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Hanna Granroth-Wilding Craig Primmer Meri Lindqvist Jenni Poutanen Olaf Thalmann Jouni Aspi Jenni Harmoinen Ilpo Kojola Toni Laaksonen 《BMC ecology》2017,17(1):44
Background
Carnivores are re-establishing in many human-populated areas, where their presence is often contentious. Reaching consensus on management decisions is often hampered by a dispute over the size of the local carnivore population. Understanding the reproductive dynamics and individual movements of the carnivores can provide support for management decisions, but individual-level information can be difficult to obtain from elusive, wide-ranging species. Non-invasive genetic sampling can yield such information, but makes subsequent reconstruction of population history challenging due to incomplete population coverage and error-prone data. Here, we combine a collaborative, volunteer-based sampling scheme with Bayesian pedigree reconstruction to describe the pack dynamics of an establishing grey wolf (Canis lupus) population in south-west Finland, where wolf breeding was recorded in 2006 for the first time in over a century.Results
Using DNA extracted mainly from faeces collected since 2008, we identified 81 individual wolves and assigned credible full parentages to 70 of these and partial parentages to a further 9, revealing 7 breeding pairs. Individuals used a range of strategies to obtain breeding opportunities, including dispersal to established or new packs, long-distance migration and inheriting breeding roles. Gene flow occurred between all packs but inbreeding events were rare.Conclusions
These findings demonstrate that characterizing ongoing pack dynamics can provide detailed, locally-relevant insight into the ecology of contentious species such as the wolf. Involving various stakeholders in data collection makes these results more likely to be accepted as unbiased and hence reliable grounds for management decisions.2.
Jaana Kekkonen Ilpo K. Hanski Henrik Jensen Risto A. Väisänen Jon E. Brommer 《Biological conservation》2011,144(12):2931-2940
A drastic decline in abundance prompts conservation measures, even though a species may still be common, partly because such a decline may be associated with loss of genetic variability. Longitudinal evidence (i.e. repeated measures across time) for loss of genetic diversity is scarce and mostly concerns organisms that have experienced a severe bottleneck. Here, we study the house sparrow in Finland, where a strong (50–86%) reduction in abundance occurred in four decades, starting earlier and resulting steeper decline in the south than in the north. Based on thirteen polymorphic microsatellites, we compared 12 Finnish populations both prior (mid-1980s) and after (2009) the major population decline. There was no evidence of bottlenecks and only little loss of genetic variation, but we found a significant threefold increase in genetic differentiation (FST) across the populations. This may reflect a non-equilibrium situation between the rates of change in the genetic diversity and differentiation and indicate future loss of genetic diversity. Our findings indicate that a strong decline in population size in a relatively common species still leaves a noticeable population-genetic imprint and warrants conservation concern. 相似文献
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Ilpo Niskanen Jorma Heikkinen Jukka Mikkonen Anni Harju Henrik Heräjärvi Martti Venäläinen Kai-Erik Peiponen 《Journal of Wood Science》2012,58(1):46-50
The purpose of this study was to determine the effective refractive index of thermally modified Scots pine (Pinus sylvestris L.) wood specimens as a quantitative measure regarding the change of wood density which is due to the thermal modification.
The refractive index of thermally modified Scots pine wood was obtained by introducing pine wood powder into an immersion
liquid and measuring light backscattering with a homebuilt multifunction spectrophotometer. The present method provides useful
information that in principle can be applied, for example, in the optimization of the thermal modification process and inspection
of the quality of thermally modified wood. 相似文献
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We examined responses of Siberian flying squirrels ( Pteromys volans ) to edges between nesting habitat (mature spruce forests), movement habitat (other forests, pine bogs), and open areas within their home ranges in southern Finland in 1996-2000. Radio-tracked squirrels (n=146) were generally associated to edges when they were ac tive at night. Compared to distances expected from the habitat pattern of their home range, squirrels occurred closer to high-contrast edges (of open areas) and low-contrast edges (nesting or movement forest types). Asso ciation with edges of open areas was more pronounced when squirrels were in movement habitat than in nesting habitat, possibly because of stronger channeling of movements in the former habitat. When in nesting habitat, squirrels responded more strongly to field edges than to recent clearcut edges, probably as a result of the pres ence of more deciduous trees on field edges, unlike clearcut edges. Responses to open areas were independent of spatial scale. However, responses to movement habitat from nesting habitat, and vice versa, were more pronounced over hundreds than tens of meters. Nesting cavities and dreys were generally located at random with respect to edges. We conclude that squirrel responses to edges of landscape attributes are diverse and depend both on spatial scale and edge contrast.This revised version was published online in May 2005 with corrections to the Cover Date. 相似文献
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Aim and Background
In order to identify potential risks of sediments contaminated by pulp and paper mill effluents, two boreal lake areas were investigated from core samples. Resin acids (RA) and their aromatized derivative retene were measured, suggesting that these aquatic toxicants can be long-lasting sources to expose benthic biota. On the other hand, dredging or other human actions can liberate toxicants, even from deep sediments, to an aqueous phase with harmful consequences to aquatic species. Since no historical sediment profiles were available, we investigated the toxic potential of sediment-water elutriates by way of the bioluminescent bacteria Vibrio fischeri. In this investigation, we therefore analyzed both the concentrations of toxic chemicals and the toxicity as profiles in two contaminated lake sediments in Finland. 相似文献6.
