70 research outputs found

    Ingrowth, survival and height growth of small trees in uneven-aged Picea abies stands in southern Finland

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    The purpose of the study was to analyse height growth, mortality, and ingrowth of individual small-sized trees in uneven-aged spruce-dominated stands. It was based on experimental data from 16 stands for a 15-year observation period including four measurements with a 5-year interval. In the data of this study, the heights of small-sized trees varied from 0.1 to about 9 m. Results showed that the growth of small trees was rather slow, particularly in the smallest size classes. With average growth rates it would take about 60 years for a freshly emerged spruce germinant to achieve 1.3 m in height. The stand density, site quality and selection cuttings affected the growth of small-sized spruces. Average five-year mortality rates for spruce, birch and pine were 17.0%, 40.9% and 33.9%, respectively. Annual ingrowth rates with the threshold height of 1.3 m for the three species were on average 30.4, 2.8 and less than 0.1 trees per hectare, respectively. Even if, a selection cutting of modest intensity (25% of basal area removed on average) seemed to have accelerated the growth of small spruces, it is recommended that more intensive harvestings be applied to enhance the survival and growth of small spruces. It is also concluded that shade intolerant species like birch and pine do not seem to be capable of developing into viable undergrowth in spruce selection stands with their current levels of stand density

    Airborne laser scanning for the identification of boreal forest site types

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    Can models for forest attributes based on airborne laser scanning be generalized for different silvicultural management systems?

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    In Finland, interest in continuous cover forestry (CCF) has increased rapidly in recent years. During those years CCF has been examined from various viewpoints but not from the perspective of forest inventories. This holds especially true for applications based on remote sensing. Conversely, airborne laser scanning (ALS) data have been widely used to predict forest characteristics such as size distribution and vertical forest structure, which are closely related to the forest information needs of CCF. In this study we used the area-based approach to predict a set of stand attributes from ALS data (5 pulses per m2) in a CCF forest management experiment in Katajama & BULL;ki, eastern Finland. In addition to the CCF stands, the experiment included shelterwood stands and untreated stands. The predicted attributes included volume, biomass, basal area, number of stems, mean diameter, Lorey's height, dominant height, standing dead wood volume, parameters of the theoretical stem diameter distribution model, understory height and number of understory stems. Our main aim was to test whether the same model could be used across different management systems. The accuracy of the attributes predicted for the CCF stands was compared with the predictions for the other management systems in the same experiment. We also compared and discussed our results in relation to the even-aged stand attribute predictions that were conducted by using separate operational forest data collected from sites surrounding Katajama & BULL;ki. The results showed that forest data from the different management systems could be combined into a single model of a stand attribute, i.e., ALS metrics were found to be suitable for comparing different management systems in regard to differences in forest structure. The accuracy of the predicted attributes in the CCF plots was comparable to that of the other management alternatives in the experiment. The accuracy was also comparable to that of even-aged forests. The results of this study were promising; the stand attributes of CCF-managed forests could be predicted analogously to those of other management systems. This indicates that for the purposes of forest inventories there may not be a need to stratify forest lands by management system. It should be noted, however, that the study area was relatively small, that the forest stands were harvested in the 1980 s, and that the attributes may not have been completely exhaustive for CCF

    Prescribing antimicrobial agents for dogs and cats via University Pharmacies in Finland : Patterns and quality of information

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    The aim of our study was to evaluate antimicrobial use in dogs and cats in Finland. Information on veterinary prescriptions was gathered from University Pharmacies (n = 17) over a one-month period, April 2001. A total of 2719 prescriptions for veterinary use were delivered, of which the majority were for dogs (70%, n = 1898) and cats (14%, n = 384). The most prescribed therapy group was per-oral antimicrobial agents (53%, n = 1449), of which 16% (n = 237) were medicines approved for humans. The most commonly used substances for dogs and cats were betalactams, 66% and 78%, respectively. The proportion of fluoroquinolones was 3–5%. The average duration of the treatment periods was 10 days with the exception of treatment of cats with macrolide lincosamides, where the mean period was 20 days. Indication was mentioned only in 37% of the prescriptions

    Rebooting an Old Script by New Means: Teledildonics—The Technological Return to the ‘Coital Imperative’

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    Teledildonics, a form of digital-mediated sexual interaction, opens new possibilities for the understanding of sexual activity. At first glance, it disrupts conventional preconditions and assumptions about sexual interaction, by allowing the dimension of touch despite the physical distance between partners and, ultimately, promoting a sexual dimension definitely disconnected from the reproductive model of sexuality. However, by scrutinizing the design and functionality of the devices, as well as the discourses presented by three commercial companies—LovePalz, Lovense and Kiiroo—I suggest that this technology reinforces the ‘coital imperative’, by equating sexual interaction with penetration of the vagina by the penis. Although permitting other formulations, specifically for non-heterosexual couples, the penetrative act remains a presupposition. In spite of structurally disrupting the reproductive model of sex, teledildonics promotes its strongest corollary.info:eu-repo/semantics/publishedVersio

    Single-tree selection in Norway spruce stands - project and experiments

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    Tilavuusmallit

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    Mallit pituus-läpimittarelaatiolle

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    Runkokäyrämallit

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