An Economic Analysis to Aid the Marginal Decision on Rotation Length: I. Presentation of the Principle

This economic analysis of the rotation problem is based on theactual decision which the forest manager must make for everystand, i.e. whether to fell now or in five years or so. Thismarginal decision becomes important, and need only be carefullyconsidered, when the stand nears financial maturity. The marginalapproach is perhaps the most realistic approach to the problemof financial rotations. The financial decision is based uponthe recognized criterion of maximum net discounted revenue (N.D.R.)per unit total invested capital. Certain theories of productioneconomics are combined with the practical methods of forestvaluation. These principles are used to present the economicanalysis as a graphical choice of the rotation at which thecombined yield of pulpwood and sawtimber maximizes N.D.R. Finally,current product prices are introduced and the optimum rotationis found. These current prices may genuinely be assumed to beconstant for any particular five-year period. A subsequent paperwill develop the basic principle into a multi-product technique.The principle is presented essentially as a fundamental techniquefor the projects of forest economics: its application and useare considered here in general terms, and for a specific Sitkaspruce (Picea sitchensis) stand type. An instrument for therapid determination of financial rotation and N.D.R. has beendeveloped from this principle of rotation determination.     

Dynamics and management of Alaska boreal forest: An all-aged multi-species matrix growth model

Studies on the dynamics of Alaska boreal forest are sporadic and rare, and forest management in the region has been conducted in the absence of a useful growth model. This paper presents a matrix stand growth model to study the dynamics and management of Alaska's boreal forest, with harvests and artificial regeneration being accounted for. The model was calibrated with data from 446 constantly monitored permanent sample plots distributed across interior and south-central Alaska, and was tested to be accurate on an independent validation sample. The present model was applied on a most frequent commercial stand in interior Alaska to study a forest management regime that is being commonly used in the region. The simulation was for 300 years with a 40-year cutting cycle, and management outcomes under various permafrost levels and site elevations were investigated with sensitivity analysis. Despite the comparatively low financial returns, current management regime may generally benefit wildlife species by maintaining continuous forest cover and decent stand diversity, and properly managed forests had potential for timber production and wood-based energy. It was predicted by the model that both permafrost and site elevation had substantial impact on the management outcomes. Other variables being held constant at sample mean, net present value of harvests increased from $434 to $831 ha⁻¹ and the annual volume of harvest more than tripled from 1.68 to 5.75 m³ ha⁻¹ y⁻¹ as permafrost declined from obvious to unlikely. Managers were also advised to focus on stands on medium elevation (300 m), as stands on lower or higher elevations were expected to produce less harvested volume and net present value. For rural Alaska communities suffering from expensive heating costs, it was suggested that approximately 20 ha of properly managed forest could sustain a household's annual heating requirement, while continuous forest coverage and decent diversity could still be maintained.     

ROTATION

The computer model ROTATION was developed to calculate and compare optimal rotation ages for even-aged forest stands according to mean annual increment, money yield table, forest rent, land expectation value, present net worth, internal rate of return, and financial maturity criteria. The program was written in Microsoft QuickBasic and h e input variables consist of volume yield data, stumpage price, land cost, stand establishment cost, stand management cost, and the rate of interest. Results are displayed in tabular format and values indicating the optimal rotation age based on each of the seven criteria are presented. A representative example is included which incorporates normal yield data for ponderosa pine (Pinus oonderosa Doual. ex Laws.) and commercial timber management revenues and expenditures approximating those currently countered in the Sierra Nevada and southern Cascades, USA. Potential users of ROTATION include forest managers and natural resource educators.     

The forest planning system in relation to the forest resource and forestry policies

