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In this paper, we examine the implications of managing for sustained yield in a world characterized by growing risk and uncertainty. We review the history of sustained yield (SY) forestry in North America, with an emphasis on economic benefits and the persistence of the SY paradigm today, despite a publicized shift towards managing for a wider range of forest values called sustainable forest management (SFM). We show that current forest management goals around sustainability as well as SFM indicators are still predicated on maximizing harvest levels and timber flows. We build a simple model to explore the implications of SY under extreme (fat-tailed) risk assumptions to show that maximizing a level of harvest without adequately accounting for risk leads towards the depletion of the forest stock with a corresponding decline in the forest economy. We discuss these results in relation to real-world events such as the increase in catastrophic fires and pest outbreaks like the mountain pine beetle in Western Canada. We then examine the theoretical and practical implications that flow from this model and analysis.

Strict forest renewal policies in western Canada focus on replicating the stand type that was cut and projecting the growth of young stands forward using simple models based upon past growing conditions. These policies arose from European principles of sustained yield and now limit options for adaptive management at the time of investment in forest renewal of public lands. We assert that such simple and restrictive policies, combined with long-term yield predictions, give a false sense of sustainability in times of increased drought, fires, and insect and disease attacks that accompany climate change. We must undertake comprehensive changes in forest policy that incorporate disturbance in our forest management planning. This is a large task! Options include (i) zoning public forests to vary intensities of management and minimize risk; (ii) changing stand- and forest-level models to increase the diversity of forests regenerated; (iii) widening the sphere of scientific experts that can influence forest policy and risk management; and (iv) reallocating expenditures on forest renewal, protection, and management to minimize negative impacts of disturbance. Such a comprehensive overhaul of forest management will be necessary as the current assumptions of forest sustainability come under further scrutiny by the public and investors.

PurposeMicrobial communities in rhizospheric soil play a significant role in sustaining the soil quality and also recognized as key ecological indicators to assess the soil health. MethodsWe studied the long-term effects of resource conservation technologies on functional microbial diversity and their interactions with soil biochemical properties and enzymatic activities in tropical rice-green gram cropping system. The experiment included conventional practice (CC), brown manuring (BM), green manuring (GM), wet direct drum sowing (WDS), zero tillage (ZT), green manuring-customized leaf colour chart based-N application (GM-CLCC N) and biochar (BC) treatments. ResultsThe result revealed that microbial biomass nitrogen (N), carbon (C) and phosphorus (P) in GM practice increased by 23.3, 37.7 and 35.1%, respectively over CC. The Shannon index and McIntosh index were higher by 86.9% and 29.2% in GM as compared to conventional practice and significantly correlated with microbial biomass (C & P) and soil microbial populations whereas, Shannon index was positively correlated with the microbial biomass (C, N & P) and soil enzyme activities. Principal component analysis showed a significant separate cluster among the treatments amended with and without biomass addition. ConclusionsMoreover, dominance of carbon utilizing microbes in biomass amended treatments indicated that these could supply good amount of labile carbon sources on real time basis for microbial activity. Which may protect the stable carbon fraction in soil, hence could support higher build-up of carbon in long run and could offer sustainable yield under rice-green gram soil.

Semi-open oak woods and solitary oaks commonly dominate the wooded fabric (i.e. the ‘oakscape’) of European traditional rural agricultural landscapes based on animal husbandry. However, modern land use systems fail to perpetuate oakscapes, posing a serious threat to biodiversity conservation and the associated diversity of ecosystem services. Reconstructing the dynamics of oakscape remnants can provide valuable insights concerning the maintenance of oakscapes. We used the socio-economic transitions at the European Union’s eastern border as a natural experiment to explore the drivers for successful oak recruitment in 27 selected units representing 4 oakscape categories. Analyses of tree-ring data, historical maps, and orthophotos were used to reconstruct the oakscapes’ establishment trajectories in relation to land use changes in the period 1790–2010. The oaks in cultural semi-open woods and wood-pastures differed substantially from those in closed canopy forests by more stocky shape and faster early age DBH annual increase. We found two distinct recruitment patterns: (1) FAST – recruitment usually completed within 2–3 decades, attributed to an unconstrained succession of abandoned agricultural land, and (2) SLOW – recruitment extending over several or more decades. In Ukraine, frequent illegal grass burning in marginal woods was the most successful mechanism perpetuating oak recruitment. Top-down policy encouraging specialized intensive farming, sustained yield forestry, and conservation efforts concentrated on the preservation of closed canopy forests compromise the future of traditional agro-silvo-pastoral systems. Maintenance of traditional integrated agro-silvo-pastoral management sustaining oakscapes needs to combine local traditional knowledge and landscape stewardship.

