Nature based management of beech in europe a multifunctional approach to forestry

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The objectives of this work package are to disseminate and discuss relevant information concerning the results of the Nat-Man project to the different interest parties, to decide upon the implications of the findings on management of beeches and forests, and, consequently, produce a set of guidelines and policy recommendations for sustainable forest management. The guidelines include the main "take-home messages" from each work-package in the Nat-Man project. They are the outcome of an iterative process between work-package leaders and core end-users (policy makers, forest practitioners and researchers). The inputs from core end-users were primarily achieved through a series of workshops held at the final Nat-Man conference in Denmark, where the guidelines were discussed in "practice meets research sessions". Typically 8-15 persons participated in each session. The main messages have been published in 6 small guidelines written in a clear and straightforward way to "people out there". One overall guideline aims towards policy recommendations and the other 5 guidelines cover important topics of the Nat-Man project. The guidelines are oriented towards practice - thus fitting in nicely with all the other dissemination activities of the project. These include the publication of 59 working papers, scientific papers (approx. 48), newsletters, workshops, a book summarising and synthesising the main findings from the Nat-Man project (to be published in Elsevier), and the final Nat-Man conference. To reach a largest and widest audience as possible an Internet home was developed (www.flec.kvl.dk/natman). Here, the newsletters, working reports, management guidelines and other publications are disseminated to all end-users and made available for download.

Present-day forest composition and genetic structure is strongly influenced by past history. Beech has increased its natural European range throughout the last 10 000 years and occurred together with many combinations of tree species in the past. The aim of the research was to document the changing distribution of beech during the Holocene and describe the past and present forest types that contained beech. Methods for assessing the distribution of beech included: pollen diagrams that contained significant records of beech (2% threshold - crudely equivalent to one tree in 50 being Beech within the surrounding 5 km of the collection site). These were collated from the European Pollen Database (EPD), the published literature, and personal contacts. 116 data points were grouped into 5 age categories: <1000, 1000-3000, 3000-5000, 5000-7000 and >7000 years BP. Latitude and longitude for each site was obtained from the EPD, published papers or an atlas, and the data-points were mapped using distinctive symbols for each age category. Using this base map, a sequence of four time-slice scenarios was reconstructed for 7000, 5000, 3000 and 1000 years ago. Data from the point samples were interpolated over the European landscape with consideration given to topography. Methods concerning forest types included: samples selected at 1000-year intervals up to the present day from most of the sites that were included in the distribution map database. The proportions of the following 14 arboreal pollen types were calculated for 326 data points: Abies, Acer, Alnus, Betula, Carpinus, Corylus, Beech, Fraxinus, Picea, Pinus, Quercus (deciduous), Quercus (evergreen), Tilia, and Ulmus. The 326 data points from all time periods were clustered into 7 forest types using the total sum of squares method. Euclidean distance between samples was chosen as the distance measure. The findings indicate 5 separate centres of beech distribution 7000 years ago, all in mountainous areas in Italy, Spain, Swiss/France, Balkan and Greece. However, 5000 years ago, four populations begin to spread - the Spanish population had become extinct. 5000 to 3000 years ago beech expands rapidly in Europe, with a maximum in the number of new sites showing rapid population increase. For the first time during the Holocene, beech begins to become established in sites away from the mountains. Long-distance colonisation and expansion are apparent with pollen evidence for populations in southeast England and southern Sweden. The rate of expansion slows down between 3000 and 1000 years ago. One possible explanation is that most of the available habitat has been colonised, but climatic explanations are also possible. Comparison with current distribution maps of beech shows little change during the last 1000 years. The seven forest types generated by the cluster analysis were named after the two or three most abundant pollen types. The types are pollen assemblages rather than stands of trees and are best interpreted as average forest composition within a plot of several kilometres radius. Betula-Beech-Corylus: This forest type has the second highest mean Beech content and at present is the commonest forest type to include Beech in Scandinavia. Peak abundance was at 1000 BP. Pinus-Beech: This forest type is one of two that is dominated by Pinus pollen, much of which can be of long-distance origin. This forest type increases in importance through time and is characteristic in mountainous regions of central and northeastern Europe. Picea-Abies-Beech: This forest type with co-dominance of three tree species first developed 4000 years ago and has had its stronghold in the Czech Republic with some outposts in Switzerland. Beech-Abies: This classic Beech forest type dominated central and Western Europe between 4000 � 2000 BP, but has recently declined in importance. This forest type has the highest mean Beech content and its recent decline reflects a general reduction in the central European populations of Beech during the last 2000 years. Quercus-Beech-Corylus: This forest type is dominated by deciduous Quercus species and contains almost as much Carpinus as Beech. It has always maintained a southerly distribution and been a constant feature in Bulgaria. Alnus-Quercus-Beech: This forest type has a centre in the Swiss Alps but is widely spread through Europe. The high values of Alnus partially reflect the bias towards wetland sites where pollen is preserved. Beech-Quercus woodland also often survives close to poorly drained areas that were deemed unsuitable for cultivation. Pinus: This forest type has increased in importance through time, particularly in Bulgaria and Spain. Recent planting has spread it further north as well. Beech is only present in small amounts on landscapes dominated by Pinus pollen.

