Metapopulation Research Group

University of Helsinki Annual Report 2000

Metapopulation Research Group

Department of Ecology and Systematics

University of Helsinki

Edited by Tapio Gustafsson E-mail and web sites

To contact us via E-mail use [email protected]

Metapopulation Research Group (UH), http://www.helsinki.fi/science/metapop/

Biodiversity in Boreal Forests (FIBRE), http://www.helsinki.fi/science/biobof/

Survival of Species in Fragmented Landscapes (EC´s TMR-Network), http://www.helsinki.fi/science/fragland/

MRG-logo designed by Gergely Várkonyi

2 Contents

Preface 5

Brief history and overview of the MRG 6

Scientific highlights of 2000 9

Structure of the MRG 19

MRG personnel and their research interests 23

Laboratory facilities 48 Helsinki Tvärminne Lammi

Field sites 50 Åland Islands Kuhmo Central Finland Lammi Kilpisjärvi Greenland

Synopsis of the year 2000 56 Budget Publications Theses External visits Seminars, lectures and talks TV, radio and newspapers Teaching and courses Honors and awards Council memberships Meetings organized by the MRG Visitors to the MRG

Prospects for the year 2001 72

3 A mating pair of the Glanville fritillary butterfly (Melitaea cinxia) in the Åland Islands, photo Tapio Gustafsson.

Occupied (filled) and empty (open) habitat patches suitable for the Glanville fritillary in the Åland Islands in the autumn 2000.

4 Preface

The turn of the millenium demarcated the beginning of our new position as one of the centres-of-excellence in research selected by the National Research Council (the Academy of Finland) in 1999. In terms of funding, the most notable change is that we now have one large research grant that replaces several smaller ones. In terms of science, our new status is a big challenge for the next six years! Research in the year 2000 advanced along the paths that had been opened up in the previous years. The section on Scientific Highlights and the individual highlights of particular results and research projects in the section MRG Personnel present a succinct overview of our main achievements. A few projects involving the joint efforts of many students and researchers deserve to be emphasized here. The 4-month long field project in boreal forest in NE China was successfully completed by the end of August, of which a big thanks goes to Mr Antti Below from the Forest and Park Service, who was the field director of the project and who completed a comprehensive census of forest birds in the study area. The Glanville fritillary Team has nearly completed the re-survey of the entire Åland Islands for the purpose of locating all the remaining suitable habitat patches for the butterfly, and the corresponding database has been greatly developed to deal with the range of different types of data now available. Marko Nieminen and Mika Siljander together with a large number of student assistants have done a splendid job. Research on the parasitoids attacking the Glanville fritillary has much expanded and progressed in 2000, the credit of which goes to Saskya van Nouhuys, who continues to share her time between Åland in spring-summer and Cornell in autumn-winter. Two visits were made to the large Estonian island of Saaremaa, to where the Glanville fritillary project is likely to expand in the coming years. The MRG put together a package of undergraduate teaching in the autumn 2000. Many thanks to Tomas Roslin for coordinating our efforts. Finally, the MRG would not function as smoothly as it does without the commitment of Anu Väisänen and Tapio Gustafsson. I trust that the rest of the MRG will gladly join me in a special thanks of the year 2000 to Anu and Tapio! The ranks of junior MRG members have enlarged in 2000. Our warm congratulations to Otso and Meri (girl), to Niklas and Hanna (boy), to Janne and Pirkko (boy) and to Atte and Laura (?). Apart from this express evidence of happiness and trust for the future, I am glad to report that the cooperative and pleasant atmosphere that we have enjoyed in the MRG has remained just the same, thanks to all the students, post docs, research assistants and technicians working in our group. I have said this before but it warrants to be repeated - it has been rewarding to work in the Metapopulation Research Group in 2000.

Ilkka Hanski

5 Brief history and overview of the MRG

Professor Ilkka Hanski has worked on spatially structured populations since the late 1970's. The early work dealt primarily with small-scale spatial population structure, but since the early 1980's the focus shifted to larger spatial scales and to metapopulation dynamics in the sense of assemblages of discrete local populations connected by migration. In 1989, Hanski organized the first international meeting on metapopulation dynamics together with Professor Michael Gilpin (San Diego, UC), which resulted in the first edited volume on the subject (Gilpin & Hanski, 1991, Metapopulation Dynamics: Empirical and Theoretical Investigations, Academic Press, London). This meeting furnished impetus for the conception of the MRG. Ongoing collaboration with Professor Mats Gyllenberg (Department of Mathematics, Turku, Finland) started in 1990, the long-term field project on the Glanville fritillary butterfly was started in 1991, and the first post graduate students and post docs were accepted in the MRG in 1992 and 1993, respectively.

The figure below illustrates the growth of the MRG since 1992:

Currently there are 12 post graduate students and 8 post docs in the MRG, representing 5 different nationalities.

6 The MRG consists of three research teams (Metapopulation Modelling Team, The Glanville fritillary Team, and the Molecular Ecology Team) and three projects of fixed duration (Old-growth forest biodiversity, small mammal population dynamics, and forest canopy insect dynamics). Additionally, the MRG (Hanski) coordinates an European Commission-funded training network (Fragland) in the TMR programme. A more detailed description of the structure of the MRG is presented on page 19.

Academic setting

The MRG is the largest research group in the Division of Population Biology (DPB), Department of Ecology and Systematics, at the University of Helsinki. The permanent staff of the DPB consists of 3 professors and 8 other academic staff. Despite its small size the DPB with several active research groups and researchers has performed well in recent years. The MRG has had an influence on the general direction of research in the DPB, which is now largely focused on spatial ecology, of which metapopulation ecology represents a key area. The DPB established a joint research programme called Spatial Ecology in 1997 (see www.helsinki.fi/ml/ekol/spatial_ecology.html).

Scientific standing

The MRG has established a solid reputation as one of the leading research groups internationally in metapopulation ecology. The two most visible achievements of the MRG are the development of effective modelling approaches to the dynamics of metapopulations living in highly fragmented landscapes and a large-scale empirical research project on the Glanville fritillary butterfly (Melitaea cinxia). The latter started as an ecological project but has subsequently expanded to cover metapopulation genetics and evolutionary biology as well. This field project, which is well known internationally, allows us to test many theoretical predictions and it hence functions as an important interface between theory and empirical research.

7 Strategic goals of the Metapopulation Research Group

· To strengthen our position as the leading research group in metapopulation biology worldwide

· To build up on our current strength in combining modelling with empirical studies

· To integrate genetic and evolutionary studies into the existing strong ecological framework and thereby to promote a comprehensive approach to metapopulation biology

· To facilitate the application of metapopulation biology in landscape-level environmental planning and management and conservation of populations.

Female Melitaea cinxia laying her eggs on Plantago leaf, photo Tapio Gustafsson.

8 Scientific highlights of 2000

Field work on the Glanville fritillary, by Marko Nieminen

Monitoring of the Glanville fritillary (Melitaea cinxia) metapopulation started in the Åland Islands in the autumn 1993 and has been continued ever since. This research is exceptional in its scale, covering an area of 50×70 km2. The habitat patch network in Åland has been under revision since 1998 and this work will finally be completed in 2001, when a highly accurate GPS-based description of all ca. 4000 known habitat patches will be available. These data will allow effective spatial analyses of the monitoring results with GIS-applications. Detailed life table information on the Glanville fritillary has been collected in 2000. These results allow us to define both the key stages in the life cycle when most of mortality occurs as well as the key factors causing the mortality. A study on spatial correlation in overwintering success has been initiated and the first results show large variability between years, subareas of Åland and host plant species. In 2000, a pilot study on habitat patch occupancy of a specialist weevil Gymnetron pascuorum and its parasitoids was conducted. This weevil is specific to Plantago lanceolata, which we have mapped as one of the two host plants of the Glanville fritillary. Gymnetron pascuorum may affect Glanville fritillary’s dynamics, as it is probably a vector of a specialist fungus species. Furthermore, Anna-Liisa Laine has started a study on population dynamics of P. lanceolata and of another fungus, the powdery mildew Sphaerotheca plantaginis. This fungus can cause the death of P. lanceolata leaves and thus affect the survival of the Glanville fritillary larvae.

The Glanville fritillary database and GIS, by Mika Siljander

The construction of the Glanville fritillary GIS (Geographical Information Systems) database was started in 2000. Approximately 2000 GPS-surveyed habitat patches have been differential corrected and converted to ArcView shapefile format suitable for further processing in GIS software. Alongside with converting GPS surveyed habitat patches to a GIS database, we have cintinued to add information on the local butterfly populations (Access 97 database). More than 3500 patches were surveyed in the field in the autumn 2000. The other piece of GIS news is the incorporation of additional spatial data to the database. Weather radar data on 12-hour cumulative rainfall for three summer months in the years 1998, 1999 and 2000 will be added to ArcView shapefile point data. GIS landscape analysis in the Stålsby area is also going on. Digital scanning has been completed for 1985 false color aerialphotographs and we

9 have started to digitize landscape patterns using 1996 orthorectified aerialphotograph. The joint project with the Finnish Forest Research Institute for using AISA (Airborne Imaging Spectrometer) -based aerial photography to describe the Åland landscape has been postponed until summer 2001.

Example of a GPS-surveyed habitat patch converted to GIS.

Research on the parasitoids of the Glanville fritillary, by Saskya van Nouhuys

The Glanville fritillary butterfly is host to two primary parasitoids and several hyperparasitoids in the Åland islands. These parasitoids have significant ecological impact on one another and on the butterfly. In 2000 we continued to work on several long term ecological studies and started to work on some new ones. The yearly intensive spring survey of the primary parasitoid Cotesia melitaearum in the Åland island host populations continued. These data will be used for future host-parasitoid dynamics modelling. Currently we are analysing the pattern and rate of successful colonisation of new populations by the parasitoid using data collected over the last 6 years. We also continued to collect samples for

10 a study of the genetic structure the primary parasitoid and hyper parasitoid populations in the Åland islands. This year we learned more about the natural history of Hyposoter horticola which is exciting because it has implications for parasitoid competition and may be an explanation for what limits the rate of parasitism by this extremely abundant parasitoid. I found that H. horticola oviposits in first instar host larvae just prior to their hatching from the eggs. This may provide a competitive advantage to H. horticola as it will be the earliest possible larval parasitoid, but it provides the species with an extremely short window of opportunity for parasitism. Two students made real progress this year working on parasitoid ecology. The Pro Gradu project of Eeva Punju is to study the competitive interaction between the two specialist parasitoids, C. melitaearum and H. horticola, inside of the host larvae. She characterised the different growth stages of the immature parasitoids and conducted an experiment to measure the outcome and hopefully witness the mechanism of competition among the immature parasitoids. Surprisingly both parasitoid species have persisted so far, and we will not know the outcome of competition until spring 2001. Christian Anton, from Jena University in Germany worked on his diploma project contrasting the behavioural and physiological responses of C. melitaearum to the two host food plant species in Åland, Plantago lanceolata and Veronica spicata. Finally I just began work on two comparative studies of C. melitaearum. One is a comparison of life history characteristics and behaviour of wasps from Åland, where host populations are small and fragmented, with wasps from an area where host populations and habitat patches are much larger. I am also comparing life history characteristics between generations of the parasitoid within Åland because there appear to be different ecological constraints on each of the three generations per year.

An effective simple description of spatially realistic metapopulation dynamics, by Otso Ovaskainen

In 1999, I showed that the threshold condition h>e/c (given by Lande’s extension to the one-dimensional spatially implicit Levins model) applies also to the n- dimensional spatially realistic Levins model, provided that the amount of habitat h is replaced by lM, the metapopulation capacity of the fragmented landscape. In 2000, I continued the work by showing that also the dynamic behaviour of the spatially realistic Levins model is captured by the simple 1-dimensional Levins model.

A key concept is Tt=w/e, the (species- and habitat patch network – specific) characteristic turnover time, describing the average time it takes for the patches to switch between occupied and empty. Here e is the characteristic

11 turnover rate of the focal species, and w is a coefficient depending on the structure of the habitat patch network. The transformation from the spatially realistic Levins model to the one-dimensional Levins model is obtained by scaling the extinction and colonization rates appropriately by the factors lM and w. The great advantage of the existence of the transformation is that it expands the range of validity of the ‘oversimplified’ but widely applied Levins model. Interpreted in an appropriate way, the one-dimensional Levins model may still be considered as a relevant tool to address a range of ecologically interesting phenomena even in the spatially realistic context. The figure gives an example,

where I consider a system of 30 habitat patches shown in panel a. After destruction of 9 patches (the crossed ones), it takes some time for the species to set to the new equilibrium. Panel b shows this time as a function of the new equilibrium state. Time delay is especially long for such species for which the deteriorated habitat patch network is close to the threshold for persistence. In panel b, the continuous line shows the time delay predicted by the spatially realistic model, and the broken line gives the prediction of the (appropriately transformed) one-dimensional model.

