Even-aged Forest Management Research Articles

How can optimized forest management plan regulate noise levels from wind turbines?

Wind energy has emerged as one of the most economically viable renewable energy options in the transition towards a fossil-free society. In Finland, wind farms, consisting of several wind turbines, are commonly located in forested areas, prompting concerns about their potential audio-visual impacts. Despite this, research into how forests might mitigate the adverse effects of wind farms are limited. Forests can effectively serve as noise barrier, with their noise attenuation capacity varying based on the forest’s characteristics. Specifically, the attenuation level depends on the sound’s travel distance through the forest, as well as the size and density of trees. Our study findings indicate that forests can provide up to 10 dB of additional noise attenuation. This was achieved by integrating a forest structure-based model into forest planning calculations, aimed at mitigating noise pollution from wind turbines. Incorporating this noise model as a management objective significantly reduced noise levels in the pilot study area, outperforming traditional business-as-usual management strategies. Furthermore, adapting a combination of uneven-aged and even-aged forest management approaches resulted in more forested landscape, which was more effective in mitigating higher noise levels. Our results contribute important insights that, along with further research, can guide future forest planning and management towards enhanced sustainability.

Short-term effect of the harvesting method on ecosystem carbon budget in hemiboreal Scots pine forest: Shelterwood cutting versus clear-cut

Shelterwood cutting (SC) has been highlighted as an alternative method to clear-cut (CC)-based even-aged forest management. However, compared to CC, the effect of SC on stand carbon (C) balance is still poorly understood at the ecosystem level. We examined the prompt effect of SC versus CC on ecosystem net primary production (NEP) on a short-term scale, using the C budgeting method combined with eddy covariance (EC) measurements in hemiboreal mature Scots pine stands.The early effect of SC on annual C budget after removing 30–40 % of the growing stock revealed diverse patterns in the studied stands; NEP varied from 0.62 to −1.3 t C ha−1 yr−1 for the C sink and the C source, respectively. However, C loss decreased already in the second post-thinning year and levelled out attaining −0.41 t C ha−1 yr−1, which is close to balance.Furthermore, C loss declined in the second post-harvesting year at the CC sites as a result of the increased production of the ground vegetation and the decreased soil heterotrophic respiration (Rh) flux. However, C loss from dry mesotrophic clear-cuts was almost −1.8 t C ha−1 yr−1 for both study sites. Since estimation of the individual C fluxes for C budgeting is associated with variability-induced errors, the estimated values of NEP contain uncertainties of various levels.The estimated annual cumulative Rh flux was significantly higher in the SC versus CC areas and the mean annual Rh values across the study sites were 3.57 ± 0.25 and 2.59 ± 0.09 t C ha−1 yr−1, respectively.Annual estimated NEE after SC was 1.8 ± 0.52 t C ha−1 yr−1, gross primary ecosystem production was 9.28 ± 0.97 and total ecosystem respiration was 7.47± 0.28 t C ha−1 yr−1. The discrepancy between the estimated values of NEE and NEP was 1.2 t C ha−1 yr−1.In the short term SC demonstrated some advantage over CC from the perspective of the C cycle, but the difference in NEP values between the SC and CC treatments was not convincingly overwhelming. Hence, SC allows to maintain the forest cover for a longer period and to avoid drastic changes in the landscape; still, after SC, C budget varied between the C sink and the C source.

Abandoning conversion from even-aged to uneven-aged forest stands – the effects on production and economic returns

ABSTRACT There is growing interest in continuous cover forestry in Sweden. The historical domination of even-aged forest management means there is a need to focus on methods for transforming even-aged to uneven-aged stands. Practical conversion management today is highly adaptive, and the possibility of failures, such as persistent lack of tree recruitment, must be allowed for. We used simulations to evaluate various scenarios in which conversion management is introduced at different development stages in even-aged stands and then abandoned in favour of clear-felling. A shift towards an inverse J-shaped diameter distribution at the end of the simulations was most evident in northern Sweden and with an early introduction of conversion forestry. The largest losses were incurred in a scenario where the conversion management started with removing larger trees at pre-commercial thinning: it reduced the volume of production by up to 25% and, if clear-felled, resulted in a lower land expectation value than conventional management. Earlier decision to abandon conversion management reduced the losses, but the effect of timing was minor. In summary, the results indicate that conversion management could be started and abandoned without any major economic loss during the timeframe of a normal rotation.