The present study is pioneering in terms of its complex approach to investigating intra- and inter-specific competition in beech and ash seedling growth in response to climate change in simulated regenerating natural forest gaps. Simulations were performed by temperature-regulated closed-top-chambers. Eight chambers were used in a factorial design with replicate treatments of [CO2] x temperature x light flux x competition design. [CO2] was ambient levels or + 360 ìgmol mol-1. Temperature was ambient levels or + 2.8 degrees Celsius. Light flux at the top of canopies was 25% or 8% of outdoor levels 1.75m above the ground (i.e. at the outdoor plot). Relative to more realistic open-field measurements (8 m above the ground) the two chamber light flux levels were 16% and 5%. There were clearly visible effects by the light and carbon dioxide treatments, and an obvious interaction between temperature and carbon dioxide. The studied climate treatments and competition designs suggested that the predicted climate change during this century of 2-3 degrees Celsius warmer air and a doubling of atmospheric carbon dioxide concentration will improve the competitive capacity of ash seedlings relative to beech seedlings in the regeneration of natural mixed beech-ash forests in Europe. It was demonstrated that an increase in temperature was the most important component in helping ash compete better with beech with a concomitant rise of [CO2] and temperature. Beech on the other hand responded more to light flux than ash. Some climate change scenarios induced ash seedlings to grow taller than beech seedlings, and at the same time attain a larger leaf area, and a larger total biomass. The advantages for ash were found particularly in the darker regions. As judged from the present study, the most likely scenario for the future climate in Europe will improve ash regeneration below an old canopy relative to beech regeneration, where it will sometimes even surpass beech, so that when a gap is formed, and the time for definitive competition to dominate the mature mixed forest arrives, a shift from beech towards ash is likely. With the existing scenarios for global climate change during this century it is of vast importance to know how these changes may affect forestry. The present study indicates that interaction between climate variables and competition can move the advantage from one major forest species to another. This should be valuable information to the forest manager. The next step, however, would be to include soil water, nutrition and more than one year of exposure and competition in future studies.

The objectives of the research were to investigate microclimatic conditions, biogeochemical processes and mycorrhizal abundance in gaps of different sizes in natural forest ecosystems as well as managed forest stands where nature-based forestry was applied. Changes and interactions were examined, with focus on differences between processes within the open gap and under the closed canopy. The specific objectives were: - To determine the influence of gap-size on nutrient cycling and soil water in European beech forests; - To determine the mycorrhizal activity/abundance in different regeneration gaps in European beech forests. The research provides results on temperature regimes, soil water, nutrient cycling and mycorrhizal abundance in and around gaps in different beech forests in Denmark, Slovenia and Hungary. Findings indicate that: - The main influence of gaps on soil processes at stand level seems related to gap area per ha forest stand rather than the size of individual gaps; - Soil temperatures were only slightly higher in gaps than under closed canopy in natural forests with abundant advanced regeneration, and the difference between gap and surrounding forest gradually disappeared as seedlings were released; - N mineralization rates tended to be higher in gaps than in the surrounding forest, but extreme increases did not occur after gap formation; - Gap formation led to significant changes in soil moisture during the growing season; - Concentrations of nitrate were significantly higher in gaps than in the surrounding forest and in longer periods exceeded the threshold value for nitrate in drinking water (11.3 mg NO3-N l-1); - Due to higher nitrate concentration in soil solution and higher water fluxes, leaching of N from gaps was higher than from under closed canopy; - Gap size appeared mainly to affect soil temperatures; - In recently established gaps there were lower numbers of ectomycorrhizae types, vital ectomycorrhizal roots, old and non-viable-mycorrhizal roots, and lower species diversity than under closed canopy and the edge of the gap. The research has contributed substantially to the European knowledge base on biogeochemistry in natural forests and forests regenerated in gap formations. A fairly large number of natural and man-made gaps were studied with variable intensity in beech forests of Denmark, Hungary and Slovenia. Such a large number of gaps have not previously been included in studies of water and nutrient dynamics. Results should thus help obtain a better understanding of natural forest ecosystems and to provide a reference for nature-based forestry.