Site selection algorithms with spatial dynamics, by Atte Moilanen and Mar Cabeza

Reserve design and site selection algorithms are a new topic for the MRG. The major contribution which we aim for is the inclusion of spatial (metapopulation) dynamics into site selection algorithms. Methods for designing regional reserve networks mostly concentrate on providing maximal representation of species occurring in the region. Representation-based methods however typically consider a static snapshot of species incidences, and the spatial dynamics of the species are ignored. It has been empirically demonstrated that reserves designed using representation do not guarantee another important goal of reserve design, long-

12 term persistence. The question we have studied is: which subset of sites do you select to maximize the long-term persistence of a species living in a metapopulation, given that each site has a cost and the amount of resource (e.g. money) available is limited. We have developed an optimization method, which uses a combination of evolutionary optimization (a genetic algorithm) and local search to find the optimal selection of sites. The quality of each candidate solution is evaluated by using a metapopulation model, such as the spatially realistic incidence function model developed by Ilkka Hanski. The proposed method has been applied to a metapopulation of the false heath fritillary butterfly (Melitaea diamina), an endangered species in Finland. With this data set the proposed estimation method produced intuitively acceptable and consistent results. The figure on the left illustrates typical results; circle color indicates the probability of a patch being included into the optimal site selection when replicating the optimization using parameter values sampled from within multi- parameter joint confidence intervals (black; P>0.95, white P<0.05). Work on site selection continues with M. Cabeza focusing on the issue of spatial dynamics and maintenence of biodiversity, and A. Moilanen focusing on site selection algorithms.

Evolution of host preference and extinction-colonization dynamics, by Ilkka Hanski

Classical metapopulations persist in a balance between local extinctions and the establishment of new local populations at currently empty but suitable habitat patches. Empirical studies of classical metapopulations have demonstrated that the probability of population extinction typically increases with decreasing population size or its surrogate, habitat patch area. The probability of colonization of an empty patch increases with connectivity to extant local populations. Additionally, many other ecological factors have been reported to influence extinctions and colonizations (e.g. Hanski 1999, Metapopulation Ecology, Oxford Univ. Press). On the other hand, there is much less information on possible effects of the phenotypic or genotypic composition of local populations on their turnover, though the proposition that the genotypic composition of populations would influence their turnover is not new - this is the idea of classical group selection. In our research on the Glanville fritillary butterfly with two larval host

13 plants, we have found conclusive evidence for population establishment (but not extinction!) being strongly influenced by the match between the host species composition of an empty habitat patch and the relative host use by larvae in previous years in the habitat patches that were well connected to the target patch (see the figure).

Colonization of Plantago- Colonization of Veronica- dominated habitat patches dominated habitat patches

30 30 683 266 178 136 60 45 21 49 61 9 23 21 45 36 26 42 18 25 127 32

25 25

20 20

15 15

10 10 Colonization rate Colonization Colonization rate Colonization 5 5

0 0 0.0 0.2 0.4 0.6 0.8 1.0 0.0 0.2 0.4 0.6 0.8 1.0

Veronica use in the neighborhood (VR) Veronica use in the neighborhood (VR)

This "colonization effect" could be due to spatially variable plant acceptability or resistance or to spatially variable insect oviposition preference or larval performance. We can refute all other explanations apart from genetically-based oviposition preference influencing the movement patterns of females and thereby the rate of colonization of a habitat patch as a function of its host plant composition. The Glanville fritillary metapopulations with a high rate of population turnover present an ecological scenario in which natural selection might act among local populations as well as among individuals within populations. We have added the colonization effect into a patch-based metapopulation model and into an individual-based evolutionary model. In both cases, model-predicted evolution of host preference due to host plant-biased colonization explained a large part of the observed variation in host use among 37 replicate metapopulations, inhabiting separate networks of habitat patches. These results suggest that the extinction- colonization dynamics have influenced, via the "colonization effect", the evolution of host use in these metapopulations.

Impact of forest fragmentation on population survival, by Gergely Várkonyi

Destruction and fragmentation of old-growth forest habitats in Finland has rapidly increased during the past decades. Populations of species inhabiting old-growth forests are likewise becoming increasingly fragmented. Metapopulation theory

14 indicates that subpopulations living on small, isolated habitat patches have a greater risk of extinction compared to subpopulations inhabiting large, nonisolated habitats. Given the stochasticity of factors affecting the extinction risk of small populations, habitat specialist species are predicted to disappear with a certain time delay after habitat patch has become isolated. Such extinctions are thought to be deterministic and cause a phenomenon known as the extinction debt. The deterministic nature of these extinctions has usually been overlooked when evaluating effects of man-caused habitat destruction on species diversity. We aim at assessing extinction debt of lichens, polypores, insects and birds in small fragments (3-13 ha) in the area of Kuhmo, eastern Finland. We chose 5 fragments in each of three distinct time-since-isolation classes as well as 5 areas within large old-growth forests (controls) and 3 naturally fragmented plots of forest, surrounded by open peatlands. For each study plot we have mapped fragmentation history from 1945 onwards in a 5-km radius area around the plots. Using these data on spatio-temporal isolation of the fragments, we predict species’ occupancy probabilities for each study plot by using a dynamic metapopulation model. We have sampled a wide range of taxa (altogether >50,000 individuals of 1300 species) and measured forest quality in both the study fragments and the control plots. We test the model by comparing predicted occupancy probabilities with the empirical species richness data.

The network of old-growth spruce forests (dark colour) in northern Kuhmo has been dramatically reduced during the past 50 years.

Our preliminary results indicate three types of response to habitat loss and fragmentation in old-growth forest specialist organisms. First, as results from old- growth spruce forest indicator lichens clearly indicate, fragments gradually loose

15 specialist species with increasing time since isolation. Second, results from bird inventories show that old-growth forest bird frequencies decrease in fragments that have been isolated more than 20 years. Third, in a study of a food-chain based on an old-growth forest fungus species, it has been found that habitat loss and fragmentation truncates food chains of specialized species as time since isolation increases.

Biodiversity in Fenglin forest, NE China, by Antti Below

Fenglin Nature Reserve is situated in Heilongjiang in NE China. The reserve is the last virgin forest in the area and has a size of 18 000 hectares. The forest belongs to the hemiboreal vegetation zone with mixed forests (photograps on page 16 and 17, by Antti Below). This area in NE China was not covered by ice during the Pleistocene glacial periods, in contrast to Fennoscandia, and may have been a refugia for species living in boreal habitats. Due to the history of the area, we hypothesize that the species and genetic diversity is higher in NE China than in Finland, which has been colonized by all species present today in the past 10,000 years. During the summer 2000 our group of eight researchers conducted field studies in the reserve in order to test the hypothesis presented above. The expedition was a part of a co-operative project between Division of the Population Biology at the University of Helsinki (FIBRE), Division of Entomology at the Finnish Museum of Natural History and Chinese Forestry Academy.

16 Butterflies and moths were collected in May and again in July. In May, the material was collected for the Finnish Museum of Natural History. In July, studies were focused mainly on a tribe of sterrhine moths (Lepidoptera: Geometridae, Scopulini) belonging to the genera Problepsis, Somatina and Scopula. This group is species rich in Asia and the collected material form an essential part of a phylogenetic analysis of Scopulini. Specimens of Diptera (Syrphidae, Sciaridae), Hymenoptera, Coleoptera (Elateroidea, Scytiscidae) and Homoptera were also collected for the museum, in addition to moths and butterflies. Beetles specializing on fungi were collected during the whole summer from the mid-May to the beginning of August by window- trapping. Traps were placed under Fomitopsis rosea, F. pinicola and F. cajanderi. Bracket fungi were collected and studied in August. Material for further genetic studies were collected for the species Amylocytis lapponica, Fomitopsis rosea and Phlebia centrifuga. Longhorn beetles (Cerambycidae) living in decaying wood were also collected for genetic studies. In July, epiphytic lichen samples were collected for comparative lichen diversity studies and genetic studies. The aim of the genetic studies is to compare the population structures of selected lichen species in Finland and in NE China. Small mammals were caught by snap traps and pitfalls in order to study their parasites. The local parasite fauna is not well known and specimens of especially Clethrionomys rufocanus and C. rutilus, which both occur in Finland and NE China, were collected for further comparison of their parasite species. Bird densities were measured by a line transect method. Densities will be compared to the Finnish and Estonian data collected from protected forest areas. Also the amount of hole-nesting birds and the total biomass of the bird population will be measured. The biodiversity project in Fenglin Nature Reserve will be continued in 2001.

17 The Chitty effect challenged, by Janne Sundell

Relatively regular oscillations of population density are a characteristic feature of vole populations in northern Europe. Also the body size of voles varies during the 3-5 year cycle, the voles being smaller in the decline and low phases than in the peak phase. The phenomenon was first described by Dennis Chitty (1952) in field vole populations in Lake Vyrnwy, Montgomeryshire, after which it has been observed in other species and areas too. Many competing hypothesis have been developed to explain this phenomenon. According to Chitty himself, larger body size in the peak populations may be associated with genetically based differences in the voles’ behaviour and reproductive capacity, which acts through spacing behaviour, and should be the main cause of the cyclicity. I have studied this ‘Chitty effect’ in cooperation with Kai Norrdahl (University of Turku; Sundell, J. & Norrdahl, K., Body size dependent refuge in voles : an alternative explanation of the Chitty effect, submitted). We have used field measurements of vole body sizes and predator densities, and laboratory experiments on the minimum passable hole size for voles and their main predators, weasels. We found that voles weighing less than 20 g can pass through smaller holes than the smallest weasels, which implies that they have refuges from weasel predation. Consequently, predation pressure is expected to be heavier on larger voles. In the field, we found a negative association between the mean body size of the voles and weasel activity. In the light of our laboratory and field results we challenge the earlier explanations of the Chitty effect and suggest that size selective predation by the least weasel is an important cause of the observed smaller size of voles in the decline phase. The critical weight of 20 g is close to the weight at maturation in voles. Possible consequences of this observation on delayed maturation of voles and size dimorphism on weasels are also an important part of the study.

18 Structure of the MRG

The diagram below illustrates the structure of the MRG and how the different teams and current projects relate to each other. Ilkka Hanski Tapio Gustafsson Anu Väisänen

The core MRG Melitaea cinxiaTeam Marko Nieminen Saskya van Nouhuys Sari Haikola Anna-Liisa Laine Juha Pöyry Niklas Wahlberg Riitta Rantala Metapopulation Mika Siljander Molecular Modelling Team Ecology Team Atte Moilanen Jodie Painter Otso Ovaskainen Maaria Kankare Mar Cabeza

Boreal Forest Biodiversity Project Ilkka Hanski Leena Suvanto Laura Kivistö Reijo Penttilä Tarja salmi Gergely Várkonyi

Tree Canopy Small Mammal Insects Project Project Ilkka Hanski Ilkka Hanski Tomas Roslin Olivier Gilg Paavo Hellstedt Janne Sundell Heikki Eerola

TMR Network Fragland * Ilkka Hanski Bob O´Hara

19 * TMR Network Fragland, the PI`s

Ilkka Hanski, co-ordinator (Helsinki, Finland) Michel Baguette (Louvain, Belgium) Paul Brakefield (Leiden, Netherlands) Diego Jordano (Cordoba, Spain) Isabelle Olivieri (Montpellier, France) Christian Thomas (Leeds, United Kingdom) Christian Wissel (Leipzig, Germany)

Melitaea cinxia team

The large-scale and long-term metapopulation study of the Glanville fritillary butterfly (Melitaea cinxia) in the Åland Islands in SW Finland comprises the largest empirical project in the MRG. The Melitaea cinxia project has produced several PhD and MSc theses and a large number of publications in top international journals, including Nature and Science. The empirical studies are often closely related to metapopulation modelling. The large-scale monitoring of hundreds oflocal populations in the Åland Islands was started in 1993 and will be continued at least until 2005.

Metapopulation Modelling Team

The research in the Metapopulation Modelling Team has been focused on ecological models of metapopulation dynamics, including both deterministic models that can be analysed mathematically and stochastic models that can be parameterized with empirical data. Of the latter, much work has been done on the Incidence Function model, which was originally developed in parallel with the empirical study of the Melitaea cinxia metapopulation. More recently, we have incorporated genetic and evolutionary components into our models, and this trend will be strengthened in the future. Substantial work has also been done on reserve site selection algorithms, in particular towards the goal of incorporating spatial dynamics into the selection procedures.

Molecular Ecology Team

The Molecular Ecology Team emerged 5 years ago when the Department of Ecology and Systematics, in cooperation with the Finnish Museum of Natural History, established a molecular laboratory. Initially, our research was focused on Melitaea cinxia, but over the past 4 years several other taxa have been studied as

20 well, including other Melitaeini butterflies, parasitoid wasps, dung beetles, old-growth forest specialist insect species, the flying squirrel, the least weasel, the aspen tree and lichens. The research conducted in the Molecular Ecology Team is typically closely related to ongoing ecological projects in the MRG.

Forest Biodiversity Project

This project is funded by the Finnish Biodiversity Research Programme (FIBRE), and has a 6 year duration (1997-2002). Our general aim is to increase the population biological knowledge of old-growth forest specialist taxa, including mammals (the flying squirrel), birds, insects, fungi and lichens. Particular projects have investigated the persistence of species in isolated fragments of old-growth forest, the spatial population structure and dynamics of aspen-associated specialist species, spore dispersal of fungi, and the use of corridors by the flying squirrel and moths. In 2000 a large field project was started in boreal forests in NE China.