Adapting the tree growth model MOSES to manage uneven-aged mixed species forests in Bosnia & Herzegovina

In Bosnia & Herzegovina, uneven-aged Plenter forest is the dominating forest management system and applied to 90% of the high forest area. This differs from most other European countries, where even-aged forest management is dominating. However, the interest in Plenter forest management is increasing, as mixed diverse forest stands are considered to be more resilient versus even-aged forests. In this study, we analyze uneven-aged forest management in Bosnia & Herzegovina and demonstrate the application of the tree growth model MOSES (Modeling Stand rESponse) for Plenter forest management in the region. After validating the model using independent data, we perform simulation scenarios to demonstrate the applicability of the model to the local conditions. Our results suggest that the model exhibits no bias or inconsistencies in the resulting predictions. The simulation runs show how the model can be used for scenario analysis within Plenter forests and that continuous management is needed to maintain the diversity of Plenter forest ecosystems.

Partial cutting of a boreal nutrient-rich peatland forest causes radically less short-term on-site CO2 emissions than clear-cutting

Wide-spread harvesting of forests growing on drained peatlands is foreseen to take place in Finland in the near future. A hot question is if continuous cover forestry utilizing partial cuttings could be used to mitigate carbon dioxide (CO2) emissions and the consequent climatic impact compared to traditional clear-cutting and even-aged forest management. To assess the impact of clear-cutting vs. partial cutting, we first measured CO2 exchange with the eddy covariance (EC) method for six years in a mature, nutrient-rich peatland forest in southern Finland. Part of the forest was then partially cut (74% of the stem volume), and part of it was clear-cut, and CO2 exchange of both areas was measured for another six years. Tree growth was recorded before and after the cuttings to separate the contributions of tree stand and forest floor to CO2 exchange. Before the cuttings, the site had an annual CO2 exchange close to zero, but both cutting methods turned it into a CO2 source. However, the first-year emissions from the partial cutting area (800 g CO2 m−2 yr−1) were markedly lower than the emissions after clear-cutting (3100 g CO2 m−2 yr−1). The partial cutting area remained a CO2 source during the first three years but turned into a CO2 sink after that, while the clear-cut area acted as a large, although diminishing, CO2 source for the whole measurement period. The total six-year CO2 balances before and after partial cutting did not differ significantly, while the emissions after clear-cutting were on average 2240 g CO2 m−2 yr−1 larger than before it. Combining the EC data with the tree growth measurements showed that the forest floor was losing C both before and after harvestings. In conclusion, partial cutting resulted in clearly smaller CO2 emissions than clear-cutting at least in the short term.

Injury Patterns among Forestry Workers in Croatia

Timber harvesting, especially motor-manual felling, in Croatia, as in many other countries, is one of the most hazardous economic activities. Consequently, the aim of this paper is to analyse and compare the latest trends and risk factors related to the incidence of work-induced injuries in structural organization units of national forest enterprise. A combined approach of literature review and assembled secondary data was applied to gather data on workplace accidents over the years 2014–2020. Work-induced injuries data were drawn from the records of the national enterprise Croatian Forests Ltd. which manages state forests (76% of total forest area). A total of 1626 work-induced injuries were processed and entered into the database. Data analysis was conducted using statistical and descriptive methods. Research results have proven a significant difference in the injury rate over the years 2014–2020 in the Croatian forest enterprise. During the analysed period the highest number of workplace accidents (51.35% of all recorded workplace accidents) occurred during the forest harvesting phase, i.e., during motor-manual felling. Trends in the incidence of work-induced injuries in the observed period do not show any significant improvement. The key findings have pointed out that forest administrations which practice even-aged forest management have 25% or more injuries than forest administrations which practice selective forest management. Related to the average rate of change by forest administration, the largest annual increase or decrease of the selected safety indicators is recorded for smallest forest administrations. Related to total number of injuries, the smallest forest administrations have the least injuries and show statistically significant difference compared to large forest administrations. When comparing the number of injuries per 1000 employees, medium sized forest administrations have the highest value of indicator and show statistical significance. Discussion and conclusion of the paper emphasizes the need for systematic research in the field of ergonomy, safety and health of forest workers in Croatian forestry sector. Additionally, the development and inclusion of proactive safety culture is recognized as a mechanism that can further reduce work injuries and improve occupational safety which should have a significant role in the process of certification of forest management according to the FSC standard.

