A century of logging and forestry in a reindeer herding area in northern Sweden

Boreal forest ecosystems are generally highly sensitive to logging and other forestry activities. Thus, commercial forestry has had major effects on the forests and landscape structure in northern Sweden since the middle of the 19th Century, when it rapidly extended across the region. Lichens (which constitute up to 80% of reindeer forage in winter and early spring) have often been amongst the most severely affected ecosystem components. The overall aim of the present study was to analyze how forestry has influenced the potential supply of ground-growing lichens as winter forage for the reindeer in this region over the past ca. 100 years. For this purpose, we analysed changes in forest and stand structure in Scots pine-dominated (Pinus sylvestris L.) reindeer wintering areas in the southern part of the county Norrbotten (covering ca. 58,000 ha) using detailed historical forest inventories and management plans. We found that the amount of the forest types considered potentially good pasture (mainly middle-aged and old pine forests) decreased during the first part of the 20th Century. However, the quality of grazing grounds was improved by forestry during this time mainly because selective logging made the forests more open which benefits lichen growth. During the last part of the 20th century forestry impaired the quality of grazing grounds in several ways, e.g. by clear-cutting and intensified use of various silvicultural measures. We conclude that ca. 30–50% of the winter grazing grounds have been lost in the study area because of intensive forest management during the last century. The spatially precise historical information about the affects of forestry on lichen pasture provided in this study can be used to direct forest management which will facilitate and promote reindeer herding in the future.     

Reindeer husbandry in a mountain Sami village in boreal Sweden: the social and economic effect of introducing GPS collars and adaptive forest management

Reindeer husbandry in northern Sweden, Norway, and Finland is an extensive agroforestry system, and the management of reindeer occurs alongside other land uses such as forestry, hunting, and tourism. The economic, social, and environmental impact of using GPS collars to track the reindeer was evaluated in the Sami village of Njaarke in boreal Sweden. A second objective was to evaluate how adapted forest management influenced reindeer husbandry. The results show that the use of GPS tracking enables the improved monitoring of the reindeer but the financial costs were greater than the financial benefits. The increased income did not cover the costs of depreciation and maintenance. Whilst the labour inputs associated with reindeer husbandry were high, 30–40% of the gross value added by village activities were related to hunting, tourism, and the renting of fishing rights. The use of adaptive forest management was assumed to increase the number of reindeer that could be reared through to slaughter and it was calculated to increase the gross value added by reindeer husbandry by more than 30%.     

Above ground biomass changes in the mountain birch forests and mountain heaths of Finnmarksvidda,northern Norway,in the period 1957–2006

Birch forests cover large areas of the northern Fennoscandia and the mountain birch (Betula pubescens ssp. czerepanovii) often forming the altitudinal and Arctic forest and tree lines. Interpreting the factors leading to landscape changes in mountain birch forest involves disturbance from anthropogenic use and climate as important factors. Using vegetation maps based on aerial photographs and satellite images from 7 years in combination with statistical data and ground estimation data of biomass in the period 1957–2006, we were able to assess the transitions among mountain heaths and different types of forest, the displacement of the altitudinal forest line and hence the change in biomass. The tree biomass as well as the growing stock for birch in Finnmarksvidda doubled in the period 1957–2006. Only lichen biomass has been significantly reduced in the period 1957 to 2000, with a subsequent slight increase of lichen biomass in the period 2000 to 2006. The results presented in this paper show significant and positive relationships between measured tree biomass and the increase in reindeer population in the period 1957–2006 in the study area. The hypothesis concerning the removal of the “lichen barrier effect” by heavy reindeer grazing which leads to increased success for birch seeds to germinate and sprout is therefore considered to be valid. However, also, climate change effects like increased precipitation, moth attacks, freezing and thawing events during winter and long-transported air pollution (e.g. nitrogen) may also have reinforced the changes in biomass. Climatic variables from regional weather stations for the period 1955–2006 did not, however, reveal any consistent change except for that the increased snow depth had a negative impact on the reindeer population while increase in snow depth hindering the reindeer in grazing seemed to have a positive impact on the lichen biomass. The ongoing development of increased forest cover and hence elevated forest line will lead to reduction of open habitats, and hence decreased grazing accessibility for the reindeer. The effects on forestry and carbon sequestration are also discussed, and here one of the suggestions is to let the northern birch forests act as carbon sinks contributing to the reduction of total net emission of CO₂ in the Nordic countries. Land use like reindeer husbandry has shown to strongly affect relationships between ecological processes like tree-growth and climate. Moreover, reindeer husbandry is such a widespread human activity in the arctic and boreal region that it might affect the global carbon budget.     