Reijo Käkelä Ilpo Pölönen Maija Miettinen Juha Asikainen 《Acta Agriculturae Scandinavica, Section A - Animal Sciences》2013,63(4):217-223
Male mink kits (n=10 for each group) were fed diets supplemented with different fats for 12 weeks (September-November). The levels of digestible fat (8%) and energy content (7 MJ kg-1) of the diets were equal. The supplements used were beef pork fat, mink fat, broiler offal, rainbow trout offal, capelin oil, soybean oil and linseed oil. The growth and hepatic lipids (analysed by a thin-layer chromatography- flame ionization detection analyser) and fatty acid composition (analysed by gas-liquid chromatography) were studied. The pattern of weight gain of the mink fed the beef pork diet differed from that of the other mink. These kits reached high but delayed weight maxima compared with the other mink but then during November they lost weight rapidly. In liver, both the capelin oil- and linseed oil-fed mink had large concentrations of total lipids and triacylglycerols. The mink fed capelin oil were significantly heavier. The fatty acid analyses of hepatic total lipids and phospholipids revealed that the f -linolenic acid (18:3 n-3) of linseed oil was not efficiently metabolized to longer chain and more unsaturated fatty acids important for cellular membranes. It is discussed that 18:3 n-3 may not be as valuable for growing mink kits as the polyunsaturated fatty acids of the fish oils. 相似文献
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Understanding dispersal is central to ecology and evolution. To integrate habitat selection and dispersal it is important to compare habitat used for movement to those available in the landscape, i.e. found in an area that an animal could access in a given time period. Here, we explore ways of determining available habitat for dispersing individuals, illustrated by recent studies on habitat selection of dispersers. 相似文献
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Oocyte-specific deletion of Pten causes premature activation of the primordial follicle pool 总被引：1，自引：0，他引：1
Reddy P Liu L Adhikari D Jagarlamudi K Rajareddy S Shen Y Du C Tang W Hämäläinen T Peng SL Lan ZJ Cooney AJ Huhtaniemi I Liu K 《Science (New York, N.Y.)》2008,319(5863):611-613
In the mammalian ovary, progressive activation of primordial follicles from the dormant pool serves as the source of fertilizable ova. Menopause, or the end of female reproductive life, occurs when the primordial follicle pool is exhausted. However, the molecular mechanisms underlying follicle activation are poorly understood. We provide genetic evidence that in mice lacking PTEN (phosphatase and tensin homolog deleted on chromosome 10) in oocytes, a major negative regulator of phosphatidylinositol 3-kinase (PI3K), the entire primordial follicle pool becomes activated. Subsequently, all primordial follicles become depleted in early adulthood, causing premature ovarian failure (POF). Our results show that the mammalian oocyte serves as the headquarters of programming of follicle activation and that the oocyte PTEN-PI3K pathway governs follicle activation through control of initiation of oocyte growth. 相似文献
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Helena Haakana Hannu Hirvelä Ilpo K. Hanski Tuula Packalen 《Scandinavian Journal of Forest Research》2017,32(2):185-195
Forecasting the potential impacts of forest policies on species of special conservation value is a prerequisite for safeguarding forest biodiversity. In this study, regional forest policy scenarios were compared in terms of predicted habitats suitable for the Siberian flying squirrel (Pteromys volans). To derive both patch- and landscape-scale models to predict species presence in a forest stand, species occurrence data from a systematic field survey covering the whole distribution area of the flying squirrel in Finland and Multi-Source National Forest Inventory data were combined. Then, the Finnish forestry model MELA and the derived occupancy models were applied to predict the quantity of suitable habitats for flying squirrels in three different 50-year policy scenarios. The results confirm that increasing the utilization of felling potential from the level of business-as-usual to the level stated as policy targets in regional forest programs decreases the amount of suitable habitat in the future. However, regional forest programs had a less drastic impact on habitats than maximum sustainable removal, except in two regions. It should be noted that the occupancy models seemed to fail on sites that experts deem to be most suitable for the species. Obviously, there are other factors than forest management affecting presence. 相似文献
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