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Silva Fennica vol. 49 no. 1 | 2015

Category: Research article

article id 1300, category Research article
Jaana Luoranen, Risto Rikala. (2015). Post-planting effects of early-season short-day treatment and summer planting on Norway spruce seedlings. Silva Fennica vol. 49 no. 1 article id 1300. https://doi.org/10.14214/sf.1300
Highlights: Summer planting and short-day treatment advanced the bud burst and increased the height of Norway spruce seedlings after planting, compared to autumn and spring planted or untreated seedlings.
Effects of short-day (SD) treatment on bud burst, growth and survival of Norway spruce (Picea abies [L.] Karst.) container seedlings after summer planting were studied in an experiment established in Suonenjoki, Central Finland. One-year-old seedlings were SD-treated for three weeks starting on 18 June, 24 June and 8 July 2004 and then planted on 22 July, 5 August, 6 September 2004 and, as a normal spring planting, on 10 May, 2005. Untreated control seedlings were also planted on these dates. Second flush on the planting year and bud burst the following spring was monitored in planted seedlings, whereas seedling height and survival were determined at the end of growing seasons 2004–2006. We observed a non-significant risk of a second flush if seedlings were SD-treated on 18 June. Also, SD-treated seedlings planted in July or August showed advanced bud burst and increased height the following growing season without significant effects on survival, compared to autumn and spring planted seedlings. Planting in July or early August was associated with a significant increase in the incidence of multiple leaders in later years. Based on our results, to begin a three-week SD treatment in late June or early July and then plant seedlings in late July or early August could be a good practice.
  • Luoranen, Natural Resources Institute Finland (Luke), Natural resources and bioproduction, Juntintie 154, FI-77600 Suonenjoki, Finland ORCID ID:E-mail: jaana.luoranen@luke.fi (email)
  • Rikala, The Finnish Forest Research Institute, Suonenjoki Unit, Suonenjoki, Finland ORCID ID:E-mail: rikala@dnainternet.fi
article id 1260, category Research article
Jyrki Hytönen, Anna Saarsalmi. (2015). Biomass production of coppiced grey alder and the effect of fertilization. Silva Fennica vol. 49 no. 1 article id 1260. https://doi.org/10.14214/sf.1260
Highlights: Fertilisation (wood ash, N, PK) did not affect grey alder biomass production; Leafless above-ground biomass of 17–20 year old stands was 52–57 Mg ha–1; MAI increased with increase of rotation length to the end of the follow-up period of 17–20 years; Coppicing increased stand density manifold.
We studied biomass production of two naturally originated grey alder (Alnus incana (L.) Moench) stands having a mixture of birch and willow located in central Finland. One of the stands was growing on a peatland site (Muhos) and the other on a mineral soil site (Juuka). The stands were clear-cut and fertilization experiments were laid out with several treatments. At Muhos, the treatments included nitrogen fertilisation with different amounts of wood ash and an unfertilized control. At Juuka, the treatments included nitrogen fertilisation either with ash or with PK, and ash and PK treatments alone and an unfertilized control. The sprouts at Muhos were grown for 17 years and at Juuka for 20 years. At Juuka the stand was clear-cut second time at the age of 20 years and grown for 8 years. The stands were measured several times and foliar samples were taken twice during the study period. Clear-cutting increased stem number manifold. The stand density of new coppiced forests after the clear-cutting decreased from 67 000–89 000 stems ha–1 at the age of 3–6 years to 10 000–12 000 stems ha–1 at the age of 17–20 years. On neither site fertilization affected biomass production of alders during the study period. Leafless above-ground biomass was 52–57 Mg ha–1 after 17–20 years. Mean annual leafless above-ground biomass production (MAI) increased with increase of rotation time. At the age of 17–20 years the MAI was 2.8–3.0 Mg ha a–1. At Muhos, ash increased foliar P and Ca concentrations, but decreased those of Mn.