Small Mammal Project

This project addresses the role of small mustelid predators (the least weasel and the stoat) in the maintenance of the regular multi-annual population cycle of voles in northern Fennoscandia. Theoretical studies have demonstrated that the predator-prey interaction may drive the vole cycle, and that generalist predators may have a strong stabilizing effect on vole dynamics. Ongoing empirical work is focused on a large-scale experiment, in which captive-born least weasels are released on experimental islands in lakes to eliminate the numerical response in weasels' population dynamics. Another field project investigates the cyclic populations of the collared lemming in eastern Greenland.

Tree Canopy Insect Project

This is a new and still relatively small project focused on the spatial structure and dynamics of insect populations living in tree canopies. The field studies were started in 2000 on selected taxa feeding on oak, which has a highly fragmented distribution in Finland and which often occurs in small groups of trees or as single isolated trees.

TMR network Fragland

This is a training network funded by the European Commission in the Training and Mobility of Researchers (TMR) Programme. The project has a 4 year duration,

21 from 1998 until 2001. Specific research tasks include a comparative study of 4 species of butterflies in the central and marginal parts of their geographic ranges in Europe, modelling of metapopulations in fragmented landscapes, inbreeding and other genetic consequences of habitat fragmentation, evolution of dispersal rate and other life-history traits in metapopulations, and an improved framework for conservation of species in highly fragmented landscapes.

Larvae of Melitaea cinxia inside their winter nest, photo Tapio Gustafsson.

22 MRG personnel and their research interests

Mar Cabeza, Post graduate student

My research interests are population biology and spatial ecology. For my PhD project I focus especially on conservation issues such as the design of nature reserves. During the last decades, systematic methods (site-selection algorithms) to select networks of reserves have been developed. So far, the current methods focus mainly on representation of biodiversity, but they ignore how well biodiversity persists once the reserve network is established. From a population dynamics (or even more from a metapopulation dynamics) point of view, current approaches may be misleading, since they are based on biodiversity static patterns, ignoring spatiotemporal dynamics.

During the past year I have concentrated in extensively reviewing current algorithms and their application. There are no studies in which species occurrence has beeen monitored once the reserve was established. Awareness of the problem with current methods has been increasing. A few recent studies found a high proportion of extinctions if the reserves are selected with the information we had x years ago, compared to selecting the reserve with current information. However, there are no studies considering the dynamics of the system. For this reason, I am currently concentrating on a theoretical approach which considers metapopulation dynamics to show how species disappear from the reserved sites, emphasizing situations where the non-reserved sites deteriorate. The final aim of my PhD is to incorporate spatiotemporal dynamics into current site-selection algorithms. In collaboration with Atte Moilanen we have been developing a first approach to the problem by focussing simply on the conservation of single-metapopulation species. My presentation of this work at the Student Conference in Cambridge 2000 was awarded with the first prize.

23 Olivier Gilg, Post graduate student

After my MSc thesis at the University of Aix-Marseille (France), where I developed a naturalness assessment method for old growth and managed forests, I worked for several years in a conservation agency. In 1998 I started my PhD project on the lemming cycle and predator-prey interactions. Several recent studies have converged to the conclusion that the periodic rodent oscillations in boreal and arctic regions are essentially maintained by the interactions between the rodents and their mustelid predators. However, before arriving at a definite conclusion for the 70-yr-old puzzle of rodent dynamics, several hypotheses need to be tested, combining appropriate empirical and theoretical approaches. For this purpose, I’m adapting and testing the empirically-based models developed by Hanski and co- workers during the past ten years on a simple and well-documented high arctic vertebrate community from Northeast Greenland. An ongoing collaborative effort between the Universities of Helsinki, Montpellier and Freiburg was initiated in 1998 in order to collect information needed to parameterize the model.

After a peak year in 1998 and an intermediate year in 1999, the lemming density (in 2000) was at its lowest level since 1988. Lemming densities are always relatively low in this high arctic community (max. 10 per ha), and are systematically declining over the summer season when nomadic (snowy owl) and migratory (long-tailed skua) predators join the resident mammalian carnivores (arctic fox and stoat). We already knew that the cycle length was 4 years, but regular trapping was done to access its amplitude. There was at least a 100-fold decrease between the highest (spring 1998) and lowest (fall 2000) densities. Most of the summer decline was due to predation (the only cause of mortality recorded for 38 radio-collared lemmings). The daily predation rate estimated from the radio- collared animals was very high in 1998 and 1999 (respectively 3,5 and 2%) and can, alone, explain the sharp summer decline recorded from trapping. Densities, reproductive success and functional responses of the predators were also investigated during the three seasons, mainly by nest censuses, territory mapping, nest monitoring and pellet/scats analysis. Other topics regarding predator-prey interactions, such as prey selection, will also be addressed in my PhD.

24 Tapio Gustafsson, Research secretary

I am working as a research secretary for Professor Ilkka Hanski. One part of my work is to take care of the computing hardware and software used in the MRG. I also produce illustrations for different purposes, including our website. I help to co-ordinate our group activities and write reports etc. During the last summer I was again teaching undergraduate students in the field course of Subarctic Ecology held at the Kilpisjärvi Biological Station.

This year I have a new big project, the MRG video. This video will present the kind of research that is being conducted in our research group, but is mainly concentrated around the research on the Glanville fritillary butterfly Melitaea cinxia. I visited the Åland Islands in June and September and filmed undergraduate students, graduate students and post docs doing their field work. I also filmed the life and habitat of M. cinxia. In the spring I filmed at the Tvärminne Biological Station where we have our M. cinxia farm, and in autumn here at the Department in Helsinki. I hope to edit the film during November so that it would be ready for the great presentation during the "Science Days" in January 2001. Finnish MTV3 is going to use a short clip of my film in their TV series "MTV Akatemia" in December. I have noticed by now that producing a vidoe is a big project. I have never filmed a video before, not to mention edit one. After 20 years of photography this is both very interesting and very challenging.

25 Sari Haikola, Post graduate student

On the basis of numerous studies it can be concluded that inbreeding lowers the general viability of an individual. It has been suggested that inbreeding depression should be low in species that have experienced inbreeding in the past. Nonetheless, there is also evidence suggesting that even highly inbred populations can suffer from inbreeding depression of high magnitude. I am addressing these questions in my PhD study, being conducted at the Tvärminne Zoological Station from the beginning of 1999. My main interests are in quantifying inbreeding depression in the Glanville fritillary butterfly, Melitaea cinxia, and investigating any possible relationship between the magnitude of inbreeding depression and a population`s past inbreeding history.

In our laboratory study (Haikola et al. in preparation) there was an average decrease in egg hatching rate of 29% in crosses within families when compared to crosses between families/populations. In the field in the Åland Islands, brother- sister matings must represent a common form of inbreeding, imposed on the populations by the spatial metapopulation structure; a large fraction of the small local populations in small habitat patches consists of just a single sib-group of larvae. The importance of inbreeding in purging deleterious recessives from a population was examined in our study by comparing the effects of inbreeding on egg hatching rate in populations from areas with different degrees of habitat, and hence population, fragmentation. Local populations in Åland are small and discrete. In contrast, in southern France M. cinxia is more widespread. For this reason local populations in Åland must have experienced more inbreeding in the past. Our results show that French populations suffered more severe inbreeding depression than populations from Åland, suggesting that deleterious alleles have to some extent been purged from inbred populations in Åland. Nevertheless, a substantial genetic load remains in the metapopulation, probably due to immigration between small local populations that carry different deleterious alleles.

26 Ilkka Hanski, Research Professor and Director of the MRG

My current research is focused on classic metapopulation biology, where I conduct both theoretical and empirical research together with many students and post docs. Our research is primarily ecological, a key question being the ability of species to persist as metapopulations in highly fragmented landscapes. Some evolutionary issues have also been addressed, such as the evolution of migration rate in classic metapopulations. My other research projects include small mammal population dynamics, especially the interaction between voles and their mammalian predators, and the biology of species living in old-growth boreal forests. Like many other population biologists, I have been keen to shift my research towards questions that are relevant for conservation. I have become increasingly concerned about the loss of natural boreal forests in Finland.

I have estimated that the “extinction debt” of boreal forest species is of the order of 1,000 species in Finland (extinction debt refers to the number of species that are declining towards extinction because of past environmental changes but which have not yet gone extinct). Using a spatially explicit metapopulation model, I have examined the likely consequences for the survival of species under different scenarios of forest management and conservation. The results point to the conclusion that it generally pays to concentrate the efforts of improving forest quality at certain areas, rather than to spread the same total effort evenly and therefore thinly throughout the entire forested landscape. The practical conclusion is that in southern Finland an extensive restoration program of managed forests to natural-like successional forests is needed to avert the imminent wave of extinctions of specialist forest species. The greatest positive effect is obtained if forests located close to the existing remnants of biologically diverse forests are restored, which would facilitate the migration of target species to the restored forests.

27 Paavo Hellstedt, Post graduate student

My Ph.D. research interests involve four aspects of stoat and weasel population biology: 1) Estimating the survival rate of captive-born least weasels in nature. We suggest that there are two main components explaining the differences of survival rate; the age of the animal, and time of year of release. 2) We also estimated the indirect effects of least weasel presence on Microtus-vole behaviour and demography. 3) In Lapland, we studied causes of change of the microtine cycles and the dynamics, habitat and prey selection of stoats. We suggested that change in mustelid densities reflected change in microtine populations. 4) We attempted to estimate the population size of stoats and least weasels, and the relationships between individuals using molecular genetic methods.

Using radio-tracking we estimated the survival rate of 27 captive-born least weasels of varying age, that we released into the wild at different times of the year in southern Finland. We also radio-tracked six wild individuals, caught on site and released, for comparison. We observed substantial differences in survival rate between wild-born and captive-born weasels. The survival rate of captive-born weasels was higher when they were released during the summer and hence were younger. The weasels released during the summer were 12–17 weeks old, and their daily survival rate (DSR) during the study period was 99.94%. Weasels released in the autumn, winter or early spring were 18 to 40 weeks old, and their DSR was 90.85%. The DSR of the wild weasels was 98.12%. Apart from the direct effect of predators, it has been suggested that small mustelids also have indirect effects on voles. We have studied the indirect effects of the least weasel on field voles and field vole populations in a field experiment. We constructed large grids made of drainpipe with small holes, covering an area of 0.24 ha (4 X 6 grid, pipes with 10-meter intervals). A least weasel moved in the experimental grid without having access to voles. We analysed the rate of vole maturation, breeding success, movement, and female home range use. The results indicate that the presence of a weasel had only minor or no influence on voles and the vole population. Growth of populations appeared somewhat different between the experimental and control grids, but the reasons may not be related to the presence of the predator.

28 Maaria Kankare, Post graduate student

My PhD is focused on the spatial genetic structure of the primary parasitoids and hyperparasitoids associated with Melitaea cinxia on the Åland islands. Here the endangered Glanville fritillary butterfly Melitaea cinxia, its primary parasitoids Cotesia melitaearum and Hyposoter horticola and the hyperparasitoids Gelis agilis and Mesochorus sp. cf. stigmaticus, form a classic host-parasitoid metapopulation. In this species complex there are two tritrophic interactions: M. cinxia - C. melitaearum - G. agilis, and M. cinxia - H. horticola – M. sp. cf. stigmaticus. Ecological studies (Lei 1997) have revealed that the primary parasitoids of M. cinxia have very different spatial patterns. H. horticola is present all over the Åland islands, while C. melitaearum is a more spatially and temporally clustered species within a habitat patch. H. horticola also occurs in more isolated and smaller host larval groups than C. melitaearum. Lei (1997) also found that H. horticola has a stronger dispersal ability and can move more frequently among larval groups than C. melitaearum. As a consequence of these behavioral differences, H. horticola and C. melitaearum are expected to show dissimilar spatial patterns in allelic distributions.

The aim of the study is to compare the genetic structure and population structure of the parasitoids. These results can then be compared to the study of the host M. cinxia population structure. This kind of comparison between a host species and its specialist parasitoids has not been conducted before on such a large spatial scale. An additional project within the study is constructing a molecular based phylogeny of Cotesia (Braconidae) species associated with Melitaeine butterflies, from different host species around the world. A molecular phylogeny for Melitaeine butterflies has been constructed by PhD student Niklas Wahlberg. This will allow us to examine to what extent the phylogeny of the parasitoid species reflects the phylogeny of the host species. I will use microsatellite and mtDNA markers to study these questions.

29 Laura Kivistö, Post graduate student

My research focuses on the effect of old-growth forest fragmentation on epiphytic lichens. Efficient forestry has changed the forest structure and the disturbance frequencies dramatically. Lack of deciduous trees and decaying wood, and changes in microclimate, greatly affect the lichen diversity. Previously I have studied the edge-effect of large clear cuts to the lichen flora of Picea abies (Lichenologist 2000). At the moment I´m analyzing the data I´ve collected from the forest fragmentation study areas in Kuhmo (middle-eastern Finland). I have mapped the occurrence and abundance of 30 epiphytic lichen species that need long, undisturbed forest continuity and a variety of substrate trees. In addition, I have investigated the total epiphytic lichen flora of Picea abies in these forest fragments. Data on the forest structure and isolation history of the forest fragments has been collected, and the effect of these variables on the lichen flora is being studied.

