PERSONNEL



Cypripedium calceolus; A. Komonen Hanski, Ilkka
Hanski, Ilpo
Heikkilä, Raimo
Hellstedt, Paavo
Ikävalko, Jussi
Kivistö, Laura
Komonen, Atte
Kuusinen, Mikko
Lindgren, Mariko
Miettinen, Otto
Ovaskainen, Otso
Painter, Jodie
Pakkala, Timo
Penttilä, Reijo
Salmi, Tarja
Selonen, Vesa
Siitonen, Juha
Siitonen, Paula
Snäll, Tord
Sundell, Janne
Suvanto, Leena
Várkonyi, Gergely



Hanski, Ilkka
Professor of Ecology, University of Helsinki


Research aimed at developing testable models and theory in population ecology, and at testing such models. Currently three main projects, metapopulation biology, predator-prey theory applied to the dynamics of microtine rodents and their mustelid predators, and population biology and biodiversity of old-growth forest specialist species. Metapopulation research includes a range of modelling studies and the supervision of empirical projects, including the large-scale and long-term study of the metapopulation biology of the Glanville fritillary butterfly (Melitaea cinxia) in Åland, SW Finland. The metapopulation approach will also be applied to the dynamics of old-growth forest specialists now restricted to small fragments of remaining old-growth, but the old-growth forest project also includes a range of other approaches with which we hope to increase the general understanding of the population biology of old-growth forest specialist species.

Check also Metapopulation Research Group


Hanski, Ilpo
University of Helsinki


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Heikkilä, Raimo


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Hellstedt, Paavo
University of Helsinki


My Ph.D. research interests involved 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 refleced 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.


Ikävalko, Jussi
Graduate student, University of Helsinki


Master thesis: Structure of insect communities inhabiting bracket fungi of genus Fomitopsis in NE China

My work is focused on the structure of insect communities in three bracket fungi species: Fomitopsis pinicola, Fomitopsis rosea and Fomitopsis cajanderi. I collected material for this study from Fenglin Forest Reserve in northeastern China in May-June 2000. Study area belongs to boreal forest region, where has not been any extensive glaciations for over two million years. Main questions of my study are:
1) what are the differences in insect species composition between these closely related fungal species at local level and
2 ) how do the insect communities in F. pinicola and F. rosea in NE China differ from results recorded from old-growth forests in Finland.


Kivistö, Laura
Post graduate student, University of Helsinki


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.

Updated 15.11.2000


Komonen, Atte
Student, University of Helsinki


I started my PhD project in the spring 1997 as a part of the comprehensive project "Biodiversity in boreal forests". My personal research interest is the structure of communities and food webs in old-growth forest specialist insect species inhabiting bracket fungi. I have especially focused on the effects of forest fragmentation on fungal insect communities in small old-growth forest fragments. The main study fungal species are the old-growth forest specialist polypores Amylocystis lapponica and Fomitopsis rosea. Since September 1999, I have been working as UNV wildlife biologist in Choibalsan, Mongolia, dealing with the biodiversity issues in Mongolia’s eastern steppe. In the autumn 2001, I will return to finish my PhD in Helsinki.


Kuusinen, Mikko
Researcher, University of Helsinki


Mikko Kuusinen, PhD, Docent, has been working as a researcher at the Department of Ecology and Systematics in the University of Helsinki in two projects:
(1) "Biodiversity in boreal forests" coordinated by prof. Ilkka Hanski and
(2) "Structure and dynamics of natural and managed boreal forest landscapes" coordinated by Dr. Timo Kuuluvainen.

Specialized on epiphytic lichens, especially species diversity, community structure and population biology of boreal forest species. A subject of particular interest has recently been the impact of forestry on epiphytic lichen and bryophyte populations and communities.

Main research tasks:
1. Spatial pattern analyses of epiphytic lichen and bryophyte populations at different scales.
2. Population biology of trembling aspen (Populus tremula) and goat willow (Salix caprea).
3. Epiphytic lichen communities in managed and old-growth boreal forests.
4. Threatened lichen species in Finland.

Currently employed as Senior adviser at the Finnish Ministry of Environment.


Lindgren, Mariko
Post graduate student, University of Helsinki


Personal homepage


Miettinen, Otto
Graduate student, University of Helsinki


Master Thesis: Polypores of aspen (Populus tremulae) their ecology and response to forest management

I studied the decomposer 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-Losonsuo, Kuhmo, Eastern Finland and in a 6 km2 area of near-by managed forest in Autumn 1998.

Altogether 59 species, including 15 red listed, 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 managed and old-growth forest area was clearly different although the number of species was approximately the same: some species preferred the shady old-growth forests and others open areas. Red listed species were more common in old-growth forests. Microclimate is suggested as a major factor behind the differences in species composition between old-growth and managed forests in the study area.


Ovaskainen, Otso
Researcher, University of Helsinki


I completed my PhD in 1998 in the laboratory of Mathematics, Helsinki Technical University. I am new in the metapopulation group, joined in June 1999.

My aim is mathematical analysis of the models used to describe metapopulation dynamics. Currently I am working with deterministic threshold conditions and their approximations for metapopulation persistence in spatially realistic landscapes. We have shown that a single measure, called Metapopulation capacity, can be extracted out from the matrix describing the habitat patch network, i.e., the areas and the spatial locations of the patches. In the framework of a few deterministic metapopulation models, this measure gives the threshold condition determining if long-term persistence is possible. The concept Metapopulation capacity can also be utilized e.g. when estimating the relative values of individual patches or analysing how different ways of destructing or deteriating the habitat patches will effect the viability of the focal species.

