Articles containing the keyword 'site preparation'.

Over 20% of regeneration operations will be on drained peatland in the next decade in Finland. There are only a few studies comparing the planting success and the risk of pine weevil (Hylobius abetis (L.) feeding damage on mineral soil and drained peatland. Thirty sites planted with Norway spruce (Picea abies (L.) H. Karst.) container seedlings in 2009 in Southern and Central Finland were inventoried three growing seasons after planting. Prediction models for the probability of survival, pine weevil damage and the presence of ground vegetation cover were done separately for peatland and mineral soil sites. The planting success was 17% lower on peatland sites (1379 surviving seedlings ha^–1) than on mineral soil (1654 seedlings ha^–1). The factors explaining the survival were the ground vegetation cover and type of the planting spot on the peatland, and the ground vegetation cover on mineral soil. On mineral soil, 76% of the planting spots were on cultivated mineral soil while on peatland only 28% of the seedlings were planted on similar spots. There were also fewer seedlings that were surrounded by dense ground vegetation on mineral soil (4%) than on peatland (14%). Pine weevil feeding damage did not differ significantly on peatland (23%) or mineral soil (18%). The more time there was from clear-cutting, the more the probability of pine weevil feeding damage was reduced on both soil classes. Additionally, cover vegetation in the vicinity of the seedlings increased on mineral soil. Cultivated planting spots, especially those covered by mineral soil, prevented pine weevil feeding and reduced the harmful effects of vegetation on the seedlings both on mineral soil and peatland.

• Luoranen, Natural Recourses Institute Finland (Luke), Production systems, Juntintie 154, FI-77600 Suonenjoki, Finland ORCID ID: https://orcid.org/0000-0002-6970-2030 E-mail: jaana.luoranen@luke.fi
• Viiri, UPM Forest, Peltokatu 26 C, P.O. Box 85, FI-33100 Tampere, Finland ORCID ID: https://orcid.org/0000-0003-3952-9481 E-mail: heli.viiri@upm.com

In Nordic forests, consistent evidence about better seedling survival rate and increased growth due to site preparation have been obtained in numerous studies. Proper site preparation method can reduce costs of the whole regeneration chain through its effects on survival of planted seedlings, abundance of natural regeneration and competition in early stand development. This study compared the natural regeneration of birches (silver birch (Betula pendula Roth) and downy birch (B. pubescens Ehrh.)), amount of exposed mineral soil, and growth of planted seedlings between spot mounding and inverting site preparation methods. Present study was conducted in eight forest stands established in 2012 or 2015. Even though difference was not statistically significant, inverting exposed less mineral soil than spot mounding and thus reduced the natural regeneration of birch seedlings by 6135 seedlings ha^–1 compared to spot mounding. However, the variation between regeneration areas was remarkable. There was no difference in seedling mortality or growth between the site preparation methods. In order to achieve high growth of conifers, moderate amount of exposed mineral soil and thus less naturally regenerated birch, inverting should be favored over spot mounding.

• Laine, Metsä Group, P.O. Box 208, FI-70101 Kuopio, Finland ORCID ID: – E-mail: tiina.laine@metsagroup.com
• Kankaanhuhta, Natural Resources Institute Finland (Luke), Natural resources, Juntintie 154, FI-77600 Suonenjoki, Finland ORCID ID: – E-mail: ville.kankaanhuhta@luke.fi
• Rantala, Metsä Group, P.O. Box 10, FI-02020 METSÄ, Finland ORCID ID: – E-mail: juho.rantala@metsagroup.com
• Saksa, Natural Resources Institute Finland (Luke), Natural resources, Juntintie 154, FI-77600 Suonenjoki, Finland ORCID ID: – E-mail: timo.saksa@luke.fi