During the summers of 1999 and 2000 there has been an exhaustive mapping of the lichen species Lobaria pulmonaria in Kuhmo. Detailed information of the lichen and its substrates has been collected, and all the potential substrate trees in 60 ha area have been mapped. This data will be used to analyse the spatial patterns of Lobaria pulmonaria populations.

30 Anna-Liisa Laine, Post graduate student

I started with the MRG in April, with a background in plant ecology. I am interested in the interactions between species which result in the spatial distribution patterns we observe in nature. What regulates these dynamics and how the feedback mechanisms work in often ambiguous co-occurrences is what I believe to be a key component of ecology and biodiversity.

To study these questions I’ve begun to work with a system involving a host plant, a parasitic fungus and a possible involvement of an insect herbivore. My field studies are conducted in the Åland islands with Plantago lanceolata, a larval host plant for Melitaea cinxia. Surveys carried out during the summer revealed some of the Plantago populations to be colonized by a powdery mildew, Sphaerotheca plantaginis. The occurrence and abundance of the fungus in Plantago populations is being studied at the regional, metapopulation, population and individual plant level. The abundance of the fungus in Plantago populations was recorded three times during the season, within 1 x 1 m quadrats, in order to obtain the fungus reproductive and dispersal rate (see Figure). Using the demographic data I’ve begun to collect for P. lanceolata, and the fungus reproductive rate obtained from the surveys, I hope to gain an understanding of the host-parasite interactions of species with presumably contrasting dynamics. Additional study questions will address the role of plant secondary metabolites in these interactions, and the role of an insect herbivore feeding on both the fungus and the plant.

31 Atte Moilanen, Researcher

In the MRG I am mostly responsible for computational work and software development. My interests include spatial population dynamics, construction, parameterization and application of predictive metapopulation models, and as a side project, computational methods of parsimony analysis. I am specialized in numerical optimization and programming (C/C++), and I have interest in modeling. In the near future my work will concentrate on reserve design and site selection methodology, a new topic for the MRG that I am studying in collaboration with Mar Cabeza, and for which I recently recieved an Academy of Finland grant. A general variant of the site selection problem can be stated as "given restrictions on resources (money etc.), what is the reserve design that will maximally maintain biodiversity"? Site selection problems can be computationally hard, and my aim is to develop improved computational techniques for important problem variants, such as the multiple representation problem. As a byproduct of these studies I am to finish a Dr. Tech. degree at the Helsinki University of Technology, on the subject of "Optimization using evolutionary algorithms and local search".

For me a highlight of this year is the third part of a study (submitted) about parameterization of patch occupancy models, a specialty of the MRG. I investigated the effects of errors in empirical data to metapopulation model parameter estimates and predictions, and found that mis-estimated patch areas and the presence of unknown patches can significantly bias estimates. In particular, false zeros (a patch is observed empty when it is truly occupied) produced serious biases. The figure on the left shows the effect of false zeros to the IFM parameter x, which determines the scaling of extinction risk as a x function of patch area; Ei=e/Ai . Values below 1 for x' indicate that x is underestimated. This study helps empirical study design, and explains anomalous estimation results obtained using bad quality data sets.

32 Marko Nieminen, Researcher

My current research focuses mainly on studies of the Glanville fritillary butterfly Melitaea cinxia in the Åland Islands, SW Finland. Two main lines of research are: (1) To study the significance and variability of different causes for the spatially correlated dynamics in M cinxia metapopulations, and the spatial scales at which they operate. Two factors are probably driving these spatially correlated dynamics; weather and changing landscape structure. They also operate indirectly via several factors (host plant characteristics, parasitoids, inbreeding effects and habitat quality) which in turn may have direct effects. (2) Running the bi-annual monitoring of all known suitable habitat patches. We collect data on habitat characteristics and larval nests every autumn, and on the numbers of larvae and parasitoids in the spring.

The latest results from the monitorings show that there was a population crash almost everywhere in Åland during summer 1999, due to a severe drought. Very low winter mortality occurred in the winter 1999-2000, which was followed by a favourable summer during 2000. These episodes resulted in many colonizations of empty habitat patches and/or large increases in population sizes in most areas in 2000 (see Figure). These latest results allow a more comprehensive analysis of colonizations than has been possible with previous census data.

Changes in the numbers of occupied habitat patches and larval groups within subareas of Åland from 1999 to 2000. (Left-hand arrows show the direction of change in no. of occupied patches and right-hand arrows in no. of larval groups).

33 Saskya van Nouhuys, Post doc

I study the population ecology and the evolution of interacting species. Most of the work that I have done is focused on the interaction between parasitoids, their hosts, and host food plants. For my PhD (finished in 1997) I studied natural selection on parasitoid searching behaviour, and genetic differentiation of behaviour among parasitoid populations from wild and cultivated host food plant habitats. As a post doc with Ilkka Hanski (since 1997) I work primarily on the large and small-scale population ecology of the parasitoids associated with the Glanville fritillary butterfly in Åland, Finland. I am interested in the ecological and evolutionary consequences of parasitoid dispersal, competition, hyperparasitism, behaviour and life history variation. The work I do is based in the field and laboratory, and in collaboration with a chemist and a population geneticist in the Metapopulation Research Group.

Cotesia melitaearum, photo Niklas Wahlberg.

See Research on the parasitoids of the Glanville fritillary on page 10.

34 Bob O´Hara, TMR Post doc

I am working in the group as a statistician, analysing data, helping other people to analyse their data and trying to make comments on other people's analyses that sound wise. The main thrust of my work is developing Bayesian methods for the analysis of ecological data. The Bayesian approach gives the statistician a large amount of flexibility in modelling the data. I have been developing methods for fitting the Incidence Function model to metapopulation data, and am now focussing on adding environmental stochasticity into the model, potentially using specific environmental variables (e.g. rainfall) as covariates in the estimation. This work has been carried out in collaboration with Elja Arjas and Hannu Toivanen from the Rolf Nevanlinna institute.

I am also working on fitting flexible curves to dispersal data, again using a Bayesian approach. One advantage of this approach is that we can combine information from different experiments in an efficient manner. I will be able to use the techniques to look at dispersal of dung beetles (thankfully I do not have to collect the data - that is being supplied by Tomas Roslin), and also the movement of spores from wood rotting fungi in old growth forests, this work being done with Reijo Penttilä. I have also been helping other people with their analysis, for example aiding Sari Heikola with analysing experimental data on inbreeding in M. cinxia. I also have an on-going collaboration with Johan Kotze analysing distribution maps of beetles. It is commonly observed that there is a positive correlation between abundance and range size of species, and a variety of explanations for this have been put forward. We have data on the range sizes and abundance of carabid beetles from Holland, Belgium and Denmark. By torturing the data with a variety of techniques, we managed to show that the relationship is not an artifact of the data, but rather that it could be due to differences in the degree of specialisation of the beetles - as predicted by the 'resource breadth hypothesis'. We are now using the same data set to investiagate predictors of decline in beetle populations. All this is possible through the aegis of the EU, who are funding me via a Europe-wide TMR project called Fragland.

35 Otso Ovaskainen, Post doc

I completed my PhD on mathematics at the Technical University of Helsinki in1998. As I am interested in ecology, I was happy to join the MRG in June 1999. My main research interest is in the mathematical analysis of spatially structured metapopulation models. I have mainly studied spatially realistic models, which take the areas and spatial locations of the habitat patches into account, but ignore any further details. This choice has turned out to be a fruitful compromise: the models are simple enough for analytical tractability, but realistic enough to give a quantitative description of metapopulation dynamics in heterogeneous landscapes.

In 2000, I applied a spatially realistic metapopulation model to study the concept of time delay, i.e. the time that it takes for a metapopulation to set back to equilibrium after a perturbation. A direct consequence of this time delay is the extinction debt – some of the species occurring in a landscape may actually be bound for extinction, only they have not had the time to disappear yet. The figure below shows a hypothetical example of the predicted change in the commonness distribution of species after habitat loss. Consider a landscape which has recently been deteriorated, such as the forests in Southern Finland, as perceived from the perspective of an old-growth forest species. The bar on the left shows the current extinction debt (crossed) and the number of species that have gone extinct (black). As demonstrated by the figure, such deteriorated landscapes are characterised by a transient ‘overabundance’ of rare species before the species actually go extinct.

36 Jodie Painter, Researcher

My research involves applying molecular genetics to address questions of population ecology, particularly mating systems and phylogeography (the study of the biogeography of a species by comparing a gene-based phylogeny with geographical distribution). In addition to doing my own research, as a senior researcher in the Molecular Ecology team I am responsible for the day to day running of the laboratory, and of teaching the MRG students wishing to add a molecular component to their ecological studies. During the spring and summer of 2000 we hosted two EU-funded students from Portugal, who successfully completed small projects that are being incorporated into larger projects run by members of the Molecular Ecology team (JP & NW).

I have worked on two research projects this year. One is to determine paternity in locally studied populations of Siberian flying squirrels, using DNA microsatellite markers that I developed during 1999. At present 3 of the > 20 loci that I have tested have enough polymorphism to allow potential fathers to be discriminated. Preliminary results for 26 juveniles revealed that paternity can be definitively assigned for 13, using the molecular data alone. When this information is combined with movement data from radiotracking studies (VS) paternity can be assigned for an additional 7 juveniles. This work is continuing, including more families and searching for additional microsatellite markers. The second project I am involved in is to investigate the post-glacial dispersal of the beetle Pytho kolwensis, an endangered boreal forest specialist. A preliminary study by Atte Komenen found no variation in a segment of the COI mtDNA gene amongst individuals collected from two sites in both Russia and Finland. I have extended this work to include most of the COI gene and many more individuals, from sites within China, Russia, Finland and Sweden. Currently there are 12 haplotypes forming two distinct groups, a ‘Finnish group’ (including all Russian, Finnish and Swedish samples), with 8 distinct haplotypes, and a ‘Chinese’ group (including only Chinese samples), with 4 haplotypes. One Chinese haplotype is almost identical to those of the Finnish group. These results are striking in comparison with data obtained from a common and widespread congeneric species, Pytho depressus (MP). Pytho depressus collected from the same locations as the P. kolwensis specimens showed 20 haplotypes among 23 individuals, with no geographic pattern. These results reflect different post-glacial colonisation histories of the two species. Continuing work on P. kolwensis phylogeography will incorporate data from microsatellite loci developed during 1999.

37 Reijo Penttilä, Post graduate student

I am interested in the population and community ecology of wood-rotting fungi, and of polypores in particular. My studies are part of the project ”Biodiversity in Boreal Forests”, led by Ilkka Hanski. Hence, I work at two different locations. In the summer and in the autumn I organize and conduct field work at the Research Station of the Friendship Park in Kuhmo, and in the winter I work as a post graduate student at the University of Helsinki. My PhD project deals with the effects of forestry and forest fires on wood-rotting fungi, and my studies focus on both the community structure and on the population structure and population dynamics of old-growth forest fungal species. I have also examined the dispersal ability and genetic structure of fungal populations.

In a recent study, I sampled the abundance and distribution of polypore species in a very large, continuous area of old-growth forest in Russian Karelia, and in a set of rather small, fragmented old-growth forest patches in mid-eastern Finland. The results demonstrate that the number of threatened polypore species, and the number of old-growth forest indicator species, are higher in the continuous forest area in Russia than in the forest fragments in Finland. Moreover, intraspecific abundances within species were very much higher in Russia than in Finland. These differences are most likely due to the fragmentation and isolation of old-growth forests in eastern Finland by intensive forestry. In another, collaborative study, we examined the effects of the fragmentation and isolation on old-growth forest species in a large fragmentation project in Kuhmo and Pohjois-Häme. Our preliminary results suggest that certain old-growth forest fungi (e.g. Amylocystis lapponica, Phlebia centrifuga) suffer from the isolation and fragmentation of suitable habitats. My extensive studies on the dispersal and spore production of an old- growth forest specialist fungus, Phlebia centrifuga, have shown that the dispersal of this species is strongly concentrated to the close vicinity of the fruitbodies. I have also made extensive measurements of several weather and landscape variables. I am now combining this information with data on dispersal and spore production in P. centrifuga, to develop a dispersal model aimed at predicting the dispersal of P. centrifuga under different environmental conditions. This is a joint study which involves several researchers and research institutes.

38 Juha Pöyry, Post graduate student

I started my PhD project in the beginning of 2000. My main objective is to empirically examine the effects of cattle grazing on insect populations. Based on this information, I will create recommendations for practical habitat management. I will also compare various local and regional factors affecting the total species richness of insects, and the occurrence of individual species, in semi-natural grassland habitats. These factors include for instance the species richness of plants, the intensity of grazing and the regional density of semi-natural fragments of grassland. My target taxa are mainly Lepidoptera (butterflies and moths) and Apoidea (wild bees). Even though my thesis is supervised by prof. Ilkka Hanski, I am permanently based at the Finnish Environment Institute (FEI) in Helsinki. Here, my work is a part of the larger project "Maintaining biodiversity in traditional rural landscapes. Optimal management and area networks", headed by Dr. Mikko Kuussaari and funded by the Finnish Biodiversity Research Programme (FIBRE).