Forest policy has developed from single to multiple objectives. This requires a transition from traditional sectoral planning to more open, multi-stakeholder approaches that take into account all dimensions of sustainability across entire landscapes and even regions. Comparisons of regions with different landscape histories and governance legacies can support collaborative learning. Following Patsy Healy’s and Frances Cleaver’s approaches, we compare institutional strategies and constraints for collaborative territorial planning in Canada and Sweden by focusing on two case study regions in steep urban-rural gradients. Both regions are facing severe challenges after a long focus on forest staples resources. To cope with the transition towards multiple objectives, efforts towards collaborative learning inspired by the Model Forest landscape approach were made. The Canadian case study had some quick successes because of government funding, and managed to begin collaborative planning, but changes in public policy led to a quick demise. The Swedish case study developed local islands of collaborative learning, provided that champions managed to sustain their work. To conclude, we see two trajectories towards collaborative territorial planning shaped by different institutions: (1) regional level public core funding that can support planning processes top-down, or (2) establishment of voluntary local win-win solutions bottom-up. Both require committed stakeholders that are willing to employ a holistic perspective, and able to sustain resources in the long-term. However, despite a clearly stated goal towards multiple-use forest management, institutional legacies aiming at supporting maximum sustained yield wood production that have ruled the relationships between the state and the industry for so many years remain key barriers for multifunctional landscapes and regions.

Guidance for sustainable exploitation of lake charr Salvelinus namaycush needs to account for an enormous diversity within an ecological context. In this chapter, we expand earlier work to develop a framework for managing lake charr fisheries across the zoogeographic range of the species. We describe how environmental attributes influence two key determinants of sustainable harvest: natural mortality rate and biomass at maximum sustained yield (MSY). Evidence is presented that mean air temperature, lake size, and lake morphometry determine lake productivity and habitat suitability for lake charr, which combine with adult body size to influence biomass density. Variation in adult body size is associated with natural mortality rates, along a climatic gradient. Our model predicts that, on average, MSY decreases with lake surface area and mean annual air temperature. MSY is also influenced by lake depth because of the need for a hypolimnetic cold-water refuge is greater in warmer climates. The model provides a basis for developing regional-scale management and assessment strategies. We demonstrate its application using three MSY-based reference points (i.e., biomass density, total mortality rate, angling effort), which can be calculated from readily available habitat data.

Tree volume tables have been recognized as one of the fundamental requirements in forest mensuration and management for providing estimates of timber volume to determine sustained yield and periodic increment. Mangroves one on important forests available in this country which also produced timber particularly for charcoal production. Thus, this study aimed at developing local volume tables for natural mangroves of Sungai Merbok Forest Reserve in Kedah. Two volume tables were developed for Bakau species (Rhizophoraapiculata&R.mucronata) and Non-Bakau species (other species) based on relation between diameter at breast height (dbh) and gross stem volume (under bark and over bark). Test of accuracy by means of standard statistical measures and relative measures, were made on all equations, where the smallest value of mean square error (MSE) and mean absolute percentage error (MAPE) as the criteria for the best fitted equation to develop the local volume table. The local volume tables for Sungai Merbok Forest Reserve were constructed based on "allometric model" which were solved by mean of weighted least square (WLS). Practically, these volume table can be applied within the area, and not applicable to estimate timber volume in other mangroves areas. Nonetheless, other mangroves areas that having similar condition with Sungai Merbok Forest Reserve as natural mangroves may use the volume table until they construct for their own. Based on this study, the best fitted equations to construct local volume table for Sungai Merbok Forest Reserve are as follows: Bakau species: Vob= 0.00045 D2.02248Vub= 0.00040 D2.04390 Non-Bakau species: Vob= 0.00088 D1.69929Vub= 0.00084 D1.70310 Note: Vob= Over bark, Vub= Under bark and D = dbh in cm

