3-level MCGP: an efficient algorithm for MCGP in solving multi-forest management problems

The efficiency gains when harvests are determined using the Faustmann approach instead of Maximum Sustained Yield (MSY), Forest Rent or some silvicultural rules were studies. The analysis was based on a variable-density stand growth model and computations over all admissible combinations of initial stand age and basal area for Finnish Norway spruce and Scots pine sites. Following MSY or Forest Rent led to a major reduction in the economic value of especially highly stocked stands. Finnish silvicultural recommendations (an example of silvicultural rules) encouraged production of higher than optimal quality timber. Applying Forest Rent, MSY or silvicultural recommendations led to respective reductions of 63%, 30% and 13% in the value of a typical conifer forest at a 4% rate of interest. The results also showed that an increase in the rate of interest may lengthen the ongoing rotation if the initial state falls outside the optimal path initiated at bare land.     

Economic Analyses of Rubber and Tea Plantations and Rubber-tea Intercropping in Hainan, China

This study uses land expectation value (LEV) as a criterion to conduct economic analyses of natural rubber (Hevea brasiliensis) and tea (Camellia sinensis var. assamica) monoculture, and rubber-tea intercropping. We calculated LEV by using the Faustmann model that combines annual revenue flow from latex production with final timber harvest of rubber trees. Production and cost data were collected from Xinwei Farm in Hainan, China. We found that rubber-tea intercropping generated higher LEV than rubber and tea monoculture under current socio-economic circumstances. Sensitivity analysis has been conducted to examine the impacts on land expectation value by interest rate, prices of natural rubber and tea, and labor costs.     

Determination of optimal rotation period under stochastic wood and carbon prices

The valuation of forest stands is traditionally based on a profit calculus involving revenue from wood sales and associated costs. Currently, the role of carbon management in forests is actively discussed. In a stochastic setting we extend the analysis of the optimal rotation period by considering uncertain revenue streams from carbon trading. We develop a real options model given uncertainties in future wood and CO₂ price behaviour. A detailed sensitivity analysis of the numerical results for both cases – with and without carbon sequestration – is provided. We find that optimal rotation periods vary considerably with (i) the type of price process, (ii) the way how carbon income is defined, and (iii) the selection of discount rates.     

Application of the Faustmann principle to a short-rotation tree species: an analytical tool for economists,with reference to Kenya and leucaena

Attention has increasingly focussed on fast-growing trees as a potential means of slowing high rates of deforestation and as a source of renewable energy. Unfortunately, the analytical tools for determining economic tractability of tree-growing projects lags behind the popular support to implement them. This paper brings the methodology of the Faustmann Principle, which was established for use with longer growing species, to bear on leucaena, a short-rotation, leguminous tree crop. The principle incorporates biological and economic parameters to derive a function relating the present value of net revenue to rotation length. Additionally, a method of incorporating secondary benefits, such as nitrogen fixation, is demonstrated. Results from the model are applied to Kenya. Research on agro-climatic zones in Kenya is used to indicate the potential volume of leucaena production.     

Introduction of sustainable management tools in central Zagros forests of Iran

Zagros forests are one of the vegetative regions which have been located in the west of Iran. The investigation of sustainable forest management in Zagros is one of the key issues which make us to consider the challenges concerned with the protection of forest resources and socioeconomic problems of local people. Demand for criteria evaluation and indicators for sustainable forest management from local to national level to conduct administrative affairs have been increased. The aim of the present study is to evaluate 7 criteria and 65 sustainable indicators which have been utilized in the Near East. Accordingly, a questionnaire, with its reliability confirmed by experts, was distributed among involved participants. The results indicated that the Cronbach’s alpha coefficient for the questionnaire was 0/729. Then, using DEMATEL model, the sustainability criteria were prioritized and the significant correlation among them determined. Likert scale was also utilized to rank all the indicators, and in terms of their relative weight they were compared with. The result indicated that the most significant criteria were legal, political, and institutional frameworks, and protective functions of forest criterion were the most influential factor. By analyzing the experts’ attitudes, reliance on natural regeneration indicator with the relative weight of 31/15% was the most significant criteria in the region. The existence of number of seed provenance with the relative weight of 9/17% was the least significant role. At the end, 27 verifiers, 25 threshold values, and the most significant indicators in this research were determined.     