In the year 2000, I collected two large data sets in the field. Based on the first data set, I will examine the effects of grazing regime and grazing intensity on insects. Butterflies and day-active moths were counted with a transect-method, and bees were collected with pollinator-traps in three different types of grassland fragments: (1) sites which have been grazed annually for > 20 years, (2) sites where grazing ceased > 20 years ago and (3) sites where grazing had ceased > 10 years ago but was reinitiated a few years ago. Six triplets of sites representing all three types of grassland were chosen for the study. The aim of the second study is to find out whether the insect diversity of a grassland fragment is better explained by the characteristics of the fragment itself, or by the amount of grassland habitats in the surrounding region. These hypotheses will be tested in a subset of 48 grassland sites from the national survey of traditional rural habitats. Again, my target taxa are butterflies, day-active moths and bees. In 2000, the total amount of grassland habitats in the surroundings of study sites was evaluated using aerial photographs, topographic maps and field surveys.

39 Tomas Roslin, Post doc

I am interested in the empirical analysis of spatial population structures. In my PhD thesis (completed in 1999) I focused on dung beetles in the genus Aphodius. My objectives were twofold: 1) to compare spatial population structures among several closely related species co-occurring on the same resource (cattle dung), and 2) to relate the spatial population structures of individual species, and groups of ecologically similar species, to their dynamics at several spatial and temporal scales. In my post doc project, I apply the same ideas to a new system: herbivorous insects on trees.

For an insect specialised on a given tree species, the landscape resembles a vast archipelago: widely scattered crowns of the host tree provide islands of suitable habitat, surrounded by a sea of unsuitable habitat. The system is highly dynamic – within islands local insect populations wax, wane, and disappear, and at a longer time scale even islands come and go. I hypothesise that the spatial structure of this landscape will have a critical effect on both local and regional population dynamics in specialist insects. Dynamically, the isolation of a host tree from other conspecific trees should modify the flux of insects between trees, affecting both the role of external processes in local dynamics, and the probability of recolonisation following local extinction events. Evolutionarily, the spatial location of a host tree should influence the potential for insects to adapt to local conditions. Experimental transplants of individuals among trees have shown that herbivorous insects may adapt to the characteristics of individual trees. Since local evolution is dictated both by local selection pressures and by gene flow from elsewhere, I expect to find stronger adaptation in isolated insect populations than in populations within dense stands of trees. To my knowledge, this crucial prediction has never been tested. My study system consists of gall wasps and leaf-mining microlepidoptera specialised on English oak, Quercus robur. During the initial stage of the project, I have mapped the regional distribution of the oak and of some thirty easily identifiable target species. Oak records were collected both from professional biologists and from the pupils in local schools. As a result, I was able to map the distribution of oaks within an area of ca 1000 km2. Field work was initiated in the early summer. To assess how the spatial context of individual oak trees affect the structure of local insect communities, I sampled both isolated oak trees and oak stands of different sizes. In the autumn, I established laboratory rearings to be used in coming transplant experiments, aimed at quantifying local adaptation under different conditions. With the pilot stage of the project now completed, the stage is set for more detailed and experimental work.

40 Tarja Salmi, Post graduate student

In January 2000, I moved into the MRG from the Department of Forest Ecology, where my main subject was silviculture. My Master's thesis (completed in 1999) dealt with the external quality of the trembling aspen (Populus tremula), and within the MRG, I will continue to work on this same tree species. In my PhD project, I will examine the population biology of aspen in both old-growth and managed forests. I will work at three different levels. At the level of the individual tree and the stand, I will study the reproductive biology of aspen (including sex ratio, seed dispersal and regeneration) in old-growth forests without large-scale disturbances. At the landscape level, I will assess the extent of and the reasons for the spatial aggregation of mature aspen trees in both managed and virgin forests.

My work will be based on an already compiled data set with spatially referenced data on ca 30,000 mature aspen trees. In the summer of 2000, I collected additional data on the regeneration of aspen. Thus, I now have data on all trees (>1 cm at breast height) within 50 hectares of old-growth forest and 23 hectares of managed forests. At the moment, I am calculating the volume of the trees. I will then start analysing data on the spatial aggregation and dynamics of coarse woody debris as well as on the regeneration of aspen. Next summer I will take core samples from trees to study the age distribution and history of the stand development. I will also do some field experiments on the germination of aspen seeds under different conditions.

41 Mika Siljander, Research assistant

Our annual field surveys of Melitaea cinxia produce a vast amount of data. My main task within the MRG is to manage all these data in an accessible form. The current database was built in Microsoft Access 97, and it has recently been linked to the ArcView GIS system. Hence, it is now easy to produce all kinds of visual output from the database (for an example, see picture below). Overall, the metapopulation database is in a state of rapid expansion – not only due to the addition of new data from the biannual field surveys, but also due to the aggregation of other types of spatially referenced data. Over the last few years, we have mapped the Melitaea cinxia patches with GPS technique, we have obtained data on patterns of rainfall from a weather radar station, we have explored changes in landscape structure around the Stålsby area by digitising aerial photographs from different time periods, and we also have obtained fine-scale data on fluctuations in temperature from different parts of Åland. As the metapopulation database continues to grow, my biggest challenge remains to manage all different spatial data in a single, functional format.

Relative changes in the population sizes of Melitaea cinxia between 1999 and 2000. Downward triangles indicate a decrease and upward triangles an increase in population sizes.

42 Janne Sundell, Post graduate student

My research interest focuses on the population dynamics of microtine rodents. In my PhD project, I experimentally test the hypothesis that small mustelid predators are the driving force behind multiannual cycles in northern vole populations. In a large-scale field experiment, I perturb vole-weasel dynamics by adding weasels to cause a premature decline of vole populations. The aim is then to keep the vole density at a permanently low level by further additions of weasels. The experiment was started in 1997, and it will be finished in 2000 or 2001. The weasels used in the experiment come from a captive breeding program. This program produces valuable information on various aspects of the demography and the reproductive biology of the least weasel.

My other interests include the functional response, the predation rate and the prey choice of the least weasel. Overall, I would like to know more about how species identity, functional group and size affects the vulnerability of a vole to weasel predation. I have studied these issues both in large outdoor enclosures, in the laboratory and in the field. These studies have also elucidated the hunting behaviour and the activity patterns of the least weasel. Finally, I have examined the effects of predation and predation risk on the behaviour, reproduction and survival of voles. All of my work serve one common goal: to understand more about the effects of predation on small mammal dynamics in Northern Fennoscandia. In the future, I will concentrate more on the impacts of avian predator on vole dynamics at a larger spatial scale. I aim to defend my PhD thesis in 2001.

43 Leena Suvanto, Post doc

My background is actually in the field of behavioural genetics. In 1999, I finished my thesis on mate choice and genetic variation in courtship song in Drosophila montana at the University of Oulu, and then moved to the MRG to work on a whole new issue: the population biology of trembling aspen (Populus tremula). This jump into the world of plant genetics has been huge, but fortunately some things in genetics seem universal. The new aspen project deals with the dynamics, reproductive biology and regeneration of aspen, with particular emphasis on old-growth forest. My own task is to clarify the clonal structure of aspen. I’m developing molecular markers (microsatellites) to identify individual clones. These molecular markers will also be used to study the genetic diversity of aspen. Another main objective is to clarify the frequency of sexual reproduction in aspen. Although P. tremula produces viable seeds every year, the establishment of sexually produced offspring seems to be rare, and the species apparently reproduces mainly through suckering. The seedlings need enough light, water and exposed warm mineral soil to survive – conditions which are typical after forest fires. Hence, the rarity of sexual reproduction in aspen may be due to the current large-scale control of forest fires.

At the moment, I am focusing on developing suitable microsatellites for clone identification. I have found primers that have been developed for other Populus species, which amplify also in P. tremula. Some of them appear to be polymorphic, and I’m currently combining these primers to distinguish between presumptive clones.

44 Gergely Várkonyi, Post graduate student

My main research interests are the ecology and taxonomy of insects, especially of parasitoid wasps and their hosts. My PhD project concerns the biology of periodical Xestia moths and their parasitoids in northern Finland. My thesis will contain studies on the following: the host-parasitoid interaction that maintains the alternate-year occurrence of Xestia moths, the estimation of population parameters important to this interaction, the early larval parasitoid assemblage attacking Xestia species, spatial patterns of the host and the parasitoid, dispersal ability of Xestia adults in ecological corridors, and population genetics of Xestia tecta. Since October 1998, I have also been involved in the "Biodiversity in boreal forests" project. I have been co-ordinating one of the main sub-projects, entitled “Impact of forest fragmentation on population survival” (see Scientific highlights), as well as the insect studies conducted in Kuhmo field site ineastern Finland.

Many insect species with fixed k-year life cycles emerge synchronously in large numbers every kth year. In the intervening years, few (or no) individuals hatch. Populations of these so-called periodic insects can be divided into as many as k temporally isolated cohorts. The important population dynamic question is what maintains the abundance difference between the sympatric cohorts. We have studied boreal Xestia species (Noctuidae) with striking two-year periodicity. We have found unique evidence which supports the hypothesis that the rare Xestia cohort in eastern Finnish Lapland is regulated by a parasitoid wasp, Ophion luteus, with one-year life cycle.. The wasp generations parasitizing the abundant host cohort attack the rare cohort, and prevent it from growing in size. Larvae and

10000 pupae of Xestia moths have such an important 1000 role in the local food 100 web, that even the 10 population size of the generalist predator 1 shrews (genus Sorex) is 0.1 Xestia Ophion Sorex fluctuating with the 0.01 Xestia numbers (see 77 82 87 92 97 time series).

45 Anu Väisänen, Research Secretary

I work as a research secretary and my work is mostly administrational. The main tasks are to help with co-ordination, manage the budget and the payment transactions and to help to prepare proposals and reports.

Daily co-ordination includes updating the web-pages and correspondence with the researches. Whenever the projects have meetings, I arrange the practical matters of the ones in Finland and help with the ones outside of Finland. This year the annual meeting of Fragland took place in Montpellier, France and I was part of the organising committee. That was huge amount of work, but I learnt many new things and above and beyond it was lots of fun as well.

Old-growth forest in Kuhmo.

46 Niklas Wahlberg, Post graduate student

My main research interests lie in integrating the ecology and evolution of butterflies, especially in the family Nymphalidae. I believe that taking a historical perspective can explain much of the patterns we observe today in nature. In my PhD thesis I have taken the first steps towards elucidating the evolutionary history of butterflies in the tribe Melitaeini. I have constructed a molecular phylogeny for the group and have thus far used this phylogenetic hypothesis to investigate the evolution of host plant use in the tribe. Other areas that will profit from a historical perspective are the evolution of egg clutch size and the possible co-evolution of melitaeines and their parasitoids. I hope to be able to look into these areas in the future.

The phylogenetic hypothesis that I have constructed for Melitaeini suggests that the group originated in the Nearctic region and that the Palaearctic and Neotropical regions have been colonized from the Nearctic. This hypothesis can give an anchor to the time scale of evolution in melitaeines. It seems apparent with the hypothesis available at the moment that the Neotropics were colonized by species in the Phycioditi some 3 million years ago, when South America joined North America. Preliminary data suggest that the rate of base changes in melitaeine mtDNA is faster than in other insects that have been studied. In future research I will try to nail down the evolutionary time period for the putatively young melitaeines and investigate the rate of sequence evolution in this group of rapidly speciating butterflies. Some groups of species within the melitaeines are so young that the process of speciation is still in progress. This process is evident in the very low divergences of mtDNA in pairwise comparisons and the presence of poly- and paraphyletic mtDNA lineages in species. I have been investigating this phenomenon in a genus of melitaeines, Phyciodes. Phyciodes comprises of 11 species, which have been informally divided into 4 species groups. One of these groups has 4 species that are morphologically very similar to each other. The patterns of mtDNA sequences are very confusing between these 4 species, and future studies will try to disentangle the effects of ancestral polymorphism, hybrid introgression and historical changes in population size in the group. Such information will help us understand the process of speciation.

47 Laboratory facilities

Helsinki

The MRG is located in the 3rd floor in the Division of Population Biology, Department of Ecology and Systematics, in the street address Arkadiankatu 7. We have 8 offices, which are currently shared by 19 people. We share a molecular laboratory with other members of the Department. The molecular laboratory is fully equipped for PCR (polymerase chain reaction)-based projects, such as mtDNA sequencing and screening DNA microsatellites. Equipment includes PCR machines and centrifuges, allozyme, agarose and acrylamide gel electrophoresis equipment and facilities, and an ABI 377 DNA sequencer (with a full-time technician who runs the machine). We also have facilities for both DNA cloning and the use of radioisotopes. And finally, we are building an extensive GIS- laboratory (GIS based data management system) for managing the Melitaea cinxia- database and all other map-related information important for the research group.

The table below shows the amount of space occupied by the MRG.

