Research Plan




Aim of the project Structure of the project
Description of individual tasks Structure of the research group
International contacts Post graduate training
Forestry and conservation of forest-dwelling species in Finland Plans for publication of the results and other means of knowledge transfer
Material resources and support available for the project General significance and application of the results
References Recent publications




Forestry and conservation of forest-dwelling species in Finland

Finnish economy continues to be largely based on forestry. Finnish forestry is also one of the best managed in the world. Inevitably, intensive forest management has changed the structure of both forest stands and entire landscapes in boreal forests. Old-growth forest has almost disappeared in the southern part of Finland and the area of old-growth has drastically declined in the north. Loss and fragmentation of previously more continuous habitats, including virgin old-growth forests, forest fire areas, areas with long continuity of decaying wood and old deciduous trees, are the primary threats to the survival of forest-dwelling species (Kouki 1993, Virkkala 1996). Since the vast majority of forests in Finland are managed, conservation area networks alone cannot provide adequate protection for biological diversity in this country. Maintaining and restoring the structural forest elements and processes in managed forests is critically important.

Recent changes in the practices of Finnish forestry represent positive steps toward an ecologically sustainable forestry, with a chance of retaining at least the majority of original forest-dwelling species in this country, as well as helping to maintain the original forest functions. In 1994, Finnish Forest and Park Service and Finnish Environment Institute initiated landscape ecological forest planning in Finland. In 1996 more than 100,000 ha of state-owned forest is covered by landscape ecological plans and the area is increasing rapidly. A landscape ecological forest plan comprises an area of 10,000-50,000 ha of forest mosaic, which can include both managed forests and conservation areas. The aim of the plan is to guide forestry, conservation and other uses of forest resources in such a way that the natural species and ecosystems of the area are maintained in the long run (Hallman et al. 1996). In a landscape ecological forest plan, isolated old-growth forest fragments, key habitats and protected areas are connected to each other via ecological corridors and stepping stones, which are expected to facilitate dispersal. Unfortunately, the ecological knowledge on which these plans can presently be based is fragmentary and limited. The planning process is presently based on an intuitive vision of the type of forest landscape that is favourable for both the maintenance of biodiversity and economical forestry. What is lacking is scientific understanding of the population biological processes that underpin the long-term survival of endangered forest-dwelling species.


Aim of the project

The primary aim of this project is to increase our understanding of the ecology and dynamics of forest-dwelling species in boreal forests, and thereby introduce the presently lacking element of population biology and ecology into the landscape ecological forest planning. We anticipate that the results of this project are applicable to forestry and conservation of both preserved and managed forest areas. This project will produce objective tools for the management of biodiversity in boreal forests.


Structure of the project

The task of combining population biology with landscape ecological planning in boreal forests is vast - so little is known of the many crucial dynamical processes, and how they interact with the structure of the landscape. We have divided the present project into 5 different tasks (see table below).

Each task comprises a semi-independent smaller project, with its own responsible principal investigator. The first three tasks are focused on a particular empirical research theme. Taken together, they cover much of the ecology and population biology that we consider to be most relevant for landscape ecological planning in boreal forests. The fourth task is specifically focused on mathematical modelling of the empirical results, with the aim of providing a common scientific framework for synthetizing our knowledge, for relating it to ecological theory, and for generating practical tools for forestry and conservation.

The fifth task has a special function. We will employ here a more experienced ecologist (at post doctoral level) familiar with forest ecology, forestry and conservation. The responsibility of this person is to feed the practical needs of forestry and conservation into this project, and to facilitate the distribution of the results of the project into forestry and conservation. We envision that the person to be employed will develop personal working relations with many key organizations and individuals in forestry and conservation in Finland, as well as among research ecologists working in boreal forests in Finland and elsewhere.

