logging instead of planned harvest in undamaged stands were used for calculation. Equivalent annual annuity with interest rates of 3%, 4%, and 5%, three different commercial thinning regimes, and different planting densities were used to assess the mean influence. Wind damage risk had a notable and significant negative effect on the financial value of Scots pine forest stands. Equivalent annual annuity decreased sharply with stand age, especially in the most productive sites (SI 36). The negative financial impact could be reduced by selection of a lower initial planting density (1000–2000 trees ha−1 instead of 3000) and by reducing the rotation period, for example, by using target diameter as the criteria for the time of final harvest.

Silvicultural characteristics of a Scots pine stand on drift sands

1992 ◽  
Vol 57 ◽  
Author(s):  
D. Maddelein ◽  
N. Lust
Keyword(s):  
Scots Pine ◽  
Mixed Forest ◽  
Rotation Period ◽  
Average Height ◽  
Indigenous Species ◽  
Pedunculate Oak ◽  
Black Cherry ◽  
Humus Layer ◽  
Pine Seedlings ◽  
Pine Regeneration

The  study of a seventy years old stand of Scots pine on drift sands proves that  Scots pine growth on these sites was and is still relatively good: average  diameter 27.6 cm, average height 19.4 m, standing volume 213 m3 and an annual increment  of 4.9 m3.ha-1.yr-1. All Scots pines  belong to the upper storey. Yet considerable differences in crown development  and vitality are observed. The current growth rate and the spontaneous  settlement of pine seedlings under canopy show the ideal conditions for the  creation of a high forest with reserves. Anyway a rotation period of more  than 70 years is recommendable.     On several places a consolidated regeneration of Scots pine seedlings under  canopy occur. Groups with a stem number of 700 to 3,500 seedlings per are, ranging  in age from 3 to 11 years and in height from 10 to 170 cm, are present. This  Scots pine regeneration has developed in a normal mor humus layer and in a  dense Deschampsia mat.      Broadleaved regeneration is not so abundant, and consists for 75 % of black  cherry. Absence of seed trees, browsing damage and the exclusive character of  black cherry are the limiting factors for the installation and survival of  valuable indigenous species, such as pedunculate oak.     Provided that black cherry is removed and that the regeneration is  protected against wild damage, it is possible to create a mixed forest  dominated by Scots pine but with a considerable admixture of indigenous  broadleaved trees. However, if black cherry will not be sufficiently  controlled, it can be expected that in a first phase black cherry will  dominate the understorey, that it will prevent the regeneration of all other  species and that, very soon, it will form an almost single-species dominated  stage in forest succession.

scholarly journals Selected physical and mechanical properties of Scots pine (Pinus sylvestris L.) wood from stands of younger age classes as criteria for rational utilization of timber

2021 ◽  
Vol 27 (1) ◽  
Author(s):  
Przemysław Marcin Pikiński ◽  
Jaroslav Szaban ◽  
Gerda Šilingienė ◽  
Robert Korzeniewicz ◽  
Witold Pazdrowski
Keyword(s):  
Mechanical Properties ◽  
Pinus Sylvestris ◽  
Scots Pine ◽  
Bending Strength ◽  
Physical And Mechanical Properties ◽  
Growth Conditions ◽  
Tree Age ◽  
Coniferous Forests ◽  
Forest Site ◽  
Quality Coefficient

The aim of this study was to assess the quality of Scots pine (Pinus sylvestris L.) wood depending on the age of trees, forest site conditions and social class of tree position in the stand. Analyses were based on the determination of specific density and static bending strength, as well as the strength quality coefficient. It was to determine changes in physical and mechanical properties of timber depending on tree age as well as growth conditions reflected in the forest site such as fresh mixed coniferous forests and fresh mixed broadleaved forests. Experimental plots were established in 6 localities with 30, 40 and 60-year-old trees. In each of the stands, a 1-hectare experimental plot was established. Based on the measured DBH and tree height, dimensions of three mean sample trees were calculated, while the classification of social class of tree position in the stand developed by Kraft (1884) was also applied. Analyses were conducted on wood samples with 12% moisture content. Strength tests on wood samples were performed on an Instron 33RH204 universal strength testing machine. A detailed analysis showed properties of pine wood are improved with an increase of tree age in both forest sites. Statistically significant differences were observed for wood density and static bending strength. More advantageous properties were observed for wood of pines from the less fertile forest site, i.e., fresh mixed coniferous forests. Density and static bending strength were markedly determined by tree age and growth conditions. The static bending strength quality coefficient from pines growing in the fresh mixed coniferous forests increased between 30 and 40 years, similarly as it was for the fresh mixed broadleaved forests, while between 40 and 60 years, it deteriorated for the fresh mixed coniferous forests. Wood density from the fresh mixed coniferous forests was by 3% to 7% greater than pines growing in fresh mixed broadleaved forests. In turn, static bending strength of wood from pines growing in fresh mixed coniferous forests was by 4% to 10% greater than trees from the fresh mixed broadleaved forests.  Keywords: Scots pine, wood properties, forest site, Poland

