Folke O. Andersson

European forest ecosystems : building the future on the legacy of the past

Abstract The viability of the many civilisations of Europe has depended, to a very large extent, on an adequate supply of wood. In the Ancient World, this supply was secured through the exploitation of forest reserves, the conquest of new territories and, when these opportunities no longer presented themselves, through the conservation of diminishing resources. Ultimately, civilisations collapsed because of the shortage of wood. Although some silvicultural techniques were known in the pre-Christian era, the scientific management of forests was not widely practised until the late 18th century. It is argued that the controlled exploitation of ‘nature’, on sustained yield principles, only became possible when men came to view the forest, not as a nuisance, an Arcadia or a pagan horror, but as a centre of wood production, a biological factory. The emergence of scientific forestry, however, did not put an end to the exploitation of forest resources. Unregulated felling and traditional practices such as litter raking exerted an insidious, negative influence on the fertility of the soil. The impact of human exploitation has often been underestimated by scientists, in recent decades, in particular, in the context of forest decline. While sustainable management, seen as sustained yield of wood supply, has been practised in forestry for centuries modern ideas of sustainability are broader in scope, embracing all the goods and services of the forest. Increasingly, forests are being managed as multifunctional ecosystems, often for amenity purposes. Forest ecosystem research, which developed from a range of traditional, highly focused disciplines, requires, if it is to make a meaningful contribution to forest management, long-term interdisciplinary studies. It provides the basis for ecologically intelligent management decisions and as such, is central to the development of sustainable forestry management. Central to the successful implementation of research findings is their efficient transfer from the researcher to the manager. If the research community identifies such an interchange as an important part of their duties, it will be a decisive step towards the better use of forests in Europe. It is only by deepening our knowledge of the past, accepting the challenge of the present and acknowledging that, as researchers, we have also a responsibility to communicate with users, that we can foster the growth in wisdom which is fundamental to the wise use of Europe’s forests in the next millennium.

Forest ecosystem research - priorities for Europe.

Abstract European Forest Ecosystem Research Network (EFERN), was set up in 1996 as one result of the Ministerial Conferences on the Protection of European Forests in Strasbourg 1990 and Helsinki 1993 with the aim of promoting ecological research for sustainable forest management. Three plenary meetings were held, each with a specific theme. The results of these meetings have been documented in 10 chapters in a volume with the title ‘Pathways to the wise use of forests in Europe’. The intention was also to give priorities for future forest ecosystem research. In accepting the idea that sustainability includes a multifunctional view of forests, there is a need to find ways of integrating classical forest ecosystem research with biodiversity, water quality and socio-economics. The balancing of the different interests in the forests can be done through planning. From this results also a choice of adequate management methods of the forest resources. The classical stand level in forestry requires now an additional scale — the landscape level. The aim with this paper is to present a concept which attempts to integrate the disciplines involved — ecosystem and landscape ecology and its components. Areas where research efforts are central are also mentioned.

Sustainable tree biomass production.

Abstract Our understanding of forest production and forest growth is incomplete. Present yield tables have not predicted the recent changes in boreal and temperate regions of Europe. We argue that we need to have a causal understanding built upon a mechanistic knowledge of important processes. Using a carbon/nitrogen model as a framework, important components and processes of the forest ecosystem are discussed and the new knowledge needed is identified. Present soil chemistry may not be fully relevant in describing plant/soil relationships. It has been shown that the near-root environment deviates from the conditions described by bulk chemistry. Modelling is discussed as an important tool for increased understanding and prediction. Sustainability of forest production is usually treated from a long-term perspective. Long-term changes can lead to deficiency or even excess of mineral nutrients, which will affect the resistance of the tree or stand to drought, frost as well as attacks of insects and pathogens. Recent ideas of tree vigour or vitality in relation to insects and pathogens are reviewed as a component for understanding production stability in short- and long-term perspectives.

