Evaluation of forest management strategies based on Triad zoning

2015 ◽  
Vol 91 (01) ◽  
pp. 40-51 ◽  
Author(s):  
Chris Ward ◽  
Thom Erdle

Triad forest management was analyzed for a New Brunswick Crown License. Fifteen forest value indicators were used to describe social, economic, and environmental outcomes from forecast Triad scenarios, including 36 scenarios where reserves and intensively managed area varied in 5% increments from 10% to 35%. Some indicators were most sensitive to intensive area (e.g., silviculture cost), other to reserve area (e.g., area containing large snags), and still others to extensive area (e.g., average harvest levels). Some indicators averaged arithmetically, and could be kept constant if increases in reserves were accompanied by equal increases in intensive area. Such averaging for timber supply is often a selling point made by Triad advocates. Indeed, many different scenarios generated the same annual harvest when averaged over the 100-year forecast time horizon; however, immediate reductions in operable timber inventory resulting from reserve increases caused short-term harvest reductions, while future gains in yield from intensive area increases caused long-term harvest increases. This timing offset between losses and gains of operable volume, and its effect on harvest timing, may be impediments to Triad implementation in jurisdictions where timber supply is fully utilized. This analysis presents methods and results that may be of value to forest managers contemplating implementation of Triad zoning.

Forests ◽  
2018 ◽  
Vol 9 (11) ◽  
pp. 704 ◽  
Author(s):  
Louis Georgi ◽  
Matthias Kunz ◽  
Andreas Fichtner ◽  
Werner Härdtle ◽  
Karl Reich ◽  
...  

The three-dimensional (3D) morphology of individual trees is critical for light interception, growth, stability and interactions with the local environment. Forest management intensity is a key driver of tree morphology, but how the long-term abandonment of silvicultural measures impacts trunk and crown morphological traits is not fully understood. Here, we take advantage of a long management intensity gradient combined with a high-resolution terrestrial laser scanning (TLS) approach to explore how management history affects the 3D structure of mature beech (Fagus sylvatica L.) trees. The management gradient ranged from long-term (>50 years) and short-term (>20 years) unmanaged to extensively and intensively managed beech stands. We determined 28 morphological traits and quantified the vertical distribution of wood volume along the trunk. We evaluated the differences in tree morphological traits between study stands using Tukey’s HSD test. Our results show that 93% of the investigated morphological traits differed significantly between the study stands. Significant differences, however, emerged most strongly in the stand where forest management had ceased >50 years ago. Furthermore, we found that the vertical distribution of trunk wood volume was highly responsive between stands with different management intensity, leading to a 67% higher taper top height and 30% lower taper of beech trees growing in long-term unmanaged stands compared to those in short-term unmanaged or managed stands. These results have important implications for management intensity decisions. It is suggested that the economic value of individual beech trees from long-term unmanaged forests can be expected to be very high. This might also translate to beech forests that are extensively managed, but we found that a few decades of implementation of such a silvicultural system is not sufficient to cause significant differences when compared to intensively managed stands. Furthermore, TLS-based high-resolution analyses of trunk and crown traits play a crucial role in the ability to better understand or predict tree growth responses to the current drivers of global change.


1995 ◽  
Vol 71 (5) ◽  
pp. 647-656 ◽  
Author(s):  
K. B. Rouck ◽  
J. D. Nelson

Partitioning the forest into sustained yield units is a complex task that involves assessing timber supply, allocation of cutting rights, and social, economic, and environmental impacts. There are numerous ways to vary the timing and intensity of harvests within individual drainages while still meeting the objectives of sustained yield. In this paper we use a spatial forest planning model to examine economic and environmental implications of varying the sustained yield unit size. Harvests for a Timber Supply Area in British Columbia are calculated using 4 sizes of sustained yield units: 1)12 small units, 2) four moderately sized units 3) two large units, and 4) one unit representing the entire forest. Relative to the 12 small units, short-term (20 year) harvest levels for the Timber Supply Area increased by 7.6%, 10%, and 10.8% for the 4, 2 and 1 unit aggregations, respectively. Medium-(21-60 years) and long-term (61-120 years) increases in harvest levels averaged approximately 75% and 40%, respectively, of those realized in the short-term. Reductions in the length of active road and delivered wood costs were also observed as sustained yield units increased in size. Small units often restrict short-term timber supply and provide continuous road access to important wildlife habitat. While larger units afford greater flexibility in meeting short-term harvests, the intensity of the harvest within individual drainages increases. However, with large units the inactive drainages can be closed for extended periods, thus limiting human access to the active drainages. Key words: timber supply, sustained yield unit size, spatial modelling, economics