Constrained Optimization of Multi-Degree-of-Freedom Mechanisms for Near-Time Optimal Motions

1992 ◽  
Author(s):  
Satish Sundar ◽  
Zvi Shiller
Keyword(s):  
Constrained Optimization ◽  
Design Method ◽  
Close Correlation ◽  
Optimization Methods ◽  
Pattern Search ◽  
Degree Of Freedom ◽  
Design Parameters ◽  
Maximum Acceleration ◽  
Time Optimal ◽  
Order Of Magnitude

Abstract This paper presents a design method of multi-degree-of-freedom mechanisms for near-time optimal motions. The design objective is to select system parameters, such as link lengths and actuator sizes, so as to minimize the optimal motion time of the mechanism along a given path. The exact time optimization problem is approximated by a simpler procedure that maximizes the acceleration near the end points. Representing the directions of maximum acceleration with the acceleration lines, and the reachability constraints as explicit functions of the design parameters, we transform the constrained optimization to a simpler curve fitting problem that can be formulated analytically. This allows the use of efficient gradient type optimizations, instead of the pattern search optimization that is otherwise required. Examples for optimizing the dimensions of a five-bar planar mechanism demonstrate close correlation of the approximate with the exact solutions, and an order of magnitude better computational efficiency than the previously developed unconstrained optimization methods.

scholarly journals Implications of Reduced Stand Density on Tree Growth and Drought Susceptibility: A Study of Three Species under Varying Climate

Forests ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 627
Author(s):  
Mathias Steckel ◽  
W. Keith Moser ◽  
Miren del Río ◽  
Hans Pretzsch
Keyword(s):  
Scots Pine ◽  
Tree Growth ◽  
Water Availability ◽  
Ponderosa Pine ◽  
Stand Density ◽  
Stand Age ◽  
Short Term ◽  
Sessile Oak ◽  
Site Water ◽  
Positive Effect

A higher frequency of increasingly severe droughts highlights the need for short-term measures to adapt existing forests to climate change. The maintenance of reduced stand densities has been proposed as a promising silvicultural tool for mitigating drought stress. However, the relationship between stand density and tree drought susceptibility remains poorly understood, especially across ecological gradients. Here, we analysed the effect of reduced stand density on tree growth and growth sensitivity, as well as on short-term drought responses (resistance, recovery, and resilience) of Scots pine (Pinus sylvestris L.), sessile oak (Quercus petraea (Matt.) Liebl.), and ponderosa pine (Pinus ponderosa Douglas ex C. Lawson). Tree ring series from 409 trees, growing in stands of varying stand density, were analysed at sites with different water availability. For all species, mean tree growth was significantly higher under low compared with maximum stand density. Mean tree growth sensitivity of Scots pine was significantly higher under low compared with moderate and maximum stand density, while growth sensitivity of ponderosa pine peaked under maximum stand density. Recovery and resilience of Scots pine, as well as recovery of sessile oak and ponderosa pine, decreased with increasing stand density. In contrast, resistance and resilience of ponderosa pine significantly increased with increasing stand density. Higher site water availability was associated with significantly reduced drought response indices of Scots pine and sessile oak in general, except for resistance of oak. In ponderosa pine, higher site water availability significantly lessened recovery. Higher site water availability significantly moderated the positive effect of reduced stand density on drought responses. Stand age had a significantly positive effect on the resistance of Scots pine and a negative effect on recovery of sessile oak. We discuss potential causes for the observed response patterns, derive implications for adaptive forest management, and make recommendations for further research in this field.

