Current issue: 53(1)

Under compilation: 53(2)

Impact factor 1.683
5-year impact factor 1.950
Silva Fennica 1926-1997
1990-1997
1980-1989
1970-1979
1960-1969
Acta Forestalia Fennica
1953-1968
1933-1952
1913-1932

Articles containing the keyword 'scarification'.

Category: Research article

article id 7751, category Research article
Göran Nordlander, Euan G. Mason, Karin Hjelm, Henrik Nordenhem, Claes Hellqvist. (2017). Influence of climate and forest management on damage risk by the pine weevil Hylobius abietis in northern Sweden. Silva Fennica vol. 51 no. 5 article id 7751. https://doi.org/10.14214/sf.7751
Highlights: Analysis of survey data from 292 reforestation areas in northern Sweden show that the probability of pine weevil damage can be predicted with a standard error of 0.12; Three variables are important in the optimal model: proportion of seedlings in mineral soil, age of clear-cut, and temperature sum; Temperature sum in the model can be adjusted to reflect future climate scenarios.

The pine weevil Hylobius abietis L. is an economically important pest insect that kills high proportions of conifer seedlings in reforestation areas. It is present in conifer forests all over Europe but weevil abundance and risk for damage varies considerably between areas. This study aimed to obtain a useful model for predicting damage risks by analyzing survey data from 292 regular forest plantations in northern Sweden. A model of pine weevil attack was constructed using various site characteristics, including both climatic factors and factors related to forest management activities. The optimal model was rather imprecise but showed that the risk of pine weevil attack can be predicted approximatively with three principal variables: 1) the proportion of seedlings expected to be planted in mineral soil rather than soil covered with duff and debris, 2) age of clear-cut at the time of planting, and 3) calculated temperature sum at the location. The model was constructed using long-run average temperature sums for epoch 2010, and so effects of climate change can be inferred from the model by adjustment to future epochs. Increased damage risks with a warmer climate are strongly indicated by the model. Effects of a warmer climate on the geographical distribution and abundance of the pine weevil are also discussed. The new tool to better estimate the risk of damage should provide a basis for foresters in their choice of countermeasures against pine weevil damage in northern Europe.

  • Nordlander, Swedish University of Agricultural Sciences (SLU), Department of Ecology, P.O. Box 7044, SE-750 07 Uppsala, Sweden ORCID ID:E-mail: Goran.Nordlander@slu.se
  • Mason, University of Canterbury, School of Forestry, Private Bag 4800, Christchurch 8140, New Zealand; Swedish University of Agricultural Sciences, Southern Swedish Forest Research Centre, P.O. Box 49, SE-230 53 Alnarp, Sweden ORCID ID: http://orcid.org/0000-0001-9024-9106 E-mail: euan.mason@canterbury.ac.nz (email)
  • Hjelm, Skogforsk, The Forest Research Institute of Sweden, Ekebo 2250, SE-268 90 Svalöv, Sweden; Swedish University of Agricultural Sciences, Southern Swedish Forest Research Centre, P.O. Box 49, SE-230 53 Alnarp, Sweden ORCID ID:E-mail: karin.hjelm@skogforsk.se
  • Nordenhem, Swedish University of Agricultural Sciences (SLU), Department of Ecology, P.O. Box 7044, SE-750 07 Uppsala, Sweden ORCID ID:E-mail: h.nordenhem@telia.com
  • Hellqvist, Swedish University of Agricultural Sciences (SLU), Department of Ecology, P.O. Box 7044, SE-750 07 Uppsala, Sweden ORCID ID:E-mail: Claes.Hellqvist@slu.se
article id 1386, category Research article
Håkan Lideskog, Magnus Karlberg. (2016). Simulated continuous mounding improvements through ideal machine vision and control. Silva Fennica vol. 50 no. 2 article id 1386. https://doi.org/10.14214/sf.1386
Highlights: Different strategies for how to utilise machine vision to streamline the mounding head movements were developed and evaluated; The theoretical minimum rate of encountered obstacles while utilising machine vision in continuous mounding is presented, provided that an optimal continuous mounding has been performed; The needed minimum resolution of a machine vision system at work on a clearcut area was found.

To promote the growth and survival of regenerated forests, site preparation prior to tree planting on clearcuts is necessary. This is often performed with scarifiers, either through trenching or mounding. Mounding is generally considered better in a plant survival perspective but is inefficient on obstacle-rich clearcuts. By utilising machine vision through e.g. remote sensing methods, new strategies can enable efficient mound positioning. In this paper, three realistic strategies utilizing ideal clearcut object identification through machine vision have been developed that can be used for more efficient mounding. The results show that mounding efficiency can be significantly improved with a new mound positioning strategy that employs ideal object identification, especially on obstacle-rich clearcuts.