Tasks of the project

  Task#
Three specific empirical research tasks 1. Population biology of the trembling aspen (Populus tremula) and the taxa associated with it in boreal forests

2. The significance of reserve networks, ecological corridors, stepping stones, and source-sink dynamics in maintaining biodiversity in boreal forests

3. Landscape ecology in highly fragmented boreal forests

Modelling 4. Modelling of the dynamics of forest-dwelling fungi, plants and animals
Knowledge transfer 5. Knowledge transfer to forestry and conservation


Description of individual tasks

button Task 1: Population biology of the trembling aspen (Populus tremula) and the taxa associated with it in boreal forests
button Task 2: The significance of reserve networks, ecological corridors, stepping stones, and source-sink dynamics in maintaining biodiversity in boreal forests
button Task 3: Species diversity in small old-growth forest fragments: the effect of the time since isolation
button Task 4: Modelling of the dynamics of forest-dwelling fungi, plants and animals
button Task 5: Knowledge transfer to forestry and conservation

Structure of the research group

This project has been formulated by a group of ecologists working in the University of Helsinki (UH), in the Finnish Forest Research Institute (FFRI), in the Finnish Environment Institute (FEI) and in the Finnish Forest Industries Federation (FFIF). These ecologists are the responsible leaders of the individual research tasks. Their salaries are not included in this application.

The project leader is professor Ilkka Hanski (University of Helsinki)

Task leaders:

Name
Mr Juha Siitonen
Dr Raimo Virkkala
Professor Ilkka Hanski
Dr Suvi Raivio
organization
FFRI
FEI
UH
FFIF
Task #
Task 1
Task 2
Task 4
Task 5

The five tasks define five semi-independent research projects, defining clearly the duties and responsibilities of the PI's as well as the students and researchers employed by and associated with this project. The five PI's form the board of leaders of this project, and they will meet regularly to monitor and discuss the progress of individual tasks and to make sure that necessary contacts are maintained between the tasks. In the initial stages of the project, the board of leaders will make any decisions concerning the ongoing planning of the project. During the course of the project, the board of leaders organizes meetings, workshops and visits, and towards the end of the project the board of leaders helps in Task 5, knowledge transfer to forestry and conservation.

Successful execution of this project calls for a range of expertises, which we have attempted to assemble together as follows:

Population biology and ecology of forest-dwelling fungi, plants and animals

It is essential that the biology of the species we are attempting to preserve in our forests is well known. Unfortunately, this task alone is enormous because of the vast numbers of species involved: there are an estimated 25,000 forest-dwelling taxa in Finland. The next best we can hope to gain is a good understanding of the biology of selected taxa. At present, the species composition of forest-dwelling taxa in Finnish forests in relatively well known, and we have a good understanding of the distribution and overall abundance of selected important taxa, including all vertebrates, beetles and moths. This project involves the following specialists on particular taxa: birds, Dr. R. Virkkala, Dr. J. Tiainen and Dr. S. Raivio; mammals, Dr. I. Hanski; beetles Mr. J. Siitonen; polypores and corticiaceae, Mr. R. Penttilä; lichens and bryophytes, Dr. M. Kuusinen.

Metapopulation biology

Questions about long-term survival of species in fragmented forest landscapes are essentially questions about metapopulation dynamics of the respective species. Professor I. Hanski is an internationally recognized metapopulation ecologist. Among other things, he has edited the two main text books in this field (Gilpin & Hanski 1991 and Hanski & Gilpin 1997, both published by Academic Press). Dr. R. Virkkala, Dr. J. Tiainen and Dr. S. Raivio have all worked on aspects of metapopulation ecology and landscape ecology on a range of forest-dwelling taxa. Dr. I. Saccheri in Prof. Hanski's laboratory is currently working on metapopulation genetics projects, and his expertise will be available for this project when needed.

Modelling of spatial dynamics

Hanski's research group is internationally well known of its contributions to metapopulation modelling (e.g. Gyllenberg & Hanski 1992, Hanski 1994a, Hanski et al. 1995a, Moilanen & Hanski 1995, Wahlberg et al. 1996). We have also the necessary knowledge to develop new approaches to modelling of spatial dynamics.