Of forest,snow and lichen: Sámi reindeer herders’ knowledge of winter pastures in northern Sweden

Over the last few decades, the use of forests both by Sámi reindeer herders and for commercial forestry has been a source of increasing conflict in northern Sweden. Forestry disturbs forest ecosystems and thus damages reindeer pastures, especially those rich in ground lichen, for which reindeer forage during the wintertime by digging through the snow. Despite increased communication between the two groups, the Sámi still feel that their interests are not adequately considered by the commercial forestry sector. This paper presents the results of an interdisciplinary study that comprised semi-directed interviews and participant observations. The objective was to understand the Sámi reindeer herders’ extensive ecological knowledge of winter forest pastures, and the characteristics they observe when managing this resource. The study also analysed specific terminology used by the Sámi herders, to describe, analyse and communicate these properties. These terms, as well as Sámi herder knowledge in general, emphasize the importance of snow cover for reindeer grazing in forest pastures, as well as the effects of forest structure and ground vegetation on variations in snow cover during the winter. Whereas the Western use of the word ‘pasture’ is often associated with a specific plant community, the Sámi herders’ understanding of the word also includes the effect of snow on grazing and for this they use a culturally specific word in their language: guohtun. This term conveys the additional notion of whether it is possible for reindeer to access the pasture under the snow. Sámi herder knowledge and know-how allow them to use the mosaic of forest ecosystems to accommodate variability in snow cover during the wintertime, using different forest areas in response to different grazing conditions. Finally, the authors argue that, in order to promote the balanced, multiple use of boreal forest ecosystems, it is necessary to acknowledge and understand Sámi reindeer herders knowledge and thus to fully integrate their needs and aspirations.     

Influence of soil scarification on reindeer foraging and damage to planted Pinus sylvestris seedlings

Abstract

The effects of soil scarification on reindeer lichen cover and re-establishment, reindeer foraging and damage possibly caused by reindeer to planted Scots pine seedlings were studied during six growing periods in a field experiment established in a reindeer lichen site that was grazed by a herd of 500–600 reindeer each winter. Seedlings (at a density equivalent to 2000 ha^?1) were planted in mounds with mineral soil on top, in tracks with exposed mineral soil, in tracks with mixed organic material and mineral soil and in intact lichen mat (control) with no soil disturbance. The disturbed area varied from 0 to 28%. After six growing periods, the reindeer lichen cover and volume were 10–20% lower in the scarified plots than in the control plots. There was no clear evidence that the reindeer avoided foraging even in plots with the highest levels of soil disturbance. However, the behaviour of the reindeer during winter grazing seemed to be affected by both coverage of reindeer lichen (positively) and the proportion of exposed mineral soil (negatively). Damage possibly caused by reindeer trampling affected 8.2% of the living seedlings each year and approximately 50% of these seedlings were subsequently infected by fungal diseases (compared with 20% of viable undamaged seedlings). Scarification treatments that exposed mineral soil mildly resulted in higher survival and growth rates than the other treatments, especially the control.     