The current forest planning system of Japan has been in place since the formulation of the Forest Law back in 1897. During this time, although addressing specified forests as demonstrated in the system for protection forests, in a more general sense, the execution of the forest planning system has placed forestry management at the core. In other words, it has instead been forest administration delivered in a manner relevant to forestry management. This trend is exhibited in, for instance, policies for the reorganization of common forest, the forest management planning system, forest owners associations, the proceeds-sharing reforestation system, cooperative silviculture management, and valley forestry revitalization; which have all been implemented.In this paper I review the results of these practices and explore the contemporary forest owners pattern of behavior. I also discuss the passive attitudes among forest owners, especially in comparison with the attitudes prevalent during the postwar reforestation era, continuing up to the 1960s, and the current tendency towards neglect in the afforested areas, as well as the increasing number of forest owners giving up forestry practice.In the postwar era (up to the 1960s), forestry had been following an upward trend of development that motivated forest owners to afforest, as this was the optimal choice for increasing the familys stocks for future generations (in the manner of holding an asset), and thus a rapid expansion of plantation forests resulted. By the 1970s, when domestic wood supply became less than a half of all domestic wood demand (it is still declining now), forest owners gradually began to lose interest in reforestation and care of the forest as a method of increasing assets. The current share of domestic wood supply in total consumption has dropped to 20%, and the annual cut volume is only 23% of the annual volume increment.Forests are as much a public property as they are private and, moreover, represent a globally significant resource. Active stewardship, such as materializing internationally agreed notions of sustainable forest management, promoting forest certification systems, and complying with the Kyoto Protocol, are now important issues, both domestically and internationally.The paradoxical gap between current forestry trends and public aspirations for forests is widening with each year, thus creating a grave social problem. I have been focusing on forestry revitalization as the primary step towards the resolution of this issue. As the logical basis for executing this policy, I review the relations between forest resource policies and forestry policies.At the same time, by reviewing the forest planning system and its developmental process, I sought to investigate what new policies would fulfill the need to realize the public functions of forests while revitalizing forestry, form the point of view of forestry policies and their influence on the forest planning system. I have concluded that there is a case for separating forest management from forest ownership in units of forest compartments; namely to establish an incorporative management system by which forest owners can invest in their stands.     

Ground-dwelling invertebrates in reforested conifer plantations

Plantation forests are an important part of the forest estate in many countries. In Ireland, they cover around 9% of the land area and many that are commercially mature are now being felled and reforested. The potential biodiversity value of such second rotation forests has yet to be determined, yet this may be particularly significant in Ireland where cover of semi-natural woodland is only 1%. Invertebrates are a vital component of forest biodiversity, functioning as decomposers and pollinators, herbivores, predators and prey. Spiders and Carabid beetles are often used in biodiversity assessment as they are easily captured using pitfall traps, are taxonomically well known and respond to changes in habitat structure. This study aimed to examine spider and Carabid beetle diversity in second rotation Sitka spruce (Picea sitchensis) plantations at different stages of the forest cycle (5, 8–12, 20–30, 35–50 years), and compare the spiders captured in second rotation forests with those from first rotation. Spider and beetle diversity was influenced by stand structural development in second rotation plantations with numbers of forest-associated species increasing over the forest cycle. Overall, spider richness declined over the forest cycle and this was related to decreasing cover of field layer vegetation and fewer open-associated species. In contrast, total beetle richness increased and became more specialised over the forest cycle which may be related to slower colonisation of disturbed areas by beetles in comparison with spiders, and fewer open specialists at the early stages of second rotation. Spider assemblages were distinguished between rotations. This may be related to differing habitat conditions in second rotation forests including dryer soils with lower pH, differing vegetation complexity and presence of brush piles. Few of the forest species accumulated during first rotation were retained and the early stages of second rotation forest cycle was characterised by a generalist open fauna. Nonetheless, as the forest cycle progressed the spider assemblages between rotations became more similar. Current forest policy supports retaining over-mature trees and creating a mosaic of different aged stands within a plantation. Such measures may provide refuge for forest species after clearfell. In countries where forest fragments exist in a landscape dominated by agriculture, consideration should be given to the capacity of mature forest adjacent to felled stands to support forest species, and to the configuration of over-mature areas retained after felling.     

辽宁省森林蓄积连年生长率的研究

利用森林资源规划设计调查的数据,以各树种(组)不同林龄的小班集合,计算各树种不同林龄的平均每公顷蓄积量,绘制森林蓄积生长曲线,选择数学模型,得出不同树种的生长规律参数;通过计算不同林龄的理论值,最后得出森林蓄积连年生长率.     