Landscape ecological planning of forest use

Much of the scientific work on which the present landscape ecological planning in the Park and Forest Service is based has been accomplished by Ms. P. Siitonen and Dr. S. Raivio, who are both involved in this project. Therefore, we know exactly what the present planning procedures involve, what are their strenghts and weaknesses, and hence we should be in a good position to strengthen the scientific basis of the landscape ecological forest planning.

Contacts to forestry and conservation

Dr. S. Raivio has recently been appointed in the Finnish Forest Industries Federation. She is therefore in the very best position to facilitate knowledge transfer between this project and forestry. Dr. R. Virkkala works in the Finnish Environment Institute and is an expert on a range of forest conservation issues, such as representativeness of nature reserve networks. Ms P. Siitonen works in the Finnish Environment Institute. She has been developing practical methods of biodiversity assessment for FPS and the Forestry Centre Tapio and knows well of their needs in this field.


International contacts

Professor Hanski has well-established international contacts among ecologists and population biologists. Among other things, he serves in the board of editors of 5 international ecological journals. Dr. Tiainen has wide contacts among European bird ecologists. He was elected in the European Bird Census Council general meeting in 1995 to the Executive Committee for a 3-yr period. He has close contacts to several European wildlife and ornithological research institutes. Mr. Siitonen is well connected among entomologists especially in the Nordic countries. He has good contacts and ongoing co-operation with Russian entomologists in the Republic of Karelia. Dr. Virkkala has several contacts among bird ecologists and among ecologists interested in forest conservation issues in Europe. In particular, he has been in close contact with several European researchers studying the white-backed woodpecker Dendrocopos leucotos, which is an endangered species in Finland and in many other European countries. Dr. Raivio has several international contacs both in the field of ecology and forestry. Through the CONNECT network (European conservation institutes research network) she has participated in biodiversity research. Forestry contacts include ecologists working in the forest industries.

We plan to hire a foreign post doctoral researcher in Task 4, largely because we anticipate that no strong Finnish candidates are available, but also to strengthen international contacts in this project. One responsibility of the person to be hired in Task 5 (knowledge transfer) is to strengthen our contacts with similar projects in Europe (especially in Scandinavia) and in North America.


Post graduate training

The five Ph.D. students working in this project, of which funding is applied for three students with this application, will all be recruited to the LUOVA graduate school at the Department of Ecology and Systematics in the University of Helsinki. This arrangement will guarantee that the students' work will be properly supervised and monitored, and that they will receive appropriate training.

Of the five organizations involved in this project, only one (Department of Ecology and Systematics, UH) is involved in post graduate training. The other organizations have Ph.D. students but these students receive their academic training and degree from some University department. Some of the PI's involved in this project have received their own degree relatively recently. For these reasons, they have no Ph.D. students who have completed their degree during the past three years.

Ph.D. students who have completed their degree during the past three years (supervisor):

Maija-Liisa Prinkkilä (Hanski)
Marko Nieminen (Hanski)
Jari Heikkilä (Hanski).


Recent publications

The following is a short list of key publications by the PI's that are related to this project and were published during the past three years:

Hanski, I. 1997. Habitat destruction and metapopulation dynamics. In: Pickett, S.T.A., R.S. Ostfeld, M. Shachak, G.E. Likens, (Eds.). Enhancing the ecological basis of conservation: heterogeneity, ecosystem function and biodiversity. Chapman & Hall, New York, in press.

Hanski, I., Gilpin, M. 1997. Metapopulation Biology: Ecology, Genetics and Evolution. Academic Press, London (published in October 1996).

Hanski, I., Hammond, P. 1995. Biodiversity in boreal forests. Trends in Ecology and Evolution 10:5-6.