本稿は、U・グローバーのnachhaltigkeitをめぐる議論にきっかけを得て、19世紀以降の森林をめぐる社会構想を、「市場社会」という歴史的局面を背景にして生じたサステイナビリティの構想の一形態として捉え直し、「富を生む森」の探求が「負債を生む森」を広く生んでいくことになるまでの過程を、とくに現代日本における森林問題をとりまく歴史に沿って明らかにする。まず、近代社会におけるサステイナビリティの構想について概観したのち、その具体的な展開、およびその帰結について、K・ポランニーの「市場社会」の概念に示唆を受けながら、主として20世紀、高度経済成長期以降の日本社会での経験を例にとってたどる。そのうえで、「負債を生む森」が広がっていった背景として、森林所有者が関与していないところで描かれた構想によって生み出された市場社会が引き起こした大きな変化に、抵抗もできずに適応を迫られていくことになった不可避の結果だということを指摘する。最後に、このような点から振り返ると、今日、各地で新たに生起している森林の持続的な利用をめぐる多様な取り組みは、森林の利用をとりまいて生じる「義務と責任を担うことによる自由」を失った人びとによる「脱市場社会のサステイナビリティ」を模索する試みとして考えうることを明らかにしていく。, Forests remain an archetype, or a model of Sustainability in the modern society. But it is the fantasy in the 21st century that we alive. In the social planning of sustainability, forest is "a forest which produces wealth". But in reality, "a forest which produces debt" spread all over the world. Under such situation, pursuit of the sustainable development causes deforestation.In this article, I discuss the limit of sustainability as a social planning in the market society that aspire to get rid of vulnerabilities of supply based on an argument around semantic analysis on Nachhaltigkeit or Sustained Yield by Ulrich Grober. At first, I survey it about a social planning of sustainability in the modern society, and clarify its development and the consequence with a Japanese forest policy as an example while receiving a suggestion in a concept of "the market society" of the Karl Polanyi. On the basis of these considerations, I point out that it created "forests which produces debt" that forest owner was not able to resist the big transformation that market society caused in the timber market of 1990s. The solution that get rid of vulnerabilities of supply was not accompanied by increase in profit of forest owners.Today, a variety of people participate in a variety of practice to manage the forest in Japan. From the abovementioned analysis, we can understand that these practices are attempts exploring "Sustainability in the Post Market Society" by the people who lost the freedom to be provided by taking obligation and responsibility in forest management.

With 20% of the world’s forests, Russia has global potential in bioeconomy development, biodiversity conservation and climate change mitigation. However, unsustainable forest management based on ‘wood mining’ reduces this potential. Based on document analysis, participant observations and interviews, this article shows how non-state actors—environmental NGOs and forest companies—address forest resource depletion and primary forest loss in Russia. We analyse two key interrelated forest discourses driven by non-state actors in Russia: (1) intensive forest management in secondary forests as a pathway towards sustained yield and primary forest conservation; (2) intact forest landscapes as a priority in primary forest conservation. We illustrate how these discourses have been integrated into policy debates, institutions and practices and discuss their relation to relevant global discourses. The article concludes that despite successful cases in conserving intact forest landscapes, there is still a frontier between sustainable forest management discourses and forestry practice in Russia. Supplementary Information The online version contains supplementary material available at 10.1007/s13280-021-01643-6.