In the future I hope to find myself analysing the stochastic variants of the metapopulation models. The analysis of the metapopulation models in a dynamic landscape would be interesting, too. And how these topics are related to biobof? Certainly very closely. Many species occur as metapopulations even in a virgin forest. Furthermore, the fragmentation of forests has made the study of metapopulation dynamics in the boreal forests even much more relevant.

Updated 15.11.2000


Painter, Jodie
Researcher


I am working on two research projects. 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.

Updated 15.11.2000


Pakkala, Timo


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Penttilä, Reijo
Researcher, Research Center of the Friendship National Park


I am interested in the population and community ecology of wood-rotting fungi, and of polypores in particular. 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.

Updated 15.11.2000


Salmi, Tarja
Post graduate student, University of Helsinki


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.

Updated 15.11.2000


Selonen, Vesa
Student, University of Helsinki


PhD work on population biology of Siberian flying squirrel.

As a main methods in my work I use radiotelemetry and microsatellite markers. At the moment my interests with flying squirrels are effect of forest fragmentation on space use and population genetics, use of ecological corridors, and natal dispersal. I started my work 1998 and PhD will be ready in late 2002. Before the flying squirrel project I have been working with butterflies (master's thesis), birds and plants. My future interests are in population and conservation ecology and in evolution & philosophy.


Siitonen, Juha
Researcher, Finnish Forest Research Institute

I work at the Finnish Forest Research Institute as a resercher. My main research interest is the effects of forest management on invertebrate fauna, particularly the relationships between coarse woody debris and saproxylic Coleoptera. In the present project, I am mainly involved in the subprojects dealing with:
Photo by Ilkka Hanski
  1. species diversity in small fragments of old-growth forest (responsible for measurements of stand characteristics and identification of beetle materials),
  2. population biology of trembling aspen and
  3. biology and genetics of the endangered old-growth specialist beetle species, Pytho kolwensis.
  4. In the photo left I have just found the first larva of P. kolwensis from the Fengling reserve in Heilongjiang province, China.


Siitonen, Paula
Researcher, Finnish Environmental Institute


I am doing PhD concerning measurement of biodiversity and landscape ecological forest planning for the department of ecology and systematic of University of Helsinki as a part of "Biodiversity in boreal forests" - project. Presently I work as a senior scientist in the Finnish Environment Institute, in Nature and Land Use Division. I am coordinating projects which aims for the development of methods for landscape ecological forest planning and assessment of forest biodiversity. Scientific work includes studies dealing with development of heuristic optimizing tools, studies on dispersal of fungi and liverworts, edge effect and fragmentation history. Method developed for the assessment of biodiversity (MoniWin) has been used since 1995 in Forest and Parks Service in landscape ecological planning.


Snäll, Tord
PhD student, Dept. of Plant Ecology
Uppsala University, Sweden


The title of my PhD project is "Dispersal and distribution patterns of mosses" and I am mainly interested in species confined to patchy substrates such as trees (epiphytic species). I study spatial patterns and dynamics of these mosses on different spatial and temporal scales.

Two of my PhD projects are part of Task 2, "Population biology of the trembling aspen (Populus tremula) and the taxa associated with it in boreal forests". In Kuhmo, central-eastern Finland I have quantified two aspen epiphytes on all trembling aspen trees within a 3 x 3 km2 square. For each tree I have estimated substrate (e.g. bark structure) and habitat (e.g. sun exposure) variables. Study species are the two aspen obligates Orthothricum speciosum and O. obtusifolium. The results strongly indicate dispersal limitation of these species in the landscape. The analysis is conducted in collaboration with Paulo Justiano Ribeiro Jr, Maths and Stats, Lancaster University, UK. (Snäll, Ribeiro & Rydin, in prep.).

I also study the genetical structure of O. speciosum and O. obtusifolium using AFLP methods. The species have been sampled on many mapped aspens in the landscape. Both within tree and between tree structure is being analysed. The work is conducted in collaboration with Johan Fogelqvist and his supervisor Martin Lascoux, both at EBC, Uppsala University, Sweden.

Updated 1.10.2001


Sundell, Janne
Post graduate student


The main interest is the population dynamics of microtine rodents. The aim of the PhD project is to test the predator-prey hypothesis about the cyclic vole populations with a large-scale field experiment, in which vole-weasel dynamics on large islands in lakes are perturbed by adding captive-born weasels to cause a premature decline of vole populations. Subsequently the aim is to keep the vole density at a permanently low lewel by further additions of weasels. The experiment was started in 1997 and will continue in 2000. My other interests include the functional response and the prey choice of the least weasel. A captive breeding program of least weasels for the large-scale field experiment will also produce valuable information on various aspects of least weasels' reproduction biology for my PhD dissertation.


Suvanto, Leena
Post doc, University of Helsinki


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.

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.

Updated 15.11.2000


Várkonyi, Gergely
Researcher, Kainuu Regional Environment Centre, Research Centre of Friendship Park

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", 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 pupae of Xestia moths have such an important role in the local food web, that even the population size of the generalist predator shrews (genus Sorex) is fluctuating with the Xestia numbers.

Updated 15.11.2000