Research Assessment Exercise 2007 University of Oulu
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3a.5 Year 2005Abbas Aflatuni (2005) The yield and essential oil content of mint (Mentha ssp.) in Northern Ostrobothnia. Acta Universitatis Ouluensis A 438. University of Oulu, Department of Biology. http://herkules.oulu.fi/isbn9514277465/ Peppermint (Mentha x piperita L.) oil is one of the most popular and widely used essential oils, mostly because of its main components menthol and menthone. Peppermint oil is used for flavouring pharmaceuticals and oral preparations. Corn mint is the richest source of natural menthol. Carvone-scented mint plants, such as spearmint (M. spicata), are rich in carvone and are widely used as spices, and they are cultivated in several countries. Studies were made into the yield and essential oil content of several mint species and the original. The general aim of the work was to examine the optimal conditions for cultivating mint in Northern Finland. The specific aims of the study were (first) to investigate the differences in the oil content for several mint species and (secondly) to compare the effect of various factors such as plant spacing (10, 20 and 30 × 50 cm), liming (0, 4, 8, 12 and 16 tons ha-1), propagation methods (micropropagated and conventionally propagated plants) and harvest date (once at the end of August in comparison with first cut at the beginning of August and second cut in mid September) on the cultivation success, quality and quantity of the plants. The constituents of the essential oil were analysed from leaf samples using GC-MS. Among the peppermints of different origins studied, peppermint of USA and Egypt origin ('Black Mitcham') contain the highest menthol and optimum oil yield. Corn mint and Sachalin mints both had high menthol content. Due to several reasons, such as no significant differences between the different densities and oil composition, markedly higher amount of weeds at 30 × 50 cm than at 10 × 50 and 20 × 50 cm spacing and the high seedling costs and the danger of fungi and disease at a 10 × 50 cm spacing, a plant optimum of 20 × 50 cm spacing is recommended for Northern Ostrobothnia. If the pH value is lower than 6, or levels of Mg and Ca are low, liming at a rate of 4–8 t ha-1 for sandy soils in Finland is recommended in order to achieve higher fresh and oil yields. In the first year, there were no differences in the dry leaf yield of micropropagated and conventionally propagated plants, but the menthol content was significantly higher in conventionally than in micropropagated plants. In the second year, only the dry leaf yield of micropropagated plants was higher than that of their conventionally propagated counterparts. Cutting peppermint only once during full bloom (the end of August) gives the maximum oil yield of good quality. In conclusion, it is possible to achieve as high as or even higher oil quality and dry yield in North Ostrobothnia than it is in central Europe or south Asia. However, this requires observing certain cultivation factors such as having the right type of mint, soil pH, planting density, harvesting time and propagation method In addition, mints must be cultivated in the same place for only two and a maximum for three years. Keywords: harvest time, in vitro propagation, Lamiaceae, lime, Mentha arvensis var. piperascens, Mentha arvensis var. sachalinensis, Mentha canadensis, Mentha x piperita, menthol, menthone, pH, plant density, propagation methods, roots, stolons Anne Jäkäläniemi (2005) Adaptation, population viability and colonization-extinction dynamics of Silene tatarica in riparian habitats. Acta Universitatis Ouluensis A 443. University of Oulu, Department of Biology. http://herkules.oulu.fi/isbn9514278208 Plants in riparian environments have to tolerate disturbances like floods and erosion. In the absence of disturbances, habitats will gradually become unfavorable for early-successional species. This can have fundamental consequences not only for adaptation at the individual level, but also for the viability of local populations as well as for the persistence of the species on a regional scale. Silene tatarica is a rare perennial plant exposed to annual floods of the Oulanka River. After sand burial most plants formed vertical rhizomes and new meristems by bud ramification. The special anatomical features of these fleshy underground structures seemed to allow the plants to be very resilient against fast-flowing water. Seed structure may enhance long-distance dispersal by water. Selection gradients for plant height were positive at the individual and group levels, but for the number of stems they were in opposition, as selection at the group level favored a smaller number of stems. This can be associated with pollination and herbivory, since taller and larger plants often attract more pollinators and mammalian herbivores. At the local level, population growth was most sensitive to the survival and growth of juvenile individuals. The populations showed different fates, and according to stochastic simulations some of them will disappear in the near future. Their colonization and extinction rates varied between the years, but their balance over the study period was positive. Small patches had the highest risk of extinction and recolonization of extinct patches was very rare. Elasticity analysis indicated that the survival of patches made a much greater contribution to patch dynamics than did the production of new patches. The short-term dynamics of S. tatarica depend primarily on local dynamics but, in the long run, the species will track the availability of habitat, and its persistence will depend on successful colonizations. The amount of suitable habitat depends on river disturbance. Conservation of this species requires the creation of new suitable open sites for colonization, a dispersal process leading to successful colonizations, and favorable habitats for survival. These conditions can be maintained either by natural processes of river disturbance or by active conservation management. Keywords: conservation, demography, flood, habitat tracking, local population, metapopulation, regional population, stochasticity Mirja Laurila (2005) Thermoregulatory consequences of starvation and digestion in birds. Acta Universitatis Ouluensis A 435. University of Oulu, Department of Biology. http://herkules.oulu.fi/isbn9514277147/ In homeothermic birds and mammals, several thermoregulatory adaptations have evolved for surviving in unstable, food-restricted conditions. This study focuses on two adaptive mechanisms in pigeons (Columba livia) and quails (Coturnix coturnix japonica): hypothermia and the adaptive use obligatory heat production connected with feeding and digestion. The plasticity of the hypothermic response in fed and fasted birds and birds with restricted feeding was studied in laboratory and outdoor winter conditions. The other objective was to study adaptive timing of digestion, and substitution of facultative thermogenesis by obligatory heat production in cold and at thermoneutrality. The results showed that fasting has a strong influence on the level of nocturnal hypothermia in laboratory conditions: hypothermia becomes progressively deeper when fasting continues. In outdoor conditions, ambient temperature and predation risk modulated the daily body temperature (Tb) pattern of fasting pigeons. In very cold conditions, diurnal Tb of fasted birds also dropped below the normal level of the active phase. Predation risk prevented diurnal hypothermia but also attenuated the depth of