Developing indicators for the sustainable management of mountain forests using a modelling approach

Methods to monitor the sustainability of forest management on local to regional scales are currently being developed in Europe, based on Pan-European criteria. However, current approaches to indicator development have several shortcomings. First, they fail to integrate the links among indicators. Second, they do not address the factors giving rise to specific indicator values explicitly. Third, they select indicators with an emphasis on data availability or ease of measurement rather than on informational content. To overcome these problems, we propose using a modelling approach to indicator development. What modelling and indicator development have in common is that they both try to capture the essence of real, complex systems. In this paper, we present an initial attempt to develop indicators for the sustainable management of mountain forests, using a modelling approach. Key issues that make the sustainable management of mountain forests a challenge, such as the poor ability of many stands to fulfil current human needs, are identified. A conceptual model depicting the most relevant system elements and links is described. In contrast to the Pan-European criteria and concept areas of sustainable forest management, which are result-oriented, the elements in the conceptual model are process-oriented. The approach could lead to a better understanding of the factors influencing the decision-making at the management unit level and to the identification of a set of meaningful indicators. To evaluate its full potential, however, a simulation model should be developed based on the conceptual model, and be applied to case studies.     

Conversion of Norway spruce forests in the face of climate change: a case study in Central Europe

Steadily increasing damage to Norway spruce forests in Europe has caused researchers and managers to consider whether these forests can be converted to more stable ecosystems. In a central European mountain region, we investigated whether management systems (MSs) specified by regional stakeholders provide sound alternatives to the currently applied management. We used the forest model Sibyla to explore whether the tested MSs differ in their sensitivity to climate change in terms of altered biomass production, stand structure, forest damage, and financial outcome. The tested MSs were no-management (NM), currently applied management (BAU), and management based on the preferences of forest managers (FM) or on the preferences of other stakeholders (OSH). With NM, spruce remained dominant during the simulation period 2010–2100, and the rate of damage significantly increased. Spruce also remained dominant with FM, while the abundance of non-spruce species significantly increased with BAU and OSH. The rate of salvage logging converged at 50% of the total harvest for all MSs up to 2050. Climate change reduced biomass production (?15%) with all MSs but had a negligible effect on biodiversity indicators. The average initial value of the simulated stands was 20,000 € ha^?1 and the nominal value in 2100 was between 1900 and 10,900 € ha^?1. The Net Present Value calculated with the 2% interest rate was negative during the whole simulation period (?5600 to ?18,500 € ha^?1 in 2100). Effect of climate change on all financial indicators was negative. Our findings indicate that secondary spruce forests are highly vulnerable and that the systems proposed by both forest managers and other regional stakeholders failed to significantly reduce forest damage and stabilize forest production.     

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.     

Western Carpathian mountain spruce forest after a windthrow: Natural regeneration in cleared and uncleared areas

A catastrophic windstorm called “bora” occurred in The Tatra National Park in Slovakia in 2004 and destroyed an extensive area of mountain spruce forests. Part of the windthrow area was left uncleared for natural development, but most of the area was cleared. We analyzed natural regeneration in cleared and uncleared windthrows, and in reference closed canopy forest in 2007 and 2008 with the aim of assessing the regeneration capability of the windthrown forests and proposing the best method for their restoration.     

Persisting bark beetle outbreak indicates the unsustainability of secondary Norway spruce forests: case study from Central Europe

? Context

Secondary Norway spruce forests in the Western Beskids are among the most damaged forests in Europe. Although spruce bark beetle (Ips typographus) has been recently causing large-scale damage to these forests, our understanding of I. typographus dynamics in this environment is inadequate for evaluating forest sustainability.

? Aim

This study aims to evaluate the patterns of damage caused by I. typographus to spruce forests with compromised ecological stability.

