Optimal Rotation Age Research Articles

Alternative Silvicultural Approaches to Managing Jack Pine Plantations for Endangered Species Habitat and Forest Products

AbstractSince the early 1980s, ca 1,550 hectares (3,800 ac) of high-density jack pine (Pinus banksiana) plantations have been established annually in northern Lower Michigan to serve as habitat for the federally endangered Kirtland’s warbler (KW; Setophaga kirtlandii). Because these plantations do not appear capable of producing merchantable sawlogs by their planned 50-year harvest age, we investigated the potential to implement reduced rotation lengths in these stands to produce biomass and/or pulpwood. We used space-for-time substitution to assess biomass and volume accrual over time, using our own locally derived allometric biomass equations. The predicted optimal rotation age for biomass was 20 years, and the predicted optimal rotation age for pulpwood volume was 28 years. We compared the total land area required for management under these rotation scenarios to continue establishing 1,550 hectares (3,800 ac) of KW habitat annually. Management on the current 50-year cycle requires ca 77,500 hectares (191,500 ac). Management for pulpwood would reduce this to ca 43,400 hectares (107,250 ac), and management for biomass would require ca 31,000 hectares (76,600 ac). Our results suggest that rotation lengths in these plantations could be substantially reduced, allowing for reductions in the total land area dedicated to warbler habitat, allowing for diversification of management at the landscape scale.

The Optimal Forest Management of an Even-Aged Stand: The Biological Rotation versus the Land Expectation Value

This 4-page fact sheet written by Andres Susaeta and Chris Demers and published by the UF/IFAS School of Forest Resources and Conservation provides a guide for forest landowners, managers, and stakeholders in conducting a valuation of timber investments. It reviews and provides examples of two different approaches for determining the optimal rotation age of even-aged forest stands. These methods can help forest landowners and managers in making forestry investment decisions. https://edis.ifas.ufl.edu/fr424

Forest management practice for enhancing carbon sequestration in national forests of Korea

This paper examines forest management planning and its possible outcomes using linear programing (LP). More specifically, the most appropriate forest harvesting schedule was selected that can maximize the carbon sequestration in the current forest areas considering forest manager’s income. The LP model allows the managers to segment forests into cutting units under rotation basis logging activities. Through harvest prescription from LP, we derived the balanced age-class distribution that constitutes improved conditions for sustainable use of forest resource. However, the solutions from LP did not achieve normal forests with perfectly even aged distribution. Instead, it produced a left-skewed age-class distribution due to the cost restriction of management ruling out the achievement of a normal forest as an optimal solution. The results from our LP model also confirm that the forest management activities will enhance yearly carbon sequestration in forests for all scenarios compared to baseline, and the shorter rotation ages tend to call for more carbon sequestration and economic profit. However, it is difficult to ensure that 50 years rotation is the optimal rotation age for the target forests, since we do not consider the benefit of biodiversity conservation.

Sustainable Management of Oleaginous Trees as a Source for Renewable Energy Supply and Climate Change Mitigation: A Case Study in China

Forests provide a range of ecosystem services, including bioenergy supply and carbon sequestration, both contributing to significant climate change mitigation. Oleaginous trees have potential to provide bioenergy supplies through biodiesel-producing seed yield as well as contributing to carbon sequestration. This paper aims to show the provisions of bioenergy and carbon savings through forest rotation management and it will investigate the potential of oleaginous forest management in China. We use the land expectation value (LEV) model to calculate the optimal joint values of timber, seed and total carbon savings, including carbon sequestration from forest and carbon reductions through energy substitutions. The results indicate that combining both values of seeds and carbon savings increase the LEV and rotation age (167,611 Yuan/ha, 78 years) compared to sole timber value (26,053 Yuan/ha, 55 years). The optimization of the LEVs and the resulting optimal rotation ages are significantly sensitive to the discounting rate. Annual biodiesel potential production from Pistacia chinensis can take up 1.7% of the national diesel consumption in China. We conclude that China can use improved forest rotation management as an effective means for achieving goals in its low-carbon energy strategy.

