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Silva Fennica vol. 51 | 2017

Category: Commentary

article id 6985, category Commentary
Eshetu Yirdaw, Markku Kanninen, Mohamed Elfadl & Daniel Tsegai. (2017). Special issue: Drought and Dryland Management – a commentary. Silva Fennica vol. 51 no. 1B article id 6985. https://doi.org/10.14214/sf.6985
  • Yirdaw, Viikki Tropical Resources Institute (VITRI), Department of Forest Sciences, P.O. Box 27, FI-00014 University of Helsinki, Finland ORCID ID:E-mail: eshetu.yirdaw@helsinki.fi (email)
  • Kanninen, Viikki Tropical Resources Institute (VITRI), Department of Forest Sciences, P.O. Box 27, FI-00014 University of Helsinki, Finland ORCID ID:E-mail: markku.kanninen@helsinki.fi
  • Elfadl, Viikki Tropical Resources Institute (VITRI), Department of Forest Sciences, P.O. Box 27, FI-00014 University of Helsinki, Finland ORCID ID:E-mail: mohamed.elfadl@helsinki.fi
  • Tsegai, UNCCD Secretariat, Platz der Vereinten Nationen 1, 53113 Bonn, Germany ORCID ID:E-mail: dtsegai@unccd.int

Category: Research article

article id 5643, category Research article
Katarzyna A. Jadwiszczak, Stanisław Kłosowski, Iwona Zalewska, Agata Banaszek & Agnieszka Chrzanowska. (2017). Genetic diversity and sexual reproduction in relict populations of Betula nana. Silva Fennica vol. 51 no. 2 article id 5643. https://doi.org/10.14214/sf.5643
Highlights: Genetic diversity parameters and meiotic recombination frequencies in the relict populations were comparable to those from widespread localities; Contribution of seeds without ovule was very high; Fully developed seeds germinated better in central populations; Significant differences of groundwater parameters were observed between relict and central populations.

In the present study, the impact of geographical isolation and habitat conditions on genetic diversity and sexual reproduction was tested in four relict populations of dwarf birch Betula nana L. in Poland and Belarus. Amplified fragment length polymorphism (AFLP) method revealed that the endangered central European stands were not genetically extirpated compared with the widespread localities from Finland and Russia, which can result from infrequent outcrossing events in long-living clonal populations. However, genetic clustering methods indicated significant differentiation of the Polish populations because of their small sizes and long-term geographical isolation. Considerable numbers of empty seeds were observed in both relict and central locations, although fully developed seeds germinated better in widespread populations. Analysis of groundwater chemical parameters indicated that two relict populations were significantly different from the remaining samples with respect to pH, electrical conductivity and concentrations of phosphorus ions, which can also influence the efficiency of sexual reproduction. In the light of results obtained it seems that endangered B. nana localities are relatively stable.

  • Jadwiszczak, Institute of Biology, University of Białystok, Ciołkowskiego 1J, 15-245 Białystok, Poland ORCID ID: http://orcid.org/0000-0002-9345-8891 E-mail: jadwiszczak2010@gmail.com (email)
  • Kłosowski, Department of Environment Protection and Modelling, The Jan Kochanowski University, Świętokrzyska 15, 25-406 Kielce, Poland ORCID ID:E-mail: stanislaw.klosowski@ujk.kielce.pl
  • Zalewska, Faculty of Pharmacy, Medical University of Białystok, Mickiewicza 2a, 15-222 Białystok, Poland ORCID ID:E-mail: iwonazalewska1988@gmail.com
  • Banaszek, Institute of Biology, University of Białystok, Ciołkowskiego 1J, 15-245 Białystok, Poland ORCID ID:E-mail: banaszek@uwb.edu.pl
  • Chrzanowska, Institute of Biology, University of Białystok, Ciołkowskiego 1J, 15-245 Białystok, Poland ORCID ID:E-mail: maga.chrzanowska@gmail.com
article id 2021, category Research article
Jonas Bohlin, Inka Bohlin, Jonas Jonzén & Mats Nilsson. (2017). Mapping forest attributes using data from stereophotogrammetry of aerial images and field data from the national forest inventory. Silva Fennica vol. 51 no. 2 article id 2021. https://doi.org/10.14214/sf.2021
Highlights: Image based forest attribute map generated using NFI plots show similar accuracy as currently used LiDAR based forest attribute map; Also similar accuracies were found for different forest types; Aerial images from leaf-off season is not recommended.

Exploring the possibility to produce nation-wide forest attribute maps using stereophotogrammetry of aerial images, the national terrain model and data from the National Forest Inventory (NFI). The study areas are four image acquisition blocks in mid- and south Sweden. Regression models were developed and applied to 12.5 m × 12.5 m raster cells for each block and validation was done with an independent dataset of forest stands. Model performance was compared for eight different forest types separately and the accuracies between forest types clearly differs for both image- and LiDAR methods, but between methods the difference in accuracy is small at plot level. At stand level, the root mean square error in percent of the mean (RMSE%) were ranging: from 7.7% to 10.5% for mean height; from 12.0% to 17.8% for mean diameter; from 21.8% to 22.8% for stem volume; and from 17.7% to 21.1% for basal area. This study clearly shows that aerial images from the national image program together with field sample plots from the NFI can be used for large area forest attribute mapping.

  • Bohlin, Department of Forest Resource Management, Swedish University of Agricultural Sciences, S-901 35 Umeå, Sweden ORCID ID: http://orcid.org/0000-0002-3318-5967 E-mail: jonas.bohlin@slu.se (email)
  • Bohlin, Department of Forest Resource Management, Swedish University of Agricultural Sciences, S-901 35 Umeå, Sweden ORCID ID: http://orcid.org/0000-0003-1224-6684 E-mail: inka.bohlin@slu.se
  • Jonzén, Department of Forest Resource Management, Swedish University of Agricultural Sciences, S-901 35 Umeå, Sweden ORCID ID:E-mail: jonas.jonzen@slu.se
  • Nilsson, Department of Forest Resource Management, Swedish University of Agricultural Sciences, S-901 35 Umeå, Sweden ORCID ID: http://orcid.org/0000-0001-7394-6305 E-mail: mats.nilsson@slu.se
article id 1781, category Research article
Petr Čermák, Michal Rybníček, Tomáš Žid, Kjell Andreassen, Isabella Børja & Tomáš Kolář. (2017). Impact of climate change on growth dynamics of Norway spruce in south-eastern Norway. Silva Fennica vol. 51 no. 2 article id 1781. https://doi.org/10.14214/sf.1781
Highlights: Correlations between tree-ring width and climate parameters showed temporal instability in their relationship during the period 1915–2012; A statistically significant positive correlation of April–May precipitation on tree-ring growth was identified since the mid-1970s; The concomitant temperature increase may have contributed to the changes of growth dynamics.

The ongoing climate change may have a distinct effect on Norway spruce growth, one of the most important tree species in European forest management. Therefore, the understanding and assessment of climate-growth relationship can help to reveal relevant patterns in temporal variability that may result in lower tree vitality and decline. The main objective of our study was to evaluate the long-term climate-growth variability of Norway spruce in south-eastern Norway, at the northern edge of the temperate zone. We sampled in total 270 dominant and co-dominant trees from 18 plots in south-eastern Norway. We analysed stem cores and evaluated crown condition parameters to assess the retrospective tree growth and vitality. Despite considerable differences in the crown parameters, high similarity among tree-ring width (TRW) series allowed compiling the regional tree-ring width chronology. Correlations between TRW and climate parameters showed temporal instability in their relationship during the period 1915–2012. While we did not detect any significant relationships between TRW and climate parameters in the first half of the study period (1915–1963), a significant correlation between TRW and spring precipitation was observed for the period 1964–2012. This shift appeared concurrent with temperatures reaching above-average values compared to the average of the climate normal period 1961–1990.