 

 

  • Lideskog, Luleå University of Technology, Department of Engineering Sciences and Mathematics, Division of Product and Production Development, SE-971 87 Luleå, Sweden ORCID ID:E-mail: hakan.lideskog@ltu.se (email)
  • Karlberg, Luleå University of Technology, Department of Engineering Sciences and Mathematics, Division of Product and Production Development, SE-971 87 Luleå, Sweden ORCID ID:E-mail: magnus.karlberg@ltu.se
article id 1312, category Research article
Simon Karl Nils Berg, Tomas Nordfjell, Dan Bergström. (2015). Effect of stump size and timing of stump harvesting on ground disturbance and root breakage diameter. Silva Fennica vol. 49 no. 5 article id 1312. https://doi.org/10.14214/sf.1312
Highlights: The ground disturbance and root breakage diameter during conventional stump harvesting on mineral soil were quantified; A function for estimating the disturbed area based on stump size was constructed; Many fine roots were found to be harvested; The total ground disturbance at the site after stump harvesting was similar to that caused by soil scarification.

Stump wood is a possible alternative to fossil fuel. Its harvesting, however, disturbs the ground and this has not yet been quantified at stump level. Such disturbance is likely to be dependent on stump size, type of soil and timing of stump harvesting. Therefore, we measured ground disturbance and root breakage diameter at two Norway spruce sites with sandy glacial till soil. The sites were harvested with a fork type head, 6 and 18 months after clear cutting. Measurements were made within 2 weeks of harvest. No difference was found between the two sites. The mean area of disturbed ground was 6.06 (std 3.14) m2 per stump and increased exponentially with stump size. A regression function modelling the relationship was constructed. Unexpectedly, many fine roots where extracted in the harvest. The arithmetic and basal area weighted mean root breakage diameter was 4.6 (std 2.2) and 29.5 (std 17.9) mm, respectively. There seems to be a limited increase in root breakage diameter with increased stump size. The small root breakage diameter is associated with reduced fuel quality and greater nutrient removal. It appears that much of the ground disturbance is associated with the creation of ruts rather than stump harvest per se. Stump harvesting disturbs a larger percentage of the area of a harvested site than mounding. Postponing stump harvest by one year did not decrease the ground disturbance or increase the root breakage diameter. To achieve less disturbance and larger root breakage diameter, probably new stump harvesting technology is required.

