Showing papers in "Forestry in 2000"

Interactions between forests and herbivores: the role of controlled grazing experiments

Abstract: Summary The use of controlled grazing by large herbivores as a research and management tool in forest systems is reviewed, with particular focus on exclosure-based studies of plant‐animal interactions within north-west Europe. Controlled grazing studies have revealed that large herbivores (wild and domestic) have a substantial influence on forest composition and dynamics. We review current knowledge and highlight the deficiencies and potentials for new research, in relation to specific areas identified as of key importance in forest dynamics. Few attempts have been made to assess critical thresholds of grazing intensity in relation to factors such as recruitment and maintenance of different tree species. Thus it is not possible to define appropriate grazing management techniques for specific aims, yet there is an urgent need for this type of knowledge, especially in countries with little remaining natural forest. Gradients of primary productivity have been shown to affect grazing choice and species responses to damage in non-forest vegetation, yet few studies have explored these effects within forest systems. More research on plant‐herbivore and herbivore‐herbivore interactions is required at a range of both plant and animal densities. The increasing awareness of biodiversity issues has also highlighted deficiencies in our knowledge of forest systems. We conclude that controlled grazing experiments have an important role to play in these key aspects of forest research, and that their potential has not yet been fully utilized.

Forest recreation in 1977 and 1997 in Sweden: changes in public preferences and behaviour

Abstract: Summary This paper focuses on changes in the relationship of the Swedish public with the forest. By repeating a postal survey after 20 years, changes in the recreational use of forests, and preferences according to suitability of forest sites for outdoor recreation, are measured. The main result is that the changes are generally small. The visiting frequency remains unaltered and the typical Swede visits a forest for recreational purposes once a week in summer and once a fortnight during the winter. A few differences between the studies in 1977 and in 1997 were observed. The amount of wild berries picked for home consumption had decreased in 1997 to about one-third of the volume picked in 1977. A black and white photo of a virgin forest was considered a more suitable image for outdoor recreation in 1997. A Scots pine (Pinus sylvestris) shelterwood was considered less suitable for outdoor recreation. It is concluded that the relationship with the forest is still close, but that public use is changing from harvesting towards purely recreational. Further conclusions are that new recommendations for silvicultural actions will be needed due to these changing preferences and that the conflict between recreational and biodiversity goals in forestry has slightly decreased.

Strict forest reserves in Europe: efforts to enhance biodiversity and research on forests left for free development in Europe (EU-COST-Action E4)

Abstract: Summary Protected forest areas have become increasingly important and strict forest reserves have an important role to play on two fronts: they are in themselves important protection sites, and they also provide the necessary reference data for nature-based silviculture in production forests. The EUCOST-Action E4 (European Forest Reserves Research Network) underlined their importance and found that there is a wide variation in conceptual approach, historical background, size and share of strict forest reserves throughout Europe. These differences are clearly linked to local forest type and forest history, land use and natural forest dynamics. Moreover, the term ‘strict’ reserve is interpreted very differently in different countries: in many cases game control, fire control and the removal of invading exotic species are allowed. The concept of complete non-intervention does not seem to be realistic for Europe. The total strictly protected forest area, for the 26 countries involved in COSTE4, is calculated to be nearly 3 million hectares or about 1.7 per cent of the total forest area. However, subjects, goals, methodologies and constraints for scientific research seem to be strikingly similar throughout Europe. Transboundary co-operation is therefore evident, and needs further promotion. For this purpose, an electronic database on strict reserves, which can be consulted through the Internet at http://www.efi.fi/Database_Gateway/FRRN, has been constructed within the framework of the COST action. Judging from the number of visits, it is likely to become an important tool for future scientific co-operation.