Hybrid aspen (Populus tremula L. × P. tremuloides Michx.) is a deciduous tree species suitable for producing large amounts of renewable biomass during short rotations. Its potential under North European conditions could be largely extended if not only agricultural land but also forest land was used for cultivation. Unfortunately, the knowledge of appropriate forest site conditions and effects of site preparation methods on hybrid aspen establishment is limited. In this paper, two studies that explore these questions are presented. In the first study, the sensitivity to acid soils was tested under greenhouse conditions in two type of soils: a) peat soil limed to certain pH levels (3.4–5.7) and b) collected forest soils where pH varied from 3.9 to 5.3. The lowest pH level resulted in reduced growth, elsewhere no significant differences were found. The second study was applied in the field and investigated the effect of four site preparation methods on survival and growth. The methods were: 1) control with no site preparation, 2) patch scarification, 3) mounding and 4) soil inversion. While no differences were found for survival, mounding was generally the method with the highest growth and patch scarification was least successful. The result was probably an effect of good soil aeration and less competition from vegetation after mounding. The field study also revealed clonal differences in growth performance, which stresses the importance of clone selection prior to planting. The results of these studies indicate that hybrid aspen is less sensitive to variation in pH and site preparation methods compared with other poplar species, as have been found in similar studies.

• Hjelm, Skogforsk, Ekebo 2250, SE-268 90 Svalöv, Sweden ORCID ID: – E-mail: karin.hjelm@skogforsk.se
• Rytter, Skogforsk, Ekebo 2250, SE-268 90 Svalöv, Sweden ORCID ID: http://orcid.org/0000-0001-6183-4832 E-mail: lars.rytter@skogforsk.se

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
• 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

• Hyppönen, Finnish Forest Research Institute, Rovaniemi Unit, P.O. Box 16, FI-96301 Rovaniemi, Finland ORCID ID: – E-mail: mikko.hypponen@metla.fi
• Hallikainen, Finnish Forest Research Institute, Rovaniemi Unit, P.O. Box 16, FI-96301 Rovaniemi, Finland ORCID ID: – E-mail: ville.hallikainen@metla.fi
• Niemelä, Finnish Forest Research Institute, Rovaniemi Unit, P.O. Box 16, FI-96301 Rovaniemi, Finland ORCID ID: – E-mail: –
• Rautio, Finnish Forest Research Institute, Rovaniemi Unit, P.O. Box 16, FI-96301 Rovaniemi, Finland ORCID ID: – E-mail: pasi.rautio@metla.fi

• Hökkä, Finnish Forest Research Institute, Rovaniemi Unit, P.O. Box 16, FI-96301 Rovaniemi, Finland ORCID ID: – E-mail: hannu.hokka@metla.fi
• Repola, Finnish Forest Research Institute, Rovaniemi Unit, P.O. Box 16, FI-96301 Rovaniemi, Finland ORCID ID: – E-mail: jaakko.repola@metla.fi
• Moilanen, Finnish Forest Research Institute, Oulu Unit, P.O. Box 413, FI-90014 University of Oulu, Finland ORCID ID: – E-mail: mikko.moilanen@metla.fi
• Saarinen, Finnish Forest Research Institute, Parkano Unit, Kaironiementie 15, FI-39700 Parkano, Finland ORCID ID: – E-mail: markku.saarinen@metla.fi

• Strömgren, Swedish University of Agricultural Sciences, Department of Soil and Environment, Uppsala, Sweden ORCID ID: – E-mail: monika.stromgren@slu.se
• Mjöfors, Swedish University of Agricultural Sciences, Department of Soil and Environment, Uppsala, Sweden ORCID ID: – E-mail: –
• Holmström, Swedish University of Agricultural Sciences, Department of Soil and Environment, Uppsala, Sweden ORCID ID: – E-mail: –
• Grelle, Swedish University of Agricultural Sciences, Department of Ecology, Uppsala, Sweden ORCID ID: – E-mail: –

• 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
• Fjeld, Swedish University of Agricultural Sciences, Dept. of Forest Resource Management, SE-901 83 Umeå, Sweden ORCID ID: – E-mail: –