Hanski, I., Moilanen, A., Pakkala, T., Kuussaari, M. 1996. Metapopulation persistence of an endangered butterfly: a test of the quantitive incidence function model. Conservation Biology 10: 578-590

Kinnunen, H., Järveläinen, K., Pakkala, T., Tiainen, J. 1996. The effect of isolation on the occurrence of farmland carabids in a fragmented landscape. Annales. Zoologici. Fennici 33:165-171

Kinnunen, H., Tiainen, J. 1994. Carabid beetles and landscape structure of agricultural environments - variations at different levels of spatial scale. In J. W. Dover (Ed.). Fragmentation in agricultural landscapes. IALE(UK). Colin Cross Printers, Garstang. 129-136

Siitonen, J. 1994. Decaying wood and saproxylic Coleoptera in two old spruce forests: a comparison based on two sampling methods. Annales Zoologici Fennici 31:89-95.

Siitonen, J., Martikainen, P. 1994. Occurrence of rare and threatened insects living on decaying Populus tremula: a comparison between Finnish and Russian Karelia. Scandinavian Journal of Forest Research 9:185-191.

Siitonen, J., Martikainen, P., Kaila, L., Mannerkoski, I., Rassi, P., Rutanen, I. 1996. New faunistic records of threatened saproxylic Coleoptera, Heteroptera, Homoptera and Lepidoptera from the Republic of Karelia, Russia. Entomologica Fennica 7:69-76

Tiainen, J. 1997. Nine chapters (six co-authored with various scientists) in W. Hagemeier & M. Blair (eds.), The EBCC atlas of European breeding birds. T & A D Poyser, London. (in press).

Virkkala, R. 1995. Bird communities. P. 335-344 in Encyclopedia of Environmental Biology, W. A. Nierenberg (Ed.), Academic Press, San Diego, USA.

Virkkala, R. 1996. Reserve network of forests in Finland and the need for developing the network - an ecological approach (In Finnish with English summary). Suomen Ympäristö 16, 53 p.

Virkkala, R., Rajasärkkä, A., Väisänen, R. A., Vickholm, M., Virolainen, E. 1994a. The significance of protected areas for the land birds of southern Finland. Conservation Biology 8:532-544.

Virkkala, R., Rajasärkkä, A., Väisänen, R. A., Vickholm, M., Virolainen, E. 1994b. Conservation value of nature reserves: do hole-nesting birds prefer protected areas in southern Finland?. Annales Zoologici Fennici 31:173-186.


Plans for publication of the results and other means of knowledge transfer

We will publish the primary scientific results in international journals. Given the significance of the project for forestry and conservation, we will simultaneously make the results available to a wider audience via popular articles. One of the purposes of Task 5 is exactly this, to make sure that the practical implications of the results are made accessible to potential users as soon as possible.

Anju Asunta's research is a literature study in which published literature on boreal forests about landscape ecology and related subjects is gathered and analyzed. The primary aim of this study is to produce a synthesis of what is already known of the requirements of the fauna in boreal forests. Subjects like the natural structure and dynamics of boreal forests and the role of ecological corridors and stepping stones as dispersal routes are thoroughly studied, and the relevant literature is assembled to a data base that can be used by other members of this research group. The second aim is to erect a scientific framework for operational landscape ecological planning in order to maintain and even increase the biodiversity in commercial forests. This framework is compared with the already established plans of the Finnish Forest and Park Service in the form of a case-study. The framework is improved according to the experiences and knowledge of the Finnish Forest and Park Service staff.