  • Čermák, Faculty of Forestry and Wood Technology, Mendel University in Brno, Zemědělská 3, 613 00 Brno, Czech Republic ORCID ID:E-mail: cermacek@mendelu.cz (email)
  • Rybníček, Faculty of Forestry and Wood Technology, Mendel University in Brno, Zemědělská 3, 613 00 Brno, Czech Republic; Global Change Research Institute, The Czech Academy of Sciences, Bělidla 986/4a, 603 00 Brno, Czech Republic ORCID ID:E-mail: michalryb@post.cz
  • Žid, Faculty of Forestry and Wood Technology, Mendel University in Brno, Zemědělská 3, 613 00 Brno, Czech Republic ORCID ID:E-mail: tom.z@centrum.cz
  • Andreassen, Norwegian Institute of Bioeconomy Research (NIBIO), P.O. Box 115, NO-1431 Ås, Norway ORCID ID:E-mail: Kjell.Andressen@nibio.no
  • Børja, Norwegian Institute of Bioeconomy Research (NIBIO), P.O. Box 115, NO-1431 Ås, Norway ORCID ID:E-mail: Isabella.Borja@nibio.no
  • Kolář, Faculty of Forestry and Wood Technology, Mendel University in Brno, Zemědělská 3, 613 00 Brno, Czech Republic; Global Change Research Institute, The Czech Academy of Sciences, Bělidla 986/4a, 603 00 Brno, Czech Republic ORCID ID:E-mail: koldatom@gmail.com
article id 1721, category Research article
Anna Hebda, Błażej Wójkiewicz & Witold Wachowiak. (2017). Genetic characteristics of Scots pine in Poland and reference populations based on nuclear and chloroplast microsatellite markers. Silva Fennica vol. 51 no. 2 article id 1721. https://doi.org/10.14214/sf.1721
Highlights: Similar genetic variation was found between Polish Scots pine populations from a wide variety of habitats based on nSSR and cpSSR markers; Homogeneity was observed in the genetic structures of Polish and Finnish populations from the continuous pine range; Genetic differentiation in microsatellite markers was identified only when populations from the central pine distribution were compared to the marginal stands.

Polymorphisms at a set of eighteen nuclear (nSSR) and chloroplast (cpSSR) microsatellite loci were investigated in sixteen populations of Scots pine (Pinus sylvestris L.) derived from the provenance trial experiment and representative of the species distribution range and climatic zones in Poland. The patterns of genetic variation were compared to the reference samples from the species distribution in Europe and Asia. A similar level of genetic variation and no evidence of population structure was found among the Polish stands. They showed genetic similarity and homogenous patterns of allelic frequency spectra compared to the Northern European populations. Those populations were genetically divergent compared to the marginal populations from Turkey, Spain and Scotland. The population structure patterns reflect the phylogeography of the species and the divergence of populations that most likely do not share recent history. As the analysed provenance trial populations from Poland are diverged in phenotypic traits but are genetically similar, they could be used to test for selection at genomic regions that influence variation in quantitative traits.

  • Hebda, University of Agriculture in Krakow, Faculty of Forestry, Institute of Forest Ecology and Silviculture, Department of Genetics and Forest Tree Breeding, 29 Listopada 46, 31-425 Kraków, Poland ORCID ID: http://orcid.org/0000-0002-3149-8644 E-mail: ana.hebda@gmail.com (email)
  • Wójkiewicz, Institute of Dendrology, Polish Academy of Sciences, Parkowa 5, 62-035 Kórnik, Poland ORCID ID:E-mail: bwojkiew@man.poznan.pl
  • Wachowiak, Institute of Dendrology, Polish Academy of Sciences, Parkowa 5, 62-035 Kórnik, Poland; Institute of Environmental Biology, Faculty of Biology, Adam Mickiewicz University, Umultowska 89, 61-614 Poznań, Poland ORCID ID:E-mail: witoldw@man.poznan.pl
article id 1713, category Research article
Lars Göran Stener, Lars Rytter & Gunnar Jansson. (2017). Effects of pruning on wood properties of planted silver birch in southern Sweden. Silva Fennica vol. 51 no. 2 article id 1713. https://doi.org/10.14214/sf.1713
Highlights: Pruning silver birch trees increased the production of defect-free wood outside the knots; Most wood defects were found inside the knots; Pruned birch trees provide butt logs with higher value than unpruned trees.

Pruning was performed at midsummer in two genetically homogenous and managed planted silver birch stands in southern Sweden – one aged 9 and one aged 10 years. Wood defects were analysed 10 years thereafter, using the five uppermost twigs of the stems up to a height of 30 dm. The number of trees examined at each site was around 70, of which half were pruned. The main findings were that: a) compared to unpruned trees, pruned trees produced more defect-free wood outside the knots; b) most wood defects were found inside the knots; and c) wood defects like rot and bark ingrowth were similar for pruned and unpruned trees, while discolouration was marginally higher for pruned trees inside knots but similar outside knots. Overall, the results confirm previous findings that pruned birch trees will provide butt logs with higher value than unpruned trees.

  • Stener, The Forestry Research Institute of Sweden, Ekebo 2250, 268 90 Svalöv, Sweden ORCID ID:E-mail: lars-goran.stener@skogforsk.se (email)
  • Rytter, The Forestry Research Institute of Sweden, Ekebo 2250, 268 90 Svalöv, Sweden ORCID ID:E-mail: lars.rytter@skogforsk.se
  • Jansson, The Forestry Research Institute of Sweden, Uppsala Science Park, 751 83 Uppsala, Sweden ORCID ID:E-mail: gunnar.jansson@skogforsk.se
article id 1678, category Research article
Juan F. Jimenez, Pedro Sánchez-Gómez, Jose Luis Cánovas, Isabell Hensen & Miloud Aouissat. (2017). Influence of natural habitat fragmentation on the genetic structure of Canarian populations of Juniperus turbinata. Silva Fennica vol. 51 no. 2 article id 1678. https://doi.org/10.14214/sf.1678
Highlights: Canarian populations of Juniperus turbinata exhibited levels of genetic diversity similar to those of mainland populations; Despite the historical geologic events occurred in Canary Islands, and the documented decrease of populations since the arrival of settlers, no genetic differentiation between islands has been observed; As it has been observed for other Macaronesian endemics, J. turbinata long dispersal ability seems to be the main force driving the genetic structure of populations.

Oceanic archipelagos provide an important platform from which to evaluate the effects of isolation and fragmentation on the genetic structure of species. As a result of oceanic isolation, such species usually show lower levels of genetic diversity and higher genetic differentiation than their mainland congeners. However, this is not necessarily the case for long distance dispersal species, whose genetic structure is not strictly defined by population isolation. We assessed the level and distribution of genetic diversity among Canarian populations of Juniperus turbinata in order to evaluate the influence of population isolation on its genetic structure. Using Amplified Fragment Length Polymorphism markers, we analyzed molecular diversity among 175 individuals from five populations occurring across the Canary Island and three Moroccan populations. Principal Coordinate Analysis, neighbor joining clustering, AMOVA and Bayesian-based analysis were applied to examine population structure. Despite the documented habitat loss and decline in Canarian populations, Amplified Fragment Length Polymorphism markers revealed levels of intra-population genetic diversity that were similar to those from mainland populations, and low levels of genetic differentiation. Bayesian analysis of population structure showed three main clusters, one comprising El Hierro population and a few individuals from several islands, a second cluster that grouped the remaining Canarian populations together, and a third cluster grouping Moroccan populations. Our results suggest that the main force driving the genetic structure of Canarian populations of J. turbinata is its capacity for long distance dispersal.

  • Jimenez, Departamento de Biología Vegetal (Botánica), Universidad de Murcia, Campus de Espinardo s/n, E-30100 Murcia, Spain ORCID ID:E-mail: fjimenez@um.es (email)
  • Sánchez-Gómez, Departamento de Biología Vegetal (Botánica), Universidad de Murcia, Campus de Espinardo s/n, E-30100 Murcia, Spain ORCID ID: http://orcid.org/0000-0001-6754-1512 E-mail: psgomez@um.es
  • Cánovas, Departamento de Biología Vegetal (Botánica), Universidad de Murcia, Campus de Espinardo s/n, E-30100 Murcia, Spain ORCID ID:E-mail: joseluis.canovas@um.es
  • Hensen,  Institut für Biologie, Martin-Luther Universitat, 06099 Halle, Germany ORCID ID:E-mail: isabell.hensen@botanik.uni-halle.de
  • Aouissat, Centre Universitaire Salhi Ahmed Naama, BP 66, Naâma, Algérie ORCID ID:E-mail: aouissatm@yahoo.fr
article id 1657, category Research article
Razvan Vasile Campu & Arcadie Ciubotaru. (2017). Time consumption and productivity in manual tree felling with a chainsaw – a case study of resinous stands from mountainous areas. Silva Fennica vol. 51 no. 2 article id 1657. https://doi.org/10.14214/sf.1657
Highlights: An important preoccupation in sustainable logging management is represented by the analysis of work time structure and productivity level in manual tree felling with a chainsaw; Sound knowledge of the factors which influence work time allows better planning of harvesting operations so that deadlines could be met and damage to forest ecosystems be minimized.

