Landscape fragmentation overturns classical metapopulation thinking.

Habitat loss and isolation caused by landscape fragmentation represent a growing threat to global biodiversity. Existing theory suggests that the process will lead to a decline in metapopulation viability. However, since most metapopulation models are restricted to simple networks of discrete habitat patches, the effects of real landscape fragmentation, particularly in stochastic environments, are not well understood.

Dynamics of a host-parasitoid interaction clarified by modelling and DNA sequencing.

It has been hypothesised that the 2-year oscillations in abundance of Xestia moths are mediated by interactions with 1-year Ophion parasitoid wasps. We tested this hypothesis by modelling a 35-year time series of Xestia and Ophion from Northern Finland. Additionally, we used DNA barcoding to ascertain the species diversity of Ophion and targeted amplicon sequencing of their gut contents to confirm their larval hosts.

Scaling up the effects of inbreeding depression from individuals to metapopulations.

Inbreeding is common in nature, and many laboratory studies have documented that inbreeding depression can reduce the fitness of individuals. Demonstrating the consequences of inbreeding depression on the growth and persistence of populations is more challenging because populations are often regulated by density- or frequency-dependent selection and influenced by demographic and environmental stochasticity. A few empirical studies have shown that inbreeding depression can increase extinction risk of local populations.

Responses of generalist and specialist species to fragmented landscapes.

Empirical studies have shown that, unlike species with specialized resource requirements, generalist species may benefit from habitat destruction. We use a family of models to probe the causes of the contrasting responses of these two types of species to habitat destruction. Our approach allows a number of mechanisms to be switched on and off, thereby making it possible to study their marginal and joint effects.

Soil exposure modifies the gut microbiota and supports immune tolerance in a mouse model.

Background: Sufficient exposure to natural environments, in particular soil and its microbes, has been suggested to be protective against allergies.

Objective: We aim at gaining more direct evidence of the environment-microbiota-health axis by studying the colonization of gut microbiota in mice after exposure to soil and by examining immune status in both a steady-state situation and during allergic inflammation.

Methods: The gastrointestinal microbiota of mice housed on clean bedding or in contact with soil was analyzed by using 16S rRNA gene sequencing, and the data were combined with immune parameters measured in the gut mucosa, lung tissue, and serum samples.

The prevalence and correlates of anticoagulant rodenticide exposure in non-target predators and scavengers in Finland.

The most common rodent control method worldwide is anticoagulant rodenticides (ARs), which cause death by internal bleeding. ARs can transfer to non-target predators via secondary exposure, i.e.

Skin microbiota and allergic symptoms associate with exposure to environmental microbes.

A rural environment and farming lifestyle are known to provide protection against allergic diseases. This protective effect is expected to be mediated via exposure to environmental microbes that are needed to support a normal immune tolerance. However, the triangle of interactions between environmental microbes, host microbiota, and immune system remains poorly understood.

" Nature step" to prevent noncommunicable inflammatory disease.

The prevention of many diseases has significantly improved by intervening in known risk factors. However, the causes of the increase in allergy and type 1 diabetes are unknown. These diseases are often associated with a low-grade inflammation and immunological imbalance.

Multilevel landscape utilization of the Siberian flying squirrel: Scale effects on species habitat use.

Animals use and select habitat at multiple hierarchical levels and at different spatial scales within each level. Still, there is little knowledge on the scale effects at different spatial levels of species occupancy patterns. The objective of this study was to examine nonlinear effects and optimal-scale landscape characteristics that affect occupancy of the Siberian flying squirrel, , in South- and Mid-Finland.

Genetic effects on life-history traits in the Glanville fritillary butterfly.

Background: Adaptation to local habitat conditions may lead to the natural divergence of populations in life-history traits such as body size, time of reproduction, mate signaling or dispersal capacity. Given enough time and strong enough selection pressures, populations may experience local genetic differentiation. The genetic basis of many life-history traits, and their evolution according to different environmental conditions remain however poorly understood.

Patterns in the skin microbiota differ in children and teenagers between rural and urban environments.

The composition of human microbiota is affected by a multitude of factors. Understanding the dynamics of our microbial communities is important for promoting human health because microbiota has a crucial role in the development of inflammatory diseases, such as allergies. We have studied the skin microbiota of both arms in 275 Finnish children of few months old to teenagers living in contrasting environments.

Ecological and genetic basis of metapopulation persistence of the Glanville fritillary butterfly in fragmented landscapes.

Ecologists are challenged to construct models of the biological consequences of habitat loss and fragmentation. Here, we use a metapopulation model to predict the distribution of the Glanville fritillary butterfly during 22 years across a large heterogeneous landscape with 4,415 small dry meadows. The majority (74%) of the 125 networks into which the meadows were clustered are below the extinction threshold for long-term persistence.

Significant disparities in allergy prevalence and microbiota between the young people in Finnish and Russian Karelia.

