Browsing by Subject "forestry"

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  • Laitakari, Erkki (Suomen metsätieteellinen seura, 1961)
  • Kilkki, Pekka; Pökälä, Raimo (Suomen metsätieteellinen seura, 1975)
  • Makkonen, Olli (Suomen metsätieteellinen seura, 1967)
  • Mykkänen, Reijo (The Society of Forestry in Finland - The Finnish Forest Research Institute, 1994)
    The study presents a theory of utility models based on aspiration levels, as well as the application of this theory to the planning of timber flow economics. The first part of the study comprises a derivation of the utility-theoretic basis for the application of aspiration levels. Two basic models are dealt with: the additive and the multiplicative. Applied here solely for partial utility functions, aspiration and reservation levels are interpreted as defining piecewisely linear functions. The standpoint of the choices of the decision-maker is emphasized by the use of indifference curves. The second part of the study introduces a model for the management of timber flows. The model is based on the assumption that the decision-maker is willing to specify a shape of income flow which is different from that of the capital-theoretic optimum. The utility model comprises four aspiration-based compound utility functions. The theory and the flow model are tested numerically by computations covering three forest holdings. The results show that the additive model is sensitive even to slight changes in relative importances and aspiration levels. This applies particularly to nearly linear production possibility boundaries of monetary variables. The multiplicative model, on the other hand, is stable because it generates strictly convex indifference curves. Due to a higher marginal rate of substitution, the multiplicative model implies a stronger dependence on forest management than the additive function. For income trajectory optimization, a method utilizing an income trajectory index is more efficient than one based on the use of aspiration levels per management period. Smooth trajectories can be attained by squaring the deviations of the feasible trajectories from the desired one.
  • Nyyssönen, Aarne (Suomen metsätieteellinen seura, 1979)
  • Rajakallio, Maria; Jyväsjärvi, Jussi; Muotka, Timo; Aroviita, Jukka (Blackwell, 2021)
    Journal of Applied Ecology 58: 7, 1523-1532
    1. Growing bioeconomy is increasing the pressure to clear-cut drained peatland forests. Yet, the cumulative effects of peatland drainage and clear-cutting on the biodiversity of recipient freshwater ecosystems are largely unknown. 2. We studied the isolated and combined effects of peatland drainage and clear-cutting on stream macroinvertebrate communities. We further explored whether the impact of these forestry-driven catchment alterations to benthic invertebrates is related to stream size. We quantified the impact on invertebrate biodiversity by comparing communities in forestry-impacted streams to expected communities modelled with a multi-taxon niche model. 3. The impact of clear-cutting of drained peatland forests exceeded the sum of the independent effects of drainage and clear-cutting, indicating a synergistic interaction between the two disturbances in small streams. Peatland drainage reduced benthic biodiversity in both small and large streams, whereas clear-cutting did the same only in small streams. Small headwater streams were more sensitive to forestry impacts than the larger downstream sites. 4. We found 11 taxa (out of 25 modelled) to respond to forestry disturbances. These taxa were mainly different from those previously reported as sensitive to forestry-driven alterations, indicating the context dependence of taxonomic responses to forestry. In contrast, most of the functional traits previously identified as responsive to agricultural sedimentation also responded to forestry pressures. In particular, taxa that live temporarily in hyporheic habitats, move by crawling, disperse actively in water, live longer than 1 year, use eggs as resistance form and obtain their food by scraping became less abundant than expected, particularly in streams impacted by both drainage and clear-cutting. 5. Synthesis and applications. Drained peatland forests in boreal areas are reaching maturity and will soon be harvested. Clear-cutting of these forests incurs multiple environmental hazards but previous studies have focused on terrestrial ecosystems. Our results show that the combined impacts of peatland drainage and clear-cutting may extend across ecosystem boundaries and cause significant biodiversity loss in recipient freshwater ecosystems. This information supports a paradigm shift in boreal forest management, whereby continuous-cover forestry based on partial harvest may provide the most sustainable approach to peatland forestry.