The purpose of this research is to establish time consumption and productivity when using Husqvarna 365 chainsaw for resinous tree felling in mountainous regions. The research was conducted in the Romanian Southern Carpathians, in two mixed spruce (Picea abies (L.) H. Karst.) and fir (Abies alba Mill.) tree stands (S1 and S2). Only one team of workers, made up of a feller and an assistant, was used in the felling operation. This was divided into nine specific stages for which work times were measured. Work time structure used here includes WP – workplace time (PW – productive work time; SW – supportive work time, NT – non-work time) and NW – non-workplace time. The results indicated a productivity of 10.138 m3 h–1 (4.55 tree h–1) in S1 and of 11.374 m3 h–1 (4.33 tree h–1) in S2. Work time structure was WP 88.61% (PW 19.59%; SW 33.88%; NT 35.14%) and NW 11.39% in S1 and WP 83.77% (PW 17.66%; SW 30.73%; NT 35.38%) and NW 16.23% in S2. The results obtained showed that the power function best describes the relationship between productivity expressed by tree h–1 and breast height diameter (dbh) (R2 = 0.89 in S1 and R2 = 0.94 in S2). When productivity is expressed by m3 h–1 the results obtained in the case of power, exponential and linear functions are comparable (R2 = 0.65 to 0.67 in S1 and R2 = 0.81 to 0.92 in S2). Productivity is also influenced by stump diameter and the distance between trees. Their influence on productivity was emphasized by linear regression equations.

  • Campu, Transilvania University of Braşov, Faculty of Silviculture and Forest Engineering, Department of Forest Engineering, Forest Management Planning and Terrestrial Measurements, Şirul Beethoven no. 1, 500123, Braşov, Romania ORCID ID:E-mail: vasile.campu@unitbv.ro (email)
  • Ciubotaru, Transilvania University of Braşov, Faculty of Silviculture and Forest Engineering, Department of Forest Engineering, Forest Management Planning and Terrestrial Measurements, Şirul Beethoven no. 1, 500123, Braşov, Romania ORCID ID:E-mail: ciuboarc@unitbv.ro
article id 1607, category Research article
Yanlin Fu, Juan A. Oliet, Guolei Li & Jiaxi Wang. (2017). Effect of controlled release fertilizer type and rate on mineral nutrients, non-structural carbohydrates, and field performance of Chinese pine container-grown seedlings. Silva Fennica vol. 51 no. 2 article id 1607. https://doi.org/10.14214/sf.1607
Highlights: We demonstrated that Chinese pine container-grown seedling nutrient status and non-structural carbohydrate content were sufficient over a wide range of fertilization rates; Fertilization at 80 mg N seedling–1 was optimal for seedling responses in the nursery and field; Nursery fertilization using controlled release fertilizer (CRF) with a single coating layer yielded better seedling nursery performance than CRF with multiple coatings.

Although controlled release fertilizer (CRF) with single and multiple-layer coatings are extensively used in tree seedlings, studies that compare the impact of CRF type and application rate on seedling growth, nutrient storage, and, most importantly, outplanting performance, are lacking. In the current study, container-grown Pinus tabulaeformis Carr. (Chinese pine) seedlings were fertilized with commercial CRF with either one or multiple coating layers with equivalent formulation and longevity, at six rates ranging from 40 to 240 mg N seedling–1. Seedlings were sampled for dry mass, non-structural carbohydrate (NSC) content, and mineral nutrient status at the end of the growing season in the nursery, and subsequently outplanted for one season. Compared to Chinese pine seedlings fertilized with single-layer CRF treatments, seedlings treated with multiple-layer CRF had higher starch concentrations but reduced dry mass and N, P, K concentrations in the nursery, and reduced diameter growth in the field. Fertilization rates of 80 and 120 mg N seedling–1 generally yielded maximal plant dry mass and mineral nutrient content. Field survival peaked at 80 mg N seedling–1. Seedling growth, soluble sugar content, and starch concentration in the nursery and survival in the field consistently decreased at rates of 200 and 240 mg N seedling–1. In our study, optimal nursery and field performance of P. tabulaeformis were observed using single layer CRF at 80 mg N seedling–1 (3.3 g CRF l–1 media).

  • Fu, Key Laboratory for Silviculture and Conservation, Ministry of Education, Beijing Forestry University; Beijing Laboratory of Urban and Rural Ecological Environment; 35 East Qinghua Road, Haidian District, Beijing 100083, China ORCID ID:E-mail: bjfu_fu@163.com
  • Oliet, Department of Natural Systems and Resources, Universidad Politécnica de Madrid, Ciudad Universitaria s/n, 28040 Madrid, Spain ORCID ID:E-mail: juan.oliet@upm.es
  • Li, Key Laboratory for Silviculture and Conservation, Ministry of Education, Beijing Forestry University; Beijing Laboratory of Urban and Rural Ecological Environment; 35 East Qinghua Road, Haidian District, Beijing 100083, China ORCID ID:E-mail: glli226@163.com (email)
  • Wang, Key Laboratory for Silviculture and Conservation, Ministry of Education, Beijing Forestry University; Beijing Laboratory of Urban and Rural Ecological Environment; 35 East Qinghua Road, Haidian District, Beijing 100083, China ORCID ID:E-mail: wjx198979@163.com
article id 1599, category Research article
Andrew McEwan, Michal Brink & Raffaele Spinelli. (2017). Factors affecting the productivity and work quality of chain flail delimbing and debarking. Silva Fennica vol. 51 no. 2 article id 1599. https://doi.org/10.14214/sf.1599
Highlights: Machine productivity averaged 59 m3 ub SMH–1, with a 19% incidence of delay time; Productivity increased 70% if tree volume increased from 0.1 to 0.4 m3 ub; Debarking quality was good for 58% of the trees, medium for 29% and poor for 13%; The more trees in a bunch and the higher BWBS, the lower debarking quality.

Chain flail delimbing and debarking may improve value recovery from small tree harvests, without renouncing the benefits of multi-tree processing. The technology is mature and capable of excellent performance, which has been documented in many benchmark studies. This paper offers new insights into the relationship between the performance of chain flail delimbing and debarking and such factors as tree volume, load volume, tree form and bark-wood bond strength (BWBS). The study was conducted in Chile, during the commercial harvesting of a Eucalyptus globulus Labill. plantation. In an observational study, researchers collected production data from over 780 work cycles, and work quality data from over 1000 individual trees. The analysis of these data shows that productivity is affected primarily by load volume. Work quality is affected by BWBS and by the number of trees in a load. Work quality degrades with increasing BWBS and tree number, since more trees tend to shield each other. Tree form has no effect on either productivity or work quality. Regression and probability functions are provided, and can be used for predictive purposes when trying to optimize current operations or to prospect the introduction of chain flail technology to new work environments.

  • McEwan, Postgraduate Forest Programme, Faculty of Natural and Agricultural Sciences, University of Pretoria, Private Bag X20 Hatfield, Pretoria, 0028, South Africa ORCID ID:E-mail: Andrew.McEwan@nmmu.ac.za
  • Brink, Postgraduate Forest Programme, Faculty of Natural and Agricultural Sciences, University of Pretoria, Private Bag X20 Hatfield, Pretoria, 0028, South Africa ORCID ID:E-mail: michal@cmo.co.za
  • Spinelli, CNR IVALSA, Via Madonna del Piano 10, I-50019 Sesto Fiorentino (FI), Italy ORCID ID: http://orcid.org/0000-0001-9545-1004 E-mail: spinelli@ivalsa.cnr.it (email)
article id 1618, category Research article
Miguel Genin, Mohamed Alifriqui, Abdessamad Fakhech, Mohamed Hafidi, Lahcen Ouahmane & Didier Genin. (2017). Back to forests in pre-Saharan Morocco? When prickly pear cultivation and traditional agropastoralism reduction promote argan tree regeneration. Silva Fennica vol. 51 no. 1B article id 1618. https://doi.org/10.14214/sf.1618
Highlights: There was a significant positive relationship between the age of implanted prickly pear orchards and natural argan tree regeneration; This relationship is mainly associated with interconnected changes in traditional land uses and the activation of facilitation factors such as an enhancement of the soil’s organic matter and nurse plant phenomena; This example constitutes a remarkable alternative model for thinking about agricultural development while combating desertification.

