Asutushistorian vaikutus Vodlajärven kansallispuiston nykyiseen metsämaisemaan Luoteis-Venäjällä

TutkimusselosteSeloste artikkelista: Tikkanen, O.P. & Chernyakova, I.A. (2014). Past human population history affects current forest landscape structure of Vodlozero National Park, Northwest Russia. Silva Fennica 48(4), article id 1207

From a rare inhabitant into a potential pest – status of the nun moth in Finland based on pheromone trapping

Forests are being hit by climate change in various ways. This includes abiotic factors such as droughts, but also an increased risk of damage caused by biotic agents such as insects. There are numerous examples from cases where a pest insect has benefitted from endured growing season or from warmer summers. Similarly, new pest insects have been able to expand their range due to climatic conditions that have changed from hostile to tolerable. Such seems to be the case with the nun moth (Lymantria monacha), Europe’s most significant defoliator of coniferous trees. For centuries, the species has had massive outbreaks across Central-Europe while it has been only a rare inhabitant in Northern Europe. Recently, the nun moth population in Finland has not only expanded in range, but also grown more abundant. This research note describes the results from the first years (2018-2019) of a monitoring program that is being conducted with pheromone traps across central and southern Finland. So far, the northernmost individuals were trapped near the 64 N degrees. However, there were more southern where no moths were trapped. The species was present in every trapping site below the latitude of 62 N degrees. More importantly, at some sites the abundance of the nun moth suggested that local forest damage may not be a distant scenario. Given the current climatic scenarios for Fennoscandia, it is likely that the nun moth populations will continue to grow, which is why systematic surveys on their abundance and range expansions are vital.202

Analysis of sub-3 nm particle growth in connection with sulfuric acid in a boreal forest

We analyzed nanoparticle growth during new-particle-formation events based on ten years of measurements carried out at a boreal forest site in Hyytiala, Finland, concentrating on the sub-3 nm particles and the role of sulfuric acid in their growth. Growth rates of 1.5-3 nm diameter particles were determined from ion spectrometer measurements and compared with parameterized sulfuric acid concentration and other atmospheric parameters. The calculated growth rates from sulfuric acid condensation were on average 7.4% of the observed growth rates and the two did not correlate. These suggest that neither sulfuric acid monomer condensation nor coagulation of small sulfuric acid clusters was the primary growth mechanism in these atmospheric conditions. Also no clear sign of organic condensation being the single main growth mechanism was seen. These observations are consistent with the hypothesis that several factors have comparative roles in the sub-3 nm growth.Peer reviewe

Comparing secondary organic aerosol (SOA) volatility distributions derived from isothermal SOA particle evaporation data and FIGAERO-CIMS measurements

The volatility distribution of the organic compounds present in secondary organic aerosol (SOA) at different conditions is a key quantity that has to be captured in order to describe SOA dynamics accurately. The development of the Filter Inlet for Gases and AEROsols (FIGAERO) and its coupling to a chemical ionization mass spectrometer (CIMS; collectively FIGAERO-CIMS) has enabled near-simultaneous sampling of the gas and particle phases of SOA through thermal desorption of the particles. The thermal desorption data have been recently shown to be interpretable as a volatility distribution with the use of the positive matrix factorization (PMF) method. Similarly, volatility distributions can be inferred from isothermal particle evaporation experiments when the particle size change measurements are analyzed with process-modeling techniques. In this study, we compare the volatility distributions that are retrieved from FIGAERO-CIMS and particle size change measurements during isothermal particle evaporation with process-modeling techniques. We compare the volatility distributions at two different relative humidities (RHs) and two oxidation conditions. In high-RH conditions, where particles are in a liquid state, we show that the volatility distributions derived via the two ways are similar within a reasonable assumption of uncertainty in the effective saturation mass concentrations that are derived from FIGAERO-CIMS data. In dry conditions, we demonstrate that the volatility distributions are comparable in one oxidation condition, and in the other oxidation condition, the volatility distribution derived from the PMF analysis shows considerably more high-volatility matter than the volatility distribution inferred from particle size change measurements. We also show that the Vogel-Tammann-Fulcher equation together with a recent glass transition temperature parametrization for organic compounds and PMF-derived volatility distribution estimates are consistent with the observed isothermal evaporation under dry conditions within the reported uncertainties. We conclude that the FIGAERO-CIMS measurements analyzed with the PMF method are a promising method for inferring the volatility distribution of organic compounds, but care has to be taken when the PMF factors are analyzed. Future process-modeling studies about SOA dynamics and properties could benefit from simultaneous FIGAERO-CIMS measurements.Peer reviewe

Optimization of process models for determining volatility distribution and viscosity of organic aerosols from isothermal particle evaporation data

The composition of organic aerosol under different ambient conditions as well as their phase state have been a subject of intense study in recent years. One way to study particle properties is to measure the particle size shrinkage in a diluted environment at isothermal conditions. From these measurements it is possible to separate the fraction of low-volatility compounds from high-volatility compounds. In this work, we analyse and evaluate a method for obtaining particle composition and viscosity from measurements using process models coupled with input optimization algorithms. Two optimization methods, the Monte Carlo genetic algorithm and Bayesian inference, are used together with process models describing the dynamics of particle evaporation. The process model optimization scheme in inferring particle composition in a volatility-basis-set sense and composition-dependent particle viscosity is tested with artificially generated data sets and real experimental data. Optimizing model input so that the output matches these data yields a good match for the estimated quantities. Both optimization methods give equally good results when they are used to estimate particle composition to artificially test data. The timescale of the experiments and the initial particle size are found to be important in defining the range of values that can be identified for the properties from the optimization