Modeling the effects of alternative management strategies on forest carbon in the Nothofagus forests of Tierra del Fuego,Chile

The impact of forest management activities on the ability of forest ecosystems to sequester and store atmospheric carbon is of increasing scientific and social concern. The nature of these impacts varies among forest ecosystems, and spatially and temporally explicit ecosystem models are useful for quantifying the impacts of a number of alternative management regimes for the same forest landscape. The LANDIS-II forest dynamics simulation model is used to quantify changes to the live overstory and coarse woody debris pools under several forest management scenarios in a high-latitude South American forest landscape dominated by two species of southern beech, Nothofagus betuloides and N. pumilio. Both harvest type (clearcutting vs. partial overstory retention) and rotation length (100 years vs. 200 years) were significant predictors of carbon storage in the simulation models. The prompt regeneration of harvest units greatly enhanced carbon storage in clearcutting scenarios. The woody debris pool was particularly sensitive to both harvest type and rotation length, with large decreases noted under short rotation clearcutting. The roles of extended rotations and partial overstory retention are noted for enhancing net carbon storage on the forest landscape.     

Policy analysis of a government-sanctioned management plan for a community-owned forest in Romania

Forest management in Romania is based on sustained yield. However, the current sustained-yield policy may be outdated and may not be the best way of achieving Romania's intended objectives of biological sustainability and community stability. The existing policy also does not incorporate objectives consistent with Romania's new economic and social systems. We examine the potential economic net benefits from timber harvests that could result from changes to the existing sustained-yield policy by comparing the state-approved management plan of a community forest with three alternative forest management plans. We find that the three alternatives appreciably increase the potential economic net benefits. Certain aspects of these alternative plans deviate from Romania's current sustained-yield criteria; however, the costs associated with changes to the current regime could be balanced by the economic net benefits of implementing an alternative management plan. To employ the same static forest management policy throughout time without adapting to a dynamic socio-economic environment will likely lead to inefficient, ineffective, and unproductive utilization of Romania's forest resources.     

集体林区林权改革对政府财政收入的影响探析——以江西遂川为例

介绍江西省遂川县集体林区林权改革现状,分析集体林区林权改革对政府财政收入的影响,并提出开征林地立地税等政策建议。     

浅谈沾益县林地使用控制规划

结合沾益县实际情况和各类经济建设规划,指出沾益县制定林地使用控制规划的必要性,并着重从林地资源消长分析、使用林地数量控制、使用林地总量控制三方面简要介绍了沾益县林地使用控制规划的主要内容。     

Increasing rotation periods during a time of decreasing profitability of forestry — a paradox?

The profitability of forestry in Germany decreased during recent decades because of more or less constant prices for forest products, increasing input prices and limited success in rationalisation. However, the volume of growing stock increased significantly during this period since forest enterprises have chosen longer rotation periods. This is especially true for state owned and community owned forests but also at least partly for private forests. It is normally not an alternative for the owners of forest enterprises in Germany to sell the forests completely, but on a first glance increasing investments in standing timber during a time of decreasing profitability of forestry seems to be inconsistent with economic theory. On the one hand this observation could be explained as the result of non-timber values. However, this paper is focused on another approach, which is an expanded Faustmann model in line with soil rent theory and focused on timber production. Profitable rotations in the future have the effect of shortening the optimal rotation period because an investment in standing timber causes opportunity costs by delaying the establishment of the next generation of the forest. Unprofitable future rotations have the opposite effect, if the landowner is forced to reforest. In case investments in reforestations are not profitable decision-makers have good reasons not to cut the mature stands, in spite of the fact that the internal rates of return of investments in standing timber are low in comparison with investments on the financial market. Empirical data for the period 1954–1998 mostly from guidelines for forest valuation are used together with inflation corrected interest rates to show that optimal rotation length increased over time. Nevertheless we have to recognise that the observed rotation periods are distinctly longer than the calculated optimal rotation lengths. Other factors which may also explain the investments in forestry are discussed later.     

类乌齐县森林资源分析与评价

根据2012年森林资源规划设计调查数据统计结果,分析类乌齐县森林资源动态变化原因,评价全县森林资源现状和动态变化,为西藏自治230个有林县制定经营管理和科学发展决策提供依据。     

Extending rotation age for carbon sequestration: A cross-protocol comparison of North American forest offsets