A process model analysis of environmental limitations on the growth of Sitka spruce plantations in Great Britain

Abstract: Summary The extent to which growth is limited by climatic factors or soil fertility is of significance to foresters concerned with the management of Sitka spruce plantations throughout Great Britain. A simplified physiologically based model, driven with monthly weather data, provided a means to assess growth limitations imposed by solar radiation, subfreezing and suboptimal temperatures, soil drought and atmospheric vapour pressure deficits, wind and soil fertility at sites differing in maximum wood volume production by fourfold. To drive the model, conventional weather station data were extrapolated to provide estimates of precipitation, solar radiation, vapour pressure deficits, suboptimal temperatures and frequency of subfreezing conditions. Variation in solar radiation associated with topography accounted for nearly half the differences observed in plantation growth. Unfavourable temperatures reduced annual photosynthesis and growth only by 10‐15 per cent as they occur primarily in months with limited solar radiation. Drought and vapour pressure deficits do not appear to offer major constraints on growth. Soil fertility, however, significantly limited growth on a number of sites. The modelling approach provides a measure of nutrient availability by predicting the maximum accumulation of nitrogen in the canopy. The modelling analysis suggests that foresters could improve forecasts of Sitka spruce plantation growth throughout the UK with better estimates of solar radiation and canopy nitrogen content than with more conventional sets of measurements.

Contingent valuation of the Natura 2000 nature conservation programme in Finland

Abstract: Summary This paper shows how contingent valuation studies can produce relevant information for public nature conservation decisions. The study analyses the preferences of Finnish households for a nature conservation programme, Natura 2000 Network, by applying a dichotomous choice referendum model of the contingent valuation survey. In order to study the influence of attitudes and beliefs on a choice between the status quo and the new conservation project, an attitude‐behaviour framework is applied. Beliefs concerning the outcomes of the nature conservation policy and evaluations of their importance describe how attitudes towards the programme are formed. The choices in the referendum are explained using a logit regression model and are found to be a function of attitude and socio-economic variables. The probability of a person supporting the proposed conservation level depends significantly on the income, age and background (urban‐rural) of the respondent. The estimated model of choice behaviour is used to calculate the average willingness to pay for the Natura 2000 Network, which is also compared to the costs of the conservation programme.

Estimation of mean wind climate and probability of strong winds for wind risk assessment.

Abstract: Summary Assessment of the relative windiness of afforestation sites has enabled the development of site classification for species selection, growth rate and wind hazard. The current development of a quantitative classification of wind risk requires a method of estimating the probability of strong winds. The relationship between wind strength and probability is commonly derived from several years of measurements at the site of interest. This is not practical when assessing wind risk for a land use rather than a single engineering structure. However, the extreme value distribution that represents the relationship between strength and probability can be derived from the mean wind climate, as represented by parameters of the parent Weibull distribution. The relationship between these parameters and previous estimates of relative windiness developed from tatter flags is explored using wind measurements from reference sites in upland Britain. A strong relationship is established between a modified geographic predictor and the Weibull c parameter. Satisfactory predictions of the Weibull c parameter are obtained for a number of validation sites using this regression and the parameters are used to derive estimates of the 1:50 year return period wind speed. A relationship between predicted and measured wind speed is also found using a dataset derived from low elevation Meteorological Office sites, but an offset is found. It is unclear whether this reflects a difference between the wind climates sampled, the effects of local surface roughness, or differences in equipment sensitivity. Further work is required to extend the method to low wind speed and high roughness sites.

The root systems of Fraxinus excelsior and Fagus sylvatica and their competitive relationships

Abstract: Summary Following reports from field foresters on so-called ‘beech regeneration dieback’, the root systems and competitive relationships of sapling-stage mixtures of beech (Fagus sylvatica L.) and ash (Fraxinus excelsior L.) were investigated in vivo and in vitro. Ash has a plate-root system from an early age, and beech a heart-root system. The distribution of ash roots is determined by competition for light under a closed overstorey of beech while the distribution of beech roots changes if there is competition with ash roots. In a replacement series experiment in a greenhouse, interspecific competition for water strongly reduced growth and survival of beech saplings. It is concluded that this competition for water could be the reason for beech regeneration dieback on sites where it occurs.