Material resources and support available for the project

The following institutions are involved in this project, with a brief description of the facilities that they provide:

Institute persons involved facilities
UH-DES Hanski, Pakkala, Moilanen, Saccheri DNA-laboratory, GIS, offices
UH-Lammi   laboratories, offices, subsidized board & lodging, vehicles, technical equipment
FEI Virkkala, P. Siitonen GIS
FFRI J. Siitonen office
FPS   landscape ecological planning area, Kainuu study areas, aerial photos, forestry data, data analysis in Ilomantsi, assistants for field works in Kainuu
RCFNP   offices, field work assistants, laboratories

Abbreviations:

UH-DES, University of Helsinki, Department of Ecology and Systematics
UH-DAZ, University of Helsinki, Department of Applied Zoology
UH-Lammi, University of Helsinki, Lammi Biological Station
FEI, Finnish Environment Institute
FFRI, Finnish Forest Research Institute
FPS, Forest and Park Service
RCFNP, Research Center of the Friendship National Park

The empirical projects will be conducted in the following study areas:

Task#
Name location
Lammi (including Evo) and Padasjoki southern Finland 1,2
Kainuu north-eastern Finland 1, 2, 4a
NN Russian Karelia 1, 2
Ilomantsi eastern Finland 2, 4a

4a is P. Siitonen's project (see Appendix 4).


General significance and application of the results

This project increases ecological knowledge of the population dynamics of species living in fragmented forest ecosystems, and the project produces tools for landscape ecological forest planning. The results obtained and the methods developed here can be used both in the planning of conservation area networks and in the planning of sustainable forest management. Results can be used for the assessment of the representativeness and complementarity of present conservation area networks. The population models and connectivity analyses produce knowledge about and practical tools for the selection of stepping stones and corridors to complement the present conservation area networks.

The modelling tools developed in Task 4 will be integrated in the GIS-based forest planning system of the Forest and Park Service. These models can be used e.g. for the comparison of alternative landscape ecological plans. Data collected in the field and the modelling results will be used in the design of landscape ecological plans for the study areas in eastern Finland.These plans can then be compared with plans drawn by the Forest and Park service for the same areas. In northern Karelia, results are used in the delimitation of the Koitajoki conservation area, as a part of the landscape ecological plan for that area. The experiences from the study areas in Kainuu and Ilomantsi should have great value in the planning of the Green Belt between Finland and Russia, and for the development of landscape ecological forest planning in Russian taiga.


References

Akçakaya, H. R., and S. Ferson. 1992. RAMAS/Space User Manual: Spatially Structured Population Models for Conservation Biology. Applied Biomathematics, New York.

Andren, H. 1994. Effects of habitat fragmentation on birds and mammals in ilandscapes with different proportions of suitable habitat. Oikos 71:355-366

Ås, S. 1993: Are habitat islands islands? Woodliving beetles (Coleoptera) in deciduous forest fragments in boreal forest. Ecography 16:219-228.

Barkman, J. J. 1958: Phytosociology and ecology of cryptogamic epiphytes. 628 pp., Van Gorcum, Assen.

Bibby, C. J., Burgess, N. D., Hill, D. A. 1992: Bird census techniques. Academic Press, London.

Blumenthal, B. E. 1942. Studier angÕende aspens förekomst och egenskaper i Finland (Untersuchungen über das Vorkommen und die Eigenschaften der Espe in Finnland). Silva Fennica 56:1-63

DeGraaf, R. M., Miller, M. I.(Eds.)1996. Conservation of faunal diversity in forested landscapes. Chapman & Hall, London.

Ehrnström, B., Walden, H. W. 1986. Fauna vård i skogsbruket. Del 2-Den lägre faunan. Fälths trykkeri. Värnamo, Sweden. 351 pp.

Esseen, P. A., Ehnström, B., Ericson, L. & Sjöberg, K. 1992. Boreal forests the focal habitats of Fennoscandia. In: Hansson, L. (Eds.), Ecological principles of nature conservation: 252-325. Elsevier Applied Science, London.

Falinski, J. B. 1986. Vegetation dynamics in temperate forests (Ecological studies in Bialowieza Forest). W. Junk Publ., Dordrecht.

Foley,P. 1997. Extinction models for local populations. In: Metapopulation biology. Hanski,I; Gilpin,ME (Eds.).Academic Press, San Diego, 512 pp.