Lichen community change in response to succession in aspen forests of the southern Rocky Mountains

In western North America, quaking aspen (Populus tremuloides) is the most common hardwood in montane landscapes. Fire suppression, grazing and wildlife management practices, and climate patterns of the past century are all potential threats to aspen coverage in this region. If aspen-dependent species are losing habitat, this raises concerns about their long-term viability. Though lichens have a rich history as air pollution indicators, we believe that they may also be useful as a metric of community diversity associated with habitat change. We established 47 plots in the Bear River Range of northern Utah and southern Idaho to evaluate the effects of forest succession on epiphytic macrolichen communities. Plots were located in a narrow elevational belt (2134–2438 m) to minimize the known covariant effects of elevation and moisture on lichen communities. Results show increasing total lichen diversity and a decrease in aspen-dependent species as aspen forests succeed to conifer cover types. The interactive roles of stand aspect, basal area and cover of dominant trees, stand age, aspen bark scars, and recent tree damage were examined as related to these trends. We developed an aspen index score based on lichens showing an affinity for aspen habitat (Phaeophyscia nigricans, Physcia tenella, Xanthomendoza fulva, Xanthomendoza galericulata) and found a significant negative relationship between the index and successional progression. Indicator species analysis showed the importance of all stages of aspen-conifer succession for lichen community diversity and highlighted the decline of aspen-dependent species with advancing succession. We present a landscape-level community analysis of lichens in the context of a conceptual model for aspen succession for the southern Rocky Mountains. We conclude that while total number of lichen species increases with succession, aspen-dependent species cover and richness will decline. In this way, epiphytic lichens communities may constitute an effective indicator of community-level diversity in for aspen-dependent species at-large.     

Re-establishment rate of reindeer lichen species following conventional disc trenching and HuMinMix soil preparation in Pinus-lichen clear-cut stands: a survey study in northern Sweden

Abstract

The re-establishment rates of reindeer lichen following conventional soil preparation by disc trenching and gentle soil preparation using HuMinMix apparatus were calculated from data acquired in surveys of 17 Pinus–lichen clear-cut stands in northern Sweden conducted 1–15 years after the treatments. The maximum lichen cover and biomass recorded in areas scarified by disc trenching were 29% and 24% of the lichen cover and biomass measured in adjacent intact lichen mats in the surveyed stands after 15 years. By contrast, 9 years after scarification, the corresponding percentages measured in areas disturbed by the HuMinMix treatment were 91% and 100%, respectively. According to calculated linear regressions, the reindeer lichen cover could be completely re-established just one decade after HuMinMix treatment. Ground lichen diversity in the scarified areas was also inventoried. The significant increase in lichen diversity for HuMinMix, especially of early-successional species, could explain the more rapid re-establishment of late-successional lichens (e.g. Cladonia stellaris spp.), compared with disc trenching. Thus, the study demonstrates that both the degree of initial disturbance and the re-establishment rate of reindeer lichen must be considered when estimating the effects of scarification on lichen loss for reindeer grazing over time.     

A critical view on benefit-cost analyses of silvicultural management options with declining discount rates

The long planning perspective is one of the unique features of forestry. How to value money flows expected in the far distant future is therefore a crucial question. Applying time declining discount rates (DDR) may offer an appropriate alternative to conventional discounting, but few studies have applied DDRs in forest economics. We expect that theoretical assumptions behind welfare analyses based on DDR will be important. Using a dataset from the UK (Davies and Kerr (2015) [Forests 6: 2424–2449]) we investigate the effects of 1) more than marginal contributions from forestry to consumption, 2) the role of the assumed scenarios for return on capital, and 3) ignoring optimization (i.e. adopting predefined management scenarios) on the ranking of different silvicultural strategies. These include various clearfelling options (with replanting, natural regeneration or underplanting) and the transition to continuous cover forestry. Our analysis reveals that changes in these aspects affect the ranking of forest management options more strongly than a pure change in the coefficients of a benefit cost analysis. Decreasing marginality, cautious assumptions about the worst-case return on capital and optimization of silvicultural operations all increase the relative attractiveness of continuous cover forestry. We conclude that applying DDR makes valuation in forestry more demanding and should be applied with appropriate care. In addition, the precise assumptions behind the particular schedule of DDRs should be explicit. Finally, theoretical considerations support the importance of combining optimization of silvicultural management strategies with their economic evaluation.     

