Karri Uotila, Timo Saksa, Juho Rantala, Nuutti Kiljunen. (2014). Labour consumption models applied to motor-manual pre-commercial thinning in Finland. Silva Fennica vol. 48 no. 2 article id 982. https://doi.org/10.14214/sf.982

Keywords: productivity; pre-commercial thinning; forest vegetation management; early cleaning; release treatment; mixed linear regression

Highlights: When a young stand grows and gets older, the work time needed to make pre-commercial thinning increases. The stands of Norway spruce (Picea abies (L.) Karst.), Scots pine (Pinus sylvestris L.) and hardwoods (Betula spp.) required an additional 8.2%, 5.2%, and 3.3% work-time per year, respectively.

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Labour models were developed to estimate the time required to Pre-Commercially Thin (PCT) with a clearing saw 4- to 20-year-old stands of the main commercial tree species in Finland. Labour (i.e., work-time consumption) was estimated from the density and stem diameter of the removal of 448 stands via an existing work productivity function. The removal based estimator attained was used as the basis for a priori mixed linear regression models. The main finding was that when a young stand grows and gets older, the work time needed to make a PCT increases. The stands of Norway spruce (Picea abies (L.) Karst.), Scots pine (Pinus sylvestris L.) and hardwoods (Betula spp.) required an additional 8.2%, 5.2%, and 3.3% work-time per year, respectively. Site fertility also played a role in that the most fertile site (mesic OMT) had an estimated labour requirement 114% higher than that for dryish VT. We also note that, per unit area, small stands require less labour than large ones and soil preparation method had a minor effect on the labour estimate. The stands which had previously gone through PCT were separately analysed. In those stands, the only significant variable concerning the labour estimate was age. The a priori models described here can help foresters to develop economic management programmes and issue quotes for forestry services.

Uotila, Finnish Forest Research Institute, Juntintie 154, FI-77600 Suonenjoki, Finland E-mail: karri.uotila@metla.fi
Saksa, Finnish Forest Research Institute, Juntintie 154, FI-77600 Suonenjoki, Finland E-mail: timo.saksa@metla.fi
Rantala, Metsä Group, Lielahdenkatu 10, FI-33400 Tampere, Finland E-mail: juho.rantala@metsagroup.com
Kiljunen, Metsähallitus, Asemakatu 7, FI-70107 Kuopio, Finland E-mail: nuutti.kiljunen@metsa.fi

article id 397, category Research article

Nuutti Kiljunen. (2005). Pricing the risk of the quality-guarantee in a stand establishment service. Silva Fennica vol. 39 no. 1 article id 397. https://doi.org/10.14214/sf.397

Keywords: quality; forest regeneration; risk; guarantee

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A stand-establishment service concept with quality guarantee was analysed. Here, the quality of stand establishment was assessed as the density of good quality seedlings evenly distributed on the plantation three years after planting. The amount of adequate premiums for the guarantee service and the risks accumulating to the service provider were studied. Monte Carlo simulation was used as a tool for analyzing the risks accumulating to the service provider of the stand-establishment in operational environments of different sizes. The premiums calculated to cover the expected amount of claims caused by the plantations not meeting the pre-set criteria were about 4–8% in addition to the approximated costs of stand establishment. The criteria used for determining the success or failure in a stand have a marked effect on the amount of premiums with a reasonable risk of ruin.

Kiljunen, Finnish Forest Research Institute, Suonenjoki Research Station, Juntintie 154, FI-77600 Suonenjoki, Finland E-mail: nuutti.kiljunen@metla.fi

article id 515, category Research article

Juho Rantala, Kari Väätäinen, Nuutti Kiljunen, Pertti Harstela. (2003). Economic evaluation of container seedling packing and disinfection machinery. Silva Fennica vol. 37 no. 1 article id 515. https://doi.org/10.14214/sf.515

Keywords: economies of scale; nursery technology; mechanisation; container seedlings; packing;

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Productivity and costs of packing container seedlings were studied in a mechanised line for packing and disinfecting seedling trays. The hypothesis was that adequate cost-efficiency could be achieved when some common principles of mechanisation were applied. Results indicated that the unit costs are lower than those of manual packing, if these principles were applied and the annual number of packed seedlings exceeded 6 million. However, most of the nurseries in Finland are still too small to gain a real advantage from large-scale production.

Rantala, Finnish Forest Research Institute, Suonenjoki Research Station, FIN-77600 Suonenjoki, Finland E-mail: juho.rantala@metla.fi
Väätäinen, Finnish Forest Research Institute, Joensuu Research Centre, FIN-80101 Joensuu, Finland E-mail: kv@nn.fi
Kiljunen, Finnish Forest Research Institute, Suonenjoki Research Station, FIN-77600 Suonenjoki, Finland E-mail: nk@nn.fi
Harstela, Finnish Forest Research Institute, Suonenjoki Research Station, FIN-77600 Suonenjoki, Finland E-mail: ph@nn.fi

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