In the southwestern pre-Saharan arid zone of Morocco, the endemic argan forest (Argania spinosa) had been almost completely destroyed in the 1960s due to intensive coal mining and mixed cereal-livestock farming. These activities turned out to be unviable and a massive rural exodus occurred in the 1970s. Local populations started to develop maintenance-free prickly pear (Opuntia ficus-indica) cultivation at large scale in order to keep their land ownership rights, while reducing their traditional agropastoral activity. We conducted a survey in order to characterize the relationships between the age of prickly pear orchards and argan tree regeneration. We also explored facilitating factors, such as soil organic matter and mycorrhiza. Results showed a high positive correlation (r2 = 0.75, p < 0.001) between the age of prickly pear orchards and argan tree resprouts, but with differences depending on a continentality gradient. The soil organic matter content also showed highly significant differences (p < 0.001) depending on the age of the prickly pear plantation, while spora density did not show such differences. The recent high economic value attributed to prickly pear fruits, and to both argan and prickly pear seed oil, has given farmers the opportunity to develop a lucrative agricultural activity, while promoting the recovery of native vegetation. This situation constitutes a remarkable example of speculative agricultural development in a very harsh environment, in phase with ecological priorities for combating desertification. It could represent an alternative to the externally-generated projects sustained by high levels of public funding, with ecological, economic and social impacts which are sometimes questionable.

  • Genin, Institut de Recherche pour le Développement (IRD) & Aix-Marseille Université, Laboratoire Population, Environnement, Développement, UMR151 AMU-IRD, Marseille, France ORCID ID:E-mail: miguel.genin@gmail.com
  • Alifriqui, Cadi Ayyad University (UCAM), Laboratoire d’Ecologie et Environnement (CNRST, URAC 32), Faculté des Sciences Semlalia, Marrakech, Morocco ORCID ID:E-mail: alifriqui@gmail.com
  • Fakhech, Cadi Ayyad University (UCAM), Laboratoire d’Ecologie et Environnement (CNRST, URAC 32), Faculté des Sciences Semlalia, Marrakech, Morocco ORCID ID:E-mail: abdessamad.fakhech@edu.uca.ac.ma
  • Hafidi, Cadi Ayyad University (UCAM), Laboratoire d’Ecologie et Environnement (CNRST, URAC 32), Faculté des Sciences Semlalia, Marrakech, Morocco ORCID ID:E-mail: hafidi.ucam@gmail.com
  • Ouahmane, Cadi Ayyad University (UCAM), Laboratoire d’Ecologie et Environnement (CNRST, URAC 32), Faculté des Sciences Semlalia, Marrakech, Morocco ORCID ID:E-mail: l.ouahmane@gmail.com
  • Genin, Institut de Recherche pour le Développement (IRD) & Aix-Marseille Université, Laboratoire Population, Environnement, Développement, UMR151 AMU-IRD, Marseille, France ORCID ID:E-mail: didier.genin@univ-amu.fr (email)
article id 1579, category Research article
Oktay Yildiz, Ernaz Altundağ, Bilal Çeti̇n, Ş Teoman Guner, Murat Sarginci & Bulent Toprak. (2017). Afforestation restoration of saline-sodic soil in the Central Anatolian Region of Turkey using gypsum and sulfur. Silva Fennica vol. 51 no. 1B article id 1579. https://doi.org/10.14214/sf.1579
Highlights: Significantly enhanced height and diameter growth of Elaeagnus angustifolia and height growth of Populus alba improved with soil chemical amendments in comparison to control; Infiltration rate on gypsum application sites was 55% higher than on sulfur application sites; Elaeagnus angustifolia survival rates with chemical treatments were 43% greater than controls; Tamarix smyrnensis had the highest mean survival rate of 80%, while Populus alba averaged 36%.

A significant amount of land area in the Central Anatolian Region of Turkey has saline-sodic soil properties. The aim of the current study was to use both soil amendment and tree to restore these degraded lands. The primary objective was to ameliorate soils by leaching excess sodium with gypsum and sulfur applications. Following soil treatments, salt cedar (Tamarix smyrnensis Bunge), Russian olive (Elaeagnus angustifolia L.) and silver poplar (Populus alba L.) seedlings were planted on experimental and control sites to evaluate the effects of the treatments on survival and growth of these species. In the fall of 2013, three-year-old seedlings were planted using 1.5 × 1.5 m spacing on each plot. Survival rates were determined and height and diameter were measured at the end of September 2015. Second year infiltration measurements indicated that both chemical treatments had significantly increased the infiltration capacity of the soil (P = 0.0003). Soil infiltration capacity on gypsum treated sites was about 55% higher than on sulfur sites. Following the second growing season, salt cedar had the highest survival rates of 80%. Silver poplar had 36% survival rates across the treatments. Russian olive had 50 cm height growth on both gypsum and sulfur application sites vs. only 25 cm on controls. Diameters of Russian olive on gypsum and sulfur sites were about 9.3 mm vs. 5 mm on the controls. Silver poplars on gypsum treated sites grew 42% taller than controls. Salt cedar had no significant growth responses among treatments. With appropriate soil amendments, especially gypsum, Russian olive gave the best overall two-year results.

  • Yildiz, Düzce University, Faculty of Forestry, 81620 Duzce, Turkey ORCID ID:E-mail: oktayyildiz@duzce.edu.tr (email)
  • Altundağ, Düzce University, Faculty of Arts and Sciences, 81620 Duzce, Turkey ORCID ID:E-mail: ernazaltundag@duzce.edu.tr
  • Çeti̇n, Düzce University, Faculty of Forestry, 81620 Duzce, Turkey ORCID ID:E-mail: bilalcetin@duzce.edu.tr
  • Guner, Eskişehir Soil and Ecological Research Institute, General Directorate of Forestry, 06560 Yenimahalle/Ankara, Turkey ORCID ID:E-mail: stguner@ogm.gov.tr
  • Sarginci, Düzce University, Faculty of Forestry, 81620 Duzce, Turkey ORCID ID:E-mail: muratsarginci@duzce.edu.tr
  • Toprak, Düzce University, Faculty of Forestry, 81620 Duzce, Turkey ORCID ID:E-mail: bulenttoprak@duzce.edu.tr
article id 1553, category Research article
Miguel Angel Salinas-Melgoza, Margaret Skutsch, Jon C Lovett & Armonia Borrego. (2017). Carbon emissions from dryland shifting cultivation: a case study of Mexican tropical dry forest. Silva Fennica vol. 51 no. 1B article id 1553. https://doi.org/10.14214/sf.1553
Highlights: Under REDD+, shifting cultivation should be considered degradation rather than deforestation; Carbon stocks in old fallows (>20 years) are higher than those in old growth forests which have never been used for shifting cultivation; Extending length of fallows increases rates of carbon emissions; Shortened fallow cycles result in higher carbon stocks and lower emissions at the landscape level; Cycle lengths could be optimized for carbon sequestration in a land sharing approach.

The article considers the relation of shifting cultivation to deforestation and degradation, and hence its impacts in terms of carbon emissions and sequestration potential. There is a need to understand these relationships better in the context of international policy on Reduced Emissions from Deforestation and Forest Degradation (REDD+). The article reviews the way in which shifting cultivation has been incorporated in global and national estimations of carbon emissions, and assembles the available information on shifting cultivation in Tropical Dry Forests (TDF) in Mexico, where it is widely practiced. It then takes the case of two villages, Tonaya and El Temazcal, which lie within the basin of the River Ayuquila in Jalisco, Mexico. Field data for the typical carbon stocks and fluxes associated with shifting cultivation are compared with stocks and fluxes associated with more intensive agricultural production in the same dry tropical forest area to highlight the carbon sequestration dynamics associated with the shortening and potential lengthening of the fallow cycles. The biomass density in the shifting cultivation system observed can reach levels similar to that of old growth forests, with old fallows (>20 years) having higher carbon stocks than old growth forests. Per Mg of maize produced, the biomass-related emissions from shifting cultivation in the traditional 12 year cycle are about three times those from permanent cultivation. We did not, however, take into account the additional emissions from inputs that result from the use of fertilizers and pesticides in the case of permanent agriculture. Shortening of the fallow cycle, which is occurring in the study area as a result of government subsidies, results in higher remaining stocks of carbon and lower emissions at the landscape level.