Evaluating the benefit of avalanche protection forest with GIS-based risk analyses—A case study in Switzerland

The protection of people, buildings and infrastructure against natural hazards is one of the key functions of mountain forests. Since the protective function strongly depends on small-scale local conditions such as terrain and stand characteristics, spatially explicit evaluation methods are necessary to provide information required for an effective and cost-efficient forest management. Risk analyses are recognized as the best method for estimating the danger from various natural hazards. Currently, however, risk-based strategies are rarely addressed in the management of protection forest. We present and discuss a risk-based approach to evaluate the protective effect of mountain forests in a spatially explicit manner to demonstrate the advantages of future risk-based protection forest management. We illustrate the approach by performing a GIS-based risk analysis in the case study area ‘Bannwald of Andermatt’ (Switzerland) for a 300-year snow avalanche event. Classifying forest structures based on aerial photographs allowed developing different forest cover scenarios and modeling potential avalanche release areas within the forest. Potential avalanche release areas above the forest and the avalanche run-out distances under five different scenarios of forest cover were calculated by using a two-dimensional avalanche simulation model. We calculated the annual collective risk for each scenario and compared the change in risk to reveal the spatial distribution of the protective effect of the forest. Resulting risks differed strongly between forest cover change scenarios. An enlargement of an existing wind-disturbed area within lower parts of the slope resulted only in a slight increase of risk. In contrast, the effect of an unforested area in the upper parts of the observed forest more than doubled the risk. These results show how a risk-based approach can help to quantify and illustrate the impact of differences in forest cover on the protective effect of mountain forests. It is a promising approach to determine the economic value of protection forests and thus provide quantitative and qualitative information for cost-efficient forest maintenance planning. With regard to the achievements of research to date, the presented approach may serve as a valuable method to support decision-making in a future protection forest management.     

湖南省森林经营现状与对策

据2002年湖南省森林资源统计年报，全省林业用地面积18343.2万亩，森林覆盖率53.13％，活立木蓄积量31352.34万m^2。文章对湖南省森林资源及现有林分结构和质量进行了分析与评价，总结了经验，对存在的问题进行了分析，并提出了加强森林经营工作的对策。     

Optimising the management of maize — Grevillea robusta fields in Kenya

The study optimised the management of a Grevillea robusta (A. Cunn.) stand growing in the central highlands of Kenya. The optimisations were conducted separately for even-aged and uneven-aged management system of trees. The management was also optimised with the requirement that maize production under the tree cover must be profitable every year. Technically, the optimisation problems were solved by linking a simulation program with the non-linear optimisation algorithm of Hooke and Jeeves. The simulation program calculated the tree growth, volumes of harvested trees, and maize yields with a given set of management parameters (decision variables). The maize yield predictions and simulated timber yields were converted into gross incomes of which the production costs were subtracted. In even-aged management the objective variable was the soil expectation value with 5% discounting rate. In uneven-aged management the mean annual net income was maximised. The optimal solutions indicated that with both management systems it is optimal to concentrate on wood production. The optimal stand densities were so high that profitable maize production was not possible under the tree cover. The mean annual wood production of the optimal management schedule was more than 50m³ ha^–1. Forcing profitable maize production in the solution decreased the wood production by 57% (even-aged forestry) or 27% (uneven-aged forestry) and net income by 45% (even-aged forestry) or 24% (uneven-aged forestry).This revised version was published online in November 2005 with corrections to the Cover Date.     

目标树经营:德国经验与湖北实践

德国是近自然林业的发源地,目标树经营法是近自然林业的重要操作方法.长期以来,德国高等院校和林业科研机构对目标树经营法进行了多方位的研究,形成了不同的经营模式,影响较大的有弗莱堡模式、巴伐利亚模式和罗腾堡模式.借鉴德国的经验,文中在进行大量调查研究的基础上,设计了基于湖北实际的目标树经营法.核心内容是:以平均胸径10 c...     