nocturnal hypothermia in fasting pigeons. This study provides the first empirical effects of predation risk on hypothermia in starving birds. The study suggests that the presence of crop in pigeons allows adaptive timing of digestion. At thermoneutrality, peak digestion appeared late in the dark phase in birds with fed in the morning. Because the Tb of the birds increases to diurnal levels late in the dark phase, this obligatory heat from digestion can be used to aid re-warming by such timing. On other hand, the results of this study were partly opposite to the classical model of thermoregulatory substitution. In line with the classical model, a postprandial increase in metabolic rate (heat increment of feeding, HIF) was seen at thermoneutrality but not in cold. However, electromyographic measurements showed that there was no postprandial decrease in the intensity of shivering in the fed birds in cold. This indicates that true thermoregulatory substitution may be less common than assumed and suggests a role for facultative thermogenesis in HIF. Keywords: birds, digestion, facultative thermogenesis, fasting, heat increment of feeding (HIF), hypothermia, obligatory thermogenesis, predation, shivering, substitution Kristian Meissner (2005) Consequences of predator-prey interactions in boreal streams. Scaling up from processes to large-scale patterns. Acta Universitatis Ouluensis A 445. University of Oulu, Department of Biology. http://herkules.oulu.fi/isbn9514278682/ In this thesis I studied lotic trout predation and its ecological effects, and investigated invertebrate predator-prey interactions under natural and anthropogenically modified flow conditions. Given the growing concern about the reliability of extrapolations from small-scale studies to larger spatio-temporal scales, results of mechanistic small-scale experiments were scaled up by linking them to large-scale field surveys. An intensive survey assessed changes in diel feeding periodicity, prey selection and daily ration of juvenile brown trout (Salmo trutta L.) over the course of the open water period. This survey provides the first field estimates of juvenile brown trout daily rations and indicates crepuscular feeding peaks. Trout selectively preyed on medium- to large-sized prey, shifting towards epibenthic feeding with increasing availability of suitable prey. In a small-scale field experiment, trout displayed clear size-related predation concentrating on invertebrate predators and cased caddisflies, a pattern that scaled up successfully in large-scale surveys. Further, predation effects on large-sized prey were also repeated in a meta-analysis on lotic salmonid predation. While dense blackfly populations in lake-outlet streams are common, mass outbreaks of blackflies in short-term regulated rivers are poorly studied. In our studies the principal invertebrate predator of vernal benthic communities, the caseless caddisfly Rhyacophila, displayed significant preference for blackflies and was almost unable to capture any other prey, thus resulting in passive selection for larval blackflies. Rhyacophila larvae displayed highest capture success in intermediate current velocities, whereas further increases in current velocities decreased capture success. Short-term regulation releases increased both predator and prey drift but, unlike for Rhyacophila, magnitude of drift was unrelated to substrate for blackflies. Indeed, field observations indicated that blackflies rarely face detrimental effects of short-term regulation due to their fast growing rates and early emergence. Moss was the most preferred habitat of Rhyacophila and provided the best buffer against sudden increases in current velocities. These results suggest that several factors maintain spring-time outbreaks of blackfly populations in short-term regulated rivers: exaptation of the dominant blackfly species to prevailing conditions, degradation of the key habitat of the predator, and recurring annual drift losses and diminished capture success of Rhyacophila during short-term regulation releases. Keywords: blackfly larvae, brown trout, macroinvertebrates, predation, prey selection, Rhyacophila, spatial scale, streams Satu Mänttäri (2005) Dihydropyridine receptors in skeletal muscle with comparative reference to muscle development and exercise in mouse and salmon. Acta Universitatis Ouluensis A 436. University of Oulu, Department of Biology. http://herkules.oulu.fi/isbn9514277201/ The dihydropyridine receptor (DHPR) in the skeletal muscle plasma membrane functions as a voltage sensor for excitation-contraction coupling. In the present work the expression and special features of DHPR were studied under various conditions. In order to localize and visualize the DHPRs, a method using fluorophore-conjugated dihydropyridine molecules as a probe was developed. In addition, different laboratory assays and electrophysiological measurements were used to study the expression of the myofibrillar proteins, force production of the muscle and conduction velocity of the plasma membrane. During the postnatal development of mouse skeletal muscle the density of DHPR increased. By the time of DHPR appearance, the expression of sodium channels had started and the typical assembly of basic structural components and membrane compartments was clearly detectable. According to the histochemical analysis, the DHPR was selectively expressed in type IIA muscle fibres of mouse. In addition to the fibre type specificity, the uneven distribution of DHPRs was also seen at the muscle level. The attenuation of the contraction force after addition of DHPR blocker was largest in muscles with a high percentage of type IIA fibres. In fish muscles, the distribution of DHPR was homogenous and the density between different fibre types was quite similar. In gastrocnemius muscle of mouse, the density and mRNA expression of DHPR increased significantly by 21.5 and 66.8%, respectively, after a 15-week aerobic exercise programme. The increase correlated significantly with the raise in % myosin heavy chain IIa isoform. In thigh and heart muscles, no significant changes were observed. In fish, the environmental change following hatchery release and downstream migration of 46.5 km induced an increase in the DHPR density in swimming muscles. Furthermore, a transition of phenotypic profile from fast-to-slow fibres was observed. Taken together, the present data provide evidence for the fact that the expression of DHPR increases during postnatal development. Moreover, the expression correlates with a specific fibre-type metabolism, thus having an impact on the overall contractile properties of the muscle. This is further manifested as an increase in the DHPR density after endurance training in mammalian as well as in fish muscle. In addition, a strong correlation exists between the level of muscle activity and the density of DHPR. Keywords: DHPR, E-C coupling, fibre types, fish swimming musculature, L-type calcium channel Pirita O. Oksanen (2005) Development of palsa mires on the northern European continent in relation to Holocene climatic and environmental changes. Acta Universitatis Ouluensis A 446. University of Oulu, Department of Biology. http://herkules.oulu.fi/isbn9514278895/ This thesis deals with the Holocene development of palsa mires in continental Europe, especially permafrost dynamics and its consequences on vegetation succession and peat accumulation. Peat deposits of four permafrost mires in boreal and subarctic northeastern European Russia and in northern oroboreal Finland have been studied using plant macrofossil