Gilpin,M.; Hanski,I.(Eds.). 1991. Metapopulation Dynamics: Empirical and Theoretical Investigations. Academic Press, London.

Gyllenberg, M., Hanski,I. 1992. Single-species metapopulation dynamics: A structured model. Theor. Popul. Biol. 42(1), 35-61

Hallman, E., Hokkanen, M., Juntunen, H., Korhonen, K. M., Raivio, S., Savela, O., Siitonen, P., Tolonen, A., Vainio, M., 1996. Alue-ekologinen suunnittelu (In Finnish, Landscape ecological planning). Metsähallituksen metsätalouden julkaisuja 3/1996, 47 pp.

Hanski,I .1994a. A practical model of metapopulation dynamics. J. Anim. Ecol. 63(1):151-162

Hanski, I. 1994b. Patch-occupancy dynamics in fragmented landscapes. Trends Ecol. Evol. 9:131-135

Hanski, I. 1997. Habitat destruction and metapopulation dynamics. In: Pickett, S. T. A., Ostfeld, R. S., Schachak, M., Likens, G. E.(Eds.).Enhancing the ecological basis of conservation: heterogeinity, ecosystem function and biodiversity. Chapman & Hall, New York. in press.

Hanski, I., Hammond, P. 1995. Biodiversity in boreal forests. Trends in Ecology and Evolution 10:5-6.

Hanski, I., Gilpin, M.E. (Eds.) 1997. Metapopulation Biology: Ecology, Genetics & Evolution. Academic Press, London.

Hanski, I., Pakkala, T., Kuussaari, M., Lei, G. (1995a). Metapopulation persistence of an endangered butterfly in fragmented landscape. Oikos. 72:21-28

Hanski, I., Pöyry, J., Kuussaari, M., Pakkala, T. (1995b). Multiple equilibria in metapopulation dynamics. Nature. 377:618-621

Hanski,I., Moilanen,T., Pakkala,T., Kuussaari,M. (1996). Metapopulation persistance of an endangered butterfly: a test of the guantitative incidence function model. Cons. Biol. 10:578-590

Helle, P., Mönkkönen, M. 1990. Forest successions and bird communities: theoretical aspects and practical implications. In A. Keast (Ed.), Biogeography and ecology of forest bird communities. SPB Academic Publishing bv., The Hague. 299-318

Hokkanen, H., Törmälä, T., Vuorinen, H., 1982. Decline of the flying squirrel Pteromys volans L. populations of Finland.. Biol. Conserv. 23:273-284

Hudson, W. E.(Ed.) 1991. Landscape linkages and biodiversity. Island Press.Washington, D.C.

Järvinen, O., Väisänen, R. A. 1979. Changes in bird populations as criteria of environmental changes. Holarct. Ecol. 2:75-80

Järvinen, O., Väisänen, R. A. 1983a. Confidence limits for estimates of population density in line transects. Ornis Scandinavica. 14:129-134

Järvinen, O., Väisänen, R. A. 1983b. Correction coefficients for line transect censuses of breeding birds. Ornis Fennica. 60:97-104

Kotiranta, H., Niemelä, T. 1981. Composition of the polypore communities of four forest areas in southern Central Finland. Karstenia 21:31-48

Kouki, J. 1993. Luonnon monimuotoisuus valtion metsissä - katsaus ekologisiin tutkimustarpeisiin ja suojelun mahdollisuuksiin. Metsähallituksen luonnonsuojelujulkaisuja. Sarja A 11. 88 s.

