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.

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.

The Price-Size Curve and Planting Density Decisions

1992 ◽  
Vol 16 (1) ◽  
pp. 24-29 ◽  
Author(s):  
Jon P. Caulfield ◽  
David B. South ◽  
Greg L. Somers
Keyword(s):  
Sensitivity Analysis ◽  
Discount Rate ◽  
Site Index ◽  
Planting Density ◽  
Tree Crop ◽  
Size Relationship ◽  
The Impact

Abstract The planting density decision is influenced by the price-size relationship existing between the tree crop grown and the products sold. Several price-size curves are presented, and their impact on the optimal economic planting density is evaluated. Results indicate that when the price-size curve is upward sloping, fairly low planting densities may be appropriate. Higher densities apply when the price-size curve is flat. Sensitivity analysis is carried out to evaluate the impact of changing site index and discount rate on the density decision. South. J. Appl. For. 16(1):24-29.

scholarly journals Stem Damage Modifies the Impact of Wind on Norway Spruces

Forests ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 463 ◽  
Author(s):  
Guntars Snepsts ◽  
Mara Kitenberga ◽  
Didzis Elferts ◽  
Janis Donis ◽  
Aris Jansons
Keyword(s):  
Tree Height ◽  
Mixed Effects ◽  
Mixed Effects Model ◽  
Wind Damage ◽  
Stand Age ◽  
Bark Stripping ◽  
Linear Mixed Effects Model ◽  
Linear Mixed Effects ◽  
Stem Damage ◽  
The Impact

Bark stripping caused by cervids can have a long-lasting negative effect on tree vitality. Such trees of low vitality might be more susceptible to other disturbances. The amplifying effects of disturbance interactions can cause significantly more damage to forest ecosystems than the individual effects of each disturbance. Therefore, this study aimed to assess the impact of bark stripping (stem damage) on the probability of wind damage and snapping height for Norway spruces (Picea Abies (L.) H. Karst.). In this study, we used the Latvian National Forest Inventory data from the period 2004–2018. In the analysis, we used data based on 32,856 trees. To analyse the data, we implemented a Bayesian binary logistic generalised linear mixed-effects model and the linear mixed-effects model. Our results showed that stem damage significantly increased the probability of wind damage and affected the snapping height of Norway spruces. Similarly, root damage, the slenderness ratio, the stand age, the stand density, the soil type, and the dominant tree species had a significant influence on the probability of wind damage. In both periods, trees with stem damage had significantly (p < 0.05) higher probability (odd ratio 1.68) to be wind damaged than trees without stem damage. The stem damaged Norway spruce trees snapped in the first 25% of the tree height, while trees without stem damage snapped around half (50%) of the tree height. Our results show that stem damage significantly alters the effect of wind damage on Norway spruces, suggesting that such damage must be incorporated into wind-risk assessment models.

scholarly journals Using the SUBER model for assessing the impact of cork debarking rotation on equivalent annual annuity in Portuguese stands

2017 ◽  
Vol 26 (1) ◽  
pp. e008 ◽  
Author(s):  
Joana A. Paulo ◽  
Margarida Tomé
Keyword(s):  
Discount Rate ◽  
Rotation Period ◽  
Site Index ◽  
Quality Characteristics ◽  
Detailed Knowledge ◽  
Management Tools ◽  
Relevant Effect ◽  
Cork Quality ◽  
Cork Thickness ◽  
The Impact

Aim of study: Use the SUBER model to evaluate the influence of the cork debarking rotation period (CDR) on equivalent annual annuity (EAA) value.Area of study: Nine simulated stands, varying in site index (14.4, 15.6, 17.1) and cork quality characteristics (high, medium, low).Material and methods: EAA values were computed considering CDR periods varying from 9 to 14 years, two contrasting structures of cork prices (high and low cork price scenarios), and three discount rate values (0.5%, 2% and 5%).Main results: For discount rates of 0.5% and 2% the impact of different CDR on the EAA is similar. In stands characterized by high to average site index values or high to medium cork quality characteristics, CDR of 9 and 11 years are associated with similar values of EAA. The variation of the CDR in stands characterized by low site index values and/or low cork quality characteristics did not have a relevant effect on the variation of EAA. For the simulations carried out with a discount rate of 5% the EAA decreases with the increase of CDR, indicating that the minimum legal value of 9 years for CDR should be applied.Research highlights: In stands characterized by high to average site index values or high to medium cork quality characteristics, a delay in the debarking may result in a significant increase of cork thickness and, as a result, of cork price. Detailed knowledge of cork and stand characteristics and updated information on cork prices structure and values are essential for the best usage of management tools such as the SUBER model, which can contribute to the decision-making process concerning the debarking operation. 