? Methods

Forest infestation by I. typographus was inferred from sanitary felling data collected from 1998 to 2004. Stand and site data were obtained from forest management plans. Spatial-dependence analysis, ordinary kriging and neural network-based regression modelling were used to investigate the patterns of infestation and the casual relationships in the studied ecosystem.

? Results

I. typographus long-distance dispersal substantially decreased with outbreak culmination. The spread of infestation was only weakly related to stand and site parameters. Infestations spread isotropically at the stand and patch level but directionally at the regional scale.

? Conclusions

The large-scale spread of infestation can be explained by the uniform age and species composition of the investigated forests and by the ability of populations to overwhelm suboptimal trees. The observations presented here suggest that secondary spruce forests in Europe may be unsustainable due to unprecedented bark beetle outbreaks, which can be further amplified by changing climate.     

Long-term adaptation potential of Central European mountain forests to climate change: a GIS-assisted sensitivity assessment

An ecological risk assessment is described for determining the adaptation potential of the approximately 11 000 Swiss Forest Inventory points (FIP) to a hypothetically changing climate. The core of the study is a spatially explicit forest community model that generates estimates of the potential natural vegetation for the entire potential forest area of Switzerland under today's as well as under altered climate regimes. The model is based on the Bayes formula. The probabilities of the communities occurring along ecological gradients are derived from empirical data featuring the relationships between quasi-natural vegetation types and measured site variables. Bioclimatological input variables are the quotient between July temperature and annual precipitation (model version A) or mean annual temperature (model version B). Other site variables include aspect, acidity of top soil and, to account for continentality, geographical region. Climate change scenarios are defined as follows: ‘Moderate climate change’ implies an increase of the mean annual temperature of 4°C to 1.4°C depending on the region (model version B) or an increase of the July temperature of 1.5°C (model version A). ‘Strong climate change’ implies an increase of the mean annual temperature of 2°C to 2.8°C (model version B) or an increase of the July temperature of 3.0°C (model version A).

The simulation experiment showed that the geographical distribution of 15 potential natural forest types (distinguished on the basis of floristic affinities) varies considerably with changing temperature. Under moderate warming 30–55% of the FIP change their potential natural vegetation type, whereas under strong climate change the values increase to 55–89% depending on the model version used. In the ecological risk assessment the existing tree species composition on any FIP was compared with the expected tree species composition under today's as well as under altered climate regimes. A major finding indicated that, under the current climate conditions, approximately 25–30% (depending on the model version used) of all FIP must be considered as poorly adapted, i.e. less than 20% of the actual basal area consists of tree species that are expected as dominating taxa. This definition applies for trees with a diameter at breast height (DBH) ≥ 12 cm. Moderate warming increases the percentage of poorly adapted FIP by 5–10% (relative to all FIP considered), strong warming leads to a 10–30% increase of poorly adapted FIP (relative to all FIP considered). If trees with a DBH < 12cm are considered, the percentage of FIP that have to be classified as poorly adapted is reduced significantly. There are strong regional differences as exhibited in risk maps of 10 km × 10 km resolution.     

White spruce regeneration following a major spruce beetle outbreak in forests on the Kenai Peninsula, Alaska

