78 research outputs found

    Pystynävertäjän tilajärjestystä ja lajinsisäistä kilpailua kuvaavia malleja.

    Get PDF
    21 graphs, 11 tables80 ref

    Insect attack and blue stain in windthrown trees in Lapland 1983-86.

    Get PDF

    Computer-aided decision making in forestry.

    Get PDF

    Hemlokin villakirvan nissimallit invaasion kattamasta Pohjois-Amerikan levinneisyysalueesta ja projektiot alkuperäiseltä levinneisyysalueelta ja tulevaisuuden ilmastosta

    Get PDF
    The hemlock woolly adelgid (Adelges tsugae Annand - HWA) is invasive in eastern North America where it causes extensive mortality to hemlock communities. The future of these communities under projected climate change is an issue of landscape ecological interest and speculation. We employed the MaxEnt algorithm with the random subset feature selection algorithm (RSFSA) in creating HWA niche models. Final models were ensembles of 12 statistically best models with six predictors each. Out of 119 climatic, topographic, and soil variables, 42 were used in at least one final model. Soil features, followed by climate and topographic features, were most common in selected models. The three most important variables among all models were November potential evapotranspiration, slope, and percent Ochrepts soil. The potential distributions of HWA within eastern North America were projected under historical and four future climate scenarios for 2050 and 2070 under low and high CO2 emissions. The mean of the minimum values for the minimum temperature of the coldest month from the 12 MaxEnt model projections in eastern North America was -15.8°C. This value was close to -15°C, the extreme minimum temperature found for both HWA occurrence points and previously reported HWA cold temperature limits. These results indicate that HWA may be close to equilibrium distribution in eastern North America under current climate. We also reverse-casted the eastern North American MaxEnt model back onto the HWA native ranges in eastern Asia and western North America. The projections match best with native ranges in Asian islands, such as Japan, and the Cascade Mountains in western North America. Statistically significant HWA range shifts of 221-468 km northwards and 110-164 km eastwards were projected by the 12 models for 2050-2070. The 2070 high CO2 emission scenario models projects HWA suitability throughout most of the northern range of eastern hemlock.Peer reviewe

    DigiWeb - a workflow environment for quality assurance of transcription in digitization of natural history collections

    Get PDF
    Data produced by digitization increases the scientific use of natural history collections. However, in mass digitization, attention must be paid to the flawless management of the workflows, and high quantities of end results should not be compromised by a low standard of quality. A web-based environment DigiWeb was created for controlling the workflow of transcribing data from images of natural history specimens. Using DigiWeb, it was possible to manage the workflow of transcription and data proofing, include all participants to the workflow, allow collaboration and training, and also to provide useful processing features. The data emerging from this process passes quality control standards which are supported by DigiWeb and based on the strict requirements of the ISO 2859 standard

    Making species checklists understandable to machines : a shift from relational databases to ontologies

    Get PDF
    Abstract Background The scientific names of plants and animals play a major role in Life Sciences as information is indexed, integrated, and searched using scientific names. The main problem with names is their ambiguous nature, because more than one name may point to the same taxon and multiple taxa may share the same name. In addition, scientific names change over time, which makes them open to various interpretations. Applying machine-understandable semantics to these names enables efficient processing of biological content in information systems. The first step is to use unique persistent identifiers instead of name strings when referring to taxa. The most commonly used identifiers are Life Science Identifiers (LSID), which are traditionally used in relational databases, and more recently HTTP URIs, which are applied on the Semantic Web by Linked Data applications. Results We introduce two models for expressing taxonomic information in the form of species checklists. First, we show how species checklists are presented in a relational database system using LSIDs. Then, in order to gain a more detailed representation of taxonomic information, we introduce meta-ontology TaxMeOn to model the same content as Semantic Web ontologies where taxa are identified using HTTP URIs. We also explore how changes in scientific names can be managed over time. Conclusions The use of HTTP URIs is preferable for presenting the taxonomic information of species checklists. An HTTP URI identifies a taxon and operates as a web address from which additional information about the taxon can be located, unlike LSID. This enables the integration of biological data from different sources on the web using Linked Data principles and prevents the formation of information silos. The Linked Data approach allows a user to assemble information and evaluate the complexity of taxonomical data based on conflicting views of taxonomic classifications. Using HTTP URIs and Semantic Web technologies also facilitate the representation of the semantics of biological data, and in this way, the creation of more “intelligent” biological applications and services

    Comparison of protection methods of pine stacks against Tomicus piniperda.

    Get PDF
    Three most promising protection methods of pine pulp wood stacks against the attacks of Tomicus piniperda were compared. The methods were the covering of stacks by fibreglass-strengthened paper or twofold achrylene netting, removing the upper parts of stacks, and enhanced planning of the placement of the timber store using ARC/INFO GIS-software. T. piniperda was observed to strongly prefer the upper parts of the stacks: 90% of the beetles occurred within 0.5 meters of the top of the stacks. Covering of the stacks decreased the attack density of T. piniperda, and the protection effect of covering was 80%. Due to long transport distances and fragmentation of forest landscape the relocation of timber store was found to be an unsuitable method in the practical level. Also, taking into account the costs of the method, removing of the upper parts of stacks was considered to be the optimal solution

    Storm and Ips typographus disturbance effects on carbon stocks, humus layer carbon fractions and microbial community composition in boreal Picea abies stands

    Get PDF
    Tree-killing forest disturbances such as storms and bark beetle outbreaks can lead to notable changes in the carbon (C) balance and functioning of forest ecosystems. In this study, the effects of a storm in 2010 followed by an outbreak of European spruce bark beetle (Ips typographus L.) on tree, litter and soil C stocks as well as humus layer C fractions and microbial community composition were examined in boreal Norway spruce (Picea abies L.) stands. Tree (aboveground), litter detritus (distinguishable twig, bark and cones) and soil (humus layer and 0-6 cm mineral soil) C stocks were quantified for undisturbed (living trees), storm disturbed (in 2010) and I. typographus disturbed (tree mortality in circa 2013-2014) plots in 2015-2016. Additional humus layer samples were collected in 2017 for determination of total microbial biomass C, ergosterol (fungal biomass indicator) and K2SO4 extractable (labile) C concentrations, as well as fungal and bacterial community composition (DNA sequencing). Ectomycorrhizal (ECM) fungal mycelial growth in topsoil was also quantified. In spite of the differing initial development and intensity of the two disturbance types, there was little difference in humus layer C and microbiology between the storm and bark beetle disturbed plot types at the time of the study. This may be due to the longer time since the disturbance at the storm disturbed plots. The shift from tree biomass to necromass C stocks was not reflected in differences in SOC stocks or humus layer extractable C concentrations between undisturbed and disturbed plot types, but the amount of litter detritus on forest floor was similar (storm) or higher (beetle) in disturbed plots in comparison to undisturbed ones. Humus layer microbial biomass C and ergosterol concentrations and ECM fungal abundance were lower on disturbed plots in comparison to undisturbed plots. The disturbed plots were also indicated to have a slightly higher abundance of some saprotrophic fungi. Differences in the effects of the two disturbance types may occur when studied at differing spatial scales and at different times after disturbance. To understand the full impact of such disturbances on forest functioning and C balance, long-term monitoring studies will be required.Peer reviewe
    corecore