The objective of the research was to evaluate the combined ecological and economical implications of nature-based management systems in European beech forests, with respect to tree regeneration, coarse woody debris (CWD) biodiversity, nutrients, profitability, and other anticipated end-user questions. Two simulation models, i.e. Regenerator and FORSPACE, were used in a number of scenarios that simulate nature-based management of beeches. Regenerator is a stand level regeneration model while FORSPACE predicts larger scale and long-term consequences of different alternatives of natural-based management of beeches. The Regenerator model was adjusted to include 13 silvicultural systems defined in cooperation with forest managers in Denmark, Germany, and Slovenia and tested in each of the three countries. In addition, a few selected silvicultural systems were replicated in Denmark and Germany with variations in the browsing level, resulting in a total of 51 scenarios. FORSPACE was set up to simulate developments of beech stands when management is aimed at converting even-aged forests to a more natural, irregular structure. It considers what strategies and regimes are appropriate to achieve this and what ecological and silvicultural outcomes will be. In FORSPACE, scenarios were developed for UK, The Netherlands, and Hungary. From scenario analyses with Regenerator it can be concluded, that the uncertainty about the choice of a silvicultural model for nature-based management of beech in Europe remains. The scenarios did not clearly point at a specific strategy for conversion of even-aged to uneven-aged management of beech forests. But neither did they identify any limitations in those systems. From the scenario analyses with FORSPACE, the results show that model can be used to realistically simulate the development of beech stands under a range of conditions and different silvicultural treatments and that it can be used to determine the outcome of different forest management regimes for European beech forests. For the UK and The Netherlands results show that various regimes can be used to convert even-aged beech stands. A successful approach could be to harvest some of the forest earlier and some later than normal (extending the rotation for the final crop trees), especially because this can maintain a reasonably high stocking and gradual harvest of trees over time. Furthermore, the scale of gap cutting used for conversion has a profound effect on the stand structure generated. Changes in the forest composition generated during the conversion will have knock on effects in terms of tree seed production and thus the potential for natural regeneration of different species. A new and important aspect of the model is that it provides outputs that can be used to assess the consequences of a management regime on biodiversity, particularly the number of associated species of fungi, mosses and higher plants on coarse woody debris (dead logs). For example, it indicates that there is a tendency to find more associated species when beech is managed on an extended rotation (of up to 200 years) as this leads to a higher input of dead wood. However, it should be noted that this measure is scale dependent: the larger the forest considered the greater the number of species that are likely to exist. Although this is still valuable information, it makes it difficult to provide general guidelines for management regimes intended to promote biodiversity. Finally, the model can also be used to demonstrate the potential trade-off between biodiversity gains and timber-quality where beech is managed on an extended rotation. In particular, the model can be used to assess the potential development of red heartwood formation in mature beech trees, which is an additional aspect to a reduced harvest where an extended rotation is used. The model indicates that where the rotation age is extended to 200 years, there is a strong increase in the probability of red heartwood formation. This can include up to 30 - 40% of the harvest, compared to only 1 - 5% when rotation ages of 120 - 150 years are used. FORSPACE will be used in future studies on the impact of forest management on forest dynamics and biodiversity.