Between 1987 and 2000, a spruce beetle (Dendroctonus rufipennis) outbreak infested 1.19 million ha of spruce (Picea spp.) forests in Alaska, killing most of the large diameter trees. We evaluated whether these forests would recover to their pre-outbreak density, and determined the site conditions on which spruce germinated and survived following the spruce beetle outbreak in forests of the Anchor River watershed, Kenai Peninsula, Alaska. White spruce (Picea glauca) and Lutz's spruce (Picea × lutzii), a hybrid between white and Sitka spruce (Picea sitchensis), dominate the study area. We measured the pre- and post-outbreak density of spruce in 108 3 m × 80 m plots across the study area by recording all live trees and all dead trees >1.5 m tall in each plot. To determine the fine scale site conditions on which spruce germinated and survived, we measured ground surface and substrate characteristics within 20 cm circular plots around a subset of post-outbreak spruce seedlings. The density of post-outbreak spruce (855/ha) was adequate to restock the stands to their pre-outbreak densities (643/ha) for trees >1.5 m tall. We could not accurately estimate recovery for pre-outbreak spruce seedlings because dead seedlings may have decayed in the 5–18 years since the beetle outbreak occurred. At the fine scale, spruce that germinated post-outbreak grew on a wide variety of substrates including downed log, stump, mesic organic mat, peat, hummocks and mineral soil. They exhibited a strong preference for downed logs (53%) and stumps (4%), and most (91%) of the downed logs and stumps that spruce rooted on were heavily decayed. This preference for heavily decayed logs and stumps was especially evident given that their combined mean cover was only 2% in the 3 m × 80 m plots. Within the 3 m × 80 m plots, spruce seedling survival was negatively correlated with bluejoint (Calamagrostis canadensis) litter cover.     

辽宁省油松林可持续经营技术的思考与对策

在扼要介绍油松自然分布及现有林分现状基础上,该文就辽宁省油松林在经营理念、经营技术、操作规程以及经济基础等方面存在的主要问题进行了归纳和总结,并就如何实现油松林可持续经营等问题,从转变经营理念、政策支持、科技攻关和资金保障等层面提出了意见和建议。     

Landscape pattern and fragmentation of natural secondary forests in the eastern mountainous region, northeast China: A case study of Mao'ershan forests in Heilongjiang Province

Mao'ershan region is a representative natural secondary forested region in the eastern mountainous region, northeast of China. Under the support of ARC/INFO and GIS technology, the landscape shape and fragment indices of Mao'ershan experimental plantation were studied by combining the forest type map (1∶10000), which was drawn from the aerial photographs (1999), field investigation (1999) and soil utilized map (1∶10000). The results showed that the shape index and shape fragment index of natural landscape were higher than those of artificial landscapes and landscape patch fragment index depended on the number of patches. The natural forest had complex shape, suffering little jamming, and its shape index was higher than that of artificial forest. The manual controlled landscape (e.g. nursery, cropland and cutting blank) had regular shape, and its shape index was smaller. The fragment index of patches in natural forest was higher than that of artificial forest. The soft broad-leaved had the highest fragment index of patch amount. Foundation item: This paper was supported by National Key Technologies P&D Program of China during the 10^th Five-Year Plan Period (2002BA515B040). Biography: LI Shu-juan (1977-), female, Lecturer in Ocean University of China, Qingdao 266003, P. R. China. Responsible editor: Zhu Hong     

Developing a quantitative index system for assessing sustainable forestry management in Heilongjiang Province,China: a case study

In this study, we developed a comprehensive index system for forestry sustainability of Heilongjiang Province, which includes forest resources sustainability,sustainable economic development, sustainable social development and sustainable advancement in science and technology. Based on this system and the regional forest development, we further evaluated the sustainability of Heilongjiang Province for year 2008–2013. The results show that even though the regional forestry has been preliminarily on the track of sustainable development, it is fragile. Four indicators, e.g. soil and water retention rate,forest stand growth(per unit area), the proportion of national investment and the annual carbon sequestration have important impact on the sustainability, with a weight of 39.0 % in all the indicators. We also analyzed the factors hindering the sustainable development. It turns out that soil and water retention rate, forest stand growth(per unit area),the proportion of science and technology funds, per capita GDP and the proportion of the tertiary industry production are the main factors hindering regional sustainable development, which accounts for 50.94 % of the total obstacle degrees in the system. At last, we discussed how to promote the regional sustainable development from the perspectives of forest resources sustainability, economic development sustainability, society development sustainability and the sustainable advancement of science and technology.     