analysis, (AMS) radiocarbon dating, dry bulk density and carbon content measurements. In addition, preliminary results are available from another palsa mire in northeastern European Russia. Modern vegetation has been investigated to support the interpretation of fossil plant assemblages. Earlier literature on vegetation, stratigraphy and dating of permafrost mires in Europe has been reviewed. The vegetation of palsa mires in general is well known. As a rule, palsas are dry ombrotrophic habitats, surrounded by wet flarks of variable trophic levels. There is a lack of information about vegetation in different small-scale habitats within palsa mires, which would have been useful when studying the permafrost-vegetation relationship. Although no functional indicator species of permafrost have been found, permafrost dynamics in peat stratigraphy can often be detected with high degree of probability based on changes in vegetation. Some plant assemblages and vegetation successions are typical on permafrost, while many species rarely grow on or near to permafrost. Relatively sudden changes between dry and wet mire environments and continuously dynamic conditions are good signs of permafrost impact. Also gradual changes towards drier conditions may be caused by permafrost; in these cases the timing of first permafrost aggradation is more difficult to ascertain and can usually be pronounced only in terms of maximum and minimum ages. Changes in peat accumulation rates and even hiatuses in stratigraphy are additional tools to support the interpretation on permafrost history at the studied sites. Dry organic matter and carbon accumulation rates for different developmental stages are calculated for the five studied mires. From earlier studies this information is not available. Accumulation rates in the permafrost environment are very variable: from zero or negative rates in old palsas to as high as 100 gC/m2yr in incipient palsas. On moist plateau palsas, permafrost flarks and in unstable permafrost conditions, accumulation continues at low to moderate rates. Thermokarst processes result in decomposition of former peat deposits with important consequences for the ecosystem carbon balance, especially in plateau palsa mires. Radiocarbon datings are available from 27 permafrost mires in continental Europe; only 5 of these are situated in Russia. Many of the published dates cannot be considered reliable as dating permafrost aggradation. Based on limited material, permafrost started to develop at latest about 3000 BP in mires of northern Russia and 2500 BP in Fennoscandia. Older permafrost formation is suggested for a few sites, but the evidence is insufficient to confirm this interpretation. The oldest preserved palsas are ca. 2500–2000 14C years old. Most of the modern palsas are less than 600 14C years old. Permafrost aggradation follows the major climate development in the Holocene, with formation being most active during the coldest stages. Global warming is expected to greatly affect the Arctic in the near future, which would imply significant changes in ecosystem functioning and carbon balance of permafrost mires. This study contributes to the understanding of the possible impacts of climate change on these ecosystems using paleoecological techniques. Keywords: peat accumulation, permafrost, plant macrofossil, radiocarbon dating, stratigraphy, vegetation Veli-Pekka Pelkonen (2005) Biotechnological approaches in lily (Lilium) production. Acta Universitatis Ouluensis A 431. University of Oulu http://herkules.oulu.fi/isbn9514276590/ Biotechnology has become a necessity, not only in research, but also in the culture and breeding of lilies. Various methods in tissue culture and molecular breeding have been applied to the production of commercially important lily species and cultivars. However, scientific research data of such species and varieties that have potential in the northern climate is scarce. In this work, different biotechnological methods were developed and used in the production and culture of a diversity of lily species belonging to different taxonomic groups. The aim was to test and develop further the existing methods in plant biotechnology for the developmental work and the production of novel hardy lily cultivars for northern climates. Most of the plant material was started from seeds, which provided genetic variability and new material for breeding. Different features in seed structure were studied with light microscopy and SEM, and different parameters affecting germination were tested. Several tissue culture protocols were also compared with different species using both solid and liquid media. Molecular biological methods were used in assessing genetic background of traditionally grown lilies. Somatic embryogenesis in callus differentiation of callus cultures was studied, and gene expression behind differentiation processes was analyzed with various molecular biological methods. Particle bombardment system was used in genetic transformation. In addition, protoplast isolation methods from various tissues were tested. The main results indicate that many tissue culture methods can be used in research and in mass production with all tested species. Especially in a large-scale production, temporary immersion system is promising. In addition to the conventional bulb scale material, seeds were found to be a suitable starting material for genetic variability required for production of new cultivars, and in the preservation of natural populations. RAPD techniques proved a suitable method for revealing phylogenetic relations of different lily species and cultivars. Methods in DNA and RNA isolation, cloning and analysis were optimized for lily material. In addition, particle bombardment system was successfully used for genetic transformation of lily callus. In the future, more information is needed to understand better the germination and differentiation processes, focusing especially in the genes, their products and function. In addition, the large and still mostly unknown lily genome is a challenge for research in the future. However, the currently presented results provide good opportunities for further developmental work and research of hardy lily species. Keywords: differentiation, genetic transformation, germination, molecular biology, morphology, somatic embryogenesis, tissue culture Heikki Pöykkö (2005) Host range of lichenivorous moths with special reference to nutritional quality and chemical defence in lichens. Acta Universitatis Ouluensis A 450. University of Oulu, Department of Biology. http://herkules.oulu.fi/isbn951427959X/ Host use and range of herbivorous insects are determined by several factors, of which nutritional quality and secondary chemistry have been shown to play very important roles. For herbivores feeding on lichens these traits are assumed to be more critical than for species feeding on higher plants, since lichens are nutritionally poor and often contain high concentrations of secondary metabolites. I examined the role of lichens' nutritional quality and secondary chemicals on the performance of lichen-feeding Lepidopteran larvae. I also tested whether females of lichenivorous species preferably oviposit on host species of the highest nutritional quality for the growth of larvae. Larvae of Eilema depressum performed best on Melanelia exasperata, which is of the highest nutritional quality, as indicated by the high N concentration and the absence of lichen secondary metabolites compared to the other lichens studied. Host nutritional quality did not promote the