The continuing flow of energy through any ecosystem depends upon maintenance of nutrient supplies to the primary producers and since there is only a limited input of nutrients from outside, a balanced cycle within the ecosystem is essential. The objectives of the research on nutrient storage in coarse woody debris (CDW) were: - To identify the role of beech CWD in nutrient storage; - To determine the relationships between beech-CWD dimensions, age, decay state and physical-chemical characteristics. The physical and chemical characteristics of beech CWD were studied in selected forest reserves in the Denmark, Hungary, The Netherlands and Slovenia. Findings indicate that the determined or calculated time for decay differed in different sites: in Hungary the decay phase 6 (most decomposed) was reached in average in 30 years after death, in Slovenia the calculated time for decay was over 52 years, in the Netherlands decay phase 5 was reached in 30 years, while in Denmark the presumed time for total decay was over 50 years since death. During decomposition, CWD underwent considerable structural and chemical changes, certain components decayed more rapidly than others, the wood became soft and cracked and the density steadily decreased. In all study sites C : N, C : S ratios and pH declined with increasing decay phase classes, while moisture, N, S and P concentrations rose with the decay phase. An increase of concentrations of N, S, P and a decrease in C : N ratio might be applied as indicators for decomposition phases. From nutrient concentration in CWD, its biomass per ha, time for decay and its role in nutrient cycling in the studied sites was extrapolated. The common conclusion was that CWD not only contributes to biodiversity by its specific dead wood habitat, but also by creating relatively moisture and nutrient-rich microsites that provide specific terrestrial habitats.

The research focused on producing a tool to help analyse the microeconomics of different management regimes of beech forests. The goal was to enable evaluation of the marketable and non-marketable costs and benefits. The fundamental economic state variables were data on silvicultural operations, wood prices and expected assortments. Economic data were supplied from Denmark and Slovenia. Two types of theoretical sensitivity analyses were carried out using the model: Shifts in wood quality and the cost of leaving coarse woody debris (CWD). With regard to wood quality, the findings indicate that quality is a key variable to the profitability and can influence the stumpage price function dramatically. A change of 5 - 10 percent-point from lower quality to higher results in a stumpage price rise of 25-50 percent at the most. The large upside rise is due to a price premium on size and especially quality. Deterioration has the same effect, but in the adverse direction. It can be explained by the relative frequency of the quality logs for large diameters. It is doubtful whether the quality will improve or deteriorate immediately after conversion from even-aged forestry to uneven-aged forestry and the impact will therefore most probably be a "sneaking effect" of the conversion. The immediate effects being saved regeneration cost and within short time a more even liquidity and improved flexibility. With regard to the cost of leaving coarse woody debris, findings indicate that aiming for a quarter of the naturally present CWD (i.e. 25-30 cubic metres) would require around one cubic metre of new CWD per hectare per year, e.g. 10 cubic metres every ten years. In comparison with the results from employing a low-end wood quality scenario, this equals a loss in NPV of around 2,000 Euro, an annual cost of 40 Euro per hectare. This cost of leaving CDW is in the order of 5-10% of the total net present value.

The objective of the study was to develop an integrated model of gap regeneration in beech forests, able to evaluate the consequences of forest management systems on tree regeneration and biodiversity at the stand level. Regenerator was created as a regeneration model for beech forests that can be used to study the effect of a number of processes on regeneration, i.e. competition between individual saplings and their interaction with the biotic and abiotic environment. The model Regenerator was used to calculate a number of scenarios to investigate alternative silvicultural methods for conversion of even-aged beech stands to uneven-aged management in three different regions in Europe. Regeneration in gaps was an important parameter, but the model is flexible enough to include other management options. The database used did not, however, allow for predictions of regeneration to a precision that is useful for forest management planning. Regenerator is therefore more a scientific and educational tool than a planning tool. The regeneration predicted with Regenerator in the scenarios resembled in density, height development, and species composition observations by forest managers from those forest types. This qualitative test of the model indicates that Regenerator is a valid representation of the regeneration system and that the model within certain bounds can be used to predict regeneration.