自然保护区集体林有效管理和可持续利用探讨

通过阐述我国自然保护区集体林分布、管理现状及有效管理的难点,梳理存在的问题,分析问题成因,提出了对策措施,为自然保护区集体林的有效管理和可持续利用提供参考。     

Legacies from natural forest dynamics: Different effects of forest management on wood-inhabiting fungi in pine and spruce forests

The species composition of wood-inhabiting fungi (polypores and corticoids) was investigated on 1138 spruce logs and 992 pine logs in 90 managed and 34 natural or near-natural spruce and pine forests in SE Norway.Altogether, the study included 290 species of wood-inhabiting fungi. Comparisons of logs with similar properties (standardized tree species, decay class, dimension class) in natural and managed forests showed a significant reduction in species number per log in managed spruce forests, but not in managed pine forests. The species number per log in managed spruce forests was 10-55% lower than on logs from natural spruce forests. The reduction was strongest on logs of large dimensions. A comparison of 200-400 spruce logs from natural and managed forests showed a 25% reduction in species richness corresponding to a conservative loss of ca. 40 species on a regional scale.A closer inspection revealed that species confined to medium and very decayed spruce logs were disfavored in managed forests, whereas species on early decay classes and decay generalists were unaffected. Similarly, species preferring large spruce logs were disfavored in managed forests. Forest management had strongest impact on low-frequent species in the spruce forests (more than 50% reduction), whereas common species were modestly affected. Corticoid fungi were more adversely affected than polypore fungi.These results indicate that wood-decaying fungi in pine forests are more adapted to forest disturbances than spruce-associated species. Management measures securing a continuous supply of dead wood are more important in spruce forests than in pine forests.     

A review of habitat thresholds for dead wood: a baseline for management recommendations in European forests

In contemporary forest management, also of commercial forests, threshold values are widely used for consideration of biodiversity conservation. Here, we present various aspects of dead-wood threshold values. We review published and unpublished dead-wood threshold data from European lowland beech–oak, mixed-montane, and boreo-alpine spruce–pine forests separately to provide managers of European forests with a baseline for management decisions for their specific forest type. Our review of dead-wood threshold data from European forests revealed 36 critical values with ranges of 10–80 m³ ha⁻¹ for boreal and lowland forests and 10–150 m³ ha⁻¹ for mixed-montane forests, with peak values at 20–30 m³ ha⁻¹ for boreal coniferous forests, 30–40 m³ ha⁻¹ for mixed-montane forests, and 30–50 m³ ha⁻¹ for lowland oak–beech forests. We then expand the focus of dead-wood threshold analyses to community composition. We exemplify the two major statistical methods applied in ecological threshold analysis to stimulate forest researchers to analyze more of their own data with a focus on thresholds. Finally, we discuss further directions of dead-wood threshold analysis. We anticipate that further investigations of threshold values will provide a more comprehensive picture of critical ranges for dead wood, which is urgently needed for an ecological and sustainable forestry.     

四川集体林权制度改革和可持续经营管理研讨会简报

2007年6月10-12日,四川省林业厅、四川省林学会、世界自然基金会和福特基金会在成都联合召开了"四川集体林权制度改革和可持续经营管理研讨会"。参加研讨会的有各市州林业局、林学会和部分县林业局的领导和代表、有世界自然基金会官员、省社科院、省扶贫办、省林业厅有关专家等共计72名。国家林业局造林司派员指导。省林业厅副厅长郭亨孝参加会议并作重要讲话,省林学会理事长曹正其主持了会议。会议交流学习了我省集体林林权制度改革的必要性、改革的目的、原则、内容、方法等,讨论了林改可能面临的困难、障碍和相应的对策措施。通过研讨大家对集体林权制度改革提高了认识、加深了理解。认为林     

Permanence of resilience and protection efficiency in mountain Norway spruce forest stands: A simulation study