The influence of canopy cover and other factors upon the regeneration of Scots pine and its associated ground flora within Glen Tanar National Nature Reserve

Abstract: Summary The aim of this study was to investigate the relative importance of selected environmental variables on the density of natural Scots pine regeneration at Glen Tanar National Nature Reserve. Data were collected, from quadrats spread throughout the forest, on both pine sapling densities and the composition of the ground vegetation. The effects of disturbance by fire, windthrow from gales and scarification were also studied. The canopy cover and soil wetness were found to have the largest statistical associations with the density of pine saplings, with interactions occurring between them. The density of pine saplings of less than 1 m tall was found to have a quadratic relationship with canopy cover, peaking at 20 per cent cover. The densities of taller classes of pine (> 1 m) were inversely associated with canopy cover. Soil wetness appeared to be an important determinant of the density of pine less than 1 m tall. Poorly drained sites contained higher densities of pine saplings. Canopy cover and soil wetness were also found to be the main factors associated with the species composition of the areas studied.

Statutory measures for the protection and enhancement of the urban forest in Guangzhou City, China

Abstract: Summary Urban-forestry management in China, due to its unique political and social environment, exists in a different legislative and administrative regime. An evaluation of the current statutory and quasistatutory administrative instruments can throw light on the status and prospects of the country’s urban-forestry programme. Guangzhou City, the largest municipality in South China, with a high green cover, was chosen for a case study. The assessment includes measures with a bearing on the planning, development, management and protection of urban trees and urban landscapes, at the national, provincial and municipal levels. Four national laws accompany a plethora of administrative documents to define an overall urban-forestry framework, and to demarcate the relevant authority and responsibility at different planes of the government hierarchy. The provincial measures play a secondary role in filling some gaps in the national legislation, with the main contributions being in allocating financial responsibilities and laying down punitive and compensatory legal procedures. Operations-related measures have been developed comprehensively at the municipal level with practical guidelines for their implementation. Special issues related to weaknesses, room for improvement, and general implications for Guangzhou and other cities are discussed. The lack of clearly defined enforcement agents and generally lax enforcement have weakened the otherwise quite comprehensive legislative measures. The widespread illegal use of urban parks for commercial and other activities by government departments has undermined statutory integrity. The continued destruction of trees due largely to government projects signifies that the relevant laws are widely disregarded and ignored by civil servants. The legal vacuum of liability related to hazardous trees needs to be promptly filled. The overwhelming domination of the government with negligible participation by citizens contrasts vividly with urban forestry in other countries and deprives the programme of the necessary popular support.

A dynamic analysis of windthrow of trees

Abstract: This paper considers the dynamics of the tipping of a tree due to a gust of wind superimposed on a steady wind. The resistance of the root system to the rotational motion of the tree is known from tree-pulling experiments. A gust of wind generates an impulsive load on the system and hence the dynamics of the tree may be modelled. An empirical formula which relates the speed of a gust of wind and its duration to the mean wind speed is used to determine the mean wind speed necessary to overturn a tree. Realistic mean wind speeds are found for trees such as Sitka spruce.

The effects of information on Danish forest visitors' acceptance of various management actions

Abstract: Summary Two national surveys show that information on why a given forest management practice has been implemented (e.g. fencing) can make that specific practice more acceptable to the forest visitor. In addition different ways of disseminating information are investigated. The surveys on the forest preferences of the Danish adult population are aimed at providing an input for the multiple-use oriented forest management teams who have to take the wishes of the population and their visitors into account. Data were collected through representative postal questionnaire surveys of 2826 individuals (response percentage 89.4 per cent) in 1977/1978; and from 2916 individuals (response percentage 83.7 per cent) in 1993/1994. The ‘Experimental Method’ was used: black-and-white photos and verbal stimuli which were pairwise or groupwise alike except for one factor were used to represent different forestry and recreation-related topics.

