Ecological Bulletins – serie

Agronomists and ecologists need each other and can learn from each other: agriculture cannot ignore ecological facts, neither can ecology study and conserve ecosystems without understanding contemporary agriculture. With this intention a symposium was organized on "the ecological implications of contemporary agriculture". Five major groups of problems were discussed, related to major elements of the system, each corresponding to a session of the symposium: - the soil and its life;- the plants, especially the unwanted ones;- the fauna, with emphasis on the control of pests;- the nutrient cycles and nutrient budgets (the driving force);- the connecting elements in the rural landscape, related as they are with lotting out.For each subject (session) two invited papers were presented in combination with a varying number of posters. All these papers were encompassed by the opening and closing lectures, which sketch the societal framework within which a more ecological approach of agriculture has to be worked out.In this overview the different elements are rearranged and assessed according to four major groups of problems: lotting out, nutrient management, soil treatment, and weed and arthropod control. It is concluded with some comments on the possibilities to realize more ecological approaches in the framework of farming-practice and EC-politics.

This type of exercise of review and analysis for one component (carbon) of a relatively simple forest type is more generally useful in focusing thought and perhaps field research; critical knowledge gaps identified for pines presumably also apply to more complex forest ecosystems. This volume also serves to illustrate the value of comparative field studies, which in this case were totally unplanned and retrospective.

After 23 formative and producive years as Director of the Abisko Scientific Research Station, Mats Sonesson will retire from his duties. To honour Mats, to celebrate his career, and to thank him for all that he has done to enhance our research, we have asked those scientists who have worked at Abisko within the subject areas closest to Mats' interests, to contribute to this Festschrift which overviews the ecology and environment of the Tornetrask region. Twenty-three chapters written by 41 scientists from 10 countries have been contributed.

Maintaining forest biodiversity by combining protection, management and restoration of forest and woodland landscapes is a central component of sustainable development.Evidence that there are threshold levels for how much habitat loss may be tolerated for viable populations of specialised species to be maintained.Policy-makers, businesses and managers pose questions about how to balance use of renewable forest resources and conserve biodiversity.Examples are presented on how biodiversity assessments can be made.Proposes how the critical gaps in our knowledge identified throughout the book could be filled through macroecological research and international co-operation.

Temperate broadleaved tree species, i.e. Acer platanoides, Carpinus betulus, Fagus sylvatica, Fraxinus excelsior, Prunus avium, Quercus robur and Q. petraea, Ulmus glabra and Tilia cordata, cover a total area of 200 000 ha of forest land in southern Sweden. Despite their documented importance for economy, biodiversity, social aspects and climate change adaptation, little applied research has focused on these forest types. With its 20 papers, this volume presents the latest findings concerning the management of broadleaved forests for multiple goals including aspects of natural resource economy, human health, habitat conservation and restoration, forest production and wood science. Thus, this volume of Ecological Bulletins should be of great interest to all actors involved in sustainable forest management.

In 1985, Abisko Scientific Research Station, situated in the mountains of subarctic Sweden, celebrated the 50th anniversary of its affiliation with the Academy with a symposium entitled Research in Arctic Life and Earth Sciences: Present Knowledge and Future Perspectives. Seven invited papers were presented covering subjects on which research is being done at the station. The abiotic environment of the Arctic, and relateed areas, was described in a series of three papers which discussed mountain climatology, geology and periglacial geomorphology. Four remaining papers considered the biota of the Arctic, from their origins through soil microbiology and plant resource utilisation to population biology. These presented papers are published in this volume together with an additional article discussing Man's direct and indirect influence on the ecosystems of the area, an influence which must, or should be, considered when evaluating environmental data today. This subject is also an important part of the research programme of the station.

This volume presents the results of the project "The Cultural Landscape during 6000 Years", based on interdisciplinary collaboration between six disciplines at Lund University during the period 1982-90. Before this project was initiated, researchers and teachers had long shown an interest in studies of the interaction of society and landscape in a historical perspective, but this interest led to only limited collaboration between the humanities and the natural sciences. One of the enthusiasts behind such collaboration in Lund has been Professor Berta Stjernquist, who also played a major role in designing the present project with its theoretical background and investigation area, the Ystad area.

This volume presents results from an integrated research programme "Effects of Air Pollutants and Acidification" funded by the Swedish Enviornmental Protection Agency (SNV) between 1988/89 and 1992/93. The programme has focussed on the fluxes and environmental effects of acidifying substances and tropospheric ozone in terrestrial, natural ecosystems. During the programme period, 71.5 million SEK were allocated to about 60 projects at different Swedish universities and research institutes.

The scope of this volume is intentionally broad. We review applications of spatially realistic occupancy models and age- or stage-structured demographic models as well as individual-based demographic models. These three main Population Viability Analysis (PVA) approaches initially are compared with other conservation assessment tools in an overview by Akcakaya, Lacy and Sjogren-Gulve and Hanski, with a special chapter on plant PVAs by Menges, all using illustrative examples. Fleishman et al. subsequently outline how nested subsets analyses can help discern focal species, taxa whose habitat requirements may encompass those of larger species groups and can be subjected to PVAs. Kindvall then compares the predictive accuracy of simpler occupancy models versus a democratic model for predicting local extinctions and colonizations in a bush-cricket metapopulation. Thereafter, four case studies which use the three model categories are presented (papers by Berglind, Ebenhard, Lennartsson, and Vos et al.). The volume concludes with Gardenfors' paper on the use of PVAs in the classification of threatened species, and Lacy's presentation of the structure and logic of VORTEX, a widely used demographic and genetic PVA model.

Today dead trees are not only viewed upon as waste and as potential sources of pest species. Instead they have gained an increased attention as key factors for biodiversity in many ecosystems. This change in focus and concern has sparked intense research activities directed to explore the ecological role of dead trees in forest ecosystems. Focus is directed into three main areas: 1) to understand thepatterns of woody debris availability in relation to forest stand dynamics and effects of forestry, 2) the role of woody debris in nutrient and particularly carbon dynamics in forest ecosystems, and 3) the pattern and biology of the utilization of woody debris for a large number of wood-dependent species. This volume summarises the present knowledge and presents a set of case studies on the role of dead wood in boreal forests. The focus is on Fennoscandian boreal forests.However, the results presented have a wide applicability and thus the volume may serve as a general introduction to the importance of woody debris in forest ecosystems.