Growth and Yield Models for Teak Planted as Living Fences in Coastal Ecuador

Teak plantations cover a total area of about 4.35 million ha worldwide. The species is currently being planted in silvopastoral systems in the coastal lowlands of Ecuador. However, there are no growth and yield models for teak grown in silvopastoral systems, especially as living fences, in this region. The aim of the present study was to develop volume and yield models for teak grown as living fences in silvopastoral systems. For teak planted as living fences, the biological rotation age was estimated to vary between 15 and 26 years. The final yield in the silvopastoral system varied from 49 m3 ha−1 at 26 years in the least productive sites to 225 m3 ha−1 at 15 years in the most productive sites in the study area. The mean annual yield for the highest quality site was 15.3 m3 ha−1 year−1 at age 15 years, for a density of 160 trees ha−1. For a base age of 10 years, height-based site indexes of nine to 23 m were established. The growth and yield model obtained may be useful to define the biological (optimal) rotation age and estimate the productivity of teak living fences in the coastal lowlands of Ecuador.

Land expectation value and optimal rotation age of maritime pine plantations under multiple risks

Maritime pine (Pinus pinaster) is the most important conifer species in France in terms of wood production. It is mostly cultivated in even-aged monoculture stands in the Landes forest. These plantations are exposed to multiple biotic and abiotic risks: most importantly the cyclical outbreaks of a defoliator, the Pine Processionary Moth (PPM, Thaumetopoea pityocampa), and storms causing large windthrown. This study aims to compute the optimal rotation age and land expectation value (LEV) for maritime pine plantations in order to assess the impact of these disturbances. Using stochastic simulation methods, we simulate multiple scenarios combining different disturbance intensities. Our results show that both disturbances reduce LEV individually. When combined together, the two disturbances generate subadditive losses (i.e. combined damages are smaller than the sum of the damages from each disturbance individually). The impact on the optimal rotation length, however, is different for the two analysed risks: While storms tend to reduce the optimal harvest age, PPM tends to increase it. Overall, the impact of PPM on the rotation length prevails and, here, risks increase rather than decrease the optimal rotation length. Thinnings play an important role. They do not only increase profitability but also constitute an effective hedging strategy against both risks since they mitigate the negative impacts of PPM and storm disturbances for all the tested scenarios.

Optimization Pine Plantation Forest Management in Kediri FMU Regional Division II East Java

Pine forest management today has not already reached its optimal state. The abnormal pine stand structure will cause a decrease in the production of pine resin. This study aimed to determine the optimal rotation of pine plantation forest and formulated the harvest scheduling to ensured optimal resin production. The determination of optimal rotation was conducted by modifying the Faustman formula to be applied on the condition in forest management in Perhutani. Simulation optimization of harvest scheduling was conducted by linear programming. Optimal rotation of pine forest plantation consists of timber rotation and resin rotation. The highest net present value of timber was obtained at 25 year cycles and the highest net present value of the resin was obtained at 35 year cycles. The inclusion of resin benefit was resulting in lengthening the optimal rotation age. The abnormal stand structure was causing the fluctuations of pine resin production. Thus, the efforts to improve it was by applying the harvest scheduling framework. This study concluded that harvest scheduling which conducted over eight periods has made the abnormal stand structure into the normal forest condition. The existence of normal forest condition led to the certainty of pine resin production sustainability.

A practical way to integrate risk in forest management decisions

The concept of expected losses is an appropriate measure for integrating risk in the determination of the optimal rotation period and choice of tree species. Natural threats are challenging forest management decisions. Essential decisions about the optimal length of a harvest period are often taken without considering risks. Here, a practical and easy to apply way to integrate risk in these decisions is shown. Furthermore, it is seen how the rotation period changes according to the risk-type and risk-level. The marginal principle of Presler’s indicator rate is developed further by including the concept of expected losses, leading to an optimal harvest age under risk. The application of the new formula is shown by a simulation, which also visualises the influence on the optimal rotation age. Whether risk influences the optimal harvest age compared to a risk free solution, depends on the relationship between expected losses in terms of land rent of the succeeding stand and expected losses in terms of value growth of the existing stand. If they are equal, the rotation age stays. If the expected loss on value growth is bigger than on land rent, the rotation period will be shorter, while it will be longer if the relation is inverse. The concept of expected losses can be applied to practically determine the optimal rotation period under risk.