Natural regeneration of Corsican pine (Pinus nigra subsp. laricio) in Great Britain

Abstract: Corsican pine (Pinus nigra subsp. laricio (Poir.) Maire) (nomenclature according to Farjon (1998)) is an important species in lowland Britain, at the last census in 1979 it occupied 47 251 ha (Locke, 1987). It grows best on warm sunny sites in the south of Britain (Fourt et al., 1971) and is not planted on elevated sites with a cool, wet climate because it is liable to attack by Brunchorstia pinea (Gremmeniella abietina) (Read, 1967; Lines, 1985). Many foresters believe that Corsican pine does not regenerate in Britain. This impression is probably caused by the contrast with Scots pine (Pinus sylvestris L.), the other major lowland pine, which regenerates freely. In addition, the fact that most Corsican pine is managed on short rotations of 55–65 years does not provide suitable conditions for the species to regenerate. However, evidence from field observations and the literature suggests that Corsican pine does have the capacity to regenerate naturally in Britain. This was noted by Brown (1967) who summarizes the problems as ‘much seed is destroyed by squirrels, in the full cone on the tree; more is doubtless devoured on the ground by squirrels, pigeons, pheasants, finches or mice: some may survive till germination time, but fail then because of unsuitable temperature, moisture, or ground cover’. There are many accounts of successful natural regeneration of Pinus nigra throughout Europe (Parde, 1962; Cucchi, 1965; Paci and Romoli, 1992; Menguzzato, 1994; Vallauri et al., 1997). Natural regeneration of Corsican pine (Pinus nigra subsp. laricio) in Great Britain

The effect of three species of Eucalyptus on growth and fecundity of the Eucalyptus snout beetle (Gonipterus scutellatus)

Abstract: Summary The Eucalyptus snout beetle, Gonipterus scutellatus, was first detected in NW Spain in 1991, in the area with the largest European eucalypt plantations. Feeding preferences in the field and the effect of three species of Eucalyptus on larval development, survival, and adult fertility were studied. It was estimated that individuals of G. scutellatus consume 1.2‐1.7 g of fresh biomass in Eucalyptus cinerea and E. globulus during their development. Diet had a significant effect on larval survival and rate of development, the least suitable tree species being E. obliqua. Nevertheless, females fed with these eucalypt species or with an alternated diet containing all three eucalypts, did not produce significantly different numbers of larvae. In the field, G. scutellatus showed a marked preference for E. globulus, E. longifolia, E. grandis and E. propinqua, and completely avoided other species.

Browsing by fallow deer (Dama dama) in young broadleaved plantations: seasonality, and the effects of previous browsing and bud eruption.

Abstract: Summary Browsing by fallow deer was assessed in young broadleaved plantations over 2 years. Most plantations were small and all were between 4 and 9 years old. Browsing was highly seasonal in occurrence, being rare in winter and most frequent in early summer. This seasonal pattern varied between tree species ‐ cherry and rowan were browsed earlier than oak and sweet chestnut. The probability of browsing was also influenced by the previous browsing history of a tree; trees that were browsed in one month were more prone to browsing subsequently. Trees browsed in year 1 were also more likely to be browsed the following year. Browsing was also related to the extent of budding of individual trees, with trees that were in leaf being more prone to damage than those without leaves erupted.

Physical and hydrological impacts of blanket bog afforestation at Bad a′ Cheo, Caithness: the first 5 years

Abstract: Summary This study was established to investigate the effects of blanket bog afforestation on the physical properties of the peat and on the quantity and timing of runoff. Three afforestation treatments, representing the options for planting on very deep blanket bog, were used: Sitka spruce (Picea sitchensis), given phosphorus (P) and potassium (K) fertilizers at planting, lodgepole pine (Pinus contorta), given no fertilizer until P was needed to relieve deficiency in year 3, and a 50:50 mixture of the two species, given P at planting. Afforestation treatments reduced annual runoff by 7 per cent compared with an unploughed, unplanted but drained control. Runoff was reduced in spring and summer but not in autumn or winter. Compared with the drained control, peak flows were increased by afforestation while the baseflow component of total flow was reduced. Sediment accumulated at a similar rate (0.016 kg dry matter per metre of drain per year) in the afforested treatments and the drained control. Afforestation lowered the water table significantly compared with the control, but there were no differences among the three treatments. Peat water content was reduced within 4 weeks by the ploughing operation that preceded planting in the afforestation treatments. In the first 5 years the undisturbed ground between plough ridges subsided by 11 (±2) cm while the tops of ridges and the bottoms of furrows subsided by 18 (±2) cm and 5 (±1) cm, respectively. Subsidence increased with proximity to a drain, from 9 (±1) cm, 10 m from the drain edge, to 16 (±2) cm, 0.1 m from the drain edge. Even in the control treatment, the perimeter drain caused a subsidence of 2 (±1) cm 10 m away, and 11 (±5) cm 0.1 m from the edge. The rate of subsidence slowed down with time and, after the third year, further subsidence only occurred in summer. Peat depth markers showed that subsidence of the ground surface was caused by consolidation of peat throughout its thickness, rather than solely by shrinkage of the drained layer. Half of the subsidence near the centre of the afforested plots was caused by compression of peat at depths of over 1.5 m. Drainage system design and maintenance needs to take account of the differential subsidence beneath planted and unplanted ground. Where drains run from planted onto unplanted ground they need to be deep enough to allow for a 0.6o reduction in gradient in the first 5 years, increasing to 1o or more subsequently. When considering pre-commercial felling to restore peatland habitats, areas of pre-thicket age first rotation forest can be considered candidates because, at this stage, the peat has not been altered to a degree which would hinder rewetting and consequent habitat development.