production of an additional generation. Larvae of E. depressum needed fewer instars and grew bigger on a high-quality diet than larvae reared on a diet of poorer quality. However, the main factor contributing to the wide variation in the number of larval instars was the question of whether or not larvae overwintered. Growth of Cleorodes lichenaria at the beginning of the larval period matched equally the nutritional quality of the hosts. However, the final larval period was shortest on Ramalina species, which was preferred by both females ovipositing their eggs and larvae searching for a host. In the field, larvae were found almost exclusively on Ramalina species. Larvae of E. depressum were not able to survive on intact thalli of Vulpicida pinastri and Hypogymnia physodes, but after removal of lichen's secondary metabolites, larval survival remained equally high as on other lichens. Larvae also showed a clear preference towards thalli with lowered concentrations of secondary metabolites in Parmelia sulcata, V. pinastri and H. physodes. Parietin in Xanthoria parietina was the only secondary metabolite that had no impact on the survival or host selection of E. depressum larvae. The present results show that the nutritional quality and some lichen secondary chemicals are important factors for the growth, survival and host selection of lichen-feeding Lepidopteran larvae. The preference-performance hypothesis is at least partly able to explain the host range of C. lichenaria, although it seems that there are also other factors, such as larval dispersal and host selection or top-down forces, that might contribute to host range of lichenivorous Lepidopteran larvae. Moreover, lichenivorous larvae seem to be partly responsible for their own host selection. Keywords: foliose lichen, growth rate, host selection, Lepidoptera, lichen secondary metabolite, neonate larva, nutritional quality, preference-performance hypothesis, survival Mona-Anitta Riihimäki (2005) Flowering time and natural selection in Arabidopsis lyrata. Acta Universitatis Ouluensis A 441. University of Oulu, Department of Biology. http://herkules.oulu.fi/isbn9514277945/ Arabidopsis lyrata is a close outcrossing relative of Arabidopsis thaliana, the model organism of plant physiology and molecular biology. I studied variation in flowering time and the factors shaping the variation within and between A. lyrata populations in different environments. The role of the two important proximate factors determining flowering time, day length and temperature, were studied in climate chambers. The southern A. lyrata populations were found to flower in high frequency and quicker than northern A. lyrata populations in all studied environments, but the reaction of northern populations on long day length was found to be stronger than that of southern populations. Differences in vernalization requirement between A. lyrata populations were found in outdoor common garden, but in the climate chambers the results of vernalization experiments were not consistent. Strength and direction of selection on flowering time and other life history traits were studied in alpine and lowland A. lyrata populations in Scandinavia. Differences in selection were found both between populations and between years. Grazing sheep caused high levels of damage in inflorescences in the alpine population. In the lowland population there was less herbivory, caused by insects and hares. The difference in selection on flowering traits in the two study populations might be partly caused by selective grazing. Completely outcrossing mating system in A. lyrata is due to well developed self-incompatibility system. However, biparental inbreeding is likely to exist in natural populations and it may lead to spatial structuring of genetic variation within populations. I studied the effects of biparental inbreeding on components of fitness in A. lyrata in three different environments. I found inbreeding depression after sib-mating to be substantial. Stressful environment reduced the overall performance of the plants, but had no effect on the magnitude of inbreeding depression. A literature survey indicates that the observed levels of inbreeding depression in self-incompatible A. lyrata were higher than those of self-compatible species. This suggests that self-compatible species have purged some of their genetic load. The genetic basis of flowering time variation in A. lyrata can be further studied by using A. thaliana molecular tools. Keywords: Arabidopsis, adaptation, day length, flowering time, inbreeding depression, mating system, natural selection, self-incompatiblity, vernalization Hannele Säkkinen (2005) Variation in the blood chemical constituents of reindeer. Significance of season, nutrition and other extrinsic and intrinsic factors. Acta Universitatis Ouluensis A 440. University of Oulu, Department of Biology. http://herkules.oulu.fi/isbn9514277732/ Reindeer management in the Fennoscandian area is currently facing challenges such as degradation of winter pastures, which may lead in the most severely affected areas to a concurrent decline in reindeer herd productivity. The use of often expensive supplementary feeding to prevent production losses has increased the demand for studies on the physiological effects of nutritional restriction and supplementary feeding. The knowledge obtained from such studies could be used, for example, to monitor the condition of reindeer in studies assessing herd productivity levels in different pasture conditions and management systems or sustainable use of pasture resources. In this thesis, the effects of season, year, pasture area, body mass, pregnancy and other extrinsic and intrinsic factors on the variation of blood chemical constituents of reindeer were studied in free-ranging animals under natural foraging conditions. The studied blood chemical constituents covered a wide range of parameters related to protein, carbohydrate, lipid and mineral metabolism. The same blood chemical constituents were studied in captive reindeer under defined feeding conditions, allowing an analysis of the effects of dietary protein, energy and mineral intake on the selected blood constituents and their comparison to a conventional measure of the animals' condition, live body mass. According to the results, free-ranging reindeer showed great variation in the concentrations of blood chemical constituents compared to the reference values of domesticated ruminants. Intrinsic factors such as body mass, pregnancy and age had only a minor influence on the variation of the studied parameters, whereas extrinsic factors such as season, year and pasture area, which were characterized by marked changes in environmental and nutritional conditions, explained the majority of the variation. The results obtained from captive animals in defined feeding conditions and from free-ranging animals foraging on natural pastures led to the conclusion that blood total proteins, albumin, urea, creatinine, urea:creatinine ratio, magnesium, inorganic phosphate and, to a lesser extent, globulins and albumin:globulin ratio responded to the changes in feed quality and availability and were the most suitable blood constituents to be used as nutritional biomarkers for reindeer. Keywords: albumin, body mass, calcium, creatinine, globulins, inorganic phosphate, magnesium, nutrition, Rangifer tarandus tarandus, total proteins, urea Niina Tero (2005) Genetic structure at different spatial scales in metapopulations of Silene tatarica. Acta Universitatis Ouluensis A 439. University of Oulu http://herkules.oulu.fi/isbn9514277694/ The genetic structure at different spatial scales and growing habitats was studied on Silene tatarica, using AFLP and microsatellite markers. S. tatarica is a rare perennial plant occurring along riverbanks and shores of two annually flooding rivers in Finland. Regional scale analysis based on AFLP fragment analysis showed that at Oulanka River population structure represented mostly classical metapopulation model. In general, colonization-extinction processes had an important role, dispersal between subpopulations was limited and genetic differentiation was independent of geographic location. The same subpopulations were partly used to study spatial genetic structuring within subpopulations. Spatial autocorrelation revealed clear spatial genetic structure in each subpopulation. Paternity analysis in an isolated subpopulation showed small amounts of inbreeding, restricted seed dispersal and pollen flow through the subpopulation. Factors affecting the creation and maintenance of spatial genetic structure within subpopulation were most likely colonization events and restricted seed dispersal. The impact of river regulation on the genetic structure of populations was studied by comparing results from Oulanka River to the results obtained from second main growing area, Kitinen River. Oulanka River is a natural river system, whereas Kitinen is a regulated river. The overall regional scale studies did not indicate major differences between river systems. There were some clear population genetic differences between rivers but there were no clear evidence that those would have been caused by river regulation. More likely differences were related to the marginal location of Kitinen population at the edge of the distribution range. Studies indicated that regardless of the species rarity in Finland, active management measures are not currently needed in either S. tatarica growing area. Species specific microsatellite loci were isolated to complement AFLP studies. During the microsatellite isolation, an interesting amplification pattern was detected and studied further. It was suggested that there were repetitive areas within genome containing microsatellites resulting in unusual amplification. The most likely explanation for this phenomenon would be transposable elements containing proto-microsatellite areas. The microsatellites isolated could have evolved mostly from those proto-microsatellites. Keywords: AFLP, microsatellite, repetitive DNA, riparian 3a.6 Year 2006Juli Broggi (2006) Patterns of variation in energy management in wintering tits (Paridae). Acta Universitatis Ouluensis A 467. University of Oulu, Department of Biology. http://herkules.oulu.fi/isbn951428173X/ Winter energy management in small passerines living year-round in boreal or alpine areas presumably results in strong selective pressure since they need to find food, at a time when natural resources diminish and become less available, and energy requirements increase dramatically. In this thesis energy management during the non-breeding season was studied in three species of tits (Parus spp.), from three different populations: Coll de Pal (Spanish Pyrenees), Lund (Southern Sweden) and Oulu (Northern Finland). Energy management strategies vary significantly between species and among populations and individuals of the same species. Such differences may depend on several environmental factors, food predictability and individual characteristics. Birds from the studied populations appear to react to energetic challenges on a short-term basis and in a highly flexible way. The coal tit (Parus ater) in Coll de Pal and the willow tit (Parus montanus) in Oulu, both hoarding species, relied mostly on short-term management of energy for winter survival. Social and residence status appeared to be the most important factors in determining the level of energy reserves, underlining the importance of food predictability for energy management in wintering tits. Further studies were carried out on two distinct populations of great tit (Parus major) exposed to different winter hardiness. Birds from both populations increased their resting metabolic rate (MR) with experimentally decreasing ambient temperatures. Birds from Oulu maintained higher expenditures than birds from Lund in all cases, but also experienced higher energetic cost of thermoregulation at the lowest temperatures. The differences probably did not arise from a differential insulation capacity between populations, despite the differences in plumage structure found, but from a differential metabolic acclimatization. Birds from Lund probably became hypothermic at the lowest temperatures, which may have exceeded the levels they were acclimatized for. The observed differences in basal MR in laboratory conditions were consistent in wild birds throughout the non-breeding season. Birds from both populations experienced similar patterns of variation in basal MR, with expenditures increasing with mass but decreasing with day length, size and age. Great tits modulate their energy expenditure in a flexible way as a means for surviving the non-breeding season. Further, despite such flexibility, populations appear to be locally adapted for such metabolic acclimatization. These results may have important implications on their life-history and distribution. Winter acclimatization appears to be a complex set of entangled strategies that are based on a metabolic adjustment to cope with changing energy requirements. Other mechanisms that apparently play a secondary role, for example the long term management of reserves through fattening or hoarding, or conserving heat through hypothermia and by developing a better insulative plumage, are certainly important emergency strategies that in natural conditions may explain how some populations can endure winter conditions. Keywords: avian energetics, ecological physiology, energy reserves, metabolic rate, winter acclimatization Erkki Jokikokko (2006) Atlantic salmon (Salmo salar L.) stocking in the Simojoki river as a management practice. Acta Universitatis Ouluensis A 472. University of Oulu http://herkules.oulu.fi/isbn9514282248/ Long-term monitoring of the wild salmon (Salmo salar L.) stock of the Simojoki river and the stocked hatchery-reared salmon parr and smolts has provided a considerable amount of information on the development of the stock and factors affecting it. Data on the relationships between wild and reared salmon were collected by tagging and trapping both smolts and adult salmon having either a wild or reared background. The tag recapture rate of wild smolts was about twice as high as that of smolts stocked as two-year-olds and slightly greater than for smolts stocked as parr. When survival was measured in relation to the smolt size, the difference between the wild and reared smolts was even greater, and it seemed to be emphasized in years with a low survival rate. The difference observed between the wild and reared salmon in the smolt phase generally disappeared in the adult phase. When adult salmon returned to the river to spawn the difference in the timing of the ascent depended more on the age or sex of the salmon, and less on their origin. Similarly, the survival of adult salmon in the river before or after spawning and later after returning to the sea depended on the sex and age of the fish. The origin of fish affected their behaviour, the reared salmon wandering more than wild adults before settling down into spawning areas. When the yield of wild and reared smolts as returning adults was compared, the wild smolts gave