scholarly journals Wind-induced stem breakage height effect on potentially recovered timber value: case study of the Scots pine (Pinus sylvestris L.) in Latvia

2018 ◽  
Vol 69 (1) ◽  
pp. 24-32 ◽  
Author(s):  
Edgars Dubrovskis ◽  
Janis Donis ◽  
Eduards Racenis ◽  
Mara Kitenberga ◽  
Aris Jansons
Keyword(s):  
Pinus Sylvestris ◽  
Scots Pine ◽  
Economic Value ◽  
Economic Assessment ◽  
Negative Influence ◽  
Wind Damage ◽  
Management Activity ◽  
Salvage Logging ◽  
Monetary Value ◽  
Stem Breakage

Abstract In Europe, salvage-logging is a common management activity to partially recover economic value from wind disturbed forests. In the near future, wind damage to forests is predicted to increase due to climate change. Therefore, an economic assessment of wind damage effects on recovered timber value is useful information in the decision-making process. In this study, we aim to assess the influence of different stem damage heights on the monetary value of recovered timber. We simulated stem breakage at three heights for the Scots pine (Pinus sylvestris L.): 3, 5, and 7 m. For comparison, we used an uprooted tree without stem breakage. Our results revealed that the most negative influence on the recovered timber value was stem breakage at 3 m, which decreased the monetary value by 35%. The stem breakage at 5 and 7 m decreased the recovered timber value by 9–10%. Over the analysed period (2006–2017), no significant differences in the monetary value of the recovered timber were found between uprooted lumber and stems with breakage at 5 and 7 m. The price fluctuations in the market have a significant influence on the recovered timber value, which might cause a larger decrease in monetary value than stem breakage.

scholarly journals Emissions of monoterpenes from new Scots pine foliage: dependency on season, stand age and location and importance for models

2020 ◽  
Author(s):  
Ditte Taipale ◽  
Juho Aalto ◽  
Pauliina Schiestl-Aalto ◽  
Markku Kulmala ◽  
Jaana Bäck
Keyword(s):  
Scots Pine ◽  
Particle Formation ◽  
Tree Age ◽  
Stand Age ◽  
Comprehensive Treatment ◽  
Terrestrial Vegetation ◽  
Monoterpene Emission ◽  
Emission Models ◽  
The Impact ◽  
Simulated Growth

Abstract. Models to predict the emissions of biogenic volatile organic compounds (BVOCs) from terrestrial vegetation largely use standardised emission potentials derived from shoot enclosure measurements of mature foliage and usually assume that the contribution of BVOCs from new conifer needles is minor to negligible. Extensive observations have, however, recently demonstrated that the potential of new Scots pine needles to emit several different BVOCs can be up to about 500 times higher than that of the corresponding mature foliage. Thus, we build on these discoveries and investigate the impact of previously neglecting enhanced emissions from new Scots pine foliage on estimates of monoterpene emissions and new atmospheric aerosol particle formation and their subsequent growth. We show that the importance of considering the enhanced monoterpene emission potential of new Scots pine foliage decreases as a function of season, tree age and latitude, and that new foliage is responsible for the majority of the whole tree's foliage emissions of monoterpenes during spring time, independently of tree age and location. Our results suggest that annual monoterpene emission estimates from Finland would increase with up to ~ 25 % if the emissions from new Scots pine foliage were explicitly considered, with the majority being emitted during spring time where also new particle formation has been observed to occur most frequently. We estimate that our findings can lead to increases in predictions of the formation rates of 2 nm particles during spring time by ~ 75–275 % in northern Finland and by ~ 125–865 % in southern Finland. Likewise, simulated growth rates of 2–3 nm particles would increase by ~ 65–175 % in northern Finland and by ~ 110–520 % in southern Finland if the enhanced emissions of monoterpenes from new Scots pine foliage were explicitly considered. Our findings imply that we need to introduce a more comprehensive treatment of the emissions of BVOCs from new coniferous foliage in biogenic emission models.