  • Salinas-Melgoza, University of Twente, Drienerlolaan 5, 7522 NB Enschede, the Netherlands ORCID ID: http://orcid.org/0000-0003-3209-1659 E-mail: ma.masm@gmail.com (email)
  • Skutsch, Universidad Nacional Autónoma de México (CIGA-UNAM), Antigua Carretera a Pátzcuaro No. 8701, Col. Ex-Hacienda de San José de la Huerta, Campus Morelia, C.P. 58190, Michoacán, Mexico ORCID ID: http://orcid.org/0000-0001-6120-4945 E-mail: mskutsch@ciga.unam.mx
  • Lovett, University of Leeds, Leeds, LS2 9JT, UK ORCID ID:E-mail: j.lovett@leeds.ac.uk
  • Borrego, CONACYT-Centro de Investigaciones en Geografía Ambiental, Antigua Carretera a Pátzcuaro No. 8701, Col. Ex-Hacienda de San José de la Huerta, Campus Morelia, C.P. 58190, Michoacán, México ORCID ID:E-mail: aborrego@ciga.unam.mx
article id 1778, category Research article
Adriano Mazziotta, Dmitry Podkopaev, María Triviño, Kaisa Miettinen, Tähti Pohjanmies & Mikko Mönkkönen. (2017). Quantifying and resolving conservation conflicts in forest landscapes via multiobjective optimization. Silva Fennica vol. 51 no. 1 article id 1778. https://doi.org/10.14214/sf.1778
Highlights: We introduce a compatibility index quantifying how targeting a management objective in the forest landscape affects another objective; To resolve conflicts we find compromise solutions minimizing the maximum deterioration among objectives; We apply our approach for a case study of forest management for biodiversity conservation and development; Multiple use management and careful planning can reduce biodiversity conflicts in forest ecosystems.

Environmental planning for of the maintenance of different conservation objectives should take into account multiple contrasting criteria based on alternative uses of the landscape. We develop new concepts and approaches to describe and measure conflicts among conservation objectives and for resolving them via multiobjective optimization. To measure conflicts we introduce a compatibility index that quantifies how much targeting a certain conservation objective affects the capacity of the landscape for providing another objective. To resolve such conflicts we find compromise solutions defined in terms of minimax regret, i.e. minimizing the maximum percentage of deterioration among conservation objectives. Finally, we apply our approach for a case study of management for biodiversity conservation and development in a forest landscape. We study conflicts between six different forest species, and we identify management solutions for simultaneously maintaining multiple species’ habitat while obtaining timber harvest revenues. We employ the method for resolving conflicts at a large landscape level across a long 50-years forest planning horizon. Our multiobjective approach can be an instrument for guiding hard choices in the conservation-development nexus with a perspective of developing decision support tools for land use planning. In our case study multiple use management and careful landscape level planning using our approach can reduce conflicts among biodiversity objectives and offer room for synergies in forest ecosystems.

  • Mazziotta, University of Jyväskylä, Department of Biological and Environmental Science, P.O. Box 35, FI-40014 University of Jyväskylä, Finland; Center for Macroecology Evolution and Climate, University of Copenhagen, Universitetsparken 15, DK-2100 Copenhagen, Denmark; Stockholm Resilience Centre, Stockholm University, Kräftriket 2b, 11429 Stockholm, Sweden ORCID ID: http://orcid.org/0000-0003-2088-3798 E-mail: a_mazziotta@hotmail.com (email)
  • Podkopaev, University of Jyväskylä, Department of Biological and Environmental Science, P.O. Box 35, FI-40014 University of Jyväskylä, Finland; Systems Research Institute, Polish Academy of Sciences, Newelska 6, 01-447 Warsaw, Poland ORCID ID:E-mail: dmitry.podkopaev@ibspan.waw.pl
  • Triviño, University of Jyväskylä, Department of Biological and Environmental Science, P.O. Box 35, FI-40014 University of Jyväskylä, Finland ORCID ID:E-mail: maria.trivino@jyu.fi
  • Miettinen, University of Jyväskylä, Faculty of Information Technology, P.O. Box 35, FI-40014 University of Jyväskylä, Finland ORCID ID:E-mail: kaisa.miettinen@jyu.fi
  • Pohjanmies, University of Jyväskylä, Department of Biological and Environmental Science, P.O. Box 35, FI-40014 University of Jyväskylä, Finland ORCID ID:E-mail: tahti.t.pohjanmies@jyu.fi
  • Mönkkönen, University of Jyväskylä, Department of Biological and Environmental Science, P.O. Box 35, FI-40014 University of Jyväskylä, Finland ORCID ID:E-mail: mikko.monkkonen@jyu.fi
article id 1718, category Research article
Mihails Čugunovs, Eeva-Stiina Tuittila, Lauri Mehtätalo, Laura Pekkola, Ida Sara-Aho & Jari Kouki. (2017). Variability and patterns in forest soil and vegetation characteristics after prescribed burning in clear-cuts and restoration burnings. Silva Fennica vol. 51 no. 1 article id 1718. https://doi.org/10.14214/sf.1718
Highlights: Soil parameter variability is similar across sites of different disturbance type; Variability of understory vegetation biomass and cover is higher and more different between sites than soil variability; Sites studied here reflect well the assumed disturbance-type gradient based on PCA; Sampling six forest sites per treatment should provide good statistical power to capture the differences in soil organic matter stocks.

Forest ecological restoration by burning is widely applied to promote natural, early-successional sites and increase landscape biodiversity. Burning is also used as a forest management practice to facilitate forest regeneration after clearcutting. Besides the desired goals, restoration burnings also affect soil biogeochemistry, particularly soil organic matter (SOM) and related soil carbon stocks but the long-term effects are poorly understood. However, in order to study these effects, a reliable estimate of spatial variability is first needed for effective sampling. Here we investigate spatial variability of SOM and vegetation features 13 years after burnings and in combination with variable harvest levels. We sampled four experimental sites representing distinct management and restoration treatments with an undisturbed control. While variability of vegetation cover and biomass was generally higher in disturbed sites, soil parameter variability was not different between the four sites. The joint ecological patterns of soil and vegetation parameters across the whole sample continuum support well the prior assumptions on the characteristic disturbance conditions within each of the study sites. We designed and employed statistical simulations as a means to plan prospective sampling. Sampling six forest sites for each treatment type with 30 independent soil cores per site would provide enough statistical power to adequately capture the impacts of burning on SOM based on the data we obtained here and statistical simulations. In conclusion, we argue that an informed design-based approach to documenting the ecosystem effects of forest burnings is worth applying both through obtaining new data and meta-analysing the existing.

  • Čugunovs, University of Eastern Finland, School of Forest Sciences, Yliopistokatu 7, P.O. Box 111, FI-80101 Joensuu, Finland ORCID ID:E-mail: mihails.cugunovs@uef.fi (email)
  • Tuittila, University of Eastern Finland, School of Forest Sciences, Yliopistokatu 7, P.O. Box 111, FI-80101 Joensuu, Finland ORCID ID: http://orcid.org/0000-0001-8861-3167 E-mail: eeva-stiina.tuittila@uef.fi
  • Mehtätalo, University of Eastern Finland, School of Computing, Science Park, Länsikatu 15, P.O. Box 111, 80101 Joensuu, Finland ORCID ID: http://orcid.org/0000-0002-8128-0598 E-mail: lauri.mehtatalo@uef.fi
  • Pekkola, University of Eastern Finland, School of Forest Sciences, Yliopistokatu 7, P.O. Box 111, FI-80101 Joensuu, Finland ORCID ID:E-mail: laura.pekkola@gmail.com
  • Sara-Aho, University of Eastern Finland, School of Forest Sciences, Yliopistokatu 7, P.O. Box 111, FI-80101 Joensuu, Finland ORCID ID:E-mail: ida.sara-aho@mhy.fi
  • Kouki, University of Eastern Finland, School of Forest Sciences, Yliopistokatu 7, P.O. Box 111, FI-80101 Joensuu, Finland ORCID ID: http://orcid.org/0000-0003-2624-8592 E-mail: jari.kouki@uef.fi
article id 1714, category Research article
Liam Donnelly, Olga M. Grant & Conor O’Reilly. (2017). Effect of deployment-type on stem growth, biomass partitioning and crown characteristics of juvenile Sitka spruce clones. Silva Fennica vol. 51 no. 1 article id 1714. https://doi.org/10.14214/sf.1714
Highlights: Deployment x clone interactions reduced tree height and diameter growth in mixed plots for one clone; Height and diameter heterogeneity was significantly greater in mixed plots; Deployment-type significantly altered relationships between crown variables and competition was more asymmetric in mixed plots compared to monoclonal.