Space no. m² Offices 8 150 DNA-laboratory* 1 120 GIS-laboratory 1 10 Total 10 280

* = shared with the rest of the Department of Ecology and Systematics.

48 Tvärminne

The primary aim of the project at the Tvärminne Zoological Station is to maintain capacity for experimental studies of the Glanville fritillary Melitaea cinxia project. Current research is focused on quantifying inbreeding depression in Melitaea cinxia and on clarifying the possible relationship between the magnitude of inbreeding depression and populations´ past inbreeding history. The results so far indicate a significant reduction in fitness due to inbreeding, the effect being more severe in continuous than in naturally fragmented populations. The project was started in Tvärminne in 1996. During these years the laboratory conditions and the rearing routines have been developed to an appropriate level to facilitate our experimental research. Adult butterflies are mated in a flying room with a large number of quartz glass fluorescent lamps, using six different broad spectral luminescent substances and oscillation frequency of 30 000 Hz. The resulting light is very close to natural light, including the proportion of UV radiation, and it practically does not oscillate. The plants needed for larval food and female egg laying are grown in a 3.65 by 7.10 m greenhouse, built specifically for this purpose. The greenhouse enables the rearing of larvae all year round and so gives the possibility of rearing more than one generation of butterflies per year.

Lammi Biological Station

We are in the process of investigating vole-weasel dynamics with a large-scale field experiment. We are releasing weasels onto large experimental islands in order to prevent the increase of vole populations, and will keep the vole densities at a low level by further additions of weasels. We have started a captive breeding program of the least weasel in facilities provided by the Lammi Biological Station. Young weasels born in Lammi have been released into experimental areas. Facilities include 17 outdoor enclosures, each 25 m2, which are used to habituate the weasels to outdoor life, and train them to hunt live prey before of release. Breeding of weasels is conducted in plexiglass cages in a greenhouse, where they are exposed to natural light conditions, but it is also possible to control the photo period. In addition we have an office in main building of the station, and facilities for housing small mammals, mainly voles, for different purposes. One part-time person has been hired to take care of animals. Near the Lammi Biological Station we have radiotracked weasels, both captive-born and wild ones, and conducted the field experiment on the influence of the presence of weasel on population dynamics and demography of voles.

49 Field sites

Åland Islands

In the Åland Islands in SW Finland, the research is focused on the Glanville fritillary (Melitaea cinxia), its parasitoid wasps and larval host plants. The main Åland island contains thousands of habitat patches (dry meadows) where at least one of the two larval host plant species, Plantago lanceolata and Veronica spicata, occurs, and which are considered to be potentially suitable for the Glanville fritillary. In each autumn, all known habitat patches are surveyed for the presence of larval groups of the Glanville fritillary, as well as scored for several habitat patch attributes. The latter include information on the occurrence of the host plants, landscape structure and habitat quality. In the following spring, all patches occupied in the previous autumn are re-visited, and the numbers of larval groups, numbers of larvae and numbers of cocoons of the local specialist parasitoid wasp Cotesia melitaearum are counted. This large-scale monitoring work has accumulated a comprehensive and unique database on the occurrence of the Glanville fritillary and on the habitat patch characteristics. Moreover, all the habitat patches are currently being positioned with an accurate GPS-machine, which allows analyses of the spatial patterns and properties of the patch network with GIS. Based on this monitoring work, we know the locations of the vast majority of the suitable habitat patches in Åland, totalling about 4200 patches on the main islands in 1999. The habitat patches are distributed across the Åland’s land area of 1480 km2 , but most of them occur in clusters, typically of tens of patches. The main reason for the aggregated distribution of habitat patches is that the meadows mainly occur within the cultural landscape on rocky outcrops, typically near small villages. The patch-aggregates form well over one hundred habitat patch networks, many of which are occupied by the Glanville fritillary, and where the respective metapopulations have relatively independent dynamics. In 1999, about 360 patches were occupied by the Glanville fritillary. The average size of the habitat patches is only 1200 m2, and the mean and median population sizes are only 4 and 2 larval groups, respectively (which translates into about 80 and 40 full-grown larvae on average). Therefore, it is easy to understand that there are numerous turnover events (extinctions and colonizations) in each year. For example, from 1998 to 1999 we recorded 40 colonizations and 126 extinctions. The turnover events are to a large extent correlated spatially, but different parts of Åland typically have independent contradictory trends between any two years.

50 Kuhmo

In the past 100 years, modern forestry has dramatically changed the Finnish landscape. Today the amount of old-growth forest remaining increases from the most densely populated south to the north, as well as from the western coast to the Russian border. On the other hand, because of climatic reasons, the natural species diversity of forest-specializing organisms decreases to the north. From these facts one may conclude that the most favourable area for studying forest-dwelling species is Kuhmo in eastern middle Finland. A further important feature is that there is a large extent of virgin forests nearby in Russia, which maintains viable populations of taiga species and may serve as a source for isolated Finnish populations.

Fallen trunks in the old-growth forest in Kuhmo, photo Reijo Penttilä.

These reasons led to cooperation between Ilkka Hanski’s MRG (Helsinki) and the Research Centre of the Friendship Park (Kuhmo), in the framework of a major mutual project entitled ”Biodiversity of Boreal Forests”. Research in Kuhmo has concentrated on spatial and temporal responses of old-growth forest species to forest management on the role of two deciduous tree species in old-growth forests and on the biology of endangered taiga species. By studying species diversity in small fragments of old-growth forest we attempt to assess the extinction debt in small forest fragments. Empirical data on a wide range of taxa, sampled from 23

51 forest fragments will be related to the history of forest fragmentation around each study fragment. Fragmentation may also cause extinction cascades, when the base of a specialized food chain disappears, as we have shown in the case study on a polypore fungus – moth – parasitoid chain. Aspen and goat willow, both living and dead, represent essential microhabitats for a diverse group of organisms in boreal forests. We have mapped all aspen and willow trees larger than 10 cm DBH within an area of 120 km2. Studies on spatial population structure and dynamics of organisms associated with the aspen, like the lichen Lobaria pulmonaria, several mosses and beetles, have been conducted by using the database on the host tree distribution. The beetle Pytho kolwensis, living in virgin spruce forests, has been one of the target species while studying the biology of endangered old-growth forest species. Special emphasis has also been put on research on spore dispersal of the endangered saproxylic fungus Phlebia centrifuga. Long-distance spore dispersal is very rare, which probably prevents patch to patch colonization in fragmented landscapes. We have started a population genetic study selected old-growth forest species including the beetle P. kolwensis. We have compared the behaviour of two moth species in a mosaic of small fragments of old-growth in otherwise managed forest landscapes. In a mark- release-recapture study we tested the significance of ’ecological corridors’ and ’stepping stones’ for the moths. Both Xestia speciosa and X. rhaetica, a generalist and an old-growth forest specialist species, respectively, preferred corridors for dispersal, but were also able to cross wide sapling stands. However, they both avoided clearcuts.

Forest fragmentation studies in central Finland

The effects of forest fragmentation on old-growth forest species have been studied in Häme, south-western Finland in 1998 and 1999. The study areas consist of 18 old-growth forest fragments, which vary in size from 2 to 250 ha. The taxa that have been studied include birds, lichens, polypores and insects (especially saproxylic beetles). Forest structure and quality were recorded by systematic line sampling, including variables such as living trees, age of the dominant tree layer, coarse woody debris, cut stumps, openness of the forest and proportion of swampy areas. Species inventories and forest structure inventories were made in 9 ha study plots if the old-growth forest fragment was greater than 9 ha.

52 Weasel-vole experiment on islands in lakes

Field vole Microtus agrestis, photo Janne Sundell.

A large-scale field experiment on the dynamics of microtine rodents and their main mammalian predator, the least weasel, is being conducted in three experimental islands in lakes in southern and central Finland. The experimental islands, as well as comparable adjacent control islands, are located in Lake Saimaa, Lake Pielinen and Lake Päijänne. Experimental and control islands are 5-10 km2 large and they all include about 1 km2 of primary field vole (Microtus agrestis) habitat, i.e. meadows, old fields and clear cut areas with plenty of hay. The vole population dynamics were studied by live-trappings in primary field vole habitats and biannual snap-trappings in these habitats as well as in forests and clear cuts. The study also involves avian predator and small game censuses. Additions of least weasels, in order to perturb the vole-weasel dynamics, have been started on all islands, and last weasels will be released in late autumn 2000. Some of the released weasels were radio-tracked in order to obtain information about their movements and survival.

Stoat dynamics in Kilpisjärvi

We have monitored stoat dynamics in the Kilpisjärvi area (69'' 10' N, 20'' 50' E) of Finnish Lapland. Most of the landscape is open tundra, but in low altitude valleys subarctic birch forest dominates. We started live trapping and radio-tracking of

53 small mustelids in summer 1998, and have continued in summer 1999. In addition, we have counted snow tracks in 10-kilometer lines in November and January.

Typical stoat habitat in the open tundra in the Kilpisjärvi area, photo Paavo Hellstedt.

The snow track lines were in two different habitats, on a more productive lakeshore line and on a less productive birch forest slope. Size of home ranges and the movements of stoats depended on season and food resources. Females and males live in different habitats. Males commonly hunt in the forest while females prefer open habitats. Females' home ranges are smaller and they move less when hunting than males. Behavioural differences between weasels and stoats, and changes in their densities might have different effects on vole population oscillations. This study will be continuing in summer 2001. We have used the Kilpisjärvi Biological Station as a base. This research is in cooperation with the Finnish Forest Research Institute (Heikki Henttonen).

Lemming cycles in Northeast Greenland

Northeast Greenland holds one of the simplest vertebrate communities on earth with only one rodent species: the collared lemming. Hence It provides a unique

54 opportunity to investigate the predator-prey interaction, which is hypothesised to control the rodent dynamics. A three-year field program has been organised jointly between the Universities of Helsinki, Montpellier and Freiburg from 1998 to 2000 in order to parameterize and test Hanski & Korpimaki’s (1995) model for the lemming cycles. Other aspects of predator-prey interactions, such as prey selection, have also been studied. The study site is about 75 km² and is located on Traill Island (72°30’ N, 24°00’ W), NE Greenland. This area, part of the high Arctic breeding range of collared lemming, consists of a wide open valley facing the Kong Oscar Fjord. Numerous raised beaches lie parallel to the present shoreline. Inland elevations do not exceed 250 m. above sea level and in contrast to other tundra areas, lakes are scarce and small in size (< 1 ha). Summer is short with only three months without snow cover, and mean summer temperatures do not exceed 5°C. The region has a discontinuous semi-desert polar vegetation. The lemming population dynamics display typical cyclic patterns (4 years) that are also reflected in the densities of predators: arctic fox, stoat, long-tailed skua and snowy owl.

Western part of the Greenland study area at the beginning of June, photo Olivier Gilg.

55 Synopsis of the year 2000

Budget

Funding Source FIM

Academy of Finland Centre-of-excellence funding to MRG 1 500 000 Metapopulation biology 1 382 189 Biodiversity in boreal forests 517 300 Tree canopy insect project 266 526 Stochastic adaptive dynamics of complex systems 96 000

University of Helsinki Centre-of-excellence funding to MRG from Ministry of Education 945 000 Salary for a technician 164 892

Ministry of Agriculture and Forestry Biodiversity in boreal forests 850 000

European Commission Survival of species in fragmented landscapes 578 820

Finnish Cultural Foundation Small mammal population dynamics 80 000

Centre for International Mobility Scholarships 60 000

TOTAL 6 440 727

Ministry of Environment * Biodiversity in boreal forests 1 000 000

* managed by the Research Centre of the Friendship Park in Kuhmo

56 Publications

Colas, B., Thomas, C.D. and Hanski, I. 2000. Evolutionary responses to landscape fragmentation. In: R. Ferriere, J.H.J. Metz and U. Dieckmann (Eds.), Evolutionary Conservation Biology. Cambridge University Press, in press.

Gilg, O., Sane, R., Solovieva, D.V., Pozdnyakov, V.I., Sabard, B., Tsanos, D., Zöckler, C., Lappo, E.G., Syroechkovski jr, E.E. and Eichhorn, G. 2000. Birds and Mammals of the Lena Delta Nature Reserve, Siberia. Arctic 53, 118-133.

Gu, W.D., Kuusinen, M., Konttinen, T. and Hanski, I. 2000. Spatial patterns in the occurrence of the lichen Lobaria pulmonaria in managed and virgin boreal forests. Ecography, in press

Hanski, I. 2000. Extinction debt and species credit in boreal forests: modelling the consequences of different approaches to biodiversity conservation. Annales Zoologici Fennici, in press.

Hanski, I. 2000. Metapopulation dynamics: theory and applications (in Chinese). In: Da-Yong Zhang (Ed.), Researches on Theoretical Ecology, pp. 123-150. CHEP and Springer, Heidelberg.

Hanski, I. 2000. Population dynamic consequences of dispersal in local populations and in metapopulation. In: A. Dhont and F. Saunier (Eds.), Evolution of Dispersal. Oxford University Press, in press.

