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Silva Fennica 1926-1997
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Acta Forestalia Fennica
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Articles containing the keyword 'America'.

Category: Research article

article id 1043, category Research article
Jorge Martín-García, Luc Barbaro, Julio Javier Diez, Hervé Jactel. (2013). Contribution of poplar plantations to bird conservation in riparian landscapes. Silva Fennica vol. 47 no. 4 article id 1043. https://doi.org/10.14214/sf.1043
Highlights: Poplar plantations should not be used as surrogate habitat for native riparian forests with the aim of preserving bird species diversity; Native riparian forests should be preserved or restored as far as possible; Bird communities occurring in poplar plantations can still accommodate rich communities of forest bird species, providing that suitable management is applied at local and landscape levels.
In Mediterranean areas, riparian zones are particularly important for maintaining biodiversity. Nevertheless, the native vegetation in these zones has been modified or lost at an alarming rate during the last decades. The main objective of this study was to investigate the influence of poplar plantations on bird diversity in riparian zones, in order to estimate the ecological implications of a substantial expansion of poplar plantations. Breeding birds were sampled by the point-count method in twenty-four poplar plantations of I-214 clone, according to a factorial design combining stand age and understory management. Furthermore, the three native riparian forests remaining in the study area were also surveyed. Explanatory variables included (1) dendrometric, (2) understory and (3) landscape variables within six different radii of circular buffers. The species richness and abundance index were higher in riparian forests than in poplar plantations. Landscape variables (percentage of poplar plantations in the surrounding landscape) strongly influenced bird diversity in poplar plantations. Furthermore, at the local scale, understory cover was also a key factor in shaping bird assemblages. This suggests that poplar plantations should not be used as surrogates for native forests. Nevertheless, poplar plantations can still accommodate rich communities of forest bird species, providing that suitable management is applied at local and landscape levels.
  • Martín-García, Sustainable Forest Management Research Institute, University of Valladolid – INIA, Avenida Madrid, 57, 34004 Palencia, Spain ORCID ID:E-mail: jorgemg@pvs.uva.es (email)
  • Barbaro, NRA, UMR 1202 BIOGECO, 69 Route d’Arcachon, F-33612 Cestas cedex, France ORCID ID:E-mail: luc@pierroton.inra.fr
  • Diez, Sustainable Forest Management Research Institute, University of Valladolid – INIA, Avenida Madrid, 57, 34004 Palencia, Spain ORCID ID:E-mail: jdcasero@pvs.uva.es
  • Jactel, NRA, UMR 1202 BIOGECO, 69 Route d’Arcachon, F-33612 Cestas cedex, France; Université de Bordeaux, UMR 1202, Bordeaux, F-33000 France ORCID ID:E-mail: herve.jactel@pierroton.inra.fr
article id 251, category Research article
Lina R. Steinke, Andrea C. Premoli, Cintia P. Souto, Mikael Hedrén. (2008). Adaptive and neutral variation of the resprouter Nothofagus antarctica growing in distinct habitats in north-western Patagonia. Silva Fennica vol. 42 no. 2 article id 251. https://doi.org/10.14214/sf.251
N. antarctica occurs in the widest range of habitat types among all South American Notho–fagus. The aim of this study is to investigate adaptive responses by variation in morphological (tree form and leaf characters), and environmental traits (soils) of the polymorphic N. ant–arctica. Also we analyze the effect of genetic drift and limited gene flow in such predominantly apomict by means of neutral variation (isozymes). We studied four potentially different morphological variants each associated with a separate habitat 1) an arboreal variant growing in optimal environments; 2) a sparsely branched variant of temporarily flooded basins or flats; 3) a dwarf variant growing at high elevation, and 4) a shrub-like variant inhabiting matorral environments. The study was restricted latitudinally to Nahuel Huapi National Park, Argentina. For each habitat type we investigated two sites. Nothofagus antarctica shows locally occurring phenotypes. The forest and the high elevation variants were morphologically distinct from the matorral and the basin types. The latter were undistinguishable except for more profuse branching in the matorral type as a result of sprouting due to recent fires. Isozyme evidence indicates a great deal of within-population genetic diversity which is maintained by outcrossing and significant among-site divergence (FST = 18%) that reflects limited gene flow.The apparent high phenotypic and genetic variability in N. antarctica is due to both plasticity and genotypic effects as a result of stable population structure and long periods of isolation which may be reinforced by selection at diverse biotopes.
  • Steinke, Plant Ecology and Systematics, Lund University, Ecology Department, 223 62 Lund, Sweden ORCID ID:E-mail:
  • Premoli, Universidad Nacional del Comahue, Laboratorio Ecotono – CRUB, Quintral 1250, 8400 Bariloche, Argentina ORCID ID:E-mail: apremoli@crub.uncoma.edu.ar (email)
  • Souto, Universidad Nacional del Comahue, Laboratorio Ecotono – CRUB, Quintral 1250, 8400 Bariloche, Argentina ORCID ID:E-mail:
  • Hedrén, Plant Ecology and Systematics, Lund University, Ecology Department, 223 62 Lund, Sweden ORCID ID:E-mail:
article id 347, category Research article
Gordon M. Hickey, John L. Innes. (2006). Monitoring and information reporting through regulation: an inter-jurisdictional comparison of forestry-related hard laws. Silva Fennica vol. 40 no. 2 article id 347. https://doi.org/10.14214/sf.347
In most jurisdictions, the rule of law has been the core instrument used to implement rules, regulations and restrictions relating to forests. The results of this approach have relied on the effectiveness of the system for regulating through monitoring and reporting. Despite the obvious differences in the wider operating environment of forestry internationally, issues related to globalization have increased the need for comparison. The potential impact of certain social, economic and environmental differences on the nature of monitoring and information reporting is, therefore, important to forest policy and management. The analysis presented here considered data associated with forestry-related monitoring and information reporting to provide a comparative description of certain hard-law requirements in a sample of jurisdictions. This was done to shed light on the potential for coordinated monitoring and information reporting objectives to be mandated through inter-jurisdictional hard law. Our research suggests that further comparative analysis of hard law monitoring and information reporting requirements could form a central theme in defining the ‘ground rules’ of a global forest law.
  • Hickey, University of British Columbia, Faculty of Forestry, Department of Forest Resources Management, 2045, 2424 Main Mall, UBC, Vancouver, Canada V6T 1Z4 ORCID ID:E-mail: ghickey@interchange.ubc.ca (email)
  • Innes, University of British Columbia, Faculty of Forestry, Department of Forest Resources Management, 2045, 2424 Main Mall, UBC, Vancouver, Canada V6T 1Z4 ORCID ID:E-mail:

Category: Article

article id 7161, category Article
Olavi Laiho. (1965). Further studies on the ectendotrophic mycorrhiza. Acta Forestalia Fennica vol. 79 no. 3 article id 7161. https://doi.org/10.14214/aff.7161

There has not been complete agreement as to what is meant by ectendotrophic mycorrhizae, and there is a wide variety of opinion among authors on mycorrhizal terminology. In this paper ectendotrophic mycorrhizae are defined to be short roots with Hartig net and intracellular hyphae in the cortex. A mantle and digestion of intracellular hyphae may be found but are not necessary. In the study of Mikola (1965) ectendotrophic mycorrhiza was found to be common in Scots pine (Pinus sylvestris L.) seedlings in Finnish nurseries. The mycorrhizae had always similar structure and the mycelium isolated from the seedlings (E-strains) was similar. The aim of this study was to find out what kind of ectendotrophic mycorrhizae exist in forests and nurseries outside Finland, what kind of mycorrhizae do the E-strains isolated from Scots pine form with other tree species, and are these associations symbiotic.

Only one type of ectendotrophic mycorrhiza was found on the 600 short roots collected from the continents of Europa and America. The type was similar to the one described by Mikola: the mycelium is coarse and forms a strong Hartig net, and intracellular infection is heavy. Evidence is convincing that this structure was formed by the same fungus species. The species is unidentified. Mycorrhizae synthesized by E-strain with six spruce species, fir, hemloch and Douglas fir were all ectotrophic.

The E-type ectendotrophic mycorrhizae proved to be a balanced symbiosis. The seedlings of 13 tree species inoculated with the E-strain grew in the experiment better than the controls. The observation that ectendotrophic mycorrhizae dominates in the nurseries but is seldom found in forests, and then only in seedlings growing in the forest, was confirmed in the study. In synthesis experiments E-strain formed either ecto- or ectendotrophic mycorrhiza depending on the tree species.