Competitive interactions in clonal forestry are not well understood and this needs to be addressed to develop better deployment strategies. Eight juvenile Sitka spruce (Picea sitchensis (Bong.) Carriére) clones were grown in monoclonal and clonal mixtures in a field experiment for three years to assess the effects of genetic diversity on shoot growth, above- and below-ground biomass partitioning and crown characteristics. Shoot elongation was measured throughout the growing season, while diameter was measured twice annually in May and December. After the third year, crown silhouette area was estimated from digitised images for one ramet per plot and ramets were then destructively harvested. Deployment × clone interactions were observed for tree height and diameter with reductions observed in mixed plots. Mixed plots had significantly greater height and diameter heterogeneity and more asymmetrical competition than monoclonal plots. Results from this study demonstrate that stem growth can be significantly altered when clones are planted in multi-clonal mixtures but for most clones, deployment-type will not significantly reduce their productivity.

  • Donnelly, UCD Forestry, University College Dublin, Belfield, Dublin 4, Ireland ORCID ID:E-mail: liam.donnelly@ucdconnect.ie (email)
  • Grant, UCD Forestry, University College Dublin, Belfield, Dublin 4, Ireland ORCID ID:E-mail: olga.grant@ucd.ie
  • O’Reilly, UCD Forestry, University College Dublin, Belfield, Dublin 4, Ireland ORCID ID:E-mail: conor.oreilly@ucd.ie
article id 1709, category Research article
Guoping Chen, Cong Shi, Shanshan Cheng, Tiejian Zhao, Guoquan Liu & Fuchen Shi. (2017). The structure and soil characteristics of a Pinus tabuliformis planted forest after 60 years of natural development in North China. Silva Fennica vol. 51 no. 1 article id 1709. https://doi.org/10.14214/sf.1709
Highlights: Increasing proportions of broadleaf tree species was shown to affect nutrient content of the forest floor and soil, and the soil microbial community in the process of natural development of Pinus tabuliformis planted forest. In this regard, this study can act as a reference for management of the near-natural transformation of P. tabuliformis planted forests and for the choice of the tree species used.

This study evaluated the transformation of a Pinus tabuliformis Carrière forest into a near-natural forest after 60 years of natural development. The structure and soil characteristics of P. tabuliformis planted forest, the near-natural forest (coniferous-broadleaved P. tabuliformis mixed forest), and secondary forest (Quercus mongolica Fisch. ex Ledeb. forest) were compared. Tree, shrub and herb species diversity of the mixed and Q. mongolica forests was higher than that of the planted P. tabuliformis forest. Examination of soil characteristics revealed that compared to the pure pine forest, nitrogen (N) and phosphorus (P) concentrations of the mixed and Q. mongolica forests increased in the forest floor and soil, but total carbon (C) concentration decreased in the forest floor, countered by increases in the soil. Furthermore, soil cation exchange capacity (CEC) and pH in the P. tabuliformis forest increased when deciduous broadleaved species were present. Total microbial biomass and bacterial biomass in the soils were greatest in the Q. mongolica forest, followed by the mixed, and then the P. tabuliformis forests. However, fungal biomass did not significantly differ among the three forests. Overall, the findings of this study suggest that different forest types can affect soil microbial biomass and community structure. Meanwhile, the natural development is recommended as a potential management alternative to near-natural transformation of a P. tabuliformis planted forest.

  • Chen, Department of Plant Biology & Ecology, College of Life Sciences, Nankai University, Weijin Road 94, Tianjin 300071, P.R. China ORCID ID:E-mail: guopingchern@mail.nankai.edu.cn
  • Shi, Graduate School of Agriculture, Hokkaido University, Sapporo, Hokkaido 060-8689, Japan ORCID ID:E-mail: cshi1@for.agr.hokudai.ac.jp
  • Cheng, School of Environment and Energy, Shenzhen Graduate School of Peking University, Shenzhen 518055, China ORCID ID:E-mail: 1401213932@sz.pku.edu.cn
  • Zhao, Baxian Mountain National Nature Reserve, Tianjin 301900, China Received 29 September 2016 Revised ORCID ID:E-mail: zhaotiejiann456@sina.com
  • Liu, Baxian Mountain National Nature Reserve, Tianjin 301900, China Received 29 September 2016 Revised ORCID ID:E-mail: liuguoquan01@163.com
  • Shi, Department of Plant Biology & Ecology, College of Life Sciences, Nankai University, Weijin Road 94, Tianjin 300071, P.R. China ORCID ID:E-mail: fcshi@nankai.edu.cn (email)
article id 1705, category Research article
Sulmaz Janfaza, Hamed Yousefzadeh, Seyed Mohammad Hosseini Nasr, Roberto Botta, Asad Asadi Abkenar & Daniela Torello Marinoni. (2017). Genetic diversity of Castanea sativa an endangered species in the Hyrcanian forest. Silva Fennica vol. 51 no. 1 article id 1705. https://doi.org/10.14214/sf.1705
Highlights: This is the first report of genetic diversity of the few remaining populations of C. sativa in the southern limits of its distribution in Eurasia; Low genetic diversity and high genetic differentiation among small isolated populations of C. sativa with low geographical distance represent serious genetic erosion indicators in the Hyrcanian forest, even hinting at an ongoing extinction vortex.

Castanea sativa Mill. is one of the most endangered tree species in Iran where it is represented by small fragmented populations in the north of the country. 18 simple sequence repeat (SSR) loci (10 nuclear and 8 chloroplastic) were used to evaluate the genetic diversity and population structure of C. sativa from the Hyrcanian forest. For nuclear SSR, the number of alleles detected per locus ranged from 1 to 5 and observed heterozygosity (HO) was between 0.125 and 1.000. Analysis of molecular variance (AMOVA) indicated a high level of variation within populations (84%) and low levels between populations (16%). Based on structure analysis, the four studied populations were divided into two main clusters that have genetic distance Fst = 0.3. The Shafaroud population was separated in the first cluster, Siyahmazgi, Qalehroudkhan and Veysroud were placed in the second cluster. The UPGMA analysis confirmed the results of Structure analysis, separating the Shafaroud population from the others. The 8 chloroplast SSR loci used to screen the populations showed no polymorphism. In General, low nuclear genetic diversity, no polymorphism in cpDNA and considerable genetic differentiation among populations in short geographical distance represent a serious genetic erosion threat for C. sativa in the Hyrcanian forest, even hinting at an ongoing extinction vortex. Therefore, due to significant decline in genetic diversity, it is essential to introduce constraints protection upon the areas of distribution of all four populations of this species in Iran.

  • Janfaza, Department of Forestry, Sari University of Agriculture Sciences and Natural Resources, Km 9 Darya Road, P.O. Box 578, Mazandaran, Iran ORCID ID:E-mail: aristocratka_b@yahoo.com
  • Yousefzadeh, Department of Environment, Faculty of Natural Resources and Marine Science ,Tarbiat Modares University, Noor, Mazandaran, Iran ORCID ID:E-mail: h.yousefzadeh@modares.ac.ir (email)
  • Hosseini Nasr, Department of Forestry, Sari University of Agriculture Sciences and Natural Resources, Km 9 Darya Road, P.O. Box 578, Mazandaran, Iran ORCID ID:E-mail: s.hosseini@sanru.ac.ir
  • Botta, Dipartimento di Scienze Agrarie Forestali e Alimentari, DISAFA, Università di Torino, Via Verdi 8, 10124 Torino, Italy ORCID ID:E-mail: roberto.botta@unito.it
  • Asadi Abkenar, Agricultural Research, Education and Extension Organization (AREEO) of IRAN, Agricultural Biotechnology Research Institute of Iran (RBRII), Branch of North Region, Guilan, Rasht, Iran ORCID ID:E-mail: asadiabkenarasad@gmail.com
  • Marinoni, Dipartimento di Scienze Agrarie Forestali e Alimentari, DISAFA, Università di Torino, Via Verdi 8, 10124 Torino, Italy ORCID ID:E-mail: daniela.marinoni@unito.it
article id 1704, category Research article
Inger Sundheim Fløistad & Toril Drabløs Eldhuset. (2017). Effect of photoperiod and fertilization on shoot and fine root growth in Picea abies seedlings. Silva Fennica vol. 51 no. 1 article id 1704. https://doi.org/10.14214/sf.1704
Highlights: Effects of photoperiod and fertilization treatment on Norway spruce seedling growth were examined; Short day treatment and ordinary K:N ratio in the fertilization proved the best combination for achieving seedlings with suitable root and shoot properties for field establishment; Increased K:N ratio in the fertilization did not reduce shoot height growth.