  • Hytönen, Natural Resources Institute Finland, Silmäjärventie 2, FI-69100 Kannus, Finland ORCID ID:E-mail: jyrki.hytonen@luke.fi (email)
  • Saarsalmi, Natural Resources Institute Finland, P.O. Box 18, FI-01301 Vantaa, Finland ORCID ID:E-mail: anna.saarsalmi@luke.fi
article id 1220, category Research article
Elisabeth Düthorn, Lea Schneider, Oliver Konter, Philipp Schön, Mauri Timonen, Jan Esper. (2015). On the hidden significance of differing micro-sites on tree-ring based climate reconstructions. Silva Fennica vol. 49 no. 1 article id 1220. https://doi.org/10.14214/sf.1220
Highlights: Pines and spruces show growth level differences in wet and dry micro-sites with higher growth rates in the dry sites; Spruces show a robust climate-growth relationship with June-July temperatures; Application of collective detrending methods can bias long-term trends in climate reconstructions, if relict and recent samples originate from different micro-sites.
Tree-ring chronologies are commonly extended back in time by combining samples from living trees with relict material preserved in man-made structures or natural archives (e.g. lakes). Although spatially close, these natural archives and living-tree-sites often comprise different micro-climates. Inhomogeneous growth conditions among these habitats, which may yield offsets in growth-rates, require caution in data processing. Here we assess species-specific growth dynamics in two micro-habitats and their potential effects on long chronologies by combining tree-ring data from different living-tree-sites with an “artificial” subfossil dataset. Well replicated (n > 80) Norway spruce (Picea abies (L.) Karst.) and Scots pine (Pinus sylvestris L.) chronologies from northern Fennoscandia, sampled directly at the lakeshore (wet) and several meters beyond the lakeshore (dry) reveal high coherence of the variance between micro-sites (rspruce = 0.59, rpine = 0.68). Significant differences of the Regional Curves (RC) indicate faster growth of both species at the drier site though. Growth differences are more pronounced between the spruce micro-sites. The combination of recent dry and wet spruce data with artificial relict data results in two long chronologies covering the last 800 years with substantially different trends, although they consist of the same relict material and the micro-site chronologies correlate significantly over the past two centuries. The combination of spruce samples from dry inland micro-sites with subfossil samples originating from the wet lake shore can result in an underestimation of past temperatures prior to the 19th century. Such effects, hidden in the composition of long chronologies (living trees + subfossil samples) can bias long-term trends in climate reconstructions.
  • Düthorn, Department of Geography, Johannes Gutenberg University, Becherweg 21, 55099 Mainz, Germany ORCID ID:E-mail: duethorn@uni-mainz.de (email)
  • Schneider, Department of Geography, Johannes Gutenberg University, Becherweg 21, 55099 Mainz, Germany ORCID ID:E-mail: l.schneider@geo.uni-mainz.de
  • Konter, Department of Geography, Johannes Gutenberg University, Becherweg 21, 55099 Mainz, Germany ORCID ID:E-mail: O.Konter@geo.uni-mainz.de
  • Schön, Department of Geography, Johannes Gutenberg University, Becherweg 21, 55099 Mainz, Germany ORCID ID:E-mail: philipp.schoen@gmx.de
  • Timonen, Natural Resources Institute Finland (Luke), Natural resources and bioproduction, FI-96301 Rovaniemi, Finland ORCID ID:E-mail: mauri.timonen@metla.fi
  • Esper, Department of Geography, Johannes Gutenberg University, Becherweg 21, 55099 Mainz, Germany ORCID ID:E-mail: J.Esper@geo.uni-mainz.de
article id 1214, category Research article
Katri Hamunen, Outi Virkkula, Teppo Hujala, Juha Hiedanpää, Mikko Kurttila. (2015). Enhancing informal interaction and knowledge co-construction among forest owners. Silva Fennica vol. 49 no. 1 article id 1214. https://doi.org/10.14214/sf.1214
Highlights: Forest owners’ own communities could complement the present expert-driven forestry extension; Enhancing informal interaction between forest owners calls for sufficiently homogeneous reference groups and also new communication contexts; New purposes of forest ownership and innovative forest management practices are suggested topics for novel owner communities; Forest professionals may initiate these communities, but the continuity depends on the owners themselves.