Testing an individual tree wind damage risk model in a naturally regenerated balsam fir stand: potential impact of thinning on the level of risk

2020 ◽  
Author(s):  
Marine Duperat ◽  
Barry Gardiner ◽  
Jean-Claude Ruel
Keyword(s):  
Risk Model ◽  
Abies Balsamea ◽  
Wind Damage ◽  
Balsam Fir ◽  
Individual Tree ◽  
Commercial Thinning ◽  
Increased Risk ◽  
Risk Of Wind Damage ◽  
The Impact ◽  
Damage Risk

Abstract Widely distributed in Quebec, balsam fir (Abies balsamea (L.) Mill.) is highly vulnerable to wind damage. Recently, there has been a trend in forest management to increase the use of partial cuttings in naturally regenerating stands, leaving the remnant trees at increased risk of wind damage. In order to limit wind damage after partial cuttings, it is therefore important to find silvicultural practices that minimize the risk of wind damage in these fir stands. Our main objective was to find balsam fir-specific values of parameters to integrate into the wind risk model ForestGALES, in order to simulate the impact of different types of commercial thinning on wind damage risk, and to determine which practice potentially minimizes the risk in a naturally regenerated stand. An anemometer placed at canopy height and strain gauges attached to the trunks of balsam firs allowed us to measure the wind-induced bending moments experienced by a sample of balsam fir trees. This enabled the calculation of the turning moment coefficients specific to each of the trees in order to compare them with the ForestGALES model predictions and to adapt the model for balsam fir stands. The model was tested first with only tree diameter and height as input variables to calculate the turning moment coefficient, then with the addition of a competition index, and finally with the addition of crown dimensions. Wind climate parameters for prediction of the probability of damage were calculated using the Wind Atlas Analysis and Application Program airflow model. The model with the highest accuracy was then used to simulate two types of thinning and determine the impact on wind damage risk for each tree in the stand. According to the model’s predictions, thinning from below has a reduced risk of wind damage compared with thinning from above.

scholarly journals Impact of Initial Planting Density on the Optimal Economic Rotation of Chinese Fir (Cunninghamia lanceolata (Lamb.) Hook) in an Experimental Forest Plantation

Forests ◽  
2019 ◽  
Vol 10 (9) ◽  
pp. 713
Author(s):  
Lin Liu ◽  
Yan Li ◽  
Jianguo Zhang ◽  
Honggang Sun
Keyword(s):  
Growth Rate ◽  
Discount Rate ◽  
Negative Impact ◽  
Cunninghamia Lanceolata ◽  
Planting Density ◽  
Stand Age ◽  
Stand Volume ◽  
The Difference ◽  
The Impact ◽  
Diameter Classes

The amount to be invested and the timing of clearcutting are central concerns in timber production. To assess the impact of the initial planting density on optimal economic rotation, we explicitly included the distribution of stand diameter classes and price differences representing the quality of stumpage in a model of forest land expected value (LEV). We selected five initial planting densities of 35-year old China fir (Cunninghamia lanceolata (Lamb.) Hook) plantations to fit the distribution of diameter classes along with stand age using a three-parameter Weibull theoretical growth model and then the Faustmann formula was used to calculate LEVs under different conditions. We found that the difference in the values of the growth rate of the stand volume and the discount rate affected the direction of the impact of initial planting density on the optimal economic rotation. If the value of the growth rate of the stand volume exceeded that of the discount rate, then the initial planting density had a negative impact on optimal economic rotation and vice versa. In addition, the quality effect, which means the shift in diameter class to a higher value attributed to the initial planting density, determined the extent of the impact of the initial planting density on the optimal economic rotation. The proportion of large-sized timber increased at a faster pace in accordance with the age of the stand in stands where the planting density was low compared with the proportion of such timber in stands with a higher initial planting density. The corresponding net stumpage price difference resulted in significant differences in LEVs. We concluded that a low-density stand of China fir was a preferred planting option for obtaining the highest LEV.