Background: Atopic allergy has been more common among schoolchildren in Finland, as compared to Russian Karelia. These adjacent regions show one of the most contrasting socio-economical differences in the world.

Objective: We explored changes in allergy from school age to young adulthood from 2003 to 2010/2012 in these two areas.

Erratum to: Home-range use patterns and movements of the Siberian flying squirrel in urban forests: effects of habitat composition and connectivity.

[This corrects the article DOI: 10.1186/s40462-016-0071-z.].

Larval growth rate is associated with the composition of the gut microbiota in the Glanville fritillary butterfly.

The rapidly increasing body of literature on commensal microbiota has revealed a large phylotypic and functional diversity of microbes associated with vertebrates and invertebrates. In insects, the gut microbiota plays a role in digestion and metabolism of the host as well as protects the host against pathogens. In the study reported here, we sampled gut microbiota of the larvae of the Glanville fritillary butterfly (Melitaea cinxia).

Oxygen and energy availability interact to determine flight performance in the Glanville fritillary butterfly.

Flying insects have the highest known mass-specific demand for oxygen, which makes it likely that reduced availability of oxygen might limit sustained flight, either instead of or in addition to the limitation due to metabolite resources. The Glanville fritillary butterfly (Melitaea cinxia) occurs as a large metapopulation in which adult butterflies frequently disperse between small local populations. Here, we examine how the interaction between oxygen availability and fuel use affects flight performance in the Glanville fritillary.

Predictable allele frequency changes due to habitat fragmentation in the Glanville fritillary butterfly.

Describing the evolutionary dynamics of now extinct populations is challenging, as their genetic composition before extinction is generally unknown. The Glanville fritillary butterfly has a large extant metapopulation in the Åland Islands in Finland, but declined to extinction in the nearby fragmented southwestern (SW) Finnish archipelago in the 20th century. We genotyped museum samples for 222 SNPs across the genome, including SNPs from candidate genes and neutral regions.

Home-range use patterns and movements of the Siberian flying squirrel in urban forests: Effects of habitat composition and connectivity.

Background: Urbanization causes modification, fragmentation and loss of native habitats. Such landscape changes threaten many arboreal and gliding mammals by limiting their movements through treeless parts of a landscape and by making the landscape surrounding suitable habitat patches more inhospitable. Here, we investigate the effects of landscape structure and habitat availability on the home-range use and movement patterns of the Siberian flying squirrel (Pteromys volans) at different spatial and temporal scales.

Stable coexistence of ecologically identical species: conspecific aggregation via reproductive interference.

Stable coexistence of ecologically identical species is not possible according to the established ecological theory. Many coexistence mechanisms have been proposed, but they all involve some form of ecological differentiation among the competing species. The aggregation model of coexistence would predict coexistence of identical species if there would be a mechanism that generates spatially aggregated distributions that are not completely correlated among the species.

Effects of ambient and preceding temperatures and metabolic genes on flight metabolism in the Glanville fritillary butterfly.

Flight is essential for foraging, mate searching and dispersal in many insects, but flight metabolism in ectotherms is strongly constrained by temperature. Thermal conditions vary greatly in natural populations and may hence restrict fitness-related activities. Working on the Glanville fritillary butterfly (Melitaea cinxia), we studied the effects of temperature experienced during the first 2 days of adult life on flight metabolism, genetic associations between flight metabolic rate and variation in candidate metabolic genes, and genotype-temperature interactions.

Temperature- and sex-related effects of serine protease alleles on larval development in the Glanville fritillary butterfly.

The body reserves of adult Lepidoptera are accumulated during larval development. In the Glanville fritillary butterfly, larger body size increases female fecundity, but in males fast larval development and early eclosion, rather than large body size, increase mating success and hence fitness. Larval growth rate is highly heritable, but genetic variation associated with larval development is largely unknown.

Flight-induced changes in gene expression in the Glanville fritillary butterfly.

Insect flight is one of the most energetically demanding activities in the animal kingdom, yet for many insects flight is necessary for reproduction and foraging. Moreover, dispersal by flight is essential for the viability of species living in fragmented landscapes. Here, working on the Glanville fritillary butterfly (Melitaea cinxia), we use transcriptome sequencing to investigate gene expression changes caused by 15 min of flight in two contrasting populations and the two sexes.

Wolbachia Infection in a Natural Parasitoid Wasp Population.

The maternally transmitted bacterium Wolbachia pipientis is well known for spreading and persisting in insect populations through manipulation of the fitness of its host. Here, we identify three new Wolbachia pipientis strains, wHho, wHho2 and wHho3, infecting Hyposoter horticola, a specialist wasp parasitoid of the Glanville fritillary butterfly. The wHho strain (ST435) infects about 50% of the individuals in the Åland islands in Finland, with a different infection rate in the two mitochondrial (COI) haplotypes of the wasp.