Through carbon offset programs, forest owners can be offered financial incentives to enhance the uptake and storage of carbon on their lands. The amount of carbon that can be claimed by an individual landowner will ultimately depend on multiple factors, including the productivity of the forest, the management history of the stand, and the program in which the landowner is participating. This project presents a modeling framework for forest carbon accounting which is driven by forest yield curves and carbon pool partitioning. Within this model the amount of creditable carbon generated from adjusting the rotation age of multiple forest stands can be estimated for 46 distinct North American forest types. The model also provides a comparison of total creditable carbon generated under three carbon accounting methodologies: the Department of Energy 1605b Registry, the Chicago Climate Exchange, and the Voluntary Carbon Standard. In our evaluation of a 5-year rotation extension across 102 unique modeling scenarios, we find large differences among the carbon accounting schemes. This has implications for both forest landowners and policymakers alike. In particular, methodologies to account for such issues as leakage, permanence, additionality, and baseline establishment, while potentially increasing the overall legitimacy of any forest carbon offset program, can reduce creditable carbon to the forest owner (by up to 70%). Regardless of the protocol used, we also note strong regional differences, with Pacific Northwest forests of fir, spruce, hemlock, alder and maple being the most effective at sequestering carbon on a per area basis.     

罗城仫佬族自治县森林资源现状分析与可持续发展探讨

利用2009年罗城仫佬族自治县森林资源规划设计调查成果和近年更新的小班数据,对全县森林资源现状进行了分析、评价,提出应加强森林资源管理、调整树种结构、实行分类经营以及培育后续资源等建议,以保证林业可持续发展及森林可持续经营。     

罗城仫佬族自治县森林资源现状分析与可持续发展探讨

利用2009年罗城仫佬族自治县森林资源规划设计调查成果和近年更新的小班数据,对全县森林资源现状进行分析、评价,提出了加强林政资源管理,调整林种、树种结构,实行分类经营以及培育后续资源等措施建议,以保证林业可持续发展及森林可持续经营。     

Planning timber harvest of residual forest stands without compromising bird and small mammal communities in boreal landscapes

Numerous efforts have been invested in designing and configuring residual forest stands in Canadian boreal forest to preserve their overall biodiversity. Now that several landscapes have been partially logged, the next issue in forest management involves the planning of residual forest stand harvesting without compromising wildlife populations. Residual stands can be cut when adjacent regeneration reaches 3 m in height according to current regulations in several Canadian provinces (e.g., Québec, Ontario, Alberta, and British-Columbia). However, little is known on whether such regenerating habitat (RE-3m) can maintain wildlife communities similar to those found in unharvested mature forest (CO). We estimated the relative abundance of small mammals and forest birds in RE-3m and CO habitats and characterized landscape and stand structures. These variables were then compared between the two contrasting successional stages and were used to build habitat use models (HUMs) for 21 species. CO and RE-3m differed with regard to several landscape characteristics and stand structure variables as a result of logging. Snowshoe Hare, Northern Flicker, Alder Flycatcher, Ruby-crowned Kinglet, White-throated Sparrow and Magnolia Warbler were more abundant in RE-3m than CO, while Red-backed Vole, Brown Creeper and Golden-crowned Kinglet exhibited lower abundances in RE-3m. No significant differences in abundance were observed for the 12 other species. Species HUMs were highly significant and explained between 64.3 and 99.1% of the total variability in abundance. Following variance partitioning, stand structure variables accounted for most of the explained variability (54.2%) while landscape characteristics accounted for only 28.7%. No difference in species richness was observed but community evenness was greater in CO than RE-3m. Our results suggest that current regulations may threaten the maintenance of 3 out of 21 censused species for which abundances were significantly lower in regenerating 3 m tall stands. As stand structure explained a large amount of variability in abundance, it should be considered during timber harvest planning in both mature and regenerating stands. Until we know more on whether the current regulations are suitable for maintaining overall biodiversity, our results suggest that some mature forest stands should be maintained within managed landscapes for a complete logging rotation period.     

Timber harvesting as ongoing disturbance in a landscape of diverse ownership

Although the northeastern US includes extensive areas of aggrading forest, uncertainty regarding the intensity and pattern of forest harvesting hampers an understanding of important ecological processes and characteristics such as carbon and nitrogen storage, habitat quality, and forest dynamics, and impedes regional conservation and management planning. Due to the complex ownership pattern dominated by thousands of non-industrial private forest (NIPF) owners and the difficulty of detecting selective logging using remote sensing, details of the harvesting regime remain largely unknown to the scientific and policy communities. To examine the value of statewide regulatory data for Massachusetts as a unique source of this critical information, we analyzed 17 years of timber harvest data gathered for regulatory purposes for a 168,000 ha forested landscape in Massachusetts that is the focus of concerted conservation planning and intensive study of landscape and ecosystem pattern and process. The North Quabbin Region is heavily wooded with a complicated ownership pattern dominated by over 2500 NIPF owners, three state agencies, and diverse conservation and municipal holdings.