It is a common concern that non-resident private forest owners are less able to make informed decisions regarding their forests. Moreover, the present guidance given by forest professionals is not reaching all owners. In this study, we suggest enhancing knowledge exchange among forest owners by increasing their mutual and informal interaction that could inspire them to co-construct new knowledge. The first objective is to identify present emerging activities that constitute knowledge exchange contexts (communities) for Finnish forest owners. The second objective is to discuss the challenges of current Finnish forest extension and their implications when introducing Communities of Practice as a complementary response to existing, yet insufficient, professional-led extension. Data consist of Finnish forest owners’ and forest professionals’ (n = 43) focus group interviews. The qualitative analysis was theoretically oriented followed by data-driven coding and grouping. According to the results, the role of expert-led encounters is strong in Finland and owners’ opportunities for good mutual communication are rare. Informal communities exist mainly in the countryside among neighbouring owners and within families. To enhance knowledge sharing among owners, one needs to identify innovative topics and activities that would inspire owners to commit to their forest property and perform active silviculture. These communities would operate as creative learning environments allowing participation of different levels. When cultivating forest owners’ communities it is important to consider actors’ roles. Forest owners themselves are responsible for the functions and continuity of these communities, although forest professionals could also initiate new and sufficiently homogenous reference groups for the owners.
  • Hamunen, Natural Resources Institute Finland (Luke), New Business Opportunities, P.O. Box 68, FI-80101 Joensuu, Finland ORCID ID:E-mail: katri.hamunen@luke.fi
  • Virkkula, Oulu University of Applied Sciences, Kotkantie 1, FI-90250 Oulu, Finland ORCID ID:E-mail: outi.virkkula@oamk.fi
  • Hujala, Natural Resources Institute Finland (Luke), New Business Opportunities, P.O. Box 18, FI-01301 Vantaa, Finland ORCID ID: http://orcid.org/0000-0002-7905-7602 E-mail: teppo.hujala@luke.fi (email)
  • Hiedanpää, Natural Resources Institute Finland (Luke), Economy and Society, Itäinen Pitkäkatu 3, FI-20520 Turku, Finland ORCID ID:E-mail: juha.hiedanpaa@luke.fi
  • Kurttila, Natural Resources Institute Finland (Luke), New Business Opportunities, P.O. Box 68, FI-80101 Joensuu, Finland ORCID ID:E-mail: mikko.kurttila@luke.fi
article id 1191, category Research article
Tore Skrøppa, Halvor Solheim, Arne Steffenrem. (2015). Genetic variation, inheritance patterns and parent–offspring relationships after artificial inoculations with Heterobasidion parviporum and Ceratocystis polonica in Norway spruce seed orchards and progeny tests. Silva Fennica vol. 49 no. 1 article id 1191. https://doi.org/10.14214/sf.1191
Highlights: Genetic variation is demonstrated in response to artificial inoculations with Heterobasidion parviporum and Ceratocystis polonica both between parents and their offspring;Strong relationships are observed between the male parents and their off-spring, less so between the female parents and their offspring.
Inoculations with the two fungi Heterobasidion parviporum and Ceratocystis polonica were made in two series of progeny tests each containing full-sib families planted at two sites and on grafts of the parents in two seed orchards. Significant variation among families in lesion lengths after inoculation was found for both fungi and a predominantly additive inheritance was indicated. The estimates of narrow sense heritability were 0.13 and 0.22 for H. parviporum and C. polonica, respectively. The estimate of the genetic correlation between the lesion lengths of the two fungi was as low as 0.12. Significant variation in lesion lengths was also found among parental clones, and within ramets of the same clone, in the seed orchards. In one of the series a high positive correlation (r = 0.88) was found between the H. parviporum lesion lengths of the male parents and offspring, but not for the female parents and off-spring. The results confirm earlier conclusions that the genetic variation and heritabilities are large enough for practical breeding for resistance.