The main goal of assessing contemporary beech management in Europe was to reveal scientific information in support of beech rehabilitation. The specific task was to: - Review the contemporary beech forest management in Europe, in view of various economic, social and ecological conditions; - Get insight into various management methods used, and their impact on biodiversity; - Develop recommendations for improving management methods to rehabilitate beech in European forests. The methods used include: - Review of literature, national statistics and management guidelines; - Regional case studies (11 in total) of actual silvicultural management in particular countries; - Conduct interviews with selected experts (16 in total) in particular countries. The following aspects of beech forest management were described: management principles; policy aims; operational guidelines; species composition; silvicultural regimes; harvesting methods; regeneration methods; fertilisations; weeding; control of pests; coarse woody debris and old-growth management; wild game management; livestock grazing; nature conservation and other special measures; recreation; and management planing. The information gained was reviewed with regard to the possible impacts of contemporary management on forest biodiversity. Further, information about (remnants of) natural and semi-natural beech forests was collected. Their research can offer a treasure of scientific information about structure and dynamics of natural beech forests, their biodiversity and ecosystem processes. Based on this, natural beech forests are seen as an important reference to man-made forests and natural processes can be a good reference to the management practice aiming at rehabilitation of beech.

Regeneration and ground vegetation was studied at selected beech forest research sites around Europe (i.e. Denmark, U.K., Netherlands, Germany, Hungary and Slovenia) to produce general recommendations and guidelines for using natural regeneration in beech forests in forest management. The general objective were: - To determine the ecological differences in gap-phase regeneration and ground vegetation patterns between natural and managed European beech forests; - To identify suitable methods to naturally regenerate beech forests. The results are based on literature review, study of current practices and field research. The general aim of the field research work was to assess the interactions between major ecological factors (light, soil conditions, and microclimate) and ground vegetation and tree regeneration patterns found in natural and managed beech forests. The research showed that within a gap size range of 10-1400m2 in natural beech forests, the relationship between gap size and the spatial distribution and level of key ecological factors (e.g. sun radiation, soil moisture) can be quite variable. This had much to do with the diversity of gap shapes, presence of features in the sub-canopy and under-storey, and topography. Gaps found in managed beech forests, tended to be more discrete and regularly circular. Accordingly, they showed a clearer, steady increase in light and soil moisture levels towards the centre. The light conditions at the forest floor were dramatically higher within gaps - radiation levels were around ten times greater (3% - 30%) and this initiated a strong regeneration response. However, no strong correlation was observed between different radiation levels and the amount of beech regeneration, which suggested that young beech seedlings have the ability to survive in a wide variety of light conditions from heavy shade to open conditions. In this way, the whole gap area, including its surroundings, are potentially suitable for beech regeneration. Gaps clearly provided conditions suitable for the rapid growth of tree seedlings and ground vegetation. Where the ground vegetation became abundant, it generally had negative effects on tree seedlings, competing with them for light and soil nutrients and water, and also by physically suppressing their upward growth and branch development. However, in some cases, the ground vegetation was thought to have positive effects, by providing protection against high temperatures, photo-inhibition, browsing and other harmful agents. At the central and south Europe study sites, up to 70,000 beech seedlings per hectare were counted: beech regularly regenerates vigorously and dominates young stands with little competition. However, at the north and northwest European study sites, beech seedlings were less frequent with counts of <20,000 per hectare. Common problems recognised widely were: (i) excessive browsing (mainly by deer), which not only results in fewer beech seedlings but also reduces the potential quality of those that survive; and (ii) excessive competition from ground vegetation, especially on fertile sites and in larger canopy gaps. Problems distinctive to north and north-west Europe were: (i) scarcity of natural regeneration, related to predation of seeds and seedlings, infrequent mast years, damage to seedlings by late-spring frost and summer drought; (ii) lack of knowledge and experience in using natural regeneration rather than planting; and (iii) lack of sustained long-term management towards natural regeneration, due to fragmentation of ownership and presence of industrialised forestry concepts and practices. A major problem identified in south-Europe was undesirable architecture of beech seedlings, which results in low quality beech timber when applying small-scale management systems. Despite the problems encountered, the results show that natural regeneration of beech can be an effective tool in restocking forests. The gap studies has in this regard provided a basic template for using gap cutting practices in promoting natural regeneration in beech forests managed under nature-based forest management regimes.