Impacts of Early Thinning of a Eucalyptus globulus Labill. Pulplog Plantation in Western Australia on Economic Profitability and Harvester Productivity

The impact of the manipulation of plantation stocking density on individual tree size can affect final harvest costs and machine productivity. This paper investigated the impact of four early-age thinning treatments applied to a Eucalyptus globulus Labill. pulplog plantation in south-west Western Australia on economic profitability and harvester productivity. Eighteen sample plots were randomly laid out in the study area. The nominal 700, 500, and 400 stems per hectare (sph) plots were thinned to waste 3.2 years after establishment while the nominal 1000 sph (UTH) plots were left unthinned. The economic analysis showed that all thinning treatments resulted in a lower Land Expectation Value (LEV) and net financial loss over the full rotation at their theoretical optimal rotation age when compared with the unthinned control treatment. Tree growth and form were positively impacted by thinning. However, associated reductions in harvesting costs were less than the value losses resulting from reduced per hectare yield.

Tree breeding model to assess financial performance of pine hybrids and pure species: deterministic and stochastic approaches for South Africa

Financial performance of the P. patula × P. tecunumanii, P. greggii × P. tecunumanii, P. taeda × P. tecunumanii hybrids and their parental species was studied for South Africa. A model was developed for use in determining the profitability of a tree-breeding program (TBP) with pine hybrids in commercial plantations. Growth measurement data were collected in four, 12-year-old genetic trials on Mondi and Sappi land holdings in South Africa. Growth models developed for P. patula and P. taeda in South Africa were used to infer models for the other taxa and to calculate the optimal financial rotation age at discount rates of 6 and 8%. Financial data on pine plantations were collected from different sources in South Africa. Optimal rotation lengths in this study were found to be between 12 and 16 years for pulpwood and 17 years for sawtimber. The model output shows the net present value (NPV), the internal rate of return, and the minimum area that a tree grower has to plant every year in order to justify the investment in a TBP. A stochastic approach with Monte Carlo simulation showed that the sensitivity of NPV to uncertainty in the wood price was greater than that for the planting, harvesting, and transport costs.

Determining subsidised forest stands to satisfy required annual wood yield with minimum governmental expense

There are regions where forestry is required for wood production but the profitability is so low that many forest stands cannot be managed without subsidisation. Hence, the policymakers should design an efficient subsidising system involving the selection of subsidised forest stands. In this paper, we present an analytical framework for the proposition through the construction of a normal forest (a forest state such that the age distribution of stands is uniform) that consists of only stands that need to be subsidised for regeneration. The normal forest is constructed so that it supplies the required annual wood yield with minimum governmental expense for the subsidy. The rotation age of the normal forest is set to an optimal rotation age based on the soil expectation value of the stands under the minimum subsidy rates. The normal forest can be derived without numerical integration when the dominant tree height distribution follows a generalised gamma distribution. We present an application of the framework for four tree species in the Nagano Prefecture, Japan. The result of the application shows that the framework enables us to select the subsidised stands for efficient governmental funding, implying the practical conditions of the stands and requirements of wood demands, by using optimisation functions in a commercial spreadsheet program.

Environmental and Financial Sustainability of Forest Management Practices

One of the guiding themes for forest management policy throughout much of North America is sustained yield. The basic premise behind this theme is that a constant or non-declining flow of services from the forest is socially desireable. Unfortunately, the act of capturing the benefits of this service (timber harvesting) often has detrimental effects on the timber-productive capacity of a forest site. This paper presents a dynamic program that is used to determine the optimal harvest system choice for a timber stand described by average piece size, stand density, a measure of site quality, and stumpage value. The harvest systems are defined by logging costs, reforesation and rehabilitation costs, and the impact of the system on the productivity of the site. An application of the model is presented for lodgepole pine in Alberta. We conclude that at high discount rates, soil conservation is not economically rational. At lower discount rates, some degree of soil conservation is desirable on the more productive sites. At lower discount rates, there also appears to be an incentive for mroe intensive forest management. Limitations on acceptable harvest practices can have a large impact on optimal rotation age and the volume harvested. There is a large opportunity cost resulting from a requirement for sustainable volume production because of the impact of harvsting on soil productivity.(This abstract was borrowed from another version of this item.)