  • Skrøppa, Norwegian Forest and Landscape Institute, Box 115, 1431 Ås, Norway ORCID ID:E-mail: tore.skroppa@skogoglandskap.no (email)
  • Solheim, Norwegian Forest and Landscape Institute, Box 115, 1431 Ås, Norway ORCID ID:E-mail: halvor.solheim@skogoglandskap.no
  • Steffenrem, Norwegian Forest and Landscape Institute, Box 115, 1431 Ås, Norway ORCID ID:E-mail: arne.steffenrem@skogoglandskap.no
article id 1141, category Research article
Isabel Miranda, Jorge Gominho, Helena Pereira. (2015). Heartwood, sapwood and bark variation in coppiced Eucalyptus globulus trees in 2nd rotation and comparison with the single-stem 1st rotation. Silva Fennica vol. 49 no. 1 article id 1141. https://doi.org/10.14214/sf.1141
Highlights: Coppiced E. globulus trees in the 2nd rotation have similar heartwood and sapwood development as single-stem trees in the 1st rotation; The initial tree planting density did not influence heartwood development of coppiced E. globulus trees; Heartwood diameter and height can be modelled with tree diameter and height respectively; Sapwood width is approximately constant within and between coppice and single-stem E. globulus trees.
Coppiced Eucalyptus globulus trees with 18 years in a 2nd rotation were analysed in relation to heartwood, sapwood and bark content taking into account the effect of the initial planting density by using a spacing trial. A total of 25 stumps, with a variable number of stems per stump from 1 to 3, were analysed. Comparison was made to the previous 1st rotation single stem trees, also harvested at 18 years. In the 2nd rotation, the stump density did not significantly affect stem height and diameter, in opposition to the 1st rotation where spacing significantly impacted on tree dimensions. The effect of the initial planting density is somewhat lost in the coppiced stand in relation with i.e. the number of stems per stump. Heartwood was present in all the coppiced trees up to 49.9% of the total tree height and heartwood volume amounted to 38.9–51.7% of the total tree volume. Within the tree, heartwood content decreased from the base upwards, representing, on average, 54.1% at the base and decreasing to 5.1% at 15.3 m. The sapwood width remained relatively constant with an average radial width of approximately 2 cm. The average stem bark content of coppiced trees was 17.4% of the total stem volume. The comparison of heartwood and sapwood development in the coppiced trees did not show significant differences to the 1st rotation trees, nor did the initial spacing. Heartwood diameter could be modelled using the tree diameter both for 1st and 2nd rotation trees.
  • Miranda, Centro de Estudos Florestais, Instituto Superior de Agronomia, Universidade Lisboa, 1349-017 Lisboa, Portugal ORCID ID:E-mail: Imiranda@isa.ulisboa.pt
  • Gominho, Centro de Estudos Florestais, Instituto Superior de Agronomia, Universidade Lisboa, 1349-017 Lisboa, Portugal ORCID ID:E-mail: Jgominho@isa.utl.pt (email)
  • Pereira, Centro de Estudos Florestais, Instituto Superior de Agronomia, Universidade Lisboa, 1349-017 Lisboa, Portugal ORCID ID:E-mail: Hpereira@isa.utl.pt
article id 1106, category Research article
Jena Ferrarese, David Affleck, Carl Seielstad. (2015). Conifer crown profile models from terrestrial laser scanning. Silva Fennica vol. 49 no. 1 article id 1106. https://doi.org/10.14214/sf.1106
Highlights: Crown models are derived from terrestrial laser data for 3 NW USA conifer species; Crown models require only crown length for implementation; Beta and Weibull curves fit to 95th percentile widths describe crown extent; Crown profile curves are species-specific and not interchangeable; Crown shape is not strongly conditioned by tree size or site.