scholarly journals Scots Pine Stem Parameters in Sites with Different Stand Densities in Lithuania

Forests ◽  
2020 ◽  
Vol 11 (7) ◽  
pp. 716
Author(s):  
Lina Beniušienė ◽  
Benas Šilinskas ◽  
Ričardas Beniušis ◽  
Marius Aleinikovas ◽  
Edmundas Petrauskas ◽  
...  
Keyword(s):  
Forest Management ◽  
Scots Pine ◽  
Management Practices ◽  
Stand Density ◽  
Management Tool ◽  
Stem Height ◽  
Bottom Part ◽  
Branch Diameter ◽  
Stem Wood ◽  
Stem Quality

Background and Objectives: The aim of this study was to determine the effects of different stand densities and thinning regimes on stem quality parameters, mainly branch characteristics, of Scots pine (Pinus sylvestris L.) trees. The study provides some input to the discussion about Scots pine stem quality responses to different forest management practices in relatively young stands. Materials and Methods: Total tree height, height to the lowest live and dead branch, diameter at breast height (DBH), and diameter of all branches from the whorls located up to 6 m from the ground were measured. The linear regression models to predict branch diameter, as the main parameter for the stem quality assessment, were developed based on stand density and stem parameters. Results and Conclusions: DBH, branch diameter and number of branches up to 6-m stem height were significantly higher in the stands with the lowest density. These stem parameters showed a relatively clear downward trend from the lowest to the highest stand densities. The main identified variables which significantly affected stem quality, were branch diameter and diameter of the thickest branch in the bottom part of the stem, at least up to 3-m stem height. For practical use, the best fitted model was estimated when stand density, DBH, and branch diameter up to 3-m height were included in a single equation. The developed model for branch diameter could be used as a forest management tool for managing stem-wood quality.

scholarly journals Assessment of Broad-Leaved Forest Stand Management

2019 ◽  
Vol 40 (2) ◽  
pp. 365-375 ◽  
Author(s):  
Yasushi Suzuki ◽  
Tetsuhiko Yoshimura
Keyword(s):  
Interest Rates ◽  
Net Present Value ◽  
Road Construction ◽  
Japanese Cedar ◽  
Charcoal Production ◽  
Fast Growing ◽  
Stand Management ◽  
Growing Stock ◽  
Large Trees ◽  
Quercus Glauca

There are many broad-leaved forests in Japan that were formerly managed for charcoal production, which have been abandoned for decades. Appropriate thinning can revitalize these forests if the cost balance of the management is positive. Two critical elements are the construction of spur roads to facilitate mechanized harvesting operations and management planning that considers stand properties such as the growing stock, species, and tree size distribution. We surveyed three abandoned former broad-leaved coppice stands; one coastal, one cool temperate and one warm temperate. The stock in all three stands exceeded 300 m3 ha-1, two- to three-fold the official forest registry data estimates. The dominant species in terms of tree numbers are Castanopsis sieboldii, Pieris japonica, and Quercus glauca. Medium-sized trees involve those well suited for firewood, i.e., Quercus acuta, Quercus glauca, Quercus serrata, etc. Each plot contained a few large trees that potentially have a high market value, e.g., Cinnamomum camphora, Zelkova serrata, Abies firma, etc. The average income from harvested trees was estimated to be 10200 JPY (Japanese Yen) m-3, whereas the thinning costs would be 3200 to 5400 JPY m-3, with the additional spur road construction costs. The management cost balance of a broad-leaved stand in a 60 year rotation was evaluated with both Net Present Value (NPV) (for interest rates of 1, 2, 3, and 4%) and Internal Rate of Return (IRR). This balance was compared with that of a typical plantation stand of Japanese cedar (Cryptomeria japonica) and of a fast-growing plantation stand of Chinese fir (Cunninghamia lanceolata). The estimated NPVs were largest for the fast-growing plantation stand, second largest for the typical plantation stand, and lowest for the broad-leaved stand with a NPV interest rate of 1 + %. However, the IRR of the broad-leaved stand was the highest, followed by that of the fast-growing plantation stand, while the IRR of the typical plantation stand was the lowest. This order was the same for NPVs assuming higher interest rates. 1 JPY=0.0086 € on April 29, 2019.

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