  • Berg, Swedish University of Agricultural Sciences (SLU), Department of Forest Biomaterials and Technology (SBT), Skogsmarksgränd, SE-901 83 Umeå, Sweden ORCID ID:E-mail: phd.simon.berg@gmail.com (email)
  • Nordfjell, Swedish University of Agricultural Sciences (SLU), Department of Forest Biomaterials and Technology (SBT), Skogsmarksgränd, SE-901 83 Umeå, Sweden ORCID ID:E-mail: tomas.nordfjell@slu.se
  • Bergström, Swedish University of Agricultural Sciences (SLU), Department of Forest Biomaterials and Technology (SBT), Skogsmarksgränd, SE-901 83 Umeå, Sweden ORCID ID:E-mail: dan.bergstrom@slu.se
article id 918, category Research article
Nelson Thiffault, François Hébert, Robert Jobidon. (2012). Planted Picea mariana growth and nutrition as influenced by silviculture x nursery interactions on an ericaceous-dominated site. Silva Fennica vol. 46 no. 5 article id 918. https://doi.org/10.14214/sf.918
We aimed at evaluating the interacting effects of silvicultural and nursery practices on planted black spruce (Picea mariana (Mill.) BSP) dimensions, growth, survival and nutrition, 8 years following planting on a carefully logged boreal stand heavily invaded by Kalmia angustifolia L. and Rhododendron groenlandicum (Oeder) Kron & Judd. We also evaluated functional traits related to light and nutrient acquisition and key environmental resource availability to interpret treatment impacts on spruce seedling leaf traits and growth. An experimental black spruce plantation, consisting in a randomized block split-split-split plot design with 13 replicates was established in northeastern Quebec (Canada). Scarification (single-pass, double-pass), fertilization at the time of planting (control; macronutrients only; macro + micronutrients), stock type (container-grown; bare-root), and initial foliar N concentration (4 increasing levels) treatments were applied, and measurements were performed 5 and 8 years following planting. Double-pass scarification significantly increased soil temperature and reduced the competition cover, compared to the single-pass treatment. As a result, double-pass scarification promoted seedling growth over the single-pass treatment, and influenced the expression of other treatment effects. However, the relative gains associated with the second scarification pass have to be balanced against the supplemental investment involved by the treatment before being recommended. Our results point to variable effects of fertilization at planting to stimulate seedling initial growth. In this ecosystem, it appears that the silvicultural gains of this treatment depend on the variable of interest. Bare-root seedlings grew faster than containerized seedlings in the most intense site preparation treatment, but the differences have limited silvicultural impacts.
  • Thiffault, Ministère des Ressources naturelles du Québec, Direction de la recherche forestière, 2700 rue Einstein, Québec, QC, Canada G1P 3W8 ORCID ID:E-mail: nelson.thiffault@mrnf.gouv.qc.ca (email)
  • Hébert, Ministère des Ressources naturelles du Québec, Direction de la recherche forestière, 2700 rue Einstein, Québec, QC, Canada G1P 3W8 ORCID ID:E-mail: ffrancois.hebert@mrnf.gouv.qc.ca
  • Jobidon, Ministère des Ressources naturelles du Québec, Direction de la recherche forestière, 2700 rue Einstein, Québec, QC, Canada G1P 3W8 ORCID ID:E-mail: robert.jobidon@mrnf.gouv.qc.ca
article id 263, category Research article
Aksel Granhus, Dag Fjeld. (2008). Time consumption of planting after partial harvests. Silva Fennica vol. 42 no. 1 article id 263. https://doi.org/10.14214/sf.263
Partial harvesting combined with underplanting may be a means to reduce the risk of regeneration failure when e.g. unfavourable microclimatic conditions or severe damage by bark-feeding insects may be expected after clear-cutting, and to maintain or establish certain stand structures or tree species mixture. In this study, we performed time studies of manual planting with and without prior site preparation (patch scarification, inverting) in partially harvested stands of Norway spruce (Picea abies (L.) Karst.). The harvest treatments included basal area removals of approx. 35, 45, and 55%, and a patch clear-cut treatment that was assumed to provide the same conditions for planting as conventional clear-cutting. Site preparation had a much larger influence on time consumption plant–1 (main time) than the harvest treatment. The lowest time consumption was found with inverting and the highest without site preparation. The time spent on walking between planting spots increased with decreasing harvest intensity, reflecting a lower density of planted seedlings in the partially harvested stands. A corresponding increase in main time per plant only occurred after site preparation, since the time spent on clearing the planting spot (removal of logging residue and humus) on untreated plots was higher at the higher harvest strengths. The variation in time consumption attributed to the six replicate stands was large and mainly due to the difference among stands planted by different workers.
  • Granhus, Norwegian University of Life Sciences, Dept. of Ecology and Natural Resource Management (INA), P.O.Box 5003, NO-1432 Ås, Norway ORCID ID:E-mail: aksel.granhus@umb.no (email)
  • Fjeld, Swedish University of Agricultural Sciences, Dept. of Forest Resource Management, SE-901 83 Umeå, Sweden ORCID ID:E-mail:

Category: Research note

article id 1716, category Research note
Nelson Thiffault, Alain Paquette, Christian Messier. (2017). Early silvicultural guidelines for intensive management of hybrid larch plantations on fertile sub-boreal sites. Silva Fennica vol. 51 no. 2 article id 1716. https://doi.org/10.14214/sf.1716
Highlights: Satisfactory growth can be obtained using a wide range of site preparation intensities; There is a net advantage of performing two motor-manual release treatments over a single release; A second release treatment cannot be replaced by more intensive site preparation; Planting depth had no influence on planted seedling growth after 6 years.

Use of fast-growing tree plantations on dedicated areas is proposed as a means of reconciling fibre production with conservation objectives. Success of this approach however requires fine-tuning silvicultural scenarios so that survival and growth are optimized while management and environmental costs are minimized. This is particularly challenging for hybrid larch (Larix × marschlinsii Coaz), a shade-intolerant species planted on fertile sites in Quebec (Canada) where legislation prevents the use of chemical herbicides. In this context, multiple motor-manual release treatments are often required, with high impacts on costs and social issues related to the scarcity of a qualified workforce. We established a split-split-plot design on a recently harvested site to assess the main and interaction effects of mechanical site preparation (MSP) intensity (five modalities of trenching or mounding), motor-manual release scenario (one or two treatments) and planting depth (0–3 cm or 3–10 cm) on hybrid larch seedling growth and survival six years after planting. Mechanical site preparation intensity and planting depth did not influence seedling growth after 6 years. The lack of significant interaction between MSP and release scenarios indicates that these operations should be planned independently. A more intensive MSP treatment cannot replace a second motor-manual release on fertile sites, as proposed to reduce costs. Our results also show the significant advantage of performing two motor-manual release treatments two years apart (the first one early in the scenario), over performing a single treatment. Our study provides silvicultural guidelines for the establishment of high-yield exotic larch plantations.