Variation among seed sources of silver birch in Scotland.

Abstract: Summary The results of five provenance trials of silver birch (Betula pendula Roth.) in Scotland are described. These comprise: (1) two trials laid out in the 1970s and 1980s comparing improved Finnish stock with unimproved Scottish material, and (2) three recently established provenance trails of Scottish seed sources for which 1‐2 year results are available. Use of planting stock of Scandinavian origin is not advisable in Scotland, or probably elsewhere in the UK, as it has poor survival and grows slowly (i.e. volume growth at years 16‐22 is only 7‐26 per cent of the Scottish controls). It is particularly prone to climatic damage due to late spring frosts. Recently established trials of seed sources from Scotland and Northern England showed significant variation among Scottish populations in growth and dates of flushing and senescence. Variation in 1-year height growth between the fastest and slowest growing provenances was about 30 per cent. Some geographic patterns of variation in early height growth and flushing were apparent among different seed sources at year 1, but equally there was considerable variation among sources which could not be simply attributed to location. A preliminary study of isozyme variation suggests that: populations are unlikely to have passed through severe population bottlenecks; that there is no consistent evidence for inbreeding within the populations; extensive gene exchange occurs between populations by pollen and/or seed flow; and there is no evidence for more than one postglacial origin for the nine populations tested. There is a need for more information on provenance performance among indigenous populations of birch in order to give useful guidance to nurseries, foresters and policy makers.

The advantages and disadvantages of the application of genetic engineering to forest trees: a discussion

Abstract: Summary This review briefly examines moral arguments for and against genetic engineering (GE) technology in trees, finding equal support for both sides of the debate. Subsequently, environmental costs and benefits are reviewed. Due to the complexity of tree‐environment interactions, clear-cut answers are not forthcoming. However, some environmental risks are deemed to be potentially serious; the nature of such risks and possibilities for their containment are described. Assessment of such risks should be undertaken by interdisciplinary teams including ecologists and microbiologists, with the onus being on biotechnological scientists to prove, to the satisfaction of consumers, that the technology they produce is safe. A well-functioning regulatory mechanism is necessary if benefits of GE technology are to be maximized while keeping to a minimum any associated risks.

The analytical use of stress waves for the detection of decay in standing trees

Abstract: Summary This paper describes the use of an innovative method to detect decay in trees. The criteria for the project required the decay detecting process to be non-invasive and to provide an estimation of the position and extent of decay. A measured impulse from a hammer blow was used to produce stress waves within the stem of a tree. The stress waves were detected by an accelerometer and the resulting amplitude-time signals were recorded on a portable oscilloscope. The time of flight and attenuation of the stress wave were determined and the signal was transformed on a computer hosting a commercial software package. Six measurements were taken between different coordinates positioned around the circumference of a tree stem that was suspected of containing decay. Analysis of the amplitude spectrum of the stress waves provided an indication of the presence of sound or decayed wood between each set of co-ordinates. Estimation of the position of decay in the stem was achieved by calculating a short-time Fourier transform on each temporal signal and mapping the path of the stress waves through sound wood. The information produced by the analysis of stress waves was confirmed by felling the tree.