  • Koivula, M.; Niemelä, J. (Finnish Forest Research Institute (Metla), 2002)
  • Keipi, Kari (Suomen metsätieteellinen seura, 1980)
  • Chambers, Philip (Helsingin yliopisto, 2019)
    Forestry is a hazardous industry globally. Physical conditions, legal frameworks and cultural norms can vary from country to country leading to different approaches to site safety management. There are international, national and regional legislation and guidelines which outline normative approaches land managers can utilise to protect forestry machine operators and the public from accident or injury. In this study, the approaches the health and safety management in forestry operations are assessed in two countries within the European Union –Scotland (as part of the UK member state) and Finland. While both countries practice sustainable forest management, it is shown that this is carried out under different legal frameworks leading to differences in approach to site safety planning. Other factors are shown to have an effect including cultural factors and land ownership patterns.
  • Aaltonen, Heidi; Tuukkanen, Tapio; Palviainen, Marjo; Laurén, Annamari (Ari); Tattari, Sirkka; Piirainen, Sirpa; Mattsson, Tuija; Ojala, Anne; Launiainen, Samuli; Finér, Leena (2021)
    Understanding the anthropogenic and natural factors that affect runoff water quality is essential for proper planning of water protection and forest management, particularly in the changing climate. We measured water quality and runoff from 10 unmanaged and 20 managed forested headwater catchments (7-12,149 ha) located in Finland. We used linear mixed effect models to test whether the differences in total organic carbon (TOC), total nitrogen (TN) and total phosphorus (TP) export and concentrations observed can be explained by catchment characteristics, land use, forest management, soil fertility, tree volume and hydrometeorological variables. Results show that much of variation in TOC, TN and TP concentrations and export was explained by drainage, temperature sum, peatland percentage and the proportion of arable area in the catchment. These models explained 45-63% of variation in concentrations and exports. Mean annual TOC export in unmanaged catchments was 56.4 +/- 9.6 kg ha(-1) a(-1), while in managed it was 79.3 +/- 3.3 kg ha(-1) a(-1). Same values for TN export were 1.43 +/- 0.2 kg ha(-1) a(-1) and 2.31 +/- 0.2 kg ha(-1) a(-1), while TP export was 0.053 +/- 0.009 kg ha(-1) a(-1) and 0.095 +/- 0.008 kg ha(-1) a(-1) for unmanaged and managed, respectively. Corresponding values for concentrations were: TOC 17.7 +/- 2.1 mg L-1 and 28.7 +/- 1.6 mg L-1, for TN 420 +/- 45 mu g L-1 and 825 +/- 51 mu g L-1 and TP 15.3 +/- 2.3 mu g L-1 and 35.6 +/- 3.3 mu g L-1. Overall concentrations and exports were significantly higher in managed than in unmanaged catchments. Long term temperature sum had an increasing effect on all concentrations and exports, indicating that climate warming may set new challenges to controlling nutrient loads from catchment areas.
  • Henly, Russell K.; Ellefson, Paus V. (Suomen metsätieteellinen seura, 1986)
  • Heikinheimo, L.; Ervasti, S.; Ahonen, L. (Suomen metsätieteellinen seura, 1959)
  • Seppälä, Kustaa (Suomen metsätieteellinen seura, 1972)
  • Ouattara, Issouf; Hyyti, Heikki; Visala, Arto (Elsevier, 2020)
    IFAC-PapersOnLine, Proceedings of the 21th IFAC World Congress, Berlin, Germany, 12-17 July 2020
    We propose a novel method to locate spruces in a young stand with a low cost unmanned aerial vehicle. The method has three stages: 1) the forest area is mapped and a digital surface model and terrain models are generated, 2) the locations of trees are found from a canopy height model using local maximum and watershed algorithms, and 3) these locations are used in a convolution neural network architecture to detect young spruces. Our result for detecting young spruce trees among other vegetation using only color images from a single RGB camera were promising. The proposed method is able to achieve a detection accuracy of more than 91%. As low cost unmanned aerial vehicles with color cameras are versatile today, the proposed work is enabling low cost forest inventory for automating forest management.
  • Lähteenoja, Pentti (Suomen metsätieteellinen seura, 1987)
  • Heliövaara, Kari; Väisänen, Rauno (Suomen metsätieteellinen seura, 1984)
  • Mikola, Peitsa (Suomen metsätieteellinen seura, 1979)
  • Nyyssönen, Aarne (Suomen metsätieteellinen seura, 1959)
  • Kuusela, Kullervo (Suomen metsätieteellinen seura, 1979)