1993 ◽  
Vol 23 (4) ◽  
pp. 563-572 ◽  
Author(s):  
Donald Ludwig

This paper presents a method to calculate the long-term effects of forest management decisions for an age-structured forest. The calculation of such effects is required to assess the sustainability and indeed the rationality of forest harvesting strategies. The primary focus of this paper is the issue of "falldown", i.e., the decrease in timber available for harvesting due to lack of large old trees. The largest net discounted economic returns are obtained by rapid harvesting (mining) of old growth. However, in the longer term the consequences of a decrease in harvest volume on local communities can be devastating. How can this conflict between short-term and long-term interests be reconciled? I consider a variety of strategies that vary in their sensitivity to the effects of falldown, and I present some pilot calculations that illustrate a method to weigh the consequences of following these strategies.


1995 ◽  
Vol 1 (1) ◽  
pp. 74
Author(s):  
Martin Knapp

Advice on enuresis has been provided by a range of individuals. Many myths and misunderstandings have been responsible for the confusing range of opinions given to those who seek help. Management should be based on an understanding of the physiology of the condition and the established facts about its treatment. There is still a lack of awareness about how effective are the management strategies now proposed by those who base their practise on the extensive research that is now documented. The best results are obtained with conditioning therapy, when this is supervised and supported. There is an important role for 'wetness' alarms in conditioning. There are now body-worn mini-alarms, established by over a decade of use, that are inexpensive and reliable. There is a decreasing role for tricyclic medication. The recently introduced pharmaceutical Minirin (desmopressin) is useful in short-term management to get dryness on social occasions and, in selected individuals, might have a role in long-term control of enuresis, when conditioning has not been effective. There is an important need to provide advice and treatment facilities for all those with enuresis - a treatable condition.


2010 ◽  
Vol 40 (4) ◽  
pp. 597-610 ◽  
Author(s):  
Anne-Hélène Mathey ◽  
Harry Nelson

We explore how forest resource managers can respond to a potential outbreak of mountain pine beetle ( Dendroctonus ponderosae Hopkins, 1902) by assessing how well different forest management strategies achieve various management objectives over time. Strategies include targeting at-risk stands as well as increasing harvest levels. Outcomes are evaluated on the basis of volume flows, net revenues, and the age class structure of the ending inventory. We use a spatially and temporally explicit model to simulate forest management outcomes and consider two different scenarios, one in which the attack occurs early and one where it is delayed. The model utilizes a planning with recourse approach in which the firm can reevaluate its harvesting schedule following the attack. We use company data from west-central Alberta for a 40-year planning exercise. The timing of the attack resulted in small differences in timber supply. However, most strategies performed better financially under an early attack, which limits the harvest of marginal stands. Increasing harvest levels performed better in economic terms but resulted in a very young growing stock with little old forest. The success of any strategy is linked to the timing of the attack and how it affects the growing stock, subsequently impacting timber and revenue flows.


2018 ◽  
Vol 6 (6) ◽  
pp. 532-551 ◽  
Author(s):  
Caichun Chai ◽  
Hailong Zhu ◽  
Zhangwei Feng

Abstract The management strategies of a firm are inevitable affected by individual behavior preferences. The effect of individual preference on the evolutionary dynamics for supply chains is studied by employing replicator dynamics. Each firm has three behavior preferences: selfishness, fairness, and altruism. Firstly, the case that the strategy set of manufacturers and retailers including two pure strategies is considered and the effect of preference parameter on the equilibrium outcome in the short-term interaction is discussed. Secondly, the equilibrium state in the short-term is always disturbed because the change of the environment, firm’s structure, and so forth. Using the replicator dynamics, the evolutionary stable strategies of manufacturers and retailers in the long-term interaction are analyzed. Finally, the extend case that the strategy set of manufacturers and retailers include three pure strategies is investigated. These results are found that the strategy profile in which both manufacturer and retailer choose fairness or altruism, or one player chooses fair or altruistic strategy and the other player chooses selfish strategy may be evolutionary stable, the stability of these equilibria depends on the the preference parameters.