Hanski, I. 2000. Metapopulations of animals in highly fragmented landscapes and the PVA. In: S.R. Beissinger & D.R. McCullough (Eds.), Population Viability Analysis. Chicago University Press, in press.

Hanski, I. 2000. Biology of extinctions in butterfly metapopulations. In: C. Boggs, W. Watt and P. Ehrlich (Eds.), Biology of Butterflies. Chicago University Press, in press.

Hanski, I. 2000. Spatially realistic models of metapopulation dynamics and their implications for ecological, genetic and evolutionary processes. In: J. Silvertown and J. Antonovics (Eds.), Plants Stand Still, But Their Genes Don’t. Blackwell, in press.

57 Hanski, I. and Henttonen, H. 2000. Population cycles of small rodents in Fennoscandia. In: A. Berryman (Ed.), Population Cycles: Evidence for Trophic Interactions. Oxford Unviersity Press, in press.

Hanski, I. and Ovaskainen, O. 2000. The metapopulation capacity of a fragmented landscape. Nature 404, 755-758.

Hanski, I., Alho, J. and Moilanen, A. 2000. Estimating the parameters of survival and migration of individuals in metapopulations. Ecology 81, 239-251.

Hanski, I., Henttonen, H., Korpimäki, E., Oksanen, L. and Turchin, P. 2000. Small rodent dynamics and predation. Ecology, in press.

Heino, M. and Hanski, I. 2000. Evolution of migration rate in a spatially realistic metapopulation model. American Naturalist, in press.

Henttonen, H. and Hanski, I. 2000. Population dynamics of small rodents in northern Fennoscandia. In: Perry, J.N., Smith, R.H., Woiwod, I. P. and Morse, D.R. (Eds.), Chaos in Real Data, pp. 73-96. Kluwer Academic Publishers, Dordrecht.

Kivistö, L. and Kuusinen, M. 2000 Edge effects on the epiphytic lichen flora of Picea abies in middle boreal Finland. Lichenologist 32, 387-398.

Komonen, A., Penttilä, R., Lindgren, M. and Hanski, I. 2000. Forest fragmentation truncates a food chain based on an old-growth forest bracket fungus. Oikos 90, 119-126.

Kuussaari, M., Singer, M. and Hanski, I. 2000. Local specialization and landscape- level influence on host use in an herbivorous insect. Ecology 81, 2177-2187.

Martikainen, P., Penttilä, R., Kotiranta, H. and Miettinen, O. 2000. New records of Funalia trogii, Perenniporia tenuis and Polyporus pseudobetulinus in Finland, with notes on their habitat requirements and conservation implications. Karstenia 40, in press.

Moilanen, A. 2000. The equilibrium assumption in estimating the parameters of metapopulation models. Journal of Animal Ecology 69, 143-153.

Nielsen, B.J., O'Hara, R.B., Damgaard, C., Østergård, H. og Munk, L. 2000. Resistente meldugsvampe på byg og hvede. Naurens. Verden 83, 32-36.

58 Nieminen, M. 2000. Metapopulationer och artskydd. I verket: M. von Numers (red.), Skärgårdsmiljöer - nuläge, problem och möjligheter, pp. 179-185. Nordiska Ministresrådets Skärgårdssamarbete & Europeiska Unionen, Åbo.

Nieminen, M. ja Kaitila, J.-P. 2000. Saaristomeren niittyjen ja hakojen perhoset. Metsähallituksen luonnosuojelujulkaisuja Sarja A, No 111, 221 s.

Nieminen, M., Leskinen, M. and Helenius, J. 2000. Doppler radar detection of exceptional mass-migrations of aphids into Finland. Journal of Biometeorology, in press.

Nieminen, M., Singer, M.C., Fortelius, W, Schöps, K. and Hanski, I. 2000. Experimental confirmation that inbreeding depression increases extinction risk in butterfly populations. American Naturalist, in press. van Nouhuys, S. and Hanski, I. 2000. Apparent competition between parasitoids mediated by a shared hyperparasitoid. Ecology Letters 3, 82-84. van Nouhuys, S. and Tay, W.T. 2000. Causes and consequences of mortality in small populations of a specialist parasitoid wasp. Oecologia, in press.

O'Hara, R.B., Nielsen, B.J. and Østergård, H. 2000. The effect of fungicide dose on the composition of laboratory populations of barley powdery mildew. Plant Pathology 49, 558-566.

Roslin, T. 2000. Dung beetle movements at two spatial scales. Oikos, in press.

Roslin, T. and Koivunen, A. 2000. Distribution and abundance of dung beetles in fragmented landscapes. Oecologia, in press.

Roslin, T. 2000. Spatial population structure in a patchily distributed beetle. Molecular Ecology, in press.

Schöps, K. and Hanski, I. 2000. Population-level correlation between pre-alighting and post-alighting host plant preference in the Glanville fritillary butterfly. Ecological Entomology, in press.

Siitonen, J., Penttilä, R. and Kotiranta, H. 2000. Coarse woody debris, polyporous fungi and saproxylic insects in an old-growth spruce forest in Vodlozero National Park, Russian Karelia. Ecological Bulletins, in press.

59 Sittler, B., Gilg, O. and Berg, T.B. 2000. Low abundance of King eider nests during low lemming years in Northeast Greenland. Arctic 53, 53-60.

Sjögren-Gulve, P. and Hanski, I. 2000. Population viability analysis using occupancy models. Ecological Bulletin, in press.

Sundell, J., Norrdahl, K., Korpimäki, E. and Hanski, I. 2000. Functional response of the least weasel, Mustela nivalis nivalis. Oikos 90, 501-508.

Suvanto, L., Liimatainen, J. O., Tregenza, T. and Hoikkala, A. 2000. Courtship signals and mate choice of the flies of inbred Drosophila montana strains. Journal of Evolutionary Biology 13, 583-592.

Sääksjärvi, I. E., Komonen, A. ja Nieminen, M. 2000. Parasitoidit - hyönteismaailman tuntemattomat pikkujättiläiset (in Finnish). Luonnon Tutkija 1, 71-80.

Turchin, P. and Hanski, I. 2000. Contrasting alternative hypotheses about rodent cycles by translating them into parameterized models. Ecology Letters, in press.

Wahlberg, N. 2000. Comparative descriptions of the immature stages and ecology of five Finnish melitaeine butterfly species (Lepidoptera: Nymphalidae). Entomologica Fennica, in press.

Wahlberg, N. and Zimmermann, M. 2000. Pattern of phylogenetic relationships among members of the tribe Melitaeini (Lepidoptera: Nymphalidae) inferred from mtDNA sequences. Cladistics 16, in press.

Zimmermann, M., Wahlberg, N. and Descimon, H. 2000. A phylogeny of Euphydryas s.l. checkerspot butterflies (Lepidoptera: Nymphalidae) based on mitochondrial DNA sequence data. Annals of the Entomological Society of America 93, 347-355.

Theses

Niklas Wahlberg, PhD: The Ecology and Evolution of Melitaeine Butterflies

Comparing different species is an excellent way to study evolutionary processes. However, species are not independent entities, as they share genealogical histories

60 to differing degrees. Thus one has to know whether two species share an adaptation due to a common ancestor or whether they have evolved convergently. This knowledge is based on a phylogenetic hypothesis of the species group in question. In my work I have studied the ecology and evolution of butterflies in the tribe Melitaeini (Lepidoptera: Nymphalidae). I have constructed a cladogram of the tribe using DNA sequences from two mitochondrial genes (COI and 16S) taken from 77 melitaeine species and 3 outgroup species. I have found that there are four distinct species groups that are monophyletic, but that several currently recognized genera are paraphyletic. With this phylogenetic hypothesis I have studied the evolution of host plant use in the Melitaeini. I have found that host plant chemistry is a more conservative trait than host plant taxonomy, though host plant families exhibit a strong phylogenetic signal. Most likely the ancestral host plant of the tribe contained secondary compounds called iridoid glycosides and belonged to the family Plantaginaceae. I next compared the dispersal abilities of five Finnish melitaeine species using mark-recapture data. I have found that the five species do not differ from each other and discuss whether the dispersal abilities are constrained in this group of related species. Related species tend to be similar ecologically, and I use this assumption to describe the metapopulation dynamics of an endangered species with information from a common related species. Finally, I investigate the metapopulation dynamics of a single species in a dynamic landscape and arrive at a conclusion that one cannot rely entirely on current models to analyze the metapopulation dynamics of species that inhabit dynamic landscapes. By using comparative methods, we will eventually be able to understand the diversity of species in this tribe and perhaps be able to extend the results to other groups of insects.

Vesa Hyyryläinen, MSc: The occurrence and ecology of two lycaenid species, silver-studded blue butterfly (Plebejus argus ) and idas blue (Lycaeides idas) in Finland

The silver-studded blue and idas blue butterflies are common and widely distributed in Finland, but their basic biology is not well known. Both species are threatened elsewhere in Europe by fragmentation of their environment. I decided to research the two species at the same time, because they coexist in the same habitat and are very much like each other. My study is the first to investigate the population biology of either species in Finland. For both P. argus and L. idas I found new characteristics which help with identification of each species. The mating and oviposition systems of P argus and L. idas are similar. I also found that the occurrence of P. argus and L. idas depend strongly on their habitat requirements, occurring in open areas where heather (Calluna vulgaris) is present.

61 Both species exist as metapopulations. P. argus is a stable species and is more common in mainland habitats than L. idas. Both species also occur on quite large islands, where L. idas is more common in a network of small islands. Each species has a mutualistic relationship with ants; P. argus with Lasius platythorax and L. idas with Formica truncorum. The density of P. argus depends on the density of host ant nests. The main cause of mortality is parasitism; in my studies I found many parasitoid wasps of both butterfly species. The host ants help to protect butterfly larvae against parasitism and predation.

Katja Ojala, MSc: The wing pattern variation and fluctuating asymmetry of the Glanville fritillary butterfly in Åland archipelago

In my thesis I studied the wing pattern variation and fluctuating asymmetry of the Glanville fritillary butterfly in the Åland archipelago. The heritability of the wing patterns was high for most characters studied. There was geographical variation in the wing patterns and wing sizes across Åland, e.g. the butterflies in the middle parts of Åland were larger than in more coastal areas. Wing pattern asymmetry did not show correlation to butterfly size, population size, or heterozygosity, but there was more asymmetry in the female butterflies than in the males.

Otto Miettinen, MSc: Polypores of aspen (Populus tremula), their ecology and response to forest management

I studied the polypore community of aspen (Populus tremula) with the aim of finding out how environmental factors and forest management affect the species composition. Polypores and certain corticoid fungi were mapped in a 3 km² area of old-growth spruce forest in Teeri-Lososuo, Kuhmo, Eastern Finland and in a 6 km² area of near-by managed forest in Autumn 1998. Altogether 59 species, including 15 red listed species, were found from the 1016 aspen trunks studied. Stage of decay, size of the tree and moisture in the surrounding habitat had an effect on species composition. Large trees in moist places had a different and more diverse polypore flora and more red listed species than smaller trees in drier places. Species composition between the managed and old-growth forest areas was clearly different although the number of species was approximately the same: some species preferred the shady old-growth forests whereas others preferred open areas. Red listed species were more common in old-growth forests. Microclimate is suggested to be a major cause of the observed differences in species composition between old-growth and managed forests in the study area.

62 External visits

Mar Cabeza visited Lund University, Sweden (December 99-January 2000). Theoretical ecology course.

Mar Cabeza visited Christian Wissel’s group in Leipzig for 1 week in July.

Ilkka Hanski visited the Department of Biology in Ann Arbor, Michigan, as a guest of their Distinguished Ecologist Programme for 5 days in March. During this visit, he gave 3 talks.

Atte Moilanen visited Christian Wissel´s group in Leipzig in July for two weeks.

The MRG organized a 3-month long study of boreal forests in the Fenglin Forest Reserve in NE China in the summer 2000. (see p. 16-17). Participants: Antti Below (15 weeks), Lei Gang (15 weeks), Jussi Ikävalko (7 weeks), Eva Kallio (4 weeks), Laura Kivistö (4 weeks), Pasi Sihvonen (3 weeks), Reijo Penttilä (3 weeks), Harri Lappalainen (3 weeks) and Jaakko Kullberg (2 weeks).

Seminars, lectures and talks

Mar Cabeza gave a talk at the 1st Student Conference in Conservation Science, Cambridge, April 2000.

Mar Cabeza gave a talk in the extinction workshop, Tvärminne, November 2000.

Olivier Gilg presented a talk “The lemming cycles and the predator-prey interactions” in a seminar on population dynamic at the University of Copenhagen, March 2000.

Olivier Gilg gave a talk “Prey selection by birds of prey on a lemming population in NE Greenland” at the VIII Meeting of Arctic Biologists in Copenhagen, March 2000.

Olivier Gilg gave a talk "Naturalness assessment in old-growth and managed beech-fir forests" in a meeting on biodiversity and conservation of boreal nature, Kuhmo (Finland), 16-19 October 2000.

Ilkka Hanski gave a talk in the meeting of Nordic Bryologists in Lammi, Finland, in March.

63 Ilkka Hanski gave a talk in the Fragland (TMR) annual meeting in Montpellier, France, in March.

Ilkka Hanski gave an invited talk in the EU biodiversity workshop in the Azores in May.