the best results, although the survival from smolt to adult was low in all smolt groups, probably due to the high fishing pressure in the sea. The smolts stocked as parr and those stocked as two-year-old fish were similar in this respect. The former group gave better results if the yield was measured as the number of returning multi-sea-winter adults, while the latter group gave better results if one-sea-winter grilse were also included in the yield. The low yield of adult salmon from stocking and the generally low survival of smolt groups irrespective of their origin emphasises the importance of fishing regulations as a tool in the maintenance or enhancement of naturally reproducing salmon stocks. However, despite the low profitability of stocking, it probably safeguarded the existence of the wild Simojoki salmon stock during its critical phase in the early 1990s. At that time the fishing regulations were not strict enough to prevent the alarming decrease in the salmon stock, and the adult spawners produced by stocking of young salmon may have had a relatively higher value than their number suggests. Keywords: ascending spawner, parr, Salmo salar, smolt, stocking, survival, tagging Marko Mutanen (2006) Genital variation in moths—evolutionary and systematic perspectives. Acta Universitatis Ouluensis A 459. University of Oulu, Department of Biology. http://herkules.oulu.fi/isbn9514280849/ Insect genital characteristics have peculiar morphological patterns. They show great divergence between species. At the same time, they are assumed to vary little within species by taxonomists who frequently use genital features to delimit species. I studied moth (Lepidoptera) genital size and shape variation within and between species. I also tested hypotheses proposed to explain rapid genital diversification among species. Studies were carried out using traditional distance measurement morphometrics and modern geometric morphometrics. Several moth species were analyzed. I found that genital structures show variation that in closely related species may show structural overlap. More surprisingly, the amount of variation in internal genitalia was equal to non-genital traits. These and some other findings are against the predictions of the lock-and-key hypothesis, which suggests that genital differences form a mechanical isolation system between species. Meanwhile, the findings are in good accordance with the various mechanisms of the sexual selection hypothesis. I found that external genital traits express varying amounts of variability. However, both external and internal genitalia consistently show small variation in size so that large individuals have disproportionately small genitalia and vice versa. This finding is consistent with the lock-and-key theory, but also with the cryptic female choice hypothesis. In conclusion, the results suggest that sexual selection plays a major role in genital diversification, but the exact mechanism remained unclear in this study. Some structures in moth genitalia strongly suggest that sexual conflict is present as well. It is possible that several mechanisms of sexual selection are in action simultaneously. My findings have implications to insect taxonomy. Genital characters, although often useful, should not be considered superior to other characters because they may vary considerably within species. I have shown that subjective visual evaluation of genital characteristics and a priori assumption of their low variability may easily lead to unsound taxonomic conclusions. Sophisticated morphometric tools are very useful and objective in delimiting sibling species. Geometric morphometrics is particularly useful since it helps to evaluate limits of variation. There are, however, no theoretical grounds to assume that genitalia are not subject to intraspecific geographic variation. Such variation was detected in this study as well. Geographic relationships should therefore be taken into consideration more frequently when delimiting populations into different species. Keywords: genital evolution, genital variation, geometric morphometrics, Lepidoptera, lock-and-key hypothesis, morphometrics, negative allometry, sexual selection, species delimitation, taxonomy Heikki Mykrä (2006) Spatial and temporal variability of macroinvertebrate assemblages in boreal streams: implications for conservation and bioassessment. Acta Universitatis Ouluensis A 468. University of Oulu, Deparment of Biology. http://herkules.oulu.fi/isbn9514281829/ In this thesis, I studied spatial and temporal variability of macroinvertebrate assemblages of boreal streams. The main objectives were (i) to characterize macroinvertebrate assemblage types across large geographical extents, and to assess the utility of assemblage types and landscape and stream type classifications as the basis of stream bioassessment and conservation programs (ii, iii). I also examined the relative roles of large-scale spatial trends and local environmental conditions in structuring macroinvertebrate assemblages (iv). Finally, I assessed (v) if assemblage classifications produce temporally stable and predictable assemblage types. Stream macroinvertebrate assemblage structure exhibited continuous variation instead of distinct assemblage types. Although ecoregions clearly accounted for a considerable amount of variation of macroinvertebrate assemblage characteristics, a combination of regional stratification and prediction from environmental factors would probably yield the most comprehensive framework for the characterizations of macroinvertebrate assemblages of boreal headwater streams. Differences in macroinvertebrate assemblage structure, as well as a group of effective indicator species for different stream types, suggest that landscape classifications could be used as a preliminary scheme for the conservation planning of running waters The strength of the relationship between assemblage structure and local environmental variables increased with decreasing extent, whereas assemblage variation related to spatially variables showed the opposite pattern. At the largest scale, spatial variation was related to latitudinal gradients, while spatial autocorrelation among neighbouring streams was the likely mechanism creating spatial structure within drainage systems. These results suggest that stream bioassessment should give due attention to spatial structuring of stream assemblage composition, considering that important assemblage gradients may not only be related to local environmental factors, but also to biogeographical constraints and neighbourhood dispersal processes. The classification strengths of macroinvertebrate assemblages based on data of three years were overall rather weak, and more importantly, the compositions of the site groups varied considerably from year to year. Such wide and continuous variation was also mirrored by low and inconsistent predictability of classifications from environmental variables. The observed level of temporal variation in assemblage structure may not be a serious problem for predictive approaches frequently used in bioassessment of freshwater ecosystems. For conservation purposes, however, alternative approaches (e.g. physical surrogates of biodiversity) need to be considered. Keywords: assemblage structure, benthic invertebrates, biomonitoring, environmental gradients, geographic extent, species richness, stability, stream conservation Pirjo Rautiainen (2006) Population biology of the Primula sibirica group species inhabiting frequently disturbed seashore meadows: implications for management. Acta