基于高保护价值森林理念的森林保护和经营对策

本文介绍了高保护价值森林的概念和内容,将高保护价值森林理念与我国现行的森林保护体系相结合,提出进一步完善森林保护体系的措施和可持续经营对策,在提高林地保护管理水平的基础上,构建国土生态安全体系。     

城市森林的经营目标与价值探析

本文简述了城市森林的闪起，讨论了城市森林的性质、经营的目标和价值。     

木兰林管局幼龄林现状及经营对策

结合木兰林管局森林资源现状与林分结构,分析了幼龄林经营中存在的主要问题,并提出了相应的经营对策和一系列的保障措施。     

易门县公益林管护中存在的问题分析

易门县2005、2009年先后启动实施国家级和省级公益林生态项目建设，针对项目实施以来公益林管护中存在的问题进行分析，藉此提出相应对策、建议。     

西藏天然林资源保护与可持续经营

探讨了西藏天然林资源的现状、特点、问题，提出了天然林资源的可持续经营措施。     

Effects of initial stand states on optimal thinning regime and rotation of Picea abies stands

Abstract

This study analysed the effects of young stand characteristics on optimal thinning regime and length of rotation periods for even-aged Norway spruce [Picea abies (L.) Karst.] stands. Stand development was based on a distance-independent, individual-tree growth model. The young stand data were collected from 12 well-stocked Norway spruce stands in southern Finland. Results showed that optimal thinning regimes and rotation period depend on site quality and initial stand characteristics. At the first thinning, optimal thinning type depended on initial density. Thinning from both ends of the diameter distribution turned out to be optimal for initially dense stands. At the second and subsequent thinnings, thinning from above was clearly superior. At a low interest rate, thinning from below was optimal for the first thinning regardless of stocking level. For the study data, optimal rotation periods varied from 61 to 92 years at 3% interest rate. The high variation in length of rotation period was due to the sensitivity of optimal length of rotation period to site qualities, initial stand structure and density.     

Contribution of participatory forest management towards conservation and rehabilitation of dry Afromontane forests and its implications for carbon management in the tropical Southeastern Highlands of Ethiopia

Participatory forest management (PFM) has been applied as an approach to create a framework for collaborative forest management between local communities and government forestry agencies. This study was designed to assess the contribution of PFM approach in improving forest status in the Southeastern Highlands of Ethiopia. Landsat satellite imageries of four years were used to evaluate the trends and rate of deforestation before and after PFM interventions. Socio-economic data were collected from sample household surveys, key participants, focus group discussions, and field observations. The results showed that there was high rate of deforestation before PFM intervention as forestland has decreased by 19% (2531 ha) between 1990 and 2000. However, after the PFM intervention (2000–2016), the forest cover has increased by 247 ha (2.2%). During this period, net 1016 ha of shrub-lands were converted into forestland owing to significant forest regeneration. In addition, most sampled households (94% and 96% from lower and upper altitudes, respectively) perceived that PFM had significantly contributed to improve forest regeneration in their locality. This study revealed that PFM can serve as a stepping stone for carbon financing mechanisms to reduce greenhouses emission and enhance carbon sinks via forest resources.     

Ecology and regeneration of tropical dry forests in the Americas: Implications for management

Dry forests represent the most endangered ecosystem in tropical regions and continue to be one of the most sought after environments for human colonization, development and production. In spite of this, dry forests are one of the least well studied tropical habitats. This special issue is dedicated to reviewing much of the information that exists about tropical dry forest in the Americas. The introduction summarizes the articles presented herein, highlighting management strategies that are suggested throughout the special issue that may be useful for conserving tropical dry forest environments.     

Integrated environmental education for sustainable forest management: the case of Nandi Hills Forests, Kenya

Environmental education (EE) is a vital dimension of modern day acumen that portends a great promise in solving the myriad environmental resource management challenges at global, regional and local levels. A study was carried out in 18 locations in the Nandi North, Nandi South and Nandi Hills districts of Kenya, which cover the Nandi Hills and Nandi Forests in Nandi County, major water catchments for Lake Victoria. A mixed methodological approach, incorporating both qualitative and quantitative data obtained from focus group discussions, key informant interviews, household survey and observations was embraced in data collection and analysis. The study reveals that there are several strategies that have been adopted by the local population and institutions involved in the management of the Nandi Hills Forests (NHFs) and that these strategies have contributed to an improvement in the perceptions of the local population in terms of the importance of environmental management of the forests. This paper highlights EE as a vehicle for ensuring a sustainable management of the Nandi Hills Forests. As such, it illuminates the great potential that lies in sustainably managing the NHFs by integrating formal and informal EE approaches. It further points out the functional gaps in the management of NHFs and proposes best-practices that could be adopted and/or domesticated in NHFs management regimes.     