Life-cycle models combine several strengths for estimating population parameters and biological reference points of harvested species and are particularly useful for those exhibiting distinct habitat shifts and experiencing contrasting environments. Unfortunately, time series data are often limited to counts of adult abundance and harvest. By incorporating data from other populations and by dynamically linking the life-history stages, Bayesian life-cycle models can be used to estimate stage-specific productivities and capacities as well as abundance of breeders that produce maximum sustained yield (MSY). Using coho salmon (Oncorhynchus kisutch) as our case study, we show that incorporating information on marine survival variability from nearby populations can improve model estimates and affect management parameters such as escapement at MSY. We further show that the expected long-term average yield of a fishery managed for a spawner escapement target that produces MSY strongly depends on the average marine survival. Our results illustrate the usefulness of incorporating information from other sources and highlight the importance of accounting for variation in marine survival when making inferences about the management of Pacific salmon.

This study aims to analyse the current perceptions of forest owners regarding long-rotation forestry in South Korea, and to explore reforestation policies, in order to identify ways in which they may improve their applicability to successful management of timber resources. The majority of forest owners had a negative perception of long-rotation forestry, and preferred to select tree species that produce short-term profits. Government subsidies to reduce the costs of timber production, tax benefits, and technical supports are required in order to encourage forest owners to pursue long-rotation forestry. Such efforts need to be enacted in conjunction with policies that improve the profitability of forest ownership in the domestic timber market, such as a new log scaling system that places higher value on locally produced timbers, as well as policies that facilitate active use of government support systems.

A holistic basis for achieving ecosystem‐based management is needed to counter the continuing degradation of coral reefs. The high variation in recovery rates of fish, corresponding to fisheries yields, and the ecological complexity of coral reefs have challenged efforts to estimate fisheries sustainability. Yet, estimating stable yields can be determined when biomass, recovery, changes in per area yields and ecological change are evaluated together. Long‐term rates of change in yields and fishable biomass‐yield ratios have been the key missing variables for most coral reef assessments. Calibrating a fishery yield model using independently collected fishable biomass and recovery data produced large confidence intervals driven by high variability in biomass recovery rates that precluded accurate or universal yields for coral reefs. To test the model's predictions, I present changes in Kenyan reef fisheries for >20 years. Here, exceeding yields above 6 tonnes km⁻² year⁻¹ when fishable biomass was ~20 tonnes/km² (~20% of unfished biomass) resulted in a >2.4% annual decline. Therefore, rates of decline fit the mean settings well and model predictions may therefore be used as a benchmark in reefs with mean recovery rates (i.e. r = 0.20–0.25). The mean model settings indicate a maximum sustained yield (MSY) of ~6 tonnes km⁻² year⁻¹ when fishable biomass was ~50 tonnes/km². Variable reported recovery rates indicate that high sustainable yields will depend greatly on maintaining these rates, which can be reduced if productivity declines and management of stocks and functional diversity are ineffective. A number of ecological state‐yield trade‐off occurs as abrupt ecological changes prior to biomass levels that produce MSY.

With the increase in outdoor recreation in the United States following WWII and the focus on multiple use management in the wake of the Multiple Use Sustained Yield Act in 1960, land managers have been under increased pressure to balance multiple objectives and ensure that visitor use impacts at the sites under their purview are kept within acceptable bounds. The Act established that multiple uses had “legitimate interests” on public lands (Adams, 1993, p. 137) and that these uses be managed in a “harmonious and coordinated manner” (Cubbage, 1993, p. 298). However, there is no uniform, universally accepted approach to determining the number of visitors at individual sites, especially in light of the various activities undertaken by the public in protected areas. A unified methodology is needed; one that is applicable across multiple types of properties. We propose a generic multi-phase stratified approach capable of capturing visitation in multiple user activity and access categories. The strata used in this protocol are access location, mode of access, day of the week, and season. Access locations are grouped together in zones for ease of data collection. The approach we propose is readily adaptable to target site-specific assessments and strikes a balance between the need to gather sufficient data and staff person-hour commitment. Data are gathered based on mode of visitor access, definable access points, site-specific trends in visitation, and manager delineated zones at each site under consideration. Initial information is used to develop weekly visitation curves (depictions of the variation in visitation by day of the week) for each manager-defined season at each site and to specific survey locations within each zone mentioned above. Weekly visitation curves are confirmed using a two-week census prior to full data collection, thereby improving statistical accuracy. Additionally, multipliers are created for each mode of visitor access to estimate total visitation during the period under review. Data are summed across all zones within the site and across all seasons to gain a full representation of visitor use for the site being studied. The suggested approach may be easily modified to address variation in spatial and temporal patterns of visitation at multiple sites, as well as variation in modes of visitor access. The use of appropriate sampling techniques allows the employment of statistical estimation, thereby greatly reducing the amount of effort required with a full census for a valid estimate of visitation at a particular site or sites. Subscribe to JPRA