The objective of this work-package is to synthesise findings on past- and present-natural dynamics and the contemporary management of European beech forests in a book readily available for end-users - by delivering and evaluating relevant, practical and scientifically-founded policy recommendations and management guidelines for sustainable forest management of beech in Europe. The book will take the form of a scientific review book acting as a key reference point for people interested in natural forests and nature-based forest management. The book will review how European beech forests have developed, how they function naturally, and identify sustainable forms of management based on natural processes and features. The tentative title is: "Beech Forest in Europe: Their History, Ecology and Nature-Based Management". This title and the extended outline of the proposed chapters have been submitted to CAB International (Wallingford, UK) and approved for publishing. The book includes nine chapters: - Chapter 1: The distribution and composition of Beech Forests in Europe; - Chapter 2: Long-term development of European beech forests; - Chapter 3: Historic use and contemporary management of European beech forests; - Chapter 4: Stand dynamics in natural beech forests in Europe; - Chapter 5: Genetic variation in European beech and its relevance for management; - Chapter 6: Biodiversity conservation and management in European beech forests; - Chapter 7: Principles of nature-based forest management; - Chapter 8: Practice of nature-based beech forest management; - Chapter 9: Deadwood in European beech forests. The book will make available an important knowledge base to a wide audience of practitioners and policy makes interested in forests, forest science, and the application of nature-based forestry and conservation management. Accordingly, the book will help facilitate the implementation of the pan-European Forestry Policy and Environment Policy of the European Commission, aimed at developing more natural forests and use more natural forms of forest management.

The objective of the research was to produce an integrated model of long-term stand development in beech forests, able to evaluate the consequences of forestry management systems on tree regeneration and biodiversity. The model was named FORSPACE, which is an acronym for FORest dynamics in SpAtially Changing Environments. FORSPACE is a spatial explicit and process-based model on forest dynamics at the landscape level, describing the processes for autonomous forest succession including dispersal of seeds, germination, establishment, growth and competition, mortality, and grazing by ungulates. Many of the formulations of the processes and the parameterisations are based on the gap model FORGRA. Most of the parameter values are obtained from literature and stored in a MS-Access database. The processes driving autonomous forest dynamics was investigated under standardised conditions and using a case study area of 200ha beech forest. The model dynamics under controlled conditions showed that based on the current initialisation and parameterisation, growth in monoculture and in mixture and forest dynamics are in most cases accurately predicted by the model for trees, shrubs and herb species, including grasses. The case study demonstrated that there are important interactions between the autonomous development of forest factors and landscape forming processes. The autonomous development of the forest is based on dispersion of seeds, establishment, growth, competition, mortality, which may be disturbed by herbivores and fire.

An important feature of natural forests is that they possess high amounts of coarse woody debris (CWD) in all stages of decay and also a high proportion of old, living trees with dead parts. These different CWD types provide important habitats for a diversity of organisms, including fungi, bryophytes, lichens, invertebrates, amphibians, cavity nesting birds and small mammals. The importance of dead wood for forest biodiversity and ecosystem function is well studied from the boreal zone in temperate region, but the knowledge of this topic is much scarcer from temperate broad-leaved forests. It is however estimated that artificial stand structure and disturbance regimes have reduced the availability of CDW considerably (up to 90-98%). The objectives of the research were to: - To identify the importance of beech dead wood as a habitat for bryophyte and fungi biodiversity in different countries (as they are principal agents of wood decay in terrestrial habitats and hence they open up the wood resource for most other organisms living in dead wood); - Produce an ecological succession model for plant and fungal community development on decaying beech dead wood, including the effect of tree related factors (tree size, tree type, and light conditions) for species composition; - Build a species-specific probability matrix based on decay stages, tree size and geographical regions, to provide input for research on scenario analysis to model landscape scale effects of CWD on biodiversity. Altogether 19 forest reserves were selected for this study: 2 in Slovenia, 2 in Hungary, 8 in The Netherlands, 5 in Denmark, and 2 sites from Belgium joined in on a voluntary basis. The criteria for site selection were the following: a) beech should be dominant and b) the sites should represent, as far as possible, the best natural reference of beech forests for the region. Dead beech trees were selected using three criteria: decay stage, size (DBH), and degree of soil contact. Different decay stages and size (DBH) categories were as evenly distributed among the approximately 200 selected trees per country as possible. For all investigated organism groups' presence/absence (binary) data were recorded from the trees. Bryophytes and vascular plants occurring on the selected trees were recorded in each country in summer and autumn 2001. Fungal sporocarps (occurring strictly on dead wood) of selected taxa were recorded on three occasions (spring, late summer, autumn) at each site in the period of 2000-2001. The inventory included the log, the uprooting part of the log, the snag (if present), and the major branches of the crown (if present). The whole dataset contains 161 bryophyte, 170 vascular and 457 fungi species. The main scientific conclusions are the following: - For the species composition of fungi, decay stage was the most important factor at the European scale, while the decay stages had a regional effect on the species composition of bryophytes. - The species pool of fungi was much larger and with higher proportion of rare species than that of bryophytes and vascular plants. - The diversity of the investigated organism groups was high in Slovenia and Hungary, while the forest remnants in Atlantic region were impoverished in dead wood living species, especially for bryophytes. In Denmark there is a potential for restoration of saproxylic fungi in the region. - For the diversity of both organism groups, management induced factors (continuity of dead wood in time, presence of all decay stages, presence of large trees) were more important than climatic factors, although low air humidity can limit the presence of epixylic bryophytes. - The presence of large dead trees is a key factor for maintaining the diversity of dead wood dwelling bryophytes and fungi communities, because several species that have become rare and endangered in Europe depend on large dead trees. For end-users (forest managers and conservation managers) the main messages of this research are: - For the maintenance of the biodiversity of saproxylic organisms it is important to conserve near-natural reserves, where dead wood continuity is long, all decay stages and large trees are present. These sites contain the source populations of saproxylic species in a region, from where they can colonize dead trees of managed forests. - Very important to leave a certain amount of dead wood also in managed forest e.g. trees of low commercial values thinned small trees, broken branches etc. - For saproxylic diversity, the presence of large trees, different decay stages and the continuity of dead wood are essential. - Heterogeneity of dead wood increase saproxylic biodiversity, i.e. the presence of different size categories (large trees, small trees, broken branches), decay stages, dead wood types (snags, logs, branches, uprooted parts).