Ilkka Hanski gave an invited talk in the British Ecological Society Symposium on plant population biology in the Royal Holloway College, UK, in August.

Ilkka Hanski gave an invited talk in the 150th anniversary meeting of the German ornithological society in Leipzig, Germany, in September.

Ilkka Hanski gave a talk in two international meetings in Kuhmo in August and October.

Ilkka Hanski gave invited talks in the Universities of Helsinki and Turku, Finland.

Ilkka Hanski gave a talk in the extinction workshop in Tvärminne, Finland, in November.

Laura Kivistö gave a talk in the workshop “Understanding bryophyte biodiversity: from population processes to landscape patterns” in Lammi biological station, Finland, in March 2000.

Laura Kivistö presented a poster “Epiphytic lichens in old-growth forest fragments in Finland” in the congress on “Disturbance dynamics in boreal forest” in Kuhmo, Finland, in August 2000.

Laura Kivistö presented a poster “Epiphytic lichens in old-growth forest fragments in Finland” in the symposium “Progress and problems in lichenology” in Barcelona, Spain, in September 2000.

Petri Martikainen and Reijo Penttilä gave a talk “Retained aspens on clearcuts: important habitats for threatened beetles and polypores.” in the conference "Disturbance dynamics in boreal forests", Kuhmo, Finland, August 2000.

Atte Moilanen gave a talk "Simple connectivity measures for metapopulation studies" in Montpellier in April 2000.

64 Atte Moilanen gave a talk "Applying the incidence function model" in Tvärminne, Finland, in February 2000.

Atte Moilanen gave a talk "Optimization using evolutionary algorithms and local search" in Tvärminne, Finland, in September 2000.

Saskya van Nouhuys gave a talk "Apparent competition between parasitoids mediated by a shared hyperparasitoid" at the annual Ecology and Evolutionary Biology Symposium, Cornell University, in January 2000.

Saskya van Nouhuys gave a talk "Population dynamics of a herbivore and its parasitoids in a fragmented landscape" at the Department of Entomology, Cornell University, in September 2000.

Saskya van Nouhuys gave a talk "The affect of relative dispersal ability on the population dynamics of two parasitoids and their shared host" at the annual meeting of the Entomological Society of America, Montreal, Canada, in December 2000.

Bob O´Hara gave an invited talk in the "Modelling - Prediction and Analysis of Biodiversity" workshop at the SLU (Sveriges Lantbruksuniversitet) in Uppsala, in November 2000.

Otso Ovaskainen gave an invited talk "Will species persist in the current Finnish forest conservation network" in a WWF´s forest conservation seminar in Stockholm, in April 2000.

Otso Ovaskainen gave a talk "Persistence of threatened species in fragmented landscapes" in the conference "Biodiversity and Conservation of Boreal Nature. Nature Reserve Friendship – 10 Years Anniversary Symposium", Kuhmo, Finland, October 2000.

Otso Ovaskainen attended the workshop "Population projection matrix models" in Montpellier, October 2000.

Otso Ovaskainen gave a talk "Stochastic vs. deterministic metapopulation models" in the extinction workshop in Tvärminne, in November 2000.

65 Reijo Penttilä and Heikki Kotiranta gave a talk “Effect of forest fires on wood- rotting fungi” in the conference "Disturbance dynamics in boreal forests", Kuhmo, Finland, August 2000.

Reijo Penttilä, Juha Siitonen, and Heikki Kotiranta “Comparison of polypore flora in old-growth forests of eastern Finland and Russian Karelia” presented in the conference "Biodiversity and Conservation of Boreal Nature. Nature Reserve Friendship – 10 Years Anniversary Symposium", Kuhmo, Finland, October 2000.

Tomas Roslin gave a talk "Spatial ecology of dung beetles" in the University of Turku, Finland in March 2000.

Tomas Roslin gave a talk "Dung beetle assemblages in changing landscapes", 21st Finnish Days of Entomology, Lammi Biological Station, May 2000.

Tarja Salmi and others presented a poster “Population biology and genetics of Populus tremula and taxa associated with it” in the conference "Disturbance dynamics in boreal forests", Kuhmo, Finland, August 2000.

Tarja Salmi attented the meeting "Sustaining Aspen in Western Landscapes" in Grand Junction, CO, USA, in June 2000.

Leena Suvanto attented the meeting "Modelling and experimental research on genetic prosesses in tropical and temperate forests", Kourou, French Guiana, September 2000.

Gergely Várkonyi gave two talks in the conference on “Disturbance Dynamics in Boreal Forests – Restoration and management of biodiversity” held in Kuhmo, Finland, August 2000: “Species richness in small fragments of old-growth forest” and “Dispersal behaviour of boreal Xestia moths in old-growth forest corridors”.

Gergely Várkonyi gave a talk in the international symposium “Biodiversity and Conservation of Boreal Nature – Nature Reserve Friendship 10 Years Anniversary Symposium”, held in Kuhmo, Finland, October 2000: “Host-parasitoid dynamics drive periodic occurrence of boreal moths”.

Gergely Várkonyi attented the workshop on “Analysis of Capture-Recapture Data – The Estimation of Population Parameters from Data on Marked Animals”, held in Montpellier, France, February 2000, organized by CEFE/CNRS.

66 Gergely Várkonyi gave a talk "Current biodiversity research in Kuhmo", in the Conservation Biology Symposium of the Finnish Environment Administration, December 2000.

TV, radio and newspapers

Ilkka Hanski, MTV3 morning TV, September 2000.

Ilkka Hanski, MTV3 Akatemia, a lecture, in December 2000.

Ilkka Hanski has been interviewed by newspapers and radio concerning the conservation of forest biodiversity and the Balzan Prize 2000.

Tomas Roslin, interviewed on dung beetle biology in Helsingin Sanomat 7.5.2000 ("Mistä koti sontiaiselle" kirjoittajana S. Korpimo)

Tomas Roslin interviewed on dung beetle biology in Eläinmaailma 7/2000 (July) ("Liukumiinassa on elämää", kirjoittajana Jani Kaaro, s. 30-34)

Tomas Roslin, interviewed on dung beetle biology in YLE Radio Suomi July 2000 (Luontoretki, toim. Juha Laaksonen)

Tomas Roslin, interviewed on dung beetle biology in MTV3 news in July 2000.

Teaching and courses

The Ultimate Course on CONSERVATION BIOLOGY IN FRAGMENTED LANDSCAPES (1-6 SW)

This course will give basic knowledge of the spatial structure and dynamics of fragmented populations. We aim for an interesting blend of theory and empirical case studies, and will put particular emphasis on the application of metapopulation theory to practical conservation issues. The lectures are given by young researchers active in the Metapopulation Research Group.

The course consists of several units:

1) Lecture series (1 sw) coordinated by Roslin, Nieminen and Moilanen, see below.

67 2) Seminar on "Conservation Biology in Fragmented Landscapes" (1 sw) coordinated by Roslin, Nieminen and Moilanen. Two days of student presentations at the Lammi Biological Station.

3) Seminar on "Biodiversity in Boreal Forests" (1 sw) coordinated by Ovaskainen Two days of student presentations at the Lammi Biological Station.

4) Book exam (2 sw) Hanski, I. 1999. Metapopulation Ecology. Oxford University Press (with some complementary material). Coordinated by Roslin, Nieminen and Moilanen.

5) Practicals (1 sw) Simulations, essays etc., based on personal agreement with the lecturers. Organized by the lecturers.

LECTURES ON CONSERVATION BIOLOGY IN FRAGMENTED LANDSCAPES

1. General introduction: Habitat loss, fragmentation and species extinction. (Roslin)

2. Empirical case studies I: Fragmented boreal forests. (Penttilä and Várkonyi)

3. Extinctions: causes and patterns. (Nieminen)

4. Population genetics of fragmented populations. (Painter)

5. Metapopulation concepts and modeling. (Moilanen)

6. Practical metapopulation modeling. (Moilanen)

7. Empirical case studies II: Melitaea cinxia. (Nieminen)

8. Habitat loss, the extinction debt and the delay to extinction. (Moilanen and Ovaskainen)

9. Empirical case studies III: Multiple species in fragmented landscapes. (Roslin)

10. The selection of natural reserves: Introduction. (Cabeza-Jaimejuan)

68 11. The selection of natural reserves: Site selection algorithms. (Cabeza-Jaimejuan)

12. Conclusions and prospects for the future. (Hanski)

Tapio Gustafsson, instructor at the field course on “Subarctic Ecology” in the Kilpisjärvi Biological Station (University of Helsinki), 27th June – 6th July 2000.

Paavo Hellstedt, lectures in the cource of "Animal identification" and "Evolution and systematics", the leader of the "Ecology and behaviour of carnivores" seminar and a teacher at the field course of "Ecological spring processes in the tundra" and "Ecology of mammals" and a leading teacher at the field course of "Ecology". Department of Ecology and systematics, University of Helsinki.

Reijo Penttilä, a lecture “Käävät boreaalisessa metsässä” in the course “Boreaalisen metsän rakenne, dynamiikka ja monimuotoisuus” at the Department of Forest Ecology, University of Helsinki.

Mika Siljander, GIS teacher in the Programme for Maintenance and Applications of Geographical Information Systems at University of Helsinki Centre for Continuing Education.

Mika Siljander, "Using ArcView GIS in ecological research: building GIS database for the Glanville fritillary; Landscape analysis using ArcView Patch Analyst and Fragstats 2.0", in the course: Ecological applications of geographic information systems. Department of Ecology and Systematics University of Helsinki.

Gergely Várkonyi, teacher in the field course on “Taxonomy and Ecology of Terrestrial Animals” of the University of Oulu in the Oulanka Biological Station.

Honors and awards

Mar Cabeza was awarded the Prize for the best presentation at the 1st Student Conference in Conservation Science, Cambridge, April 2000.

Ilkka Hanski was awarded the Balzan Prize 2000 for Ecological Sciences (http://www.balzan.it/).

69 Council Memberships

Ilkka Hanski has served in the Scientific Advisory Board of the National Center for Ecological Analysis and Synthesis (NCEAS) in Santa Barbara (US).

Ilkka Hanski has served in the Scientific Advisory Board of the Faculty of Science, University of Helsinki.

Ilkka Hanski served in a panel assessing projects in the International Institute of Applied Systems Analysis (IIASA) in Laxenburg, Austria, in May 2000.

Marko Nieminen has served as a board member and conservation committee member in the Finnish Lepidopterological Society and as an editor of supplementary volumes.

Reijo Penttilä has served as a Member of the Organizing Committee for the international conference "Disturbance Dynamics in Boreal Forests", held in Kuhmo, Finland, in August 2000.

Tomas Roslin has served as a Member of the Board of the Societas Entomologica Helsingforsiensis, Helsinki, Finland.

Meetings organized by the MRG

Annual Meeting of the MRG, at the Lammi Biological Station in January.

Fragland (TMR) workshop "Explanation and demonstration of models of movement behaviour and evolution of migration rate" in Tvärminne, Finland, in February (23 participants).

Fragland (TMR) Mid-Term Review in Montpellier, in March-April 2000 (65 participants).

Meeting of the China expedition 2000, in October (see p. 16-17).

Symposium on Insects and Their Host Plants - A Complex Interaction, October 26th 2000.

70 Workshop on Population Extinction, Tvärminne Zoological Station, Finland, in November 2000 (25 participants).

Annual meeting of the Scientific Advisory Board of the three ecological centres of excellence in research selected by the Academy of Finland, Helsinki in November.

Visitors to the MRG

Mattias Forshage, collaborative research with Tomas Roslin and participation in the 21st Finnish Days of Entomology, May 2000.

John Kean, to discuss his work with the members in the MRG and collaborative research, September 2000.

Mike Singer, examiner to Niklas Wahlberg´s academic dissertation "The Ecology and Evolution of Melitaeine Butterflies" and collaborative research, February and October 2000.

Tony Ives, Population Extinction workshop and collaborative research, November 2000.

Michael Whitlock, Population Extinction workshop and collaborative research, November 2000.

71 Prospects for the year 2001

In contrast to the relatively minor changes in the personnel and projects in 2000, more substantial changes will occur in 2001. Several students and post docs are expected to move on to other positions after having completed their projects with us, and they will be replaced by new recruits. I especially look forward to a new wave of research on small populations of shrews on islands, which was for some time my primary research interest in the 1980's. The plan is to combine the substantial research opportunities provided by island populations of shrews with the existing tools of DNA markers. Whether we are able to start making real progress with the genetic study of the Glanville fritillary metapopulation in the Åland Islands is still an open question, but I do expect that the revision of the complex database of the Åland metapopulation will be completed in 2001. The Glanville fritillary project will probably expand to the large Estonian island of Saaremaa in 2001. Boreal forest reseach will continue in NE China, though definite plans have not yet been made. Some new lines of modelling will be started in 2001, and the prospects are generally bright for the ongoing modelling work to produce several really exciting and important results in the coming year. In brief, many new things will happen in the MRG in 2001!

Ilkka Hanski

Typical Melitaea cinxia habitat patch in the Åland Islands.

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