Growth,forest floor,and soil chemical analysis comparison between two management practices in chestnut forests of Greece

The effects of management mode and intensity both on growth parameters (diameter and height of sprouts) and soil fertility were studied in experimental plots in coppice chestnut forests of Athos and Pelion mountains – Greece. The empirical management practice applied in Athos is intensive with a rotation period every 20–22 years, including removal of timber products during selective loggings and final clear-cut loggings. The management type applied in Pelion by the Forest Service is more flexible (much longer rotation period) with remaining in situ of plant residues. The soils of both areas were originated by the same parent material (gneiss), they have loamy texture, similar bulk density values, and they are acidic. Higher values of diameter and height of sprouts were observed in Athos compared to Pelion (statistically significant differences). Pelion soils presented higher levels of soil fertility, i.e., in forest floor higher organic matter and nutrients content (significant differences for P, Ca, Na, Cu, and Mn), and in soil higher levels of N, Ca, Na, Fe, Cu, Zn, Mn and organic matter (significant differences for N, Cu, Mn, and organic matter). The findings of this work could be an important tool to the perspective of chestnut forests management practices.     

Goal programming approach for sustainable forest management （case study in Iranian Caspian forests）

We used a goal programming technique to determine the optimal harvest volume for the Iranian Caspian forest. We collected data including volume, growth, wood price at forest roadside, and variable harvesting costs. The allometric method was used to quantify seques- trated carbon. Regression analysis was used to derive growth models. Expected mean price was estimated using wood price and variable harvesting costs. Questionnaire was used to determine the constraints and the equation coefficients of the goal programming model. The optimal volume was determined using the goal programming method according to multipurpose forest management. LINGO software was used for analysis. Results indicated that the optimum volumes of species were 250.25 m3.ha-1 for beech, 59 m3.ha-1 for hornbeam, 73 m3.ha-1 for oak, 41 m3.ha-1 for alder, and 32 m3.ha-1 for other species. The total optimum volume is 455.25 m3.ha-1.     

Preference and adoption of Farmer Field School (FFS) Prosopis juliflora management practices: Experiences in Baringo District, Kenya

This research was carried out to evaluate the preference and adoption of harvesting, uprooting, stump burning, pruning and thinning practices for controlling the spread of Prosopis juliflora (prosopis) within Marigat Division of the Baringo District, Kenya. A survey methodology was employed using a random sample of 25 Farmer Field School (FFS) members and 5 non-FFS members from each of the five locations of Marigat Division. In total, 100 FFS members and 25 non-FFS members participated in the study; additional supplementary data were collected from the Kenya Forestry Research Institute (KEFRI), a major facilitator and trainer of the identified FFS activities and practices in the study area since 2004. More than 80% of the local community never undertook any form of prosopis management practice; however, this changed after FFS training, indicating an acquisition and retention of knowledge which probably diffused to the non-FFS counterparts, through either formal or informal ways. Harvesting was the most preferred (100%) and stump burning the least preferred (46%) practice of managing the spread of prosopis. The success and preference of any prosopis management practice was attributed to wood and non-wood benefits derived from prosopis and growing of animal fodder and food crops on rehabilitated land. More than 80% of respondents attributed ineffectiveness of any prosopis management practice to coppicing and viable seed banks of the tree, while 50% highlighted a lack of consistency and integration in carrying out management practices. The reported negative attitude towards prosopis changed after training with none of the view to eradicate it. Labor intensity and frequent regeneration of seedlings were identified as the major challenges faced during the implementation of prosopis management practices. In conclusion, the study shows that harvesting, uprooting, stump burning, pruning and thinning realized through consistent holistic integration contribute to containing the spread of prosopis trees in Baringo, Kenya.     

黔南州公益林管理现状浅析及建议

森林生态效益补偿是国家为了巩固生态建设成效,对林权所有者和使用者进行适当补助的惠民政策,自实施以来得到了林区广大群众的拥护和支持,生态得到了保护和发展,林农得到了实惠。本文在对黔南州公益林管理现状进行了深入调研的基础上,分析了黔南州公益林管理存在的问题,并提出了解决问题的办法及建议,促进了公益林管护水平的提高。     

基于管理学的林地落界项目管理探讨

从林地落界背景实际出发,考虑地方林地利用监管现状,从管理学角度重新对林地落界项目进行认识、分析、讨论,并从管理学的四种基本职能出发,对林地落界项目进行管理可行性探讨.