2019 ◽  
Vol 18 (3) ◽  
pp. 97-119 ◽  
Author(s):  
Jesper Haga ◽  
Fredrik Huhtamäki ◽  
Dennis Sundvik

ABSTRACT In this study, we investigate how country-level long-term orientation affects managers' willingness to engage in earnings management and choice of earnings management strategy. Using a comprehensive dataset of 47 countries for the period from 2003 to 2015, we find that firms in long-term-oriented cultures rely relatively more on earnings management through accruals, while firms in short-term-oriented cultures engage in relatively more real earnings management. Furthermore, we find a larger discontinuity around earnings benchmarks in long-term-oriented cultures suggesting that manipulation of accruals enables benchmark beating with high precision. JEL Classifications: M14; M16; M21; M41.


Author(s):  
Mohammad Ayub Khan

This chapter discusses the emerging models of knowledge cities in many countries of the world and the potential challenges posed by them for the existing as well as the future academic institutions of higher education (universities) in those countries in particular and in the in world in general. Specifically, this chapter is dedicated to the study of various issues and themes that concern the evolving knowledge cities such as the long-term and short-term objectives behind the establishment of knowledge cities and their potential benefits (i.e., social, economic, financial, environmental, and knowledge) for their societies. The chapter concludes that the development of knowledge cities are beneficial for all stakeholders including the academic institutions of higher education that directly or indirectly associated with such programs.


2020 ◽  
Vol 81 (6) ◽  
pp. 1099-1113 ◽  
Author(s):  
Yuan Zhang ◽  
Pingping Luo ◽  
Shuangfeng Zhao ◽  
Shuxin Kang ◽  
Pengbo Wang ◽  
...  

Abstract Accelerated eutrophication, which is harmful and difficult to repair, is one of the most obvious and pervasive water pollution problems in the world. In the past three decades, the management of eutrophication has undergone a transformation from simple directed algal killing, reducing endogenous nutrient concentration to multiple technologies for the restoration of lake ecosystems. This article describes the development and revolution of three remediation methods in application, namely physical, chemical, and biological methods, and it outlines their possible improvements and future directions. Physical and chemical methods have obvious and quick effects to purify water in the short term and are more suitable for small-scale lakes. However, these two methods cannot fundamentally solve the eutrophic water phenomenon due to costly and incomplete removal results. Without a sound treatment system, the chemical method easily produces secondary pollution and residues and is usually used for emergency situations. The biological method is cost-effective and sustainable, but needs a long-term period. A combination of these three management techniques can be used to synthesize short-term and long-term management strategies that control current cyanobacterial blooms and restore the ecosystem. In addition, the development and application of new technologies, such as big data and machine learning, are promising approaches.


2011 ◽  
Vol 162 (9) ◽  
pp. 300-311 ◽  
Author(s):  
Edgar Kaufmann

Potential of sustainable wood production in Swiss forests In the Swiss National Forest Inventory (NFI), the data collected in the three inventories (NFI1 1983–1985, NFI2 1993–1995, NFI3 2004–2006) provide the basis not only for analysing the present state of the forest and how it has developed up to now, but also for assessing, with the help of models, how it might develop in future. The scenario model «Massimo 3», developed at the Swiss Federal Institut for Forest, Snow and Landscape Research, is an empirical and stochastic simulation model. It relies on data from the NFI and forecasts the development of the forest according to how it is managed. Six scenarios with different management regimes were defined according to the economic, silvicultural and ecological aspects considered. In three scenarios the growing stock is kept constant at the level of NFI3, but different management strategies are used (Scenario A: basis [business as usual], Scenario E: even-aged forests are transformed into uneven-aged forests, and Scenario F: near-natural percentages of conifers are promoted). In two scenarios forest management is partially abandoned for either ecological reasons (Scenario B: reservations, 10% of the forest area is left unmanaged) or for economic reasons (Scenario C: harvesting costs, 40% of the forest area is left unmanaged). Scenario D (rotation periods are shortened) was used to study the effects of augmenting the annual harvesting amount. A forecasting time period of 100 years was selected to assess the long-term effects of the scenarios. Scenarios A, D, and E show that the sustainable harvesting potential of merchantable wood lies in a relatively narrow range of 7.1 to 7.3 million m3/year, even though in Scenario D the growing stock is reduced from 360 m3/ha to 305 m3/ha. In Scenario F regeneration is systematically established with near-natural percentages of conifers, the long-term harvesting potential is slightly less: about 6.5 million m3/year of merchantable wood. If forest management is abandoned for economic reasons on as much as 40% of the forest area (Scenario C, harvesting costs), the impact on the wood reserves is very negative.


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