Kuuluvainen, T. 1994. Gap disturbance, ground microtopography, and the regeneration dynamics of boreal coniferous forests in Finland: a review. Ann. Zool.Fennici 31:35-51

Kuusela, K., Salminen, S. 1991. Forest resources of Finland in 1977-1984 and their development in 1952-1980. Acta For. Fennica 220:1-84

Kuusinen, M. 1994. Epiphytic lichen flora and diversity on Populus tremula in old-growth and managed forests of southern and middle boreal Finland. Ann. Bot. Fennici. 31:245-260

Kuusinen, M. 1995a. Cyanobacterial macrolichens on Populus tremula as indicators of forest continuity in Finland. Biological Conservation. 75: 43-49

Kuusinen, M. 1995b: Epiphytic lichen diversity on Salix caprea and Populus tremula in old-growth forests of Finland. Mitt. Eidgen¸ss. Forsch.anst. Wald Schnee Landschaft 70:125-132

Kuusinen, M. 1996. Epiphyte flora and diversity on six common old-growth forest tree species in southern and middle boreal Finland. Lichenologist 28 (in press).

Kuusinen, M., Jääskeläinen, K., Kivistö, L., Kokko, A., Lommi, S. 1995. Indikaattorijäkälien kartoitus Kainuussa (Indicator lichens in old-growth forests of Kainuu). Metsähallituksen luonnonsuojelujulkaisuja A39:1-24 (In Finnish).

Lawton, J. H., May, R. M.(Eds.) (1994). Extinction rates. Oxford university press, New York. 233 pp

Lindenmayer, D.B., Possingham, H. P. (Eds.) (1994). The risk of extinction. The Australian National University, Canberra. 204 pp.

May, R. M., Lawton, J. H., Stork, N. E. (1994). Assessing extinction rates. In: Extinction rates.: Lawton, J. H., May, R, M. (Eds.). Oxford University Press, New York, .

Moilanen, A., Hanski,I (1997). A parameterized metapopulation model: the incidence function model complemented with environmental factors. manuscript. Pakkala, T. in prep. Bird community composition in old-growth forests in Evo, Lammi. Metsähallituksen Luonnonsuojelujulkaisuja (Finnish with English summary). Penttilä, R. 1994. Kainuun vanhojen metsien kääpälajisto (Polypore flora of old-growth forests in Kainuu). Metsähallituksen luonnonsuojelujulkaisuja A35:1-32 (In Finnish).

Pettersson, R. B., Ball, J. P., Renhorn, K. E., Esseen, P. A., Sjöberg, K. 1995. Invertebrate communities in boreal forest canopies as influenced by forestry and lichens with implications for passerine birds. Biol. Conserv. 74: 57-63

Pressey, R. L., Humpries, C. J., Margules, C. L., Vane-Wright, R. I., Williams, P. H. 1993. Beyond opportunism: key principles for systematic reserve selection. Trends Ecol. Evol. 8:124-128

Pulliam, H. R. 1988. Sources, sinks, and population regulation. American Naturalist 132:652-661

Pulliam, H. R. 1996. Source-sink dynamics. In: Pickett, S. T. A., Ostfeld, R. S., Schachak, M., Likens, G. E.(Eds.).Enhancing the ecological basis of conservation: heterogeinity, ecosystem function and biodiversity. Chapman & Hall, New York. in press.

Rassi, P., Kaipiainen, H., Mannerkoski, I., Ståhls, G. (Eds.) 1992. Uhanalaisten eläinten ja kasvien surantatoimikunnan mietintö (Report on the monitoring of threatened animals and plants in Finland) in Finnish with English summary. Valtion painatuskeskus, Helsinki. 328 pp.

Renvall, P. 1995. Community structure and dynamics of wood-rotting Basidiomycetes on decomposing conifer trunks in northern Finland. Karstenia 35:1-51

Rukke, B., Midtgaard, F. 1996.The importance of scale and spatial variables for the fungivorous beetle Bolitophagus reticulatus (L.) (Coleoptera, Tenebrionidae) in a fragmented forest landscape. In: Midtgaard, F.: The significance of fragmentation of boreal forests for the occurrence of selected Coleoptera. Dr. Scient. Thesis, Division of Zoology, Department of Biology, University of Oslo, Norway.