Thinning promotes the nitrogen and phosphorous cycling in forest soils

Thinning, a major practice of even-aged forest management, notably affects the stand structure and microclimates and thus in turn soil nitrogen (N) and phosphorous (P) cycling. However, the magnitude and direction of these effects remain uncertain. We performed a meta-analysis of 1228 observations from 115 studies worldwide to explore the effects of thinning on forest soil N and P processes. The results showed that thinning increased the concentrations of soil nitrate, total P, and available P by 11.7%, 6.1%, and 11.4%, respectively, but had no effect on the concentrations of soil total N and ammonium. Thinning stimulated soil microbial activities regulating soil N and P cycling, evidenced by the increased microbial biomass N and the activities of N- and P-acquiring extracellular enzymes. Thinning also increased net N mineralization and nitrification rates, but did not significantly affect N2O emission. However, these thinning effects varied with climates and forest biomes. The effect sizes of N-cycling processes were significantly correlated with mean annual precipitation or mean annual temperature, implying that these N fluxes are more sensitive to thinning in warm and humid regions. Collectively, our meta-analysis indicates that thinning promotes forest soil N and P cycling and increases the soil fertility, which are conducive to improving forest ecosystem functions.

Summer Bat Habitat Use and Forest Characteristics in Managed Northeastern Forests

AbstractThere has been limited research investigating summer habitat use of bats in managed forests in the northeastern United States. Consequently, there is limited knowledge to inform forest managers seeking to maintain or enhance bat habitat, particularly for several federally threatened, endangered, or candidate species. In summer 2017–2018, we conducted repeated acoustic surveys to determine what forest characteristics are associated with bat habitat use in managed forests in the Adirondack region of upstate New York. We modeled detection corrected probability of occupancy for bats in three phonic groups: high, mid, and low frequency. Across all phonic groups, probability of occupancy increased with decreasing canopy cover. High-, mid-, and low-frequency bats were more likely to use recently harvested sites (<10 years since harvest). High-frequency bats also used mature stands. Midfrequency bats demonstrated a preference for further distances from forest roads, whereas low-frequency bats preferred areas with a higher percentage of clutter. Our results suggest that tending and regenerating even-aged forest management practices can provide habitat for foraging bats in the Adirondacks.

Wood Products for Cultural Uses: Sustaining Native Resilience and Vital Lifeways in Southeast Alaska, USA

Ongoing revitalization of the >5000-year-old tradition of using trees for vital culture and heritage activities including carving and weaving affirms Alaska Native resilience. However, support for these sustained cultural practices is complicated by environmental and political factors. Carving projects typically require western redcedar (Thuja plicata) or yellow cedar (Callitropsis nootkatensis) trees more than 450 years of age—a tree life stage and growth rate inconsistent with current even-aged forest management strategies. Herein, we qualitatively assess the significance of wood products to rural communities and Indigenous cultures with implications for natural heritage sustainability. In partnership with Alaska Native Tribes, we engaged local youth programs to lead community discussions throughout southeast Alaska to provide specificity to the suite of cultural activities linked to regional forest lands. Results from 58 discussions across 11 southeast Alaska communities (primarily Alaska Native participants) highlighted the cultural importance of forest products including totem poles, dugout canoes, longhouses, woven hats, and woven baskets. Findings indicated spiritual well-being, health, education, tourism, and livelihood significance attributed to these products. Participant-suggested management strategies for increasing supply and expanding access to trees on public lands included: engaging local artisans in forest planning, selecting and delivering specific trees to roads as part of ongoing timber sales, allowing bark removal prior to forest-timber sales, simplifying the tree-acquisition permit process, and setting aside cultural forest groves to sustain trees seven generations into the future. By facilitating discussions, this study fostered relevant place-based youth and community engagement, benefiting youth and enhancing community knowledge transfer while simultaneously summarizing the significance of forest products for resilient culture and heritage activities. Forest management plans aiming to support Alaska Native lifeways may benefit from improved understanding of Indigenous perspectives and worldviews; designation of “culture market values” and “culture targets” can help deliver a broad array of ecosystem services.