Picea abies seedlings were given three different fertilization treatments in the nutrient solution by varying the potassium:nitrogen (K:N) ratios (2.5, 3.0 or 3.9 g g–1). All fertilization treatments were combined with short-day (SD) treatment or no such treatment (control). Above- and belowground growth responses in the seedlings were analyzed. The SD treatment resulted in significantly reduced shoot height, compared to untreated control, irrespective of K:N ratio. No combination of photoperiod treatment or fertilization treatment affected the root collar diameter. In the current year root fraction with diameter < 0.5 mm, the highest K:N ratio led to significantly increased root length in control plants. In each 0.1 mm root diameter class up to 0.5 mm, the highest K:N ratio significantly stimulated root growth in control plants, while the effect was less evident for SD plants. SD treatment stimulated length growth in some fine root diameter classes. We conclude that SD treatment is a good and sufficient measure to reduce height growth without compromising fine root growth of P. abies seedlings. Fertilization treatment did not significantly improve aboveground growth in SD treated seedlings, and only limited effects on root growth was seen on control plants.

  • Fløistad, Norwegian Institute of Bioeconomy Research (NIBIO), P.O. Box 115, NO-1431 Ås, Norway ORCID ID:E-mail: inger.floistad@nibio.no (email)
  • Eldhuset, Norwegian Institute of Bioeconomy Research (NIBIO), P.O. Box 115, NO-1431 Ås, Norway ORCID ID:E-mail: toril.eldhuset@nibio.no
article id 1694, category Research article
Katri Luostarinen, Katja Hakkarainen & Henri Kaksonen. (2017). Wood anatomy of seed and basal bud originated downy birches (Betula pubescens Ehrh.) grown at four different sites. Silva Fennica vol. 51 no. 1 article id 1694. https://doi.org/10.14214/sf.1694
Highlights: Young xylem of sprouts did not clearly show more mature characteristics than that of seedlings; Marked differences in xylem structure could be observed between growing sites.

In trees, xylem must fulfil three important tasks: conducting water to leaves, storing nutrients and water, and supporting the trunk. The origin of the trunk, i.e., seed or basal bud that forms sprouts, and the growth site may affect xylem anatomy, differences of which can affect successful growth of trees. Both seedlings and sprouts of downy birch (Betula pubescens Ehrh.) from four different growth sites with two different soil media, peat and mineral soil, were studied. The diameter of fibres and vessels and the thickness of the double fibre wall were measured, and the number of vessels, rays and axial parenchyma cells was counted. The fibre wall:lumen ratio, vessel percentage area and vessel size:number ratio were calculated. Xylem from sprouts showed only occasionally more mature characteristics than that of seedlings. The number of rays was similar at all four sites, but differences were observed in all other studied characteristics between sites, particularly if soil type was different. The vessel size and number correlated with the number of axial parenchyma cells in juvenile wood, which emphasises the importance of their connections with storage cells particularly at this stage of growth. Good water conductivity was connected with weaker wood, particularly in maturing wood.

  • Luostarinen, School of Forest Sciences, University of Eastern Finland, P.O. Box 111, FI-80101 Joensuu, Finland ORCID ID:E-mail: katri.luostarinen@uef.fi (email)
  • Hakkarainen, Natural Resources Institute of Finland (Luke), Yliopistokatu 6, FI-80100 Joensuu, Finland ORCID ID:E-mail: katjahak@gmail.com
  • Kaksonen, School of Forest Sciences, University of Eastern Finland, P.O. Box 111, FI-80101 Joensuu, Finland ORCID ID:E-mail: hkaksone@gmail.com
article id 1692, category Research article
Aleksey Fedorkov & Ludmila Gutiy. (2017). Performance of lodgepole pine and Scots pine in field trials located in north-west Russia. Silva Fennica vol. 51 no. 1 article id 1692. https://doi.org/10.14214/sf.1692
Highlights: Stem volume was bigger for lodgepole pine in comparison to local Scots pine except for the southernmost origin; The proportion of stems with no defects was lower for all lodgepole pine seed sources than for local Scots pine; Lodgepole pine stem growth traits were significantly related to latitude of seed origin.

Mortality, stem growth and quality of lodgepole pine (Pinus contorta var. latifolia) originating from the six Swedish seed orchards and local Scots pine (Pinus sylvestris L.) were estimated in four field trials established in the Komi Republic (north-west Russia). A randomized row-plot design with 6–12 replicates of each entry was used. The tree mortality was slightly higher for Scots pine than that for lodgepole pine, except for the lodgepole pine seed sources of the southern origins with lower survival. Scots pine stem quality was better than that of lodgepole pine, but the lodgepole pine stem growth was faster except the seed source of the southernmost origin. The lodgepole pine seed sources of northern origins had better stem growth (height, diameter at breast height and volume), while the effect of latitude on the quality traits was insignificant.

  • Fedorkov, Institute of Biology, Komi Science Center, Russian Academy of Sciences, 28 Kommunisticheskaya st., Syktyvkar 167982, Russia ORCID ID: http://orcid.org/0000-0001-7800-7534 E-mail: fedorkov@ib.komisc.ru (email)
  • Gutiy, Syktyvkar Forest Institute (branch), Saint-Petersburg State Forest Technical University, 39 Lenin st., Syktyvkar 167000, Russia ORCID ID:E-mail: lguti@mail.ru
article id 1684, category Research article
Anna Kowalska, Jan Marek Matuszkiewicz, Jerzy Solon & Anna Kozłowska. (2017). Indicators of ancient forests in nutrient-deficient pine habitats. Silva Fennica vol. 51 no. 1 article id 1684. https://doi.org/10.14214/sf.1684
Highlights: Distinct groups of species with a preference for ancient pine and mixed oak-pine forests can be determined; The ancient forest indicator composition in pine habitats differs remarkably from ancient forest indicators in deciduous forests; Dispersal-related traits significantly distinguish ancient forest indicators from other species found in nutrient-poor forest habitats.

Pine forests are common in many European regions. Nonetheless, there are only a few studies on regeneration of plant species populations in nutrient-deficient pine habitats. Ancient temperate forests are perceived to be particularly important objects of environmental conservation, due to their ability to sustain a considerable number of rare and vulnerable species. In this paper, we present indicator species of ancient pine and mixed oak-pine forests, together with their trait profiles. Phytosociological relevés were collected from mature stands in the Masuria and Kurpie regions of central Poland. Forest persistence was determined on the basis of historical maps, with the data set divided into three categories. The indicator value of species was evaluated using Tichý and Chytrý’s phi coefficient. Functional response traits of indicator species were identified. Distinct groups of species with a preference for ancient forests can be determined. The dispersal-related traits significantly distinguish ancient forest indicators from other species found in nutrient-poor forest habitats. Since the low potential for long-distance dispersal hinders the establishment of new plant populations in isolated stands, we stress the need to avoid ancient forest clearance and fragmentation of woodland; afforestation should be located in the vicinity of ancient stands. Moreover, as recent forests have turned out to support several rare plant species, to maintain phytodiversity on a landscape level a mixture of ancient and recent forests, both managed and strictly protected, is needed.