Commonly-used sustained yield harvest policies ensure sustained supply of harvest timber volume over a planning horizon. However, implemented policies gradually decapitalize forest values over time that threatens the sustainability of ecosystem and wood industries. Different business units of a forest-product supply chain have different ways of valuing forestry resources, different supply and demand policies, and corresponding business policy models to implement them. The objective of this study was to evaluate ecological and economic impacts to participating business units of a supply chain when implementing different business policies. We constructed six business models in a linear programming framework and solved them using data from commercially-managed forests. Our empirical results showed that compared to a base model (Model 1; unilateral decision by forest business unit), the best model (Model 6; integrated harvest and production planning) reduced the median harvest volume and area by 25% (12–31%) and 24% (7–40%), respectively, but increased net revenue by 88% (6–218%) over a 150-year planning horizon. Hence, efficiency increased by 158% (20–373%) per unit of harvest area and 163% (23–364%) per unit of harvest volume. Furthermore, when the models were simulated using a hard constraint to preserve at least 20% of old-growth forest area, the revenue was least affected (15%; 11–19%) by Model 6 compared to Model 1 (26%; 14–45%). We conclude that vertically-integrated harvest policy that embeds forest values in the planning model reduces the gap between the business units, and enhances ecosystem conservation with the least fluctuation of harvest and revenue by period over a planning horizon.

Prior to Alaska statehood in 1959, Alaska’s salmon and steelhead stocks were severely depleted, primarily as a result of unsustainable fishing practices and inadequate federal fisheries management. Over the past 38 years, Alaska has focused considerable state resources on the conservation and management of its salmon stocks and associated habitats. Sustained yield management has been a cornerstone of the state’s fisheries management program. Other key elements of the program include effective habitat protection, separation of allocation and conservation decisions through the establishment of the Alaska Board of Fisheries, and strong support from the fishing industry and the communities that depend on these resources. This chapter provides a brief description of Alaska’s approach for achieving sustainable fisheries and outlines some of the recent initiatives that emphasize Alaska’s commitment to this goal.

Large volumes of water must be pumped from coalbeds to initiate coalbed natural gas production. When gas production commences, water production declines to a low sustained yield that is maintained for the production life of the well. The quality of produced water from coalbed methane wells varies widely, ranging from high-quality water that is sometimes used for drinking to hypersaline water that cannot be treated economically, and is injected into deep saline aquifers. Designing treatment for this water is challenging because a high-flow treatment capacity is needed when a well field is being developed but that capacity may be excessive when the field is in production. This chapter discusses treatment and management practices that are currently used for coalbed methane produced water and reviews emerging treatment technologies for their applicability to this problem.

This chapter describes the complex ways modern humans use and degrade the environment, and suggests the kind of research activities which anthropologists—and other social scientists—must engage in to make a contribution to the unravelling of these complex processes. Ecosystem is really one of the specialized concepts pertaining to empirical systems and consists of a set of generalizations about the interdependent nutritional and populational processes of plant and animal species living in defined physical environments. The basic ideas associated with the ecosystem concept are expressed by the tendency for natural species to exchange energy in such a manner as to create cyclical movement. Tribal herding societies in Africa constitute an unusually complete case of changing resource practices, illustrating shifts from ecologically benign to abusive systems. The concept of sustained yield is usually offered as the major general objective of resource management systems designed to achieve something like ecosystemic continuity.