Regional crown profile models were derived for three conifer species of the interior northwestern USA from terrestrial laser scans of eighty-six trees across a range of sizes and growing conditions. Equations were developed to predict crown shape from crown length for Pseudotsuga menziesii, Pinus ponderosa, and Abies lasiocarpa from parametric curves applied to crown-length normalized laser point clouds. The 95th width percentile adequately described each crown’s outer limit; alternate width percentiles produced little profile shape variation. For P. menziesii and P. ponderosa, a scaling parameter-modified beta curve gave the most accurate fit (using cross-validated Mean Absolute Error) to aggregated 95th width percentile points. For A. lasiocarpa, beta and Weibull curves (equivalently modified) produced similar results. For all species, modified beta and Weibull curves fit crown points with less error than conic or cylindrical profiles. Crown profile curves were species-specific; interchanging among species increased error significantly. Laser-derived crown base metrics provided objectivity and consistency, but underestimated field-derived base heights through inclusion of dead branches. Profile curve parameters were not correlated with tree or stand characteristics suggesting that crown shape is not strongly conditioned by size and site factors. However, laser sampling necessarily favored more open growing conditions, potentially under-representing variations in crown shape associated with social position. Overall, Terrrestrial Laser Scanning (TLS) lends itself to detailed measurements of external crown architecture with occlusion-imposed limits to characterization of internal features. Yet, the time and cost of collecting and processing individual tree data precludes use of TLS as a common field sampling tool.
  • Ferrarese, College of Forestry and Conservation, The University of Montana, Missoula, MT, USA; (present) Center for the Environmental Management of Military Lands, 1490 Campus Delivery, Colorado State University, Fort Collins, CO 80523, USA ORCID ID:E-mail: jena.ferrarese@colostate.edu (email)
  • Affleck, College of Forestry and Conservation, University of Montana, Missoula, MT, USA ORCID ID:E-mail: david.affleck@cfc.umt.edu
  • Seielstad, College of Forestry and Conservation, University of Montana, Missoula, MT, USA ORCID ID:E-mail: carl.seielstad@firecenter.umt.edu

Category: Research note

article id 1255, category Research note
Āris Jansons, Roberts Matisons, Līga Puriņa, Una Neimane, Jānis Jansons. (2015). Relationships between climatic variables and tree-ring width of European beech and European larch growing outside of their natural distribution area. Silva Fennica vol. 49 no. 1 article id 1255. https://doi.org/10.14214/sf.1255
Highlights: In western Latvia, variation of tree-ring width of European beech and European larch within stands was similar; Dry summers and cold winters caused common event years in tree-rings; Moisture availability at the end of summer was apparently the main limiting factor for tree-ring width; Winter and spring temperature did not have significant and lasting effect on variation of tree-ring width.
Relationships between climatic variables and tree-ring width (TRW) of dominant European larch (Larix decidua Mill.) and European beech (Fagus sylvatica L.) trees growing outside of their natural distribution area in western Latvia were studied. Chronologies of TRW, which covered the periods 1949–2012 and 1911–2012, were produced for beech and larch, respectively. Common signatures in TRW between both species were observed, but their amplitude differed. Correlation analysis showed that variation of TRW of both species was affected by drought related climatic variables. Tree-ring width of beech was affected by temperature in the previous July and August and the effect of spring and autumn temperature was observed. Since the 1980s, the effect of July precipitation has become significant. Summer precipitation was significant for larch in the mid-part of the previous century; however, temperature in the previous September has become a limiting factor since 1970s. The limiting effect of winter and spring temperature apparently lost its significance around the 1950s.
  • Jansons, LSFRI „SILAVA”, Rigas Str. 111, Salaspils, Latvia, LV2169 ORCID ID:E-mail: aris.jansons@silava.lv
  • Matisons, LSFRI „SILAVA”, Rigas Str. 111, Salaspils, Latvia, LV2169 ORCID ID:E-mail: robism@inbox.lv (email)
  • Puriņa, LSFRI „SILAVA”, Rigas Str. 111, Salaspils, Latvia, LV2169 ORCID ID:E-mail: liga.purina@silava.lv
  • Neimane, LSFRI „SILAVA”, Rigas Str. 111, Salaspils, Latvia, LV2169 ORCID ID:E-mail: una.neimane@silava.lv
  • Jansons, Forest Competence Centre, Dzerbenes str. 27, Riga, Latvia, LV1006 ORCID ID:E-mail: janis.jansons@mnkc.lv

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