• Chantal, University of Helsinki, Dept. of Forest Ecology, P.O. Box 27, FIN-00014 University of Helsinki, Finland ORCID ID: – E-mail: michelle.dechantal@helsinki.fi
• Eskola, University of Helsinki, Dept. of Forest Ecology, P.O. Box 27, FIN-00014 University of Helsinki, Finland ORCID ID: – E-mail: –
• Ilvesniemi, University of Helsinki, Dept. of Forest Ecology, P.O. Box 27, FIN-00014 University of Helsinki, Finland ORCID ID: – E-mail: –
• Leinonen, University of Helsinki, Dept. of Forest Ecology, P.O. Box 27, FIN-00014 University of Helsinki, Finland ORCID ID: – E-mail: –
• Westman, University of Helsinki, Dept. of Forest Ecology, P.O. Box 27, FIN-00014 University of Helsinki, Finland ORCID ID: – E-mail: –

• Haeussler, C2 Site 81 RR#2 Monckton Rd., Smithers, B.C., Canada V0J 2N0 ORCID ID: – E-mail: skeena@bulkley.net
• Bedford, B.C. Ministry of Forests, P.O. Box 9513 Stn. Prov. Govt., Victoria, B.C., Canada, V8W 9C2 ORCID ID: – E-mail: –
• Leduc, Groupe de recherche en écologie forestière interuniversitaire, Université du Québec à Montréal, CP 8888, Succursale A, Montréal, Québec, Canada, H3C 3P8 ORCID ID: – E-mail: –
• Bergeron, Groupe de recherche en écologie forestière interuniversitaire, Université du Québec à Montréal, CP 8888, Succursale A, Montréal, Québec, Canada, H3C 3P8 ORCID ID: – E-mail: –
• Kranabetter, B.C. Ministry of Forests, Bag 5000, Smithers, B.C., Canada, V0J 2N0 ORCID ID: – E-mail: –

• Karlsson, Swedish University of Agricultural Sciences, Department of Silviculture, S-901 83 Umeå, Sweden ORCID ID: – E-mail: anders.karlsson@ssko.slu.se
• Albrektson, Swedish University of Agricultural Sciences, Department of Silviculture, S-901 83 Umeå, Sweden ORCID ID: – E-mail: –
• Forsgren, Swedish University of Agricultural Sciences, Department of Silviculture, S-901 83 Umeå, Sweden ORCID ID: – E-mail: –
• Svensson, Swedish University of Agricultural Sciences, Department of Silviculture, S-901 83 Umeå, Sweden ORCID ID: – E-mail: –

• Kärhä, Stora Enso Wood Supply Finland, Talvikkitie 40 C, FI-01300 Vantaa, Finland ORCID ID: – E-mail: kalle.karha@storaenso.com

Five ploughed research areas from Finnish Norther Karelia were selected for comparison studies of plough ridges and untouched soil. Measurements were made at a depth of 10 cm in sample plots on both mineral and paludified mineral soil and peatland parts of these areas. In summer 1987 daily soil water matric potential was measured using tensiometers, and volumetric soil moisture content and density were determined from soil samples at two dates during the summer. Water characteristics of the core samples were also determined. On paludified mineral and peat soils the water table depth from the soil surface was measured.

The results indicated that in plough ridges matric potential was lowest. Plough ridges were also seen to dry and wet faster and to a greater degree than untouched soils. In untouched soils, soil water relations and aeration were not affected by the distance to the furrow. The effect of the plough ridge was smallest on peatland, where there was a good capillary connection from plough ridge to the ground water, if the ditches were not very effective. The soil in the ridges did not dry too much to restrict seedling growth. The untouched surface soil in poorly drained peat and paludified minear soil was, at least in a rainy growing season, often and also for long times so wet that 10% minimum air space required for good seedling root growth was not available.

The PDF includes an abstract in English.

• Mannerkoski, ORCID ID: – E-mail: –
• Möttönen, ORCID ID: – E-mail: –

The winter 1986–87 was unusually cold; the snow cover remained thin and consequently the soil froze to a considerable depth. In spite of the severe frost, the lowest temperatures measured at the ground surface was -10.3°C and in the soil at the depth of 10 cm -5.8°C. The temperature sum of the following summer was unusually small and the soil frost melted more slowly than usual. The winter frosts did not have a decisive influence on the survival of planted seedlings.

The PDF includes an abstract in English.

• Kubin, ORCID ID: – E-mail: –