  • Kowalska, Institute of Geography and Spatial Organization, Polish Academy of Science, Twarda 51/55, 00-818 Warsaw, Poland ORCID ID:E-mail: aniak@twarda.pan.pl (email)
  • Matuszkiewicz, Institute of Geography and Spatial Organization, Polish Academy of Science, Twarda 51/55, 00-818 Warsaw, Poland ORCID ID:E-mail: jan.mat@twarda.pan.pl
  • Solon, Institute of Geography and Spatial Organization, Polish Academy of Science, Twarda 51/55, 00-818 Warsaw, Poland ORCID ID:E-mail: j.solon@twarda.pan.pl
  • Kozłowska, Institute of Geography and Spatial Organization, Polish Academy of Science, Twarda 51/55, 00-818 Warsaw, Poland ORCID ID:E-mail: a.kozl@twarda.pan.pl

Category: Review article

article id 1673, category Review article
Eshetu Yirdaw, Mulualem Tigabu & Adrian Monge. (2017). Rehabilitation of degraded dryland ecosystems – review. Silva Fennica vol. 51 no. 1B article id 1673. https://doi.org/10.14214/sf.1673
Highlights: The prospect of restoring degraded drylands is technically promising; The forest landscape restoration concept can be used as the overarching rehabilitation framework; Development of process-based models that forecast rehabilitation outcomes is needed; Rehabilitation methodologies developed for moist areas are not necessarily suitable for drylands; More data is needed on cost-benefit analysis of rehabilitation interventions.

Land degradation is widespread and a serious threat affecting the livelihoods of 1.5 billion people worldwide of which one sixth or 250 million people reside in drylands. Globally, it is estimated that 10–20% of drylands are already degraded and about 12 million ha are degraded each year. Driven by unsustainable land use practices, adverse climatic conditions and population increase, land degradation has led to decline in provision of ecosystem services, food insecurity, social and political instability and reduction in the ecosystem’s resilience to natural climate variability. Several global initiatives have been launched to combat land degradation, including rehabilitation of degraded drylands. This review aimed at collating the current state-of-knowledge about rehabilitation of degraded drylands. It was found that the prospect of restoring degraded drylands is technically promising using a suite of passive (e.g. area exclosure, assisted natural regeneration, rotational grazing) and active (e.g. mixed-species planting, framework species, maximum diversity, and use of nurse tree) rehabilitation measures. Advances in soil reclamation using biological, chemical and physical measures have been made. Despite technical advances, the scale of rehabilitation intervention is small and lacks holistic approach. Development of process-based models that forecast outcomes of the various rehabilitation activities will be useful tools for researchers and practitioners. The concept of forest landscape restoration approach, which operates at landscape-level, could also be adopted as the overarching framework for rehabilitation of degraded dryland ecosystems. The review identified a data gap in cost-benefit analysis of rehabilitation interventions. However, the cost of rehabilitation and sustainable management of drylands is opined to be lower than the losses that accrue from inaction, depending on the degree of degradation. Thus, local communities’ participation, incorporation of traditional ecological knowledge, clear division of tasks and benefits, strengthening local institutions are crucial not only for cost-sharing, but also for the long-term success of rehabilitation activities.

  • Yirdaw, Viikki Tropical Resources Institute (VITRI), Department of Forest Sciences, P.O. Box 27, FI-00014 University of Helsinki, Finland ORCID ID:E-mail: eshetu.yirdaw@helsinki.fi (email)
  • Tigabu, Sveriges Lantbruks Universitet (SLU), Swedish University of Agricultural Sciences, Southern Swedish Forest Research Centre, P.O. Box 49, SE-230 53, Alnarp, Sweden ORCID ID:E-mail: Mulualem.Tigabu@slu.se
  • Monge, Viikki Tropical Resources Institute (VITRI), Department of Forest Sciences, P.O. Box 27, FI-00014 University of Helsinki, Finland ORCID ID:E-mail: adrian.mongemonge@helsinki.fi
article id 1650, category Review article
Uriel Safriel. (2017). Land Degradation Neutrality (LDN) in drylands and beyond – where has it come from and where does it go. Silva Fennica vol. 51 no. 1B article id 1650. https://doi.org/10.14214/sf.1650
Highlights: LDN, a mechanism for offsetting new losses of land’s productivity by restoring productivity of already degraded lands, would maintain the balance of productive lands; As target of Sustainable Development Goal LDN highlights the significance of land whose biological productivity is critical to human survival; Commissioning UNCCD to oversee the implementation of LDN empowers the UNCCD and its impact on sustainability.

The paper first reviews the desertification/land degradation syndrome, the shortcomings of attempts to control it and the consequences of this failure, including to climate change and biodiversity. It then examines the experience gained by carbon and biodiversity offsets that helped adapting the offsetting principle to the context of land degradation, by emphasizing the restoration of the many already degraded lands on earth, as major component of the Land Degradation Neutrality (LDN) mechanism. LDN is a new voluntary and aspirational target of a Sustainable Development Goal (SDG) under the UN 2030 Agenda for Sustainable Development, aimed at neutralizing the rate of lands coming under degrading use of their productivity. This by balancing the ongoing added degradation with similar rate of restoring equivalent lands whose productivity had been already degraded. If extensively implemented, LDN would stabilize the global amount of productive land by 2030. This would increase global food security and reduce poverty of land users, thus contributing to global sustainability. This review maintains that the failure of United Nations Convention to Combat Desertification (UNCCD) to reduce desertification triggered the emergence of LDN as a mechanism for addressing land degradation globally, rather than just desertification in the drylands. LDN accepted as target of a Sustainable Development Goal also legitimized UNCCD to lead and oversee the aspired process of achieving land degradation neutral world. This paper reviews the development of the LDN concept expressed in scientific deliberations and political advocacy, throughout the five years from inception in 2011 at the UNCCD Secretariat, to early 2016. It notes the fast and increasing acceptance of LDN, expressed in the initiation of implementation already in April 2015 by an increasing number of countries, and in the growing interest and engagement of scientists and policy-makers. But the paper also express concern regarding potential misuse of the concept.

  • Safriel, Hebrew University of Jerusalem, Givat Ram, Jerusalem 9190401, Israel ORCID ID:E-mail: uriel36@gmail.com (email)

Category: Research note

article id 1717, category Research note
Jussi Manner, Olle Gelin, Anders Mörk & Martin Englund. (2017). Forwarder crane’s boom tip control system and beginner-level operators. Silva Fennica vol. 51 no. 2 article id 1717. https://doi.org/10.14214/sf.1717
Highlights: Boom tip control (BTC) allows the operator to control boom tip movements directly, instead of controlling each movement separately to achieve the desired boom tip movement; BTC eased boom control, so beginner-level operators using BTC achieved higher productivity than beginner-level operators using a conventional (reference) system; There were no significant differences in the slopes of learning curves between the systems.

The forwarder loads processed wood and transports it to a landing. Productivity of forwarding could be improved by increasing driving speed, but difficult forest terrain limits this. According to current literature, crane work is the most time-consuming work element of forwarding, so improving crane work productivity is essential for improving forwarding productivity. One way to do this is through automation of recurrent boom movement patterns, or alternatively automation can be used to ease crane work. When using conventional boom control (CBC), the operator manually controls each of the independent boom joint movements and combines them to achieve a desired boom tip movement, but boom tip control (BTC) allows the operator to control boom tip movements directly. The objective of the present study was to examine whether BTC facilitates crane work and affects the slopes of learning curves for beginner-level forwarder operators. The study was carried out using a standardised test routine to evaluate effects of two fixed factors, system (levels: CBC, BTC) and point of time (four levels), on five dependent variables. Four of the five dependent variables measured ease of boom control and the fifth measured crane work productivity. The results showed that there were no significant differences in the slopes of learning curves between the systems but the BTC did increase crane work productivity and made boom control easier.

  • Manner, The Forestry Research Institute of Sweden (Skogforsk), Uppsala Science Park, SE-751 83 Uppsala, Sweden ORCID ID: http://orcid.org/0000-0002-4982-3855 E-mail: jussi.manner@skogforsk.se (email)
  • Gelin, The Forestry Research Institute of Sweden (Skogforsk), Uppsala Science Park, SE-751 83 Uppsala, Sweden ORCID ID:E-mail: olle.gelin@skogforsk.se
  • Mörk, The Forestry Research Institute of Sweden (Skogforsk), Uppsala Science Park, SE-751 83 Uppsala, Sweden ORCID ID:E-mail: anders.mork@skogforsk.se
  • Englund, The Forestry Research Institute of Sweden (Skogforsk), Uppsala Science Park, SE-751 83 Uppsala, Sweden ORCID ID:E-mail: martin.englund@skogforsk.se
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

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