scholarly journals A review of thinning effects on Scots pine stands: From growth and yield to new challenges under global change

2017 ◽  
Vol 26 (2) ◽  
pp. eR03S ◽  
Author(s):  
Miren Del Río ◽  
Andrés Bravo-Oviedo ◽  
Hans Pretzsch ◽  
Magnus Löf ◽  
Ricardo Ruiz-Peinado
Keyword(s):  
Ecosystem Services ◽  
Pinus Sylvestris ◽  
Scots Pine ◽  
Growth And Yield ◽  
Distribution Area ◽  
Stand Age ◽  
Positive Effects ◽  
Pine Stands ◽  
The Impact ◽  
Scots Pine Stands

Aim of the study: Thinning experiments in Scots pine (Pinus sylvestris L.) stands have been carried out since long in different regions of its distribution. The aim of this paper is to gather the knowledge about the thinning effects on Scots pine stands, from the effects on growth and yield to the provision of ecosystem services in the framework of climate change.Area of study: The review covered studies from different regions of the distribution area of Scots pineAim of the study: Thinning experiments in Scots pine (Pinus sylvestris L.) stands have been carried out for many years in different regions of its distribution. The aim of this paper is to gather knowledge regarding the effects of thinning on Scots pine stands, from the effects on growth and yield to the provision of ecosystem services in the context of climate change.Area of study: The review covers studies from different regions of the distribution area of Scots pineMaterial and methods: We reviewed the effect of thinning on four aspects: growth and yield, stability against snow and wind, response to drought, and ecosystem services.Main results: Heavy thinning involves a loss in volume yield, although the magnitude depends on the region, site and stand age. Thinning generally does not affect dominant height while the positive effect on tree diameter depends on the thinning regime. The stability of the stand against snow and wind is lower after the first thinning and increases in the long term. The impact of extreme droughts on tree growth is lower in thinned stands, which is linked to a better capacity to recover after the drought. Thinning generally reduces the wood quality, litter mass, and stand structural diversity, while having neutral or positive effects on other ecosystem services, although these effects can vary depending on the thinning regime. However, scarce information is available for most of the ecosystem services.Research highlight: Existing thinning experiments in Scots pine stands provided valuable information about thinning effects, but new experiments which cover a broad range of ecosystem services under different site conditions are still needed.

scholarly journals Cost–Benefit Analysis of Measures to Reduce Windstorm Impact in Pure Norway Spruce (Picea abies L. Karst.) Stands in Latvia

Forests ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 576 ◽  
Author(s):  
Valters Samariks ◽  
Oskars Krisans ◽  
Janis Donis ◽  
Ilze Silamikele ◽  
Juris Katrevics ◽  
...  
Keyword(s):  
Norway Spruce ◽  
Plant Material ◽  
Net Present Value ◽  
Spatial Information ◽  
Cost Benefit Analysis ◽  
Rotation Period ◽  
Wind Damage ◽  
Financial Benefit ◽  
Precommercial Thinning ◽  
The Impact

Wind is one of the major natural forest disturbances in Europe, and reduces the total economic (including carbon sequestration) value of forests. The aim of this study was to assess the financial benefit of silvicultural measures in young, pure, planted Norway spruce stands by reduction in the impact of wind damage over the rotation period. The analyzed measures are promptly applied precommercial thinning and low-density planting with improved plant material. Spatial information on factors affecting wind damage—wind climate and soil—were gathered and combined with the local growth model and empirical data from tree pulling experiments in Latvia to assess the economic value loss due to wind damage over a rotation period. Timely precommercial thinning and lower-density planting with improved plant material would ensure a positive net present value with an interest rate of 3%, using conservative estimates. The financial benefit is highest in windier (coastal) regions and for the planting, followed by moderate thinning. The results demonstrate that, even without changing the dominant tree species, a considerable reduction in wind-damage risk can be achieved.

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