Maintaining natural and traditional cultural green infrastructures across Europe: learning from historic and current landscape transformations

ContextMaintaining functional green infrastructures (GIs) require evidence-based knowledge about historic and current states and trends of representative land cover types.ObjectivesWe address: (1) the long-term loss and transformation of potential natural forest vegetation; (2) the effects of site productivity on permanent forest loss and emergence of traditional cultural landscapes; (3) the current management intensity; and (4) the social-ecological contexts conducive to GI maintenance .MethodsWe selected 16 case study regions, each with a local hotspot landscape, ranging from intact forest landscapes, via contiguous and fragmented forest covers, to severe forest loss. Quantitative open access data were used to estimate (i) the historic change and (ii) transformation of land covers, and (iii) compare the forest canopy loss from 2000 to 2018. Qualitative narratives about each hotspot landscape were analysed for similarities (iv).ResultsWhile the potential natural forest vegetation cover in the 16 case study regions had a mean of 86%, historically it has been reduced to 34%. Higher site productivity coincided with transformation to non-forest land covers. The mean annual forest canopy loss for 2000–2018 ranged from 0.01 to 1.08%. The 16 case studies represented five distinct social-ecological contexts (1) radical transformation of landscapes, (2) abuse of protected area concepts, (3) ancient cultural landscapes (4) multi-functional forests, and (5) intensive even-aged forest management, of which 1 and 4 was most common.ConclusionsGIs encompass both forest naturalness and traditional cultural landscapes. Our review of Pan-European regions and landscapes revealed similarities in seemingly different contexts, which can support knowledge production and learning about how to sustain GIs.

Boreal peatland forests: ditch network maintenance effort and water protection in a forest rotation framework

Ditch network maintenance promotes forest growth in drained peatland forests but increases nutrient and sediment loads, which are detrimental to water quality. Society needs to balance the harvest revenue from improved forest growth against deteriorating water quality. We examine socially optimal even-aged forest management in drained peatlands when harvesting and ditch network maintenance cause nutrient and sediment loading. The means to reduce loading include establishing overland flow fields and abstaining from ditch network maintenance. We characterize this choice analytically in a rotation framework and examine, in a numerical model, the key factors affecting the choice of forest management and water protection measures. We choose a drained peatland forest site located in northeastern Finland in the vicinity of ecologically vulnerable forest headwater streams. On the given drained forest site, we find a set of parameters under which implementing ditch network maintenance is privately but not socially optimal.

Impacts of climate change on biological rotation of Larix olgensis plantations for timber production and carbon storage in northeast China using the 3-PGmix model

Biological rotation length is a key parameter of even-aged forest management. Future climate change is expected to affect forest growth and thus modify biological rotation age, but knowledge about the effect of climate change on the rotation for both timber production and carbon storage remains limited from process-based growth model. The biological rotation age (BRA) of Larix olgensis plantations in China is technically set for 40 years according to the principle of maximizing timber production, and it is necessary to further examine the BRA with consideration of site quality differences and climate change. On the basis of 164 sample plots from the National Forest Inventory across the Jilin Province, Northeast China, we use the process-based model 3-PGmix to simulate the change of the BRA of Larix olgensis plantations for timber production and carbon storage under climate change. Different climate scenarios are investigated across different site productivity levels. Under the current climate scenario, the BRAs for timber production and carbon storage are approximately 23.8–41.5 years and 25.0–46.4 years, respectively. The BRAs are reduced by 2–9 years under RCP 4.5 and RCP 8.5 climate scenarios. The BRA modification by climate change was site-dependent, and stands with good productivity sites led to shorter BRAs than those with poor productivity sites. The 3-PGmix model effectively simulates the dynamic change of stand volume and biomass for larch plantations. Future climate change with rising temperature, increased precipitation and elevated CO2 concertration is conducive to the growth of stand volume and carbon storage in the order of RCP 8.5 > RCP 4.5 > current. Results can provide scientific implications for adaptive management of Larix olgensis plantations, and shorter biological rotation is suggested for rotation modification under the future climate change in the region.

Effects of shelterwood method and plant stock type on the early growth and survival of pine seedlings in regeneration stands under hemiboreal conditions

ABSTRACTShelterwood forest regeneration methods are increasingly used in northern Europe to reduce clear-cut based even-aged forest management. However, empirical knowledge about seedling performance under various shelterwood methods is still incomplete. We analysed the effects of three shelterwood methods (uniform (UNI), strip felling (STR) and group selection (GRO)) on four types of Scots pine plant stock type height growth and survival during the first 6 years in hemiboreal Estonia. After 6 years, the height of the planted seedlings was 35% lower in GRO and 47% lower in UNI compared to STR. A similar outcome was observed for the height growth of the sown seedlings. Competition with the nearest shelter trees had a negative effect on seedling height growth. Lower height growth in UNI can be attributed to more intensive root competition with shelter trees. Artificial sowing and natural seeding can provide sufficient regeneration, but height growth was significantly lower compared to that of planted seedlings. Shelterwood methods delay seedling growth compared to clear-cut area reforestation. The lag in regeneration height growth was the smallest in STR and the greatest in UNI. The growth lag can be reduced by using complementary planting to natural regeneration.