The extent and intensity of harvesting were surprising, with an annual disturbance rate of 1.5% and a mean intensity of 44.7 m³ ha⁻¹ (approximately one-fourth of average stand volume). The predominant form of harvesting was selective removal of commercially valuable tree sizes, grades and species (e.g., Quercus rubra and Pinus strobus). The spatial pattern of logging was random with regards to major physical, biological, or cultural factors. However, logging was strongly related to landowner class. NIPF owners control 60% of the forest area and were responsible for 64.1% of harvest area, but the highest logging intensity (volume per area harvested; 69.3 m³ ha⁻¹) among major landowners was conducted by the state agency responsible for managing southern New England’s largest conservation property, the watershed of Boston’s drinking reservoir.

This regime of chronic disturbance is occurring over the entire landscape and exerting a major influence on forest composition, dynamics, and habitat quality. However, dispersed selective harvesting is largely unnoticed by residents, is routinely overlooked by ecologists and conservationists, and would remain unrecognized in the absence of this previously unused regulatory data. These results identify the value of regional regulatory spatial information to estimate ecological trends and to assist in conservation planning. Given similarities among ownership and forest patterns for much of the northeastern US, we expect that the broad findings of this study to have regional application.     

浅谈长兴桃花岕省级森林公园总体规划

在分析长兴桃花岕省级森林公园基本情况和资源特色的基础上,结合森林旅游业的发展方向和趋势,提出森林公园的发展定位,系统研究总体规划和功能分区,分别阐述了各个功能区的规划思路,为其他森林公园的规划设计和开发建设提供参考.     

丽水市莲都区生态公益林资源结构动态变化研究

根据1999年和2008年公益林区两期的森林资源调查数据,采用对比分析和数理统计方法,从时间尺度上对公益林区的森林资源格局动态变化情况进行了研究,掌握了莲都区公益林在林龄、郁闭度、疏密度、森林类型等方面的变化情况。通过1999年到2008年的十年建设,幼、中龄林与近、成、过熟林面积比例由78:22演变到40:60,蓄积比由54:46演变到23:77;低郁闭度(郁闭度小于0.7)林分由76.57%下降到25.14%,高郁闭度林分则从23.43%上升到74.86%;阔叶林面积占比从11.43%增加到11.57%,针阔混交林面积从26.86%增加到40.29%;单位面积平均蓄积从25.65 m3·hm-2增长到37.95 m3·hm-2,年均净增率4.30%。     

Oak decline in the Boston Mountains,Arkansas, USA: Spatial and temporal patterns under two fire regimes

A spatially explicit forest succession and disturbance model is used to delineate the extent and dispersion of oak decline under two fire regimes over a 150-year period. The objectives of this study are to delineate potential current and future oak decline areas using species composition and age structure data in combination with ecological land types, and to investigate how relatively frequent simulated fires and fire suppression affect the dynamics of oak decline. We parameterized LANDIS, a spatially explicit forest succession and disturbance model, for areas in the Boston Mountains of Arkansas, USA. Land type distribution and initial species/age class were parameterized into LANDIS using existing forest data. Tree species were parameterized as five functional groups including white oak (Quercus alba L., Quercus stellata Wangenh., Quercus muehlenbergii Engelm.), red oak (Qurecus rubra L., Quercus marilandica Muenchh., Quercus falcata Michx., Quercus coccinea Muenchh.), black oak (Quercus velutina Lam.), shortleaf pine (Pinus echinata Mill), and maple (Acer rubrum L., Acer saccharum Marsh.) groups. Two fire regimes were also parameterized: current fire regime with a fire return interval of 300 years and a historic fire regime with an overall average fire return interval of 50 years. The 150-year simulation suggests that white oak and shortleaf pine abundance would increase under the historic fire regime and that the red oak group abundance increases under the current fire regime. The black oak group also shows a strong increasing trend under the current fire regime, and only the maple group remains relatively unchanged under both scenarios. At present, 45% of the sites in the study area are classified as potential oak decline sites (sites where red and black oak are >70 years old). After 150 simulation years, 30% of the sites are classified as potential oak decline sites under the current fire regime whereas 20% of the sites are potential oak decline sites under the historic fire regime. This analysis delineates potential oak decline sites and establishes risk ratings for these areas. This is a further step toward precision management and planning.