Dan Bergström, Urban Bergsten, Tomas Nordfjell. (2010). Comparison of boom-corridor thinning and thinning from below harvesting methods in young dense Scots pine stands. Silva Fennica vol. 44 no. 4 article id 134. https://doi.org/10.14214/sf.134

Keywords: bioenergy; comparative time studies; energy wood; geometric thinning; pre-commercial thinnings; systematic thinnings

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At present, only a small proportion of the potential extractable bioenergy from young dense forests in Sweden is utilized. The conventional mechanized first thinning systems used in such stands suffer from low productivity, so the operation is only profitable in stands with bigger trees and high standing volumes. Conventional harvesters are used for this operation equipped with accumulating felling heads designed for handling several trees during each crane cycle. In thinning from below the felling and bunching work requires many time-consuming non-linear crane movements to avoid felling or damaging of future crop trees. However, higher productivity can be achieved when trees between strip roads are harvested in about 1 m-wide corridors with a length corresponding to the reach of the crane. We refer to this operation as boom-corridor thinning. The objective of this study was to compare felling and bunching productivity in young dense stands when employing thinning from below or boom-corridor thinning. Experiments were performed using a randomized block design involving between 4400 and 18 600 trees x ha^-1 with a corresponding average tree size of 7.2 and 3.2 cm dbh, respectively. Based on the average tree being removed at a dbh of 5.7 cm, the productivity (ODt x PW-hour^-1) was significant (almost 16%) higher for the boom-corridor thinning than for thinning from below treatment. At the same time, the time taken for the work element “Crane in-between” (the period between the loaded crane starting to move towards a tree and the felling head rapidly slowing down for positioning) was significantly reduced, by almost 17%. The positive results were achieved even though the operator was new to the method. To achieve a significantly higher efficiency during the felling and bunching operation, development of new harvesting equipment and operating techniques seems crucial.

Bergström, Swedish University of Agricultural Sciences, Dept of Forest Resource Management, Section of Planning and Operations Management, Umeå, Sweden E-mail: dan.bergstrom@srh.slu.se
Bergsten, Swedish University of Agricultural Sciences, Dept of Forest Resource Management, Section of Planning and Operations Management, Umeå, Sweden E-mail: ub@nn.se
Nordfjell, Swedish University of Agricultural Sciences, Dept of Forest Resource Management, Section of Planning and Operations Management, Umeå, Sweden E-mail: tn@nn.se

Category : Research note

article id 9911, category Research note

Tālis Gaitnieks, Indulis Brauners, Kristīne Kenigsvalde, Astra Zaļuma, Lauma Brūna, Jurģis Jansons, Natālija Burņeviča, Andis Lazdiņš, Rimvydas Vasaitis. (2018). Infection of pre-commercially cut stumps of Picea abies and Pinus sylvestris by Heterobasidion spp. – a comparative study. Silva Fennica vol. 52 no. 1 article id 9911. https://doi.org/10.14214/sf.9911

Keywords: Norway spruce; Scots pine; pre-commercial thinnings; Heterobasidion

Highlights: In pre-commercial thinnings both Heterobasidion infection frequency and the extent of surface colonization correlated positively with stump diameter of both Norway spruce and Scots pine; Spruce stumps were significantly more often subjected to primary infections than pine stumps; The pathogen exhibited more extensive surface colonization of spruce stumps than of pine stumps.

Abstract | Full text in HTML | Full text in PDF | Author Info

The aim was to investigate relative susceptibility of stumps of spruce and pine to airborne infections by Heterobasidion following pre-commercial thinnings. The proportions of infected stumps and colonized stump surface areas were analysed in 16 forest stands. In total, 746 spruce and 1063 pine stumps were sampled, and 184 and 105 infected stumps, respectively, were analysed. In conclusion, the present study demonstrated that in the investigated area: i) both Heterobasidion infection frequency and the extent of surface colonization correlated positively with stump diameter of both spruce and pine; ii) spruce stumps were significantly more often subjected to primary infections than pine stumps; iii) the pathogen exhibited more extensive surface colonization of spruce stumps than of pine stumps.

Gaitnieks, Latvian State Forest Research Institute “Silava”, 111 Rigas str., Salaspils, LV-2169, Latvia E-mail: talis.gaitnieks@silava.lv
Brauners, JSC “Latvia’s State Forests”, 1 Vainodes str., Riga, LV-1004, Latvia E-mail: i.brauners@lvm.lv
Kenigsvalde, Latvian State Forest Research Institute “Silava”, 111 Rigas str., Salaspils, LV-2169, Latvia E-mail: kristine.kenigsvalde@silava.lv
Zaļuma, Latvian State Forest Research Institute “Silava”, 111 Rigas str., Salaspils, LV-2169, Latvia E-mail: astra.zaluma@silava.lv
Brūna, Latvian State Forest Research Institute “Silava”, 111 Rigas str., Salaspils, LV-2169, Latvia E-mail: lauma.bruna@silava.lv
Jansons, Latvian State Forest Research Institute “Silava”, 111 Rigas str., Salaspils, LV-2169, Latvia E-mail: jurgis.jansons@silava.lv
Burņeviča, Latvian State Forest Research Institute “Silava”, 111 Rigas str., Salaspils, LV-2169, Latvia E-mail: natalija.arhipova@silava.lv
Lazdiņš, Latvian State Forest Research Institute “Silava”, 111 Rigas str., Salaspils, LV-2169, Latvia E-mail: andis.lazdins@silava.lv
Vasaitis, Swedish University of Agricultural Sciences (SLU), P.O. Box 7026, SE-75007 Uppsala, Sweden E-mail: Rimvys.Vasaitis@slu.se

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