An objective of mountain forest management is to increase the ability of forest stands to protect human activities against natural hazards such as rock-falls and snow avalanches in a sustainable way. The challenge is to find a compromise between efficient instantaneous protection, favoured by dense stands, and continuous renewal, minimizing time periods of low protection efficiency. We used a Norway spruce stand dynamics model to compare the respective advantages of individual tree and gap selection silviculture in this context. We simulated stand dynamics over 800 years with either individual tree or gap thinning every 20 years with several thinning intensities. At each time step, we evaluated stand resilience, protection efficiency against rock-falls, protection efficiency against avalanches, and structural complexity with four indicators based on stand structure. Every scenario produced short time periods with low stand resilience and protection efficiency. Such periods can be tolerated if they are sufficiently rare compared to the local disturbance regime. We characterized the permanence of resilience and protection of a forest stand as its ability to remain within boundary values of the different indicators, without going out of them during continuous time periods longer than fixed maximum durations. Permanence of resilience and permanence of protection decreased with thinning intensity. Efficient protection against rock-falls was obtained with gap thinning of intermediate intensity while protection against avalanches was obtained only for very low thinning intensities. For our ecological context, the best compromise between resilience and protection was obtained with three 10 m radius gaps per hectare every 20 years (9.5% of the area of a stand). This strategy led to uneven-aged stand structures with a high diversity of diameters classes. Our results suggest that small gap silviculture may be a good way to combine forest renewal and protection efficiency in mountain regions.     

Landscape metrics for characterization of forest landscapes in a sustainable management framework: Potential application and prevention of misuse

? The use of landscape indices in the analysis of forest landscapes offers great potential for integration of spatial pattern information in management processes, but requires understanding of the limitations and correct interpretation of results. In this sense, awareness of scale effects on landscape indices is essential, especially when the data available is restricted to low-resolution maps.

? In this study, developed within the framework of the FORSEE project, the objective was to define accurately the potential usefulness of applying landscape indices to low-resolution maps commonly used in forestry studies. Landscape indices were applied to two maps differing in spatial resolution, and subsets were defined for three spatial extensions. Correlation analysis and comparison of the results were carried out to enable identification of the most suitable indices for use with low resolution data.

? The analysis enabled identification of the least scale-dependent indices, which are thus more useful for extrapolating results from low-resolution data. In general terms, diversity and edge indices provided the best results.

? We conclude that some (but not all) of the landscape indices can be used to analyse low-resolution maps with acceptable results. Additional advice is made to prevent misuse of the application of landscape indices.

     

Quantitative stand structure of woody components of homestead forests and its implications on silvicultural management: a case study in Sylhet Sadar, Bangladesh

This study determined existing quantitative stand structure and its implication on silvicultural management of homestead forestry. The results showed that fruit and timber species have importance values of 57% and 43%, respectively, in the study area, which is in contrast to the commonly held view of absolute domination of fruit species. The fruit species were only moderately dominant over timber species in relation to the quantitative stand structure of homestead forests. Two fruit species, Mangifera indica and Artocarpus heterophyllus, contribute about one third of the stand structure, while amongst the timber species Samanea saman and Albizia spp. are the most important species. A simulated evaluation of soil expectation value of homestead forest showed that the existing stand structure would not maximize the financial gain perpetually, in contrast, the quantitative stand structure could be effectively regulated to maximize grower benefit without compromising the existing biodiversity. Optimization of the quantitative stand structure of homestead forests could be achieved by changing the species composition, specifically by increasing the percentage of commercially valuable species like Michelia champaca, Tectona grandis, Artocarpus chapalasha, Gmelina arborea, Litchi chinensis, Citrus grandis, Psidium guajava, Lagerstroemia speciosa, Swietenia mahogany, etc., reducing the percentage of species like Mangifera indica, Artocarpus heterophyllus, Cocos nucifera, Samanea saman, Spondias pinnata, Phoenix sylvestris, etc., and eradicating species like Lannea coromandelica and Ficus benghalensis. It was estimated that the optimal relative density of fruit and timber species that would generate optimal financial benefit would be 40.4% and 59.6%, respectively.