Universitatis Ouluensis A 453. University of Oulu, Department of Biology. http://herkules.oulu.fi/isbn9514280253/ Many plant species inhabiting the seashore meadows of the Bothnian Bay, especially early successional ones, have become threatened. Isostatic land uplift creates virgin land for early successional species to colonise. However, at the same time it gradually elevates the habitat and eventually makes the habitat unsuitable for them. Disturbances of the waterfront may slow down succession and create new empty sites. In order to persist on the shores, pioneer species have to be able to colonise new sites by seeds, vegetative propagules or growth. In this thesis I studied the status of an endangered early successional grass species, A. fulva var. pendulina, at the Liminka Bay. According to a matrix population model based on eight years of observations (1992–1999), the population seemed not to be in immediate danger of extinction. However, simulations based on four-year field observations (2000–2003) indicated that if the current trend continues, the species will decrease considerably in area in the next 30 years. In the field studies no seedlings or viable seeds of A. fulva were found. In spite of this, high genotypic diversity was found in the A. fulva population, suggesting that sexual reproduction has taken place at some time during the history of the population. Analysis of the population structure revealed a low level of genotypic differentiation between subpopulations and significant sub-structuring within subpopulations. The overall pattern of genetic variation suggests that the population has characters of both stepping-stone and metapopulation models. The results of the study on the ability of a seashore plant Potentilla anserina ssp. egedii to change its allocation of resources to sexual and vegetative reproduction according to competitive stress implied that the species can modify the allocation of resources to different life-history traits. For a plant living in disturbance-prone environment, it may be beneficial to be able to rapidly track the competition-free space formed by disturbances by changing its reproductive pattern. Management studies on three endangered seashore plant species showed that deterioration of suitable habitats of A. fulva and Primula nutans var. jokelae could be slowed down by management, and the vegetative and/or sexual reproduction of these species was enhanced. However, in the case of Puccinellia phryganodes, no positive response to management was observed. Keywords: between-genet competition, Bothnian Bay seashore meadows, genetic diversity, genetic population structure, management, population viability analysis, Primula sibirica group, threatened species, within-genet competition Antti Rönkä (2006) Dynamics, genetic structure and viability of a small and declining Temminck's stint (Calidris temminckii) population. Acta Universitatis Ouluensis A 465. Universtiy of Oulu. http://herkules.oulu.fi/isbn9514281446/ Globally, populations of several wader species are in decline. However, for most populations, information on abundance, its changes and the causes of declines is insufficient for designing successful management strategies to recover threatened populations. In this thesis I studied the status and population trends, nesting success, genetic structure and viability of a small, declining and threatened Temminck's stint population in the Bothnian Bay in the northern Baltic Sea. Historical population data, recent population counts in the early 1990s and in 1999–2002 and the demographic data showed that the decline is continuing, paralleled by declines in nesting success, recruitment and adult survival. Decline in nesting success was caused by a coincident increase in nest predation. Depredation was the main cause of nest losses. The common gull (Larus canus) and the ruddy turnstone (Arenaria interpres) were found to be the most important nest predators. I tested if an increase in nest concealment and consequent decrease in visibility lowers the efficiency of the early-departure antipredator behaviour of the species. An expected positive correlation emerged between visibility and flushing distance in the presence of alarm-giving birds, but not without them. This indicates that Temminck's stint exploits signals from other birds as early warning of an approaching predator. More nests were lost to predation on narrow than on wide shores. The nest predation rate was not related to habitat (natural vs. man-made) nor to differences in microhabitat characteristics associated with concealment. Overall variability of the mitochondrial control region was low in the one northeast Siberian and the three Fennoscandian populations studied. The occurrence of two maternal lineages in all Fennoscandian populations points to mixing of two previously isolated populations. The overall microsatellite genetic structuring (6 loci) in Fennoscandia was low. The pairwise comparison revealed a low but significant degree of differentiation between the Bothnian Bay and the two other Fennoscandian populations. However, no clear indication of genetic effects of small population size in the Bothnian Bay was detected. Matrix and Pradel-λ projection models, based on a ten year (1994–2003) capture-recapture data set, predicted a steep future decrease and a high risk of extinction within 50 years. Without immigration the decline would lead to extinction within 20 years. Population growth was the most sensitive to changes in adult survival, the rate of which declined during the study. Factors affecting adult survival most likely operate primarily during the non-breeding season in locations specific to the study population that are virtually unknown. Management efforts in the Bothnian Bay should, in addition to improving hatching success, first of all guarantee availability of wide, low-sward coastal breeding habitats for potential immigrants and recruits. Keywords: conservation, extinction, nest predation, wader Miika Tapio (2006) Origin and maintenance of genetic diversity in northern European sheep. Acta Universitatis Ouluensis A 473. University of Oulu, Department of Biology. http://herkules.oulu.fi/isbn9514282353/ The Nordic and Baltic countries and North-western Russia have >20 old native sheep breeds. These together with recently synthesized breeds and local populations of international breeds make up the northern European sheep diversity. Changes in agriculture threaten to erode genetic diversity in sheep. Molecular genetic variation was assessed to understand genetic diversity in northern European sheep. Distribution of maternal lineages were studied based on mitochondrial control region variation in 76 sheep breeds in northern Europe and in a wide neighbouring area extending to the Caucasus and Central-Asia. Autosomal microsatellite variation was studied in 37 northern European breeds, and autosomal blood protein variation was studied in six Finnish and Russian breeds. Four distinct maternal lineages were observed in Eurasian sheep. Their distribution agrees with sheep expansion starting from the Near East. Two most common distinct lineages were recorded in northern Europe. Majority of northern sheep have the lineage, which predominates in other parts of Europe. Results suggest that the main maternal origin of northern sheep is in the south. However, rare "Asian" lineage was observed in several old northern European breeds. The rare type in the Nordic sheep is descendant to the type observed in the Middle Volga region, which suggest that some sheep were brought to