Filamentous Fungi and Yeasts Associated with Mites Phoretic on Ips typographus in Eastern Finland

The European spruce bark beetle (Ips typographus) has become a major forest pest in Finland in recent years. The beetle is a well-known vector of mainly ophiostomatoid fungi causing blue-stain of timber and pathogens that have the ability to amplify the insect damage. It also vectors other associated organisms, such as phoretic mites. The ecology of these mites remains poorly understood, including their associations with fungi. In this study, we considered filamentous fungi and yeasts associated with mites phoretic on I. typographus. Fungal identifications were based on DNA sequences and phylogenetic analyses of the ITS and/or partial β-tubulin gene regions. Fifteen fungal species were detected, including eight yeasts and seven filamentous fungi. Eleven percent of the beetles carried mites and of these 74% carried at least one fungal species. An average of two fungal species were carried per mite. The most commonly found filamentous fungi were Grosmannia penicillata (25%), Ophiostoma bicolor (19%), O. ainoae (12%) and O. brunneolum (12%). Of the yeast species, the most commonly found was Wickerhamomyces bisporus (47%). This study is the first to report yeasts associated with I. typographus and its phoretic mites in Finland. Majority of the filamentous fungal species found are those previously reported in association with I. typographus. The results also confirmed that many of the fungal species commonly found on I. typographus are also associated with its phoretic mites. However, the nature of the symbiosis between the mites, beetles and fungal associates remains to be understood

Filamentous Fungi and Yeasts Associated with Mites Phoretic on Ips typographus in Eastern Finland

The European spruce bark beetle (Ips typographus) has become a major forest pest in Finland in recent years. The beetle is a well-known vector of mainly ophiostomatoid fungi causing blue-stain of timber and pathogens that have the ability to amplify the insect damage. It also vectors other associated organisms, such as phoretic mites. The ecology of these mites remains poorly understood, including their associations with fungi. In this study, we considered filamentous fungi and yeasts associated with mites phoretic on I. typographus. Fungal identifications were based on DNA sequences and phylogenetic analyses of the ITS and/or partial β-tubulin gene regions. Fifteen fungal species were detected, including eight yeasts and seven filamentous fungi. Eleven percent of the beetles carried mites and of these 74% carried at least one fungal species. An average of two fungal species were carried per mite. The most commonly found filamentous fungi were Grosmannia penicillata (25%), Ophiostoma bicolor (19%), O. ainoae (12%) and O. brunneolum (12%). Of the yeast species, the most commonly found was Wickerhamomyces bisporus (47%). This study is the first to report yeasts associated with I. typographus and its phoretic mites in Finland. Majority of the filamentous fungal species found are those previously reported in association with I. typographus. The results also confirmed that many of the fungal species commonly found on I. typographus are also associated with its phoretic mites. However, the nature of the symbiosis between the mites, beetles and fungal associates remains to be understood

Factors controlling the evaporation of secondary organic aerosol from alpha-pinene ozonolysis

Secondary organic aerosols (SOA) forms a major fraction of organic aerosols in the atmosphere. Knowledge of SOA properties that affect their dynamics in the atmosphere is needed for improving climate models. By combining experimental and modeling techniques, we investigated the factors controlling SOA evaporation under different humidity conditions. Our experiments support the conclusion of particle phase diffusivity limiting the evaporation under dry conditions. Viscosity of particles at dry conditions was estimated to increase several orders of magnitude during evaporation, up to 10(9)Pas. However, at atmospherically relevant relative humidity and time scales, our results show that diffusion limitations may have a minor effect on evaporation of the studied -pinene SOA particles. Based on previous studies and our model simulations, we suggest that, in warm environments dominated by biogenic emissions, the major uncertainty in models describing the SOA particle evaporation is related to the volatility of SOA constituents.Peer reviewe

Filamentous fungi and yeasts associated with mites phoretic on Ips typographus in Eastern Finland

The European spruce bark beetle (Ips typographus) has become a major forest pest in Finland in recent years. The beetle is a well-known vector of mainly ophiostomatoid fungi causing bluestain of timber and pathogens that have the ability to amplify the insect damage. It also vectors other associated organisms, such as phoretic mites. The ecology of these mites remains poorly understood, including their associations with fungi. In this study, we considered filamentous fungi and yeasts associated with mites phoretic on I. typographus. Fungal identifications were based on DNA sequences and phylogenetic analyses of the ITS and/or partial -tubulin gene regions. Fifteen fungal species were detected, including eight yeasts and seven filamentous fungi. Eleven percent of the beetles carried mites and of these 74% carried at least one fungal species. An average of two fungal species were carried per mite. The most commonly found filamentous fungi were Grosmannia penicillata (25%), Ophiostoma bicolor (19%), O. ainoae (12%) and O. brunneolum (12%). Of the yeast species, the most commonly found was Wickerhamomyces bisporus (47%). This study is the first to report yeasts associated with I. typographus and its phoretic mites in Finland. Majority of the filamentous fungal species found are those previously reported in association with I. typographus. The results also confirmed that many of the fungal species commonly found on I. typographus are also associated with its phoretic mites. However, the nature of the symbiosis between the mites, beetles and fungal associates remains to be understood.The members of the Tree Protection Co-operative Programme (TPCP) and the THRIP initiative of the Department of Trade and Industry, South Africa; the YeastsGoWild!—project and Developing monitoring and control of forest insect damage increasing with warming climate, particularly those caused by spruce bark beetles, Natural Resources Institute Finland (Luke).https://www.mdpi.com/journal/forestsam2022BiochemistryForestry and Agricultural Biotechnology Institute (FABI)GeneticsMicrobiology and Plant Patholog