Forest management has reduced the structural diversity of residual boreal old-growth forest landscapes in Eastern Canada

The impact of traditional even-aged forest management on landscape age structure, tree composition, and connectivity has been well documented. Very little, however, is known about the impact on stand structural diversity. This study aims to compare the structural and abiotic characteristics of forest stands disturbed by clearcut logging and by stand-replacing fire in Quebec’s boreal landscapes. We hypothesized that unlike fire, logging specifically targeted stands having a higher economic value, i.e., merchantable volume, leaving altered forest characteristics on post-harvested landscapes. We compared two aerial forest surveys of a 2200 km2 study area, one survey completed before any logging activity (preindustrial survey; 1980s), and the second survey collected >10 years after logging activity (modern survey; 2000s). Forest stands at the time of the preindustrial survey were primary forests. We identified stands as either burned, logged, or left aside after forest management of the area (remaining stands) between the two surveys and compared their structural and abiotic characteristics using logistic regression. The structural and abiotic characteristics of burned and logged stands differed significantly. Relative to the burned stands, logged stands were older, denser, and marked by poorer drainage and a higher proportion of black spruce; therefore post-harvest and post-burn landscapes differed in terms of their structural diversities. Traditional even-aged forest management has significantly altered the boreal forest landscape by targeting specific stands having higher economic value and leaving behind stands of lower economic value. Remaining high economic stands should be protected, and a more balanced approach to harvesting must be used in the context of ecosystem-based management.

Implications of the reservation price strategy on the optimal harvest decision and production of nontimber goods in an even-aged forest stand

This study analyzes the effects of adopting an adaptive harvest strategy in even-aged forest management under timber price uncertainty on the production of nontimber goods. We use the reservation price strategy (“harvest when the observed timber prices are higher than the reservation prices”) on a longleaf pine (Pinus palustris Mill.) stand and employ the Faustmann–Hartman model as a benchmark. We assume that a longleaf pine stand can be managed for timber production, water production, carbon sequestration, and pine straw raking, depending on the planting density. Our results indicate that the reservation price strategy leads to longer expected harvest age when planting density is high. The reservation price strategy does not lead to increases in water production and carbon sequestration with low planting density. With high planting density, the reservation price strategy leads to increases in the amount of in situ carbon sequestered by 14.4–24.7 Mg·ha–1. Our findings suggest that managing longleaf pine forests in good- or poor-quality sites is a profitable alternative and enables water production and carbon sequestration.

A note on the regularity of a new metric for measuring even-flow in forest planning

In this work we deal with the mathematical analysis of a new metric for measuring even-flow in even-aged forest management planning. We begin writing the most used way of measuring even-flow, and showing the main disadvantages of this classical procedure. Next, we introduce the new metric and study the regularity of the corresponding function, which results to be continuous and to have continuous derivatives in almost all points. We give an explicit expression for these derivatives and analyze its usefulness by comparing a gradient-type method with a derivative-free algorithm (widely used in forestry) to maximize even-flow in a forest of 51 Eucalyptus globulus Labill. stands in Galicia (NW Spain). We observe that gradient-type methods work well with the new even-flow metric, which enables this type of methods for solving the multi-objective problems that can be formulated in forest planning.

Cyclic small rodents in boreal forests and the effects of even-aged forest management: Patterns and predictions from a long-term study in southeastern Norway