Enhancing public participation in state forest management: a user council survey

Abstract: Summary User councils were introduced in all Danish state forest districts in 1995 with the objective of enhancing the influence of local users on forest management. Based on a survey among user council members in 1998, this paper examines to what extent the members of forest user councils perceive that they have gained influence over the management of state forests and whether perceptions vary with organizational or district affiliation, occupation or gender. Results show that the present structure and procedure of the user councils is quite balanced, as none of the stakeholders seems significantly more or less satisfied with the procedure than others. However, the objective of enhancing the influence of local users is only partly achieved, as only half of the respondents have a clear perception of having gained influence, whereas almost one-third reported that they did not experience increased influence.

Models of crown architecture in Quercus petraea and Q. robur : shoot lengths and bud numbers

Abstract: Summary The shape of shoot-length frequency distributions in oak can be described for each branching order using a limited number of mathematical models. In general, shoot lengths decreased with increasing branching order. The shape of these frequency curves is very similar among different species. The number of subapical buds showed very little variation, whereas that of median buds was normally distributed. The possibilities for using frequency distributions of shoot lengths and bud numbers for structural models are discussed.

Site quality and stand structure in Pinus halepensis forests of north Greece

Abstract: Summary Pinus halepensis forests depend partly on the relatively adverse drought conditions prevailing in the area and on human management through the centuries. A major and decisive factor for the establishment and maintenance of these forest ecosystems is fire, which defines their expansion. The degradation of these forests as a consequence of constant pressure by natural and human-caused fires, grazing and clearance, has led to the formation of scrub associations of the Cisto‐Micromerietea. The phytosociological study of the area and the analysis of the vegetation table showed the existence of three site quality types I, II and III. The structure of stands in these site types is mostly even-aged, occurring after a fire, in age classes 10‐20, 25‐35, 40‐50 and 60‐80 years. The biggest mean diameter, total basal area and mean dominant height of the overstorey, occurred on the more soil-fertile site type I.

Temperature and provenance as two factors affecting Eucalyptus nitens seed germination.

Abstract: The European Union (EU) cellulose pulp marketshows a deficit in eucalypt pulp that is being com-pensated for mainly by the import trade fromSouth American countries. Improving the produc-tivity of plantations by breeding and bettermanagement practices will result in an improvedemployment of the areas where

Forest management for recreation and conservation: new challenges

Abstract: Summary New demands are being made by society on forest managers. They are obliged to implement silviculture practices which prioritize recreation and conservation over wood production. The decision-making about priorities is taken by the political authorities, who depend upon preliminary studies by multidisciplinary teams and on an objective knowledge of the social demands. Development for recreation, adapted to each individual case, depends upon an analysis of the environmental conditions. The conservation objective implies, for a fraction of the forests in question, the creation of reserves of various types: integral or managed, etc. For the remainder of the landscape, an adapted sylviculture will promote biodiversity, carried out by a precise ecological zoning, the management of landscapes and the protection of patrimonial riches. This paper emphasizes the specific problems of the Mediterranean region, where the restoration of degraded zones generally implies a different approach from that adopted in the countries of central and northern Europe. Implementing a forestry policy that focuses on conservation and recreation ‐ even when limited to only a part of the totality of forests ‐ is not cost-free. It assumes complementary financing if the income from the sale of wood cannot cover management costs.

Crown architecture in Quercus petraea and Q. robur: the fate of buds and shoots in relation to age, position and environmental perturbation

Abstract: Summary Shoot and bud dynamics of peripheral crown portions of mature pedunculate and sessile oak trees (Quercus robur L., Q. petraea (Matt.) Liebl.) were monitored over almost three vegetation periods. The formation and shedding of buds and extension units (eus) was mapped in the form of simplified drawings. Branches were additionally subjected to manipulative treatments simulating herbivore (defoliation at different times, loss of certain bud types) and abiotic damage (artificial acid rain) and the effects on branch architecture analysed. Branch characteristics, such as branching order and age structure, had a large influence on the growth and dynamics of peripheral branch portions, even greater than that of the manipulative treatments, with the exception of spring defoliation and shoot tip removal, which led to increased shoot shedding. In order to quantify the observed changes in crown structure with time, new measures were introduced: the shedding ratio corresponds to the number of shed eus divided by the total number of eus present and produced since a given starting point. The vitality ratio was defined as the total number of eus produced in 1 year, divided by the total number of eus shed during the same time. The vitality ratio could thus be ‐ on a small scale ‐ the quantitative measure of Roloff’s vitality classes (Roloff, 1987, 1988, 1989).