Biophysical and Economic Analysis of Black Spruce Regeneration in Eastern Canada Using Global Climate Model Productivity Outputs

We explore the biophysical potential and economic attractiveness of black spruce (Picea mariana) regeneration in eastern Canada under the high greenhouse gas emission scenario (RCP 8.5) of the Intergovernmental Panel on Climate Change (IPCC). The study integrates net primary productivity and net ecosystem productivity estimates from three major global climate models (GCMs), growth and yield equations specific to black spruce, and economic analyses to determine spatially varying investment values of black spruce regeneration—both including and excluding carbon sequestration benefits. Net present value (NPV) was used to represent financial attractiveness. It was assumed that stands would not be harvested at volumes less than 80 m3·ha−1. A baseline case with the stumpage price set to $20 m−3, stand establishment cost $500 ha−1, and the discount rate 4%, was used with wide-ranging sensitivity analyses conducted around these assumptions. These values represent the wide range of choices and outcomes possible with black spruce regeneration investments. The results indicated a latitudinal gradient in economic attractiveness, with higher forest productivity and NPVs in the southern portion of the study area; however, black spruce regeneration was not economically attractive unless regeneration costs were very low (representing something closer to a natural regeneration type scenario) and/or carbon sequestration benefits of at least $5 ton−1 CO2 were realized. In general, the optimal harvest rotation age increased with increasing carbon price by approximately 9 to 18 years. Results of this study highlight the importance of future price and yield expectations and establishment costs in evaluating forest investments.

The Biodiversity Benefits and Opportunity Costs of Plantation Forest Management: A Modelling Case Study of Pinus radiata in New Zealand

This study modelled the potential biodiversity benefits and the opportunity costs of a patch-clear-cutting strategy over a clear-cutting strategy for Pinus radiata in New Zealand. Patch-clear cutting is a special case of clear cutting involving the removal of all the trees from strips or patches within a stand, leaving the remainder uncut or clear cutting a series of strips or patches. A forest-level optimisation model was extended to include uncertainty in timber growth, plant diversity, and cutting costs. Using a species-area relationship and economies of cutting scale, the net present value and optimal rotation age under alternative management strategies were calculated. Results suggested that the optimal rotation ages were similar (24 and 25 years) for the two cutting strategies. Patch-clear cutting provided higher biodiversity benefits (i.e., 59 vs. 11 understorey plant species) with an opportunity cost of 27 NZD (18 USD) per extra plant species or 1250 NZD (820 USD) ha−1. However, the true benefits of patch-clear cutting would be even greater if other benefits of stand retention are included. Our research can potentially inform local decision making and inform international systems of payment for environmental services, such as the REDD+ (Reducing Emissions from Deforestation and Forest Degradation) program, to conserve biodiversity in developing countries with plantation forests.

Forest Value and Optimal Rotations in Continuous Cover Forestry

The Faustmann forest rotation model is a celebrated contribution in economics. The model provides a forest value expression and allows a solution to the optimal rotation problem valid for perpetual rotations of even-aged forest stands. However, continuous forest cover forest management systems imply uneven-aged dynamics, and while a number of numerical studies have analysed specific continuous cover forest ecosystems in search of optimal management regimes, no one has tried to capture key dynamics of continuous cover forestry in simple mathematical models. In this paper we develop a simple, but rigorous mathematical model of the continuous cover forest, which strictly focuses on the area use dynamics that such an uneven-aged forest must have in equilibrium. This implies explicitly accounting for area reallocation and for weighting the productivity of each age class by the area occupied. We present results for unrestricted as well as area-restricted versions of the models. We find that land values are unambiguously higher in the continuous cover forest models compared with the even-aged models. Under area restrictions, the optimal rotation age in a continuous cover forest model is unambiguously lower than the corresponding area restricted Faustmann solution, while the result for the area unrestricted model is ambiguous.

Do the Risk Attitudes of Smallholder Forest Managers Drive Their Forest Carbon Supply: A Risk Experiment in China

It is widely recognized that enhancing forest carbon sequestration (FCS) can be an effective approach for mitigating climate change. Given the uncertainty about carbon pricing and the outcomes of FCS management, household perceptions of FCS management will be heavily dependent upon their risk attitudes, especially in developing countries with rich forest resources. Using a survey of 200 smallholder forest managers in Zhejiang Province in China and a risk experiment, this paper analyzes how the risk attitudes of households drive their FCS supply. We simulated the carbon supply with different risk attitudes of households based on a revised Faustmann model and a sensitivity analysis. A key finding is that compared with a timber benefit only, FCS management will generate more investment value. However, households have little incentive to change their harvest decision-making when the carbon price is low. Among the three identified risk attitude groups, although they have the same optimal rotation age when the carbon value is considered, their carbon supply per hectare is different due to difference in their planting densities. Also, the rotation age with FCS management and the FCS supply per hectare do not change significantly unless there is a substantial change in the carbon price, the management costs and the discount rate for all three risk attitude groups completely.