Small mammals, especially microtine rodents, play an important role in the dynamics of boreal forest ecosystems. Even-aged forest management, in which old, semi-natural forests are converted to clear-cuts and culturally regenerated stands, is expected to have pronounced impact on the abundance and composition of this group of animals due to changes in the understory vegetation. During a 39 year-period we sampled autumn numbers of small mammals in uncut, semi-natural old forest and in recent clearcuts, supplemented by a 7-year sample from middle-aged plantations. Field voles Microtus agrestis were almost exclusively trapped in clearcuts. Bank voles Myodes glareolus dominated in the old forest, but reached equal or higher densities than field voles in clearcuts. Here, their combined abundance exceeded that of bank voles in old forest. Some years, wood lemmings Myopus schisticolor contributed significantly to vole abundance in old forest. Other rodents Apodemus spp. were rarely captured, mainly in clearcuts, and shrews Sorex spp. numbered <15 percent of the total number of captured animals. Throughout the whole period we discerned 11 vole cycles, with highest peaks in bank voles in old forest. After high numbers during the 1980s, abundances of all species fell markedly during the 1990s, most distinctively in clearcuts, where the field vole almost totally disappeared. From the late 2000s, abundances of all species returned to pre-1990 levels and beyond. In the early and late periods, combined vole numbers were 26% higher in clearcuts compared to old forest, whereas the opposite was true in the middle period. In middle-aged plantations, bank voles numbered only one third of what it was in clearcuts and old forest, and other voles were rarely trapped. The results support the general notion that bank voles thrive in bilberry-rich, older forest and field voles in grass-dominated habitat. Contrary to general assertions, bank vole was abundant also in clearcuts, possibly due to invasion from surrounding old forest, but peak densities were lower than in old forest, possibly due to suppression by field voles. The variation of small mammals in forest age classes concurred closely with recent results reported from Finland. On a landscape scale, the results from these two and other studies predict that the total biomass of small rodents will be reduced by even-aged forest management, not because of conversion of older, semi-natural forest to clearcuts, but because of a decline in numbers in middle-aged and older, secondary forests.

A Markov Chain Model for Simulating Wood Supply from Any-Aged Forest Management Based on National Forest Inventory (NFI) Data

Markov chain models have been applied for a long time to simulate forest dynamics based on transitions in matrices of tree diameter classes or areas of forest size and structure types. To date, area-based matrix models have been applied assuming either even-aged or uneven-aged forest management. However, both management systems may be applied simultaneously due to land-use constraints or the rationality of combining the systems, which is called any-aged management. We integrated two different Markov chain models, one for even-aged and another for uneven-aged forest management, in an area-based approach to analyze wood supply from any-aged forest management. We evaluate the impacts of parameterizing the model based on available data sets, namely permanent and temporary Finnish National Forest Inventory (NFI) sample plots and a plot-level simulator to determine transitions due to different types of thinning treatments, and present recommendations for the related methodological choices. Our overall observation is that the combined modelling chain simulated the development of both the even- and uneven-aged forest structures realistically. Due to the flexibility of the implementation, the approach is very well suited for situations where scenario assumptions need to be varied according to expected changes in silvicultural practices or land-use constraints, for example.

Habitat network assessment of forest bioenergy options using the landscape simulator LandSim – A case study of Kronoberg, southern Sweden

Forest biomass is a renewable resource that is increasingly utilised for bioenergy purposes in Sweden, which along with the extraction of industrial wood may conflict with biodiversity conservation. The aim of this paper is to present a method for integrated sustainability assessment of forest biomass extraction, particularly from bioenergy and biodiversity perspectives. The landscape simulator LandSim was developed and linked with models for the assessment of biomass yields and habitat networks representing prioritised biodiversity components. It was applied in a case study in Kronoberg County in southern Sweden. Forest growth and management were simulated for the period 2010–2110, following two land zoning scenarios, one applying even-aged forest management on all forest land except for protected areas (EAF-tot), and one applying continuous cover forest management on parts of the forest land, combined with protected areas and an intensified even-aged management on the other parts (CCF-int). The EAF-tot scenario implied higher yields of biomass feedstock for bioenergy, the CCF-int scenario only giving 66% of that yield, while the CCF-int scenario performed substantially better when it came to the habitat network indicators, if habitat suitability was ensured. Conclusively, the case study confirmed that the modelling framework of the LEcA tool, linking the landscape simulator LandSim with the biomass yield assessment and the habitat network model can be used for integrating main policy concerns when assessing renewable energy options.

Optimal management of naturally regenerating uneven-aged forests

A shift from even-aged forest management to uneven-aged management practices leads to a problem rather different from the existing straightforward practice that follows a rotation cycle of artificial regeneration, thinning of inferior trees and a clearcut. A lack of realistic models and methods suggesting how to manage uneven-aged stands in a way that is economically viable and ecologically sustainable creates difficulties in adopting this new management practice. To tackle this problem, we make a two-fold contribution in this paper. The first contribution is the proposal of an algorithm that is able to handle a realistic uneven-aged stand management model that is otherwise computationally tedious and intractable. The model considered in this paper is an empirically estimated size-structured ecological model for uneven-aged spruce forests. The second contribution is on the sensitivity analysis of the forest model with respect to a number of important parameters. The analysis provides us an insight into the behavior of the uneven-aged forest model.