Acidic deposition and its effects on the forests of Nordic Europe

Air pollution effects on the forest of Nordic Europe are analyzed with respect to the situation before and after 1980. No adverse effects were reported up to 1980. Inventories of forest vitality in terms of needle loss or crown density as well as tree growth have been made in parts of Norway and the whole of Sweden. For Norway spruce, needle loss was found to increase with tree age and climatic stress with increasing latitude and altitude. However, decreased crown density was also reported for SW Sweden. Needle loss is a non-specific signal not reacting to air pollution alone. Direct effects of gases such as SO2 are not likely to occur, but high episodic levels of O3 have been measured at a level possibly leading to chronic injuries. Increasing soil acidity is reported from forests in SW Sweden and also from an alpine locality in southern Norway. A differentiation of biological and deposition-dependent acidification has been attempted. A soil acidification of up to 1 pH unit has occurred in both humus and mineral soil layers. An increased release of A1 and heavy metals combined with an increased loss of basic cations is now occurring. Soil acidification probably also results in less available amounts of phosphorus and is suggested to interact with N as limiting forest growth.

Terrestrial ecosystem ecology : principles and applications

Preface Prologue: environmental changes and ecosystem effects - two historical examples Part I. History and Concepts: 1. History of ecosystem research and ecosystem knowledge 2. Ecology, ecosystem and ecosystem science 3. Ecosystem ecology - cornerstones and scientific methodology Part II. Ecosystem Structure and Function: 4. Ecosystem structure - vegetation and soil 5. Energy and water 6. Plant production 7. Soil organic matter processes 8. Organisms and ecosystem processes 9. Element cycles 10. Principles Part III. Ecosystem Dynamics at Different Time Scales: 11. Tectonic to orbital changes 12. Millennial to centennial or postglacial changes 13. Centennial to annual changes Part IV. Applications: 14. Air pollution and forest ecosystems 15. Global change Epilogue: society and terrestrial ecosystem ecology Appendices: Appendix 1. Abbreviations Appendix 2. Glossary Appendix 3. Some useful values and symbols used to represent them Appendix 4. Data on selected ecosystems Index.

Pathways to the wise management of forests in Europe

Ministerial Conference Resolution 6, Strasbourg 1990 The modern concept of sustainable forest management brings to bear a wide range of disciplines on the management of the forest. The goals of management too, have been expanded to re ̄ect the broad demands placed upon the forest by modern, af ̄uent society. While experience in Europe, in recent decades, has demonstrated the bene®ts of international research cooperation, the limited interaction between northern and southern Europe has served to emphasise differences in perspective and priority between regions. Despite this, the awareness of the commonality of problems, at a fundamental level, has highlighted the potential bene®ts to the European Union as a whole, of a truly pan-European network devoted to co-ordinated research into forest ecosystems. European Forest Ecosystem Research Network (EFERN), was conceived, following a meeting of experts from 20 European countries, in Warsaw, Poland, in 1995. The following year, a concerted action, under the EU Food and Agriculture Programme (FAIR), was approved with the objectives of establishing a database of European forest ecosystem research, determining forest ecosystem research priorities for Europe and advancing new multi-disciplinary and multinational research co-operation. The programme has been directed by a co-ordinating group, the composition of which is listed below. Special thanks are due to the secretary of the group, Dr. Roland Berger, who also assisted in editing this volume. An electronic communication system Ð the EFERN database of institutions, projects and scientists is now available, operating on the Internet. The development of priorities for research started with a meeting in Vienna, in 1996, where major research themes were delineated. A thematic framework was then established for analysis of these areas. This framework was built on the fundamental concepts of sustainability, productivity, biodiversity, ecosystem stability±resilience, and multifunctionallity. The contents of this volume has evolved from the ®rst presentation at a meeting in Paris, 1997, through a series of discussions and interactions, using modern electronic communication systems, a ®nal plenary meeting in Sweden in 1998 and a series of meetings of the co-ordinating group. The ®nal paper, in particular, is based on the presentations and results from working groups at a meeting in Sweden 1998. It has developed further after discussions and attempts to identify the appropriate focus of research for the development of sustainable forestry founded on ecological and ecosystem principles with an integration of Socio-economic and planning. Knowledge of the past, which affords an understanding of how previous land-use has in ̄uenced the forests we have today, provides the only ®rm foundation for an effective research programme. This special issue begins, therefore, with an exploration of the impact of history and of the development of ideas on forests and forest management. This is followed, in the same paper with a history of forest ecosystem research, which together form the basis of future Forest Ecology and Management 132 (2000) 3±4

Nutritional status of a Norway spruce stand in SW Sweden in response to compensatory fertilization