Optimal forest rotation for carbon sequestration and biodiversity conservation by farm income levels

This study aimed to estimate the optimal forest rotation age for tropical plantations of a native tree species, Canarium album (Lour.) under the management of high, medium, and low income groups of farm households of Vietnam. The results suggest that: (i) the optimal rotation age for the low income group is longer than that for the high income group; (ii) low income farmers are more sensitive in terms of the land expectation value to changes in discount rate; (iii) low income farmers gain less if the carbon price increases; and (iv) the carbon payment scheme at the start of a rotation is more financially attractive to forest farmers, but the carbon payment scheme at the end of a rotation is more advantageous in terms of forest biodiversity. These findings lead to potential policy implications for forest management for the provision of multiple ecosystem services in the context of a developing country, demonstrating a tradeoff between forest income and biodiversity conservation. While an increase in carbon prices would benefit forest farmers, we also suggest that these farmers could be compensated for their income losses or rewarded to maintain or increase forest biodiversity. However, relatively greater attention could be paid to compensating low income farmers as they potentially lose more with an increase in discount rate and gain less with an increase in carbon price.

Could the Faustmann model have an interior minimum solution?

The growth of an even-aged stand usually follows a S-shaped pattern, implying that the growth function is convex when stand age is low and concave when stand age is high. Given such a growth function, the Faustmann model could in theory have multiple optima and hence an interior local minimum solution. To ensure that the rotation age at which the first derivative of the land expectation value equals zero is a maximum, it is often assumed that the growth function is concave in stand age. Yet there is no convincing argument for excluding the possibility of conducting the final harvest before the growth function changes to concave. We argue that under normal circumstances the Faustmann model does not have any interior minimum. It is neither necessary nor proper to assume that the growth function is concave in the vicinity of the optimal rotation age. When the interest rate is high, the optimal rotation may lie in the interval on which the growth function is convex, i.e. before volume or value growth culminates.

Optimal forest species mixture with carbon storage and albedo effect for climate change mitigation

Accounting for carbon storage and the albedo effect through Payments for Ecosystem Services (PES) or mandatory offset permits aims to internalize the environmental externalities of forest management. This can shift the economically optimal rotation age, and incorporate rents for a wider range of ecosystem service offerings. A mixed stand economic optimization model was used to determine the optimal stand mixture and inter-species climate regulation trade-offs. Mixed forest dynamics between deciduous silver birch (Betula pendula Roth.) and coniferous Norway spruce (Picea abies Karst.) were evaluated. The sensitivity of our results to the absolute species-specific differences in albedo parameter values was also conducted. Results indicated that a synergistic climate regulation trade-off between the two species exists. The optimal rotation for the combined carbon storage and albedo effect was equivalent to that of the carbon storage only case. Differences in absolute albedo impacts were most sensitive at high discount rates, for ‘climate only’ management, and over increasing offset prices. These results demonstrate the importance of parameter certainty in the promotion of PES in forestry. They also show that mixed stands can promote more efficient trade-offs between forest ecosystem service offerings and provide a basis for diversifying between ecosystem functions.

Optimal Forest Rotation Age for Carbon Sequestration and Biodiversity Conservation by Farm Income Levels

This study aimed to estimate the optimal forest rotation age for tropical plantations of a native tree species, Canarium album (Lour.) under the management of high, medium, and low income groups of farm households of Vietnam. The results suggest that: (i) the optimal rotation age for the low income group is longer than that for the high income group; (ii) low income farmers are more sensitive in terms of the land expectation value to changes in discount rate; (iii) low income farmers gain less if the carbon price increases; and (iv) the carbon payment scheme at the start of a rotation is more financially attractive to forest farmers, but the carbon payment scheme at the end of a rotation is more advantageous in terms of forest biodiversity. These findings lead to potential policy implications for forest management for the provision of multiple ecosystem services in the context of a developing country, demonstrating a trade off between forest income and biodiversity conservation. While an increase in carbon prices would benefit forest farmers, we also suggest that these farmers could be compensated for their income losses or rewarded to maintain or increase forest biodiversity. However, relatively greater attention could be paid to compensating low income farmers as they potentially lose more with an increase in discount rate and gain less with an increase in carbon price.