The objective of the research was to improve the understanding of the characteristics, potential states and processes that operate in near-natural beech woodland reserves. This was achieved by assessing the patterns of tree regeneration, growth, mortality, stand development phases, coarse woody debris, browsing, and natural disturbance in present-day natural European beech forests - with the aim of establishing a reference point for nature-based management of beech forests. This was achieved by completing the following research tasks: - Literature review: Existing materials on natural dynamics in beech forests on the whole European range were collected, i.e. Britain, the Atlantic seaboard of NW Europe, the Baltic region, Central Europe, Eastern Central Europe, and Southern Europe. - New studies based on permanent plot studies extended the knowledge base on natural dynamics by re-recording or establishing a number of permanent plot studies in various beech forest reserves in Europe (26 in total). The plots contained mapped records of individual trees, fallen logs and other features from which information could be gained on tree growth, regeneration, mortality, canopy gaps, dead wood and browsing. - New mapping studies of developmental stages and canopy gaps using maps, aerial photographs and remote-sensed images facilitated new or further recording of forest development stages and canopy gaps in natural beech forests. The use of remote sensing images was a trial to see if this approach could work across the largest expanse of near-natural beech forest in Europe. - New sampling of dead wood levels as this was an area in particular need of development. The literature reviews were important in pulling together existing research on natural beech forest dynamics from across Europe, including information from a number of unpublished studies, less accessible articles, and a range of languages. By presenting the material in English the findings become accessible to a much larger audience. The site-based studies generated important new information on natural stand dynamics and the factors driving this. This included new information on the impact of rare natural disturbances in the form of severe windstorms and ice-breakage events. Not only were the immediate impacts of these quantified, but studies were made of the relationships with the size and shape of trees and the topographical layout of the terrain. In several cases the long-term consequences were also studied based on permanent plots. New information was gained on the growth, mortality and regeneration of trees, levels of dead wood in natural beech forests, and the pattern and long-term dynamics of developmental phases and canopy gaps. The latter included the first study of gap characteristics using satellite image analysis. Other new studies (in Britain) focused on the impact of large herbivores and grey squirrels on beech forests. Most importantly, the establishment and extension of several long-term permanent plot is particularly important in the study of stand dynamics in natural forests, especially because it allows short-term changes to be placed in a long-term context and validates hypotheses developed from other approaches. In combination, the literature reviews and new site-based studies have substantially improved the understanding of the functioning, diversity and stability of forest ecosystems and they provide a scientifically robust means to develop criteria and indicators for sustainable forest management.

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