The response of a Norway spruce (Picea abies L. Karst.) forest, located in SW Sweden, to various combinations of nitrogen, phosphorus, potassium and dolomite was investigated two and five years after fertilization in a semi-factorial experiment. The aim has been to apply a diagnostic field test as a base for development of suitable composition of compensatory or vitality fertilizers within an area showing nutritional imbalances. Different ways of describing foliar analysis were tested: current needle (C) critical concentrations, Deviation from Optimum Percentage (DOP), and nutrient/N percentage ratios. The graphical Relative Concentration and Content change (RCC) technique was also used. Nutritional status of the control plots showed deficiency in N, P and K. According to the analyses, N alone or N together with P are the growth-limiting elements. Fertilization with N alone induced limitation of K or P. Based on our results, NPK is a suitable compensatory fertilizer at the site. The only significant difference between dolomite and non-dolomite treatments was in Ca and Mg concentrations. The effect of dolomite on Ca and Mg became more evident during the fifth season following fertilization.

Forest Ecosystem Responses to Acid Deposition - Hydrogen Ion Budget and Nitrogen/Tree Growth Model Approaches

In order to assess the nature and the extent of acid deposition in the environment an ecosystem approach is often recommended. What do we then mean with ecosystem approach? - It can be defined as studies on an areal basis of basic ecosystem processes such as primary production, decomposition, mineralization and leaching and the integration of these processes as appearing in the biogeochemical cycling of elements. Preferably, there ought to be a coupling between trophic levels or processes representing different levels in order to describe and analyze the time behaviour of different functional parts of the ecosystem.

AIR POLLUTION IMPACT ON SWEDISH FORESTS - PRESENT EVIDENCE AND FUTURE DEVELOPMENT *

Research during the last five years has provided evidence that there is a long-term influence of air pollutants on forest ecosystems also in the southern parts of North Europe. High loads of acidity, sulphur and nitrogen affect soil conditions, trees as well as other organisms.In South and West Sweden changes in soil acidity (pH) have been registered during the last 60 years. The changes not only occur in the humus layer, but also in the lower part of the mineral soil. These latter changes cannot be explained without the action of strong acids originating from anthropogenic air pollution.Losses of elements like magnesium, calcium and potassium occur and phosphorus become less available to plants. An increased demand for plant mutrients is a consequence of the increased fall-out of nitrogen compounds. Nutrient imbalances of trees seem to be the result. Increased sensitivity to frost and drought as well as insects and pathogens is expected.The increased soil acidity and the eutrophication of soils caused by the continued input of nitrogen contributes to changes in plant communities.If we assume that there are no changes in deposition, land-use and management of the forests in SW Sweden, the better forest soils (brown forest soils) will have a continued acidification of humus and mineral soil layers resulting in high levels of aluminium and low levels of calcium. This will create a critical situation for roots and mycorrhiza. Soils that are already acid may not become more acidified, but will still be subject to losses of essential elements.Critical deposition levels or loads of acids (hydrogen ions) and nitrogen rendering no further deterioration of soils and leaching have been set to 0.1–0.2 keq·ha-1yr-1 for S Scandinavia (present level 1 keq·ha-1yr-1). For nitrogen the critical load is 10–20 kg N ha-1yr-1 (present range 10–25 kg ha-1yr-1).

A European Network in Support of Sustainable Forest Management

Summary Today, sustainability is a political priority at the regional, national, and international levels. It is thought to be attained by political instruments and adequate management. The Ministerial Conference on the Protection of Forests in Europe (MCPFE) is the European forum and reference for sustainable forest management (SFM). The MCPFE has developed criteria and indicators for implementing SFM in Europe. However, there is a gap between policy makers, stakeholders, and researchers with regard to the implementation of the criteria and indicators. A research strategy is proposed by the COST Action E25-European Network for Long-Term Ecosystem and Landscape Research, whereby these gaps are identified, and means for bridging these gaps are suggested. For example, economic and social-cultural criteria and indicators are poorly developed or missing-there is a need for disciplinary and multidisciplinary research. Furthermore, the knowledge base of forests and forestry is well developed in Europe, but could be better communicated to parties involved. Decision-support systems and “landscape laboratories” are suggested as tools for bridging this gap. Furthermore, resources are scarce, so new approaches should be developed that take advantage of existing resources and experiences. Information systems for maintaining and developing long-term information, and increased European collaboration are needed to harmonize existing and future initiatives.