northern Europe from the east. Microsatellites showed clustering of geographically neighbouring sheep, when breed locations are corrected for the recent transportations. The analysis separated long and short-tailed sheep, although this macroscale structure explains a small proportion of breed differences. Differentiation among the northern European breeds is stronger than typically observed in sheep. Many native breeds are less inbred than the local populations of the international breeds, but some rare breeds and subpopulations of divided unofficial strains were inbred. Some breeds require more careful maintenance due to recent population size reduction. Maintaining prolificacy in breeds such as the Finnsheep and the Romanov may require efficient avoidance of inbreeding. The breeds were ranked for conservation using simultaneously within-breed variation and breed divergence. Set of important breeds included seven rare old native breeds or strains which merit efficient conservation measures urgently. Keywords: conservation, domestic animals, genetic marker, Ovis aries Robert L. Thomson (2006) Breeding habitat selection and its consequences in boreal passerines. Using the spatial dispersion of predators and heterospecifics as a source of information. Acta Universitatis Ouluensis A 456. University of Oulu, Department of Biology. http://herkules.oulu.fi/isbn9514280504/ Habitat selection decisions are crucial in determining fitness. Research indicates that individuals of many taxa are flexible in habitat selection and gather information prior to decision-making in order to control for environmental unpredictability. For time limited migrant birds, cues provide a quick and reliable information source with which to make habitat selection decisions. In this thesis I investigate habitat selection decisions, and their fitness consequences, of boreal passerines using heterospecifics or predators as cues. In support of the heterospecific attraction hypothesis, plots with augmented resident titmice densities attracted increased migrant densities. The predicted negative effects stemming from competition did not occur even at unnaturally high resident densities. This suggests that in the north it may always be beneficial for migrants to use residents as cues in habitat selection decisions. By manipulating habitat selection, I found that great tits (Parus major) had poorer reproductive success when forced to breed in close proximity to pied flycatcher (Ficedula hypoleuca) compared to when breeding alone. Flycatchers, in contrast, did slightly better when breeding close to tits. These results indirectly suggest that heterospecific attraction may not be a mutually positive species interaction. Indeed, flycatchers seem to parasitize the high quality microhabitat indicated by breeding great tits. I also tested if residents provide a reliable cue relative to predation risk. However, willow tit (P. montanus) nest location appeared random relative to avian predator nests. They do not appear to reliably indicate safe breeding habitats to later arriving migrants. In addition, closer proximity to breeding avian predators had a negative impact on willow tit reproductive output. Later arriving migrants may be in a better position to avoid avian predator nests during habitat selection. Pied flycatchers avoid settling in the immediate vicinity of sparrowhawk (Accipiter nisus) nests. However, nest box occupation, laying dates and initial reproductive investment (clutch size) showed a unimodal relationship with distance to sparrowhawk. A unimodal trend in these measures indicates there may be a trade-off between the costs (increased adult predation risk) and potential benefits (decreased nest predation risk) of settling in proximity to avian predator nests. Spatially predictable predation risk gradients that emanate from predator nests are termed a "predation risk landscape". Furthermore, flycatchers nesting closer to sparrowhawks produced fewer and smaller nestlings than those farther away. In addition, measures of maternal physiological stress (body condition and stress protein levels) had a negative linear relationship with distance to sparrowhawk nest. It appears that increased perceived predation risk near avian predator nests results in stressful and poor conditions for adult passerines, which results in lower reproductive output. This thesis highlights the importance of information gathering prior to making habitat selection decisions in order to optimise territory location relative to heterospecifics or predators. These decisions clearly impact individual fitness. Keywords: cue-using, heat shock proteins, predation risk, public information Piippa Wäli (2006) Environment and genetic background affecting endophyte-grass symbiosis. Acta Universitatis Ouluensis A 466. University of Oulu, Department of Biology. http://herkules.oulu.fi/isbn9514281632/ Mutualism is often conditional and the associations vary from antagonism to mutualism along environmental conditions and genotypes of interacting species. I studied antagonism-mutualism continuum hypothesis of symbiosis experimentally using two different Epichloë/Neotyphodium endophytes and their host grasses, agricultural meadow fescues and natural fine fescue, as study systems. These systemic fungal endophytes live asymptomatically within aerial tissues of grasses, and are vertically transmitted to the next grass generation via seeds. Thus, asexual endophyte strains are dependent on the growth, survival and reproduction of their hosts. Epichloë/Neotyphodium endophytes are considered plant mutualists, because they improve the resistance of the host against various stresses, e.g. herbivores. In addition to experimental approach, I examined prevalence and genetic structure of Epichloë festucae in natural grass populations. Finally, current knowledge concerning grass endophytes was reviewed and the effects of variable environment and genetic background on the ecology and the evolution of grass-endophyte symbiosis were discussed. The endophyte improved the performance of the agronomic meadow fescues, but the beneficial effects were dependent on the grass cultivar and the growth environment. The endophyte-infected (E+) meadow fescues were more susceptible to the pathogenic snow molds and they suffered increased winter damage compared to the endophyte-free (E-) plants. Many natural Festuca rubra and F. ovina populations were either endophyte-free or had low infection frequency. The highest infection frequencies were found in subarctic areas where the infection incidence differed between habitats. Twenty out of the 25 E. festucae genotypes detected were carrying multiple alleles in microsatellite loci indicating multiple infections or vegetative hybridization of the fungus. A dominant genotype (63.5% of all isolates) occurred in all populations suggesting that this fungus is mainly asexual. E+ F. ovina seedlings performed worse than endophyte-free E- seedlings. In F. rubra, the river bank originated E+ seedlings allocated fewer, but longer and heavier tillers than the other seedlings indicating possible improved performance of the endophyte infected grasses in harsh river bank conditions. In short, I detected both positive and negative effects of endophyte infection on grasses varying along species, environment and genotypic background of study subjects. The results support the antagonism-mutualism continuum hypothesis. Keywords: cultivar, endophytic fungi, fine fescues, genetic structure, grass, interaction, meadow fescue, mutualism, seedling establishment, snow mold, symbiosis |