Schelhas, J., Greenberg, R.(Eds.)1996. Forest patches in tropical landscapes. Island Press, Covelo, California.

Siitonen, J. 1994. Vanhan haavikon uhanalaiset. Metsäntutkimuslaitoksen Tiedonantoja 523:87-94

Siitonen, J., Martikainen, P. 1994. Occurrence of rare and threatened insects living on decaying Populus tremula: a comparison between Finnish and Russian Karelia. Scandinavian Journal of Forest Research 9:185-191

Simberloff, D. 1992. Do species-area curves predict extinction in fragmented forests. In: Whitmore,TC; Sayer,JA (Eds.). Tropical deforestation and species extinction. Chapmann & Hall, London. 153 pp.

Syrjänen, K., Kalliola, R., Puolasmaa, A., Mattsson, J. 1994. Landscape structure and forest dynamics in subcontinental Russian European taiga. Ann. Zool. Fennici. 31:19-34

Temple, S. A. 1986. The problem of avian extinctions. Current Ornithology 3:453-485

Tiainen, J., Martin. J., L. Pakkala, T., Piiroinen, J., Solonen, T., Vickholm, M., Virolainen, E. 1980. Efficiency of the line transect and point count methods in a South Finnish forest area. In H. Oelke (Ed.), Bird census work and nature concervation. Dachverband deutscher Avifaunisten, Göttingen. 107-113

Tiainen, J., Vickholm, M., Pakkala, T., Piiroinen, J., Virolainen, E. 1983. The habitat and spatial relations of three Phylloscopus warblers and the coldcrest Regulus regulus in southern Finland. Ann. Zool. Fennici 20:1-12

Tiainen, J., Vickholm, M., Pakkala, T., Piiroinen, J., Virolainen, E. 1985. Impact of the amount of edges and habitat diversity on the breeding forest bird community in southern Finland. in K. Taylor, R. J. Fuller & P. C. Lack (Eds.), Bird census work and atlas studies. BTO, Tring. 231-241 pp

Tiainen, J., Toivanen, J., Kallela, K., Oja, S.1996. Influence of modern forest management on breeding forest bird communities in southern Finland. Manuscript.

Tikka, P. 1954. Structure and quality of aspen stands. I. Structure. (In Finnish with English summary.). Comm. Inst. For. Fenniae 44(4):1-31

Tilman, D., May, R. M., Lehman, C. L., Nowak, M. A. (1994). Habitat destruction and and the extinction debt. Nature 371, 65-66.

Virkkala, R. 1996. Reserve network of forests in Finland and the need for developing the network - an ecological approach (In Finnish with English summary). Suomen Ympäristö 16, 53 p.

Virkkala, R., Rajasärkkä, A., Väisänen, R. A., Vickholm, M., Virolainen, E. 1994a. The significance of protected areas for the land birds of southern Finland. Conservation Biology 8:532-544.

Virkkala, R., Rajasärkkä, A., Väisänen, R. A., Vickholm, M., Virolainen, E. 1994b. Conservation value of nature reserves: do hole-nesting birds prefer protected areas in southern Finland?. Annales Zoologici Fennici 31:173-186.

Wahlberg N., Moilanen A., Hanski I. 1996. Predicting the occurence of endangered species in fragmented landscapes. Science 279:1536-1538

West, D. C., Shugart, H. H., Botkin, D. E. (Eds.) 1981. Forest succession. Concepts and applications. Springer Verlag, New York.

Whitmore, T. C., Sayer, J. A. (Eds.) (1992). Tropical deforestation and species extinction. Chapmann & Hall, London. 153 pp

Wiens, J. A. 1989a. The ecology of bird communities. Vol. 2. Processes and variations. Cambridge University Press, Cambridge.

Wiens, J. A. 1989b. Spatial scaling in ecology. Functional Ecology 3:385-397