Trade-offs between seedling growth,thinning and stand stability in Sitka spruce stands: a modelling analysis

The forest industry is increasingly adopting alternative silvicultural systems, involving regeneration beneath an existing forest canopy, rather than clear-felling and replanting. To apply these silvicultural systems in windy regions such as Britain and Ireland, it is essential that the interactions between thinning intensity, stand stability and seedling growth are properly understood. Here, we present a modelling analysis of the three key relationships between: (i) stand density and the proportion of incident radiation transmitted through a forest canopy as a stand is thinned; (ii) transmitted radiation and seedling growth, and (iii) stand density and stand stability. These relationships were examined using separate models of radiative transfer (MAESTRO), seedling growth, and stand stability/wind risk (ForestGALES). Output from the three models was synthesised to calculate whether a given stand thinned to a pre-defined stability limit would allow sufficient light to penetrate the canopy for seedling growth. A minimum transmittance of 20% was identified as a requirement for seedling growth, which corresponds to removing 45% of stand basal area. A thinning of this intensity left some stands susceptible to unacceptable wind damage, especially in old or previously thinned stands on soils where rooting is impeded. The results emphasised the fact that rooting conditions, thinning history and age of intervention are major constraints on the silvicultural options. In general, older stands are not suitable for conversion to continuous cover forestry (CCF) systems, and the transformation process should begin at pole stage, when heavy thinning does not leave the stand unstable. The analysis approach used here illustrates the potential for combining models to address complex forest management issues.     

森林生长经营模拟平台CAPSIS及其应用

林业工作者通过建立生长模型来研究、理解和展示林分的生长过程并制定经营决策,特定的计算机工具经常用来实现这些模型。CAPSIS是一个致力于建立森林生长模型并能充分整合各种模型的通用共享森林建模平台,可提供森林经营管理的工具设计和比较不同的森林经营方案。笔者对CAPSIS森林生长经营模拟平台及其在林业上的应用进行了介绍,并讨论了建模者和林业工作者利用这一共享森林建模平台进行森林生长研究、经营管理决策等的优势。     

Effect of the season and forest management on the visual quality of the nature-based tourism environment: a case from Finnish Lapland

The growth of nature-based tourism has raised the need to better understand tourists’ expectations towards outdoor recreation environments. There is little knowledge, however, of international tourists’ attitudes towards forest management practises or of their effect during winter. This study investigated how commercial forests correspond to the environmental expectations of international nature-based tourists and how the season affects tourists’ landscape preferences. Altogether 750 foreign visitors to Finnish Lapland responded to a survey and evaluated photographs presenting various types of forest landscapes in summer and winter. Beautiful scenery was the most important motive for the choice of travel destination and for participating in outdoor recreation. The results highlight the strong impact of seasons on the perceived quality of the landscape in commercial forests. Seasonal differences are largest in regeneration areas as snow cover mitigates the effects of forestry operations. Even-aged, middle-aged and mature forest stands were considered to be suitable for tourism in both summer and winter. There is a demand for adapted management regimes in commercial forests targeting year-round nature-based tourism. In conclusion, forestry and tourism can coexist in the same area with good planning and with management actions that take visual quality and recreational values of the environment into account.     

Agroforestry and its application in amelioration of saline soils in eastern China coastal region

Some environmental problems, especially soil salinity hinder the regional sustainable development of eastern China coastal region. Salinity mainly comes from tide weave, seawater flooding and seawater intrusion. Over exploitation of groundwater,which is the result of unfitful land use systems, leads to seawater intrusion and salt concentration increase. Agroforestry systems can enrich soil fertility and prevent soil salinization, furthermore help maintain biodiversity and enhance productivity. For the intergrated multiple ecosystems the most critical issue is to select optimum tree species and rationally arrange these plants. The basics of this multiple ecosystem is that different plants will occupy variable ecological niches within an area, both in space and in soil depth.Shelterbelts and trees intercropping with agricultural crops are major types of the multiple ecosystem. Shelterbelts can reduce wind speed and consequently lessen evaporation and erosion of the soil, increase pasture growth by up to 60% on exposed sites, increase crop yields by up to 25%. Besides intercropping with jujube, other agroforestry multiple ecosystem such as forestry plus agriculture,forestry plus agriculture plus fishery, and forestry plus animal husbandry are the most appropriate ways to utilise land resource in this region.     