Valuing forest land under hazards to crop survival.

Abstract: Summary Forest crops face various hazards throughout their life, which are often not accounted for in formal valuation calculations. One technical problem is what value should be included for successor crops, when the time of replacement depends on the incidence of hazards, rather than on a planned rotation. Relatively simple algebraic manipulations make it possible to solve this problem, provided that a reasonable estimate of hazards through the crop’s life can be made. The method can be adapted to any number of hazards, any profile of probability, and to circumstances where the crop replacement strategy depends on the fate of the initial crop.

Experiences in participatory planning of designated areas: the Bavona Valley in Switzerland

Abstract: Summary The paper describes a regional forest planning experience in a designated area situated in an alpine environment, notable in particular for its natural features and landscape characteristics. The first part illustrates recent developments in forest management in Switzerland with particular emphasis on the role of regional forest management planning. In the second part, planning procedures are described in detail, highlighting participatory aspects. The final part assesses the validity of such a tool in the context of designated areas.

Socio-economics of nature protection policies in the perspective of the implementation of Natura 2000 Network: the Spanish case

Abstract: Summary Spain’s experience in nature protection is analysed from the perspective of the implementation of a new EU-wide nature protection network: Natura 2000. Natura 2000 aims at a harmonized nature protection policy at the European level. It opens the opportunity for a review of the existing protection policies. Due to its wide range of climates, Spain will be the leading country in the Natura 2000 protected area. Following the holistic approach of sustainability ‐ environmental, economic and social ‐ as defined in UNCED (Rio de Janeiro (1992), Helsinki (1993) and Lisbon (1998)) special attention is given to the distribution of the costs and benefits of the protected-areas policy. Several socio-economic proposals for an improved protected-areas policy are developed.

Species and seasonal variability in the sensitivity of seedling conifer roots to drying and rough handling.

Abstract: More than 90 per cent of the conifers raised for forest planting in Britain are grown in open nurseries. During the interval between lifting from the nursery and planting in the forest, seedlings are exposed to a range of stresses including desiccation and physical damage. Once lifted from the protective environment of the soil, roots are more readily damaged than shoots. Insley and Buckley (1985), for example, demonstrated that the shoots of Betula pubescens (Ehrh.) and Fraxinus angustifolia (Vahl) were more resistant to desiccation than the roots, while Species and seasonal variability in the sensitivity of seedling conifer roots to drying and rough handling

Fungal disease and parasitism in Panolis flammea during 1998: evidence of change in the diversity and impact of the natural enemies of a forest pest.

Abstract: Summary The population of Panolis flammea in Northern Scotland was severely affected by fungal disease during the summer of 1998. The fungi, Entomophaga aulicae, Nomuraea rileyi and Beauveria bassiana are recorded from P. flammea and the infection of the larvae by these fungi occurred in a density-dependent fashion. The incidence of parasitism was different between the two sites studied; however, there was no difference in the parasitism between high and low density host populations. This is the first study to demonstrate that the diversity and impact of fungal pathogens affecting P. flammea is much greater now than in the past.

Discrete event simulation model for purchasing of marked stands, timber harvesting and transportation

Abstract: Summary Research on customer-oriented timber procurement has basically consisted of the modelling of the separate elements of procurement chains, especially of the machinery used. In the present study, the procurement process is modelled by using the discrete-event simulation technique, including formulation of the characteristics of marked stands, the purchasing process, timber harvesting, and transportation. The model is supposed to be an artificial timber procurement environment for both research and education purposes. The initial theoretical model is developed further on the basis of empirical data. The model developed was found to function properly in the testing environment. The functioning of stand and tree generators was particularly convincing.