  • Thiffault, Direction de la recherche forestière, Ministère des Forêts, de la Faune et des Parcs du Québec, 2700 rue Einstein, Québec, QC, Canada G1P 3W8; Centre d’étude de la forêt, CP 8888, Succursale Centre-ville, Montréal, QC, Canada H3C 3P8 ORCID ID: http://orcid.org/0000-0003-2017-6890 E-mail: nelson.thiffault@mffp.gouv.qc.ca (email)
  • Paquette, Centre d’étude de la forêt, CP 8888, Succursale Centre-ville, Montréal, QC, Canada H3C 3P8; Université du Québec à Montréal, Département des sciences biologiques, CP 8888, Succursale Centre-ville, Montréal, QC, Canada H3C 3P8 ORCID ID: http://orcid.org/0000-0003-1048-9674 E-mail: alain.paquette@gmail.com
  • Messier, Centre d’étude de la forêt, CP 8888, Succursale Centre-ville, Montréal, QC, Canada H3C 3P8; Université du Québec à Montréal, Département des sciences biologiques, CP 8888, Succursale Centre-ville, Montréal, QC, Canada H3C 3P8; Institut des Sciences de la Forêt tempérée (ISFORT), 58 rue Principale, Ripon, QC, Canada JOV 1V0 E-mail nelson.thiff ORCID ID:E-mail: christian.messier@uqo.ca
article id 1661, category Research note
Āris Jansons, Linda Robalte, Roberts Čakšs, Roberts Matisons. (2016). Long-term effect of whole tree biomass harvesting on ground cover vegetation in a dry Scots pine stand. Silva Fennica vol. 50 no. 5 article id 1661. https://doi.org/10.14214/sf.1661
Highlights: After 47 years, whole tree harvesting (WTH) increased richness of ground cover species compared to conventionally managed stands; Higher occurrence of the oligotrophic species after WTH suggested reduction of soil nutrient content, hence formation of different plant community; WTH, apparently, facilitated recovery of species typical for later successional stages.

Long-term (47 years) effect of experimental whole tree harvesting (WTH) with a heavy soil scarification on ground cover vegetation was assessed in a dry nutrient-poor Scots pine (Pinus sylvestris L.) stand in Latvia. Neighbouring conventionally managed young (10 years) and mature (119 years) stands of the same type were used for comparison. Higher species richness was observed in the WTH stand compared to conventionally managed young and mature stands (24, 18 and 16 species, respectively), likely due to the profound disturbance. The Shannon diversity index was higher in the young than in the WTH and mature stands (2.36, 1.77 and 1.63, respectively); still, the composition and structure of ground cover vegetation in WTH was more similar to the mature stand. Nevertheless, the occurrence of oligotrophic species in the WTH stand suggested decreased soil nutrient content and potential development of different plant community. Hence, such method might be considered for restoration of oligotrophic stands. Nevertheless, the period of 47 years appeared sufficient for the ground cover vegetation to recover after the WTH.

  • Jansons, Latvian State Forest Research Institute “Silava”, 111 Rigas Str., LV 2169, Salaspils, Latvia ORCID ID:E-mail: aris.jansons@silava.lv
  • Robalte, Latvian State Forest Research Institute “Silava”, 111 Rigas Str., LV 2169, Salaspils, Latvia ORCID ID:E-mail: robalte.l@gmail.com (email)
  • Čakšs, Latvian State Forest Research Institute “Silava”, 111 Rigas Str., LV 2169, Salaspils, Latvia ORCID ID:E-mail: chakijs95@gmail.com
  • Matisons, Latvian State Forest Research Institute “Silava”, 111 Rigas Str., LV 2169, Salaspils, Latvia ORCID ID:E-mail: roberts.matisons@silava.lv

Register
Click this link to register for Silva Fennica submission and tracking system.
Log in
If you are a registered user, log in to save your selected articles for later access.
Contents alert
Sign up to receive alerts of new content
Your selected articles

Committee on Publication Ethics A Trusted Community-Governed Archive