Effects of administrative land-use and technical land-form constraints on timber production at the landscape level

Abstract

This study quantified, across a landscape in Eastern Finland, the influence of administrative land-use and technical land-form constraints on timber production. Spatially explicit data about the nature conservation areas, land use plans and steep slopes were integrated with Multi-source National Forest Inventory (MS-NFI) data. The Finnish forestry model MELA was used in the calculations related to updating forest data and estimating different scenarios of timber production with and without constraints. In the study area, the annual volume of maximum sustainable cutting removal defined for the next 30 years was decreased by one-third due to restrictions. The presented approach could be used, for example, to assess timber availability at the landscape level. Future challenges include ensuring the compatibility of spatially explicit data obtained from different sources, identifying the feasibility of forest management operations in the restricted area, and incorporating near-nature forest management operations in the forest planning system in order to estimate the timber production.     

Retention of canopy lichens after partial-cut harvesting in wet-belt interior cedar–hemlock forests,British Columbia,Canada

Old-growth cedar–hemlock forests of the interior wet-belt of British Columbia are rich in abundance and diversity of canopy lichens, but are subject to forest harvesting. If these distinctive canopy lichen communities are to be conserved, it is important to learn how they are affected by forestry practices, including partial-cutting techniques designed to retain old-growth attributes. The retention of canopy lichens after 30 and 70% partial-cut harvesting (immediate post-harvest and 2-year post-harvest measurements) was examined using direct canopy access methods (tree climbing) in two old-growth interior cedar–hemlock forest stands of the upper Fraser River valley. Mean lichen loading was generally lower in all treatment areas, including control sites, 2 years after harvesting. However, three of four lichen-sampling groups (cyanolichen, foliose, and Bryoria group lichens) did not show significant treatment effects (total lichen loading) by harvesting type (30, 70 or 100% retention), when data sets were standardized against initial post-harvest lichen loading. Only in Alectoria group lichens were treatment effects observed. Although cyanolichen loading was not significantly different in retained trees in most harvest blocks, many thalli, especially those near south-facing edges, were discolored, suggesting that future cyanolichen loading may be lower within partial-cut harvest blocks. Litterfall in general was greater during 2001/2002 than 2002/2003, even in the control units, suggesting weather-related differences between years. For Alectoria, there appeared to be a treatment-related pulse of litterfall that was more pronounced in the 70% removal than the 30% removal treatment unit. Deposition patterns of litterfall components in relation to edges of openings indicated a heightened level of Alectoria litterfall along edges. Treatment-related differences were absent or weak in other groups, and cyanolichen litterfall did not differ between years in any study area/treatment unit combination. These findings suggest that lichen retention in the residual stand of both partial-cut treatments was adequate to meet management goals, but also point to the necessity of future monitoring, as other edge effects (e.g. microclimate changes) influence future lichen growth and mortality.     

澳大利亚维多利亚州公有林管理

维多利亚州是澳大利亚重要的林业省份之一,在其2000多万hm2白土地上,公有土地为910万hm2,森林覆盖率高达80%.公有林业作为公共事业的一个重要组成部分,其管理体制经历了不断改革和发展的过程,特别是1986年以后,随着维州政府《木材工业战略》的颁布和实施,维州的公有林管理进入了一个新的时期。介绍了维州公有林业的主管机构及其职能、天然林资源管理及规划、公有人工林管理及改革,探讨了其林业发展政策及存在的问题。     

山区建设必须以林业为基础

我国2/3为山地,《国家十四个重要领域技术政策要点》没有把山区建设作为重点加以研究。目前全世界对山区建设也极少开展理论研究。恩格斯《自然辩证法》所告诫的错误,仍在当今世界的各地重演。不重视基础研究,没有基础理论做指导,在我们社会主义中国的山区建设中也难免还要犯严重错误。