  • Laiho, ORCID ID:E-mail:
article id 7423, category Article
Hardy L. Shirley. (1954). Education of foresters in America. Acta Forestalia Fennica vol. 61 no. 11 article id 7423. https://doi.org/10.14214/aff.7423

Forestry has developed at an extremely rapid pace in the United States during the past eight years. This has created job opportunities for foresters educated in the schools of forestry. From 1946 to 1953 American schools of forestry graduated 9,719 foresters.

The schools of forestry are gradually being emancipated from the control by colleges of agriculture and mechanical art. Professional demands are growing at a rapid pace, and the schools are expanding their programs to meet these changes. Faculties have responded to these new needs by adding new courses and curriculums. Colleges can perform their task best through improving the faculty and organizing courses in which the student becomes an active learner rather than a passive recipient of information.

The Silva Fennica issue 61 was published in honour of professor Eino Saari‘s 60th birthday.

  • Shirley, ORCID ID:E-mail:
article id 7387, category Article
L. Runeberg. (1946). Trade in forest products between Finland and the United States of America. Acta Forestalia Fennica vol. 54 no. 1 article id 7387. https://doi.org/10.14214/aff.7387

The purpose of the analysis presented in the article was to form an estimate as to future Finnish-American trade in forest products. The Finnish-American trade, that had its beginning in 1919, has been steadily growing and at the outbreak of the Second World War occupied third place in Finland’s total foreign trade. Over 90% of the Finnish exports consisted of forest industry products, pulp and newsprint being the most important items. The sales associations of the pulp and paper industries made it possible for the industries to gain a footing in the American market.

The production of pulp and most kinds of paper has increased in the USA up to 1942, but production of newsprint has tended to decrease. The timber resources of the country are large, but there is a considerable timber deficit in the northeastern states, therefore, these regions must be the principal aim for a campaign to build up the future market. According to the survey of future need of imports to the USA, more than two million tons of pulp and 2-3 million tons of paper products are needed in the immediate post-war period. The Canadian and Swedish competition will remain at about the same level, but one Finnish advantage, the quality, has disappeared on account of the progress made by research in the USA during the war.

The PDF includes a summary in Finnish.

  • Runeberg, ORCID ID:E-mail:
article id 5621, category Article
Pentti Hakkila. (1997). Peter Koch. 1996. Lodgepole pine in North America. Volumes I, II and III. Silva Fennica vol. 31 no. 2 article id 5621. https://doi.org/10.14214/sf.a8522

This article is a book review on a book ’Lodgepole pine in North America’ by Peter Koch, which is based partly on a synthesis of more than 6,000 papers on lodgepole pine, and partly on a systematic collection and analysis of wood and bark from branches, stems, stumps, and roots, as well as of foliage, of lodgepole pines.

  • Hakkila, ORCID ID:E-mail:
article id 5612, category Article
Gregory S. Amacher. (1997). The design of forest taxation: A synthesis with new directions. Silva Fennica vol. 31 no. 1 article id 5612. https://doi.org/10.14214/sf.a8513

In this paper, different approaches and results concerning forest tax design are reviewed. In particular, comparisons are made between Scandinavian approaches, which rely on the two-period model, and North American approaches, which largely rely on the Faustmann model. Existing work is critically evaluated according to several stylized facts that are common among forest taxation problems. These include the second-best forest policy environment, joint production of public and private forest goods, the dynamic nature of forest capital, public and private ownership, competition between forest and non-forest sectors, and global policy constraints on taxation design. The gaps in addressing stylized facts are used to motivate new research directions. Problems and appropriate public finance literature are identified for investigating forest tax policy under government budget constraints, fiscal federalism, dynamic forest tax design, open economy forest tax policy, and econometric studies of reform. One conclusion reached from discussing future research is that two period and dynamic models will continue to prove useful in analysing taxation design from the government's perspective.

  • Amacher, ORCID ID:E-mail:
article id 5597, category Article
John C. Brissette. (1996). Effects of intensity and frequency of harvesting on abundance, stocking and composition of natural regeneration in the Acadian forest of eastern North America. Silva Fennica vol. 30 no. 2–3 article id 5597. https://doi.org/10.14214/sf.a9242

In a silviculture experiment in east-central Maine, USA, natural regeneration was sampled to measure the effects of: (1) a range of partial harvest intensities, and (2) repeated partial harvest at one intensity. Under the first objective, five treatments were compared with residual basal areas ranging from 15 to 24 m2 ha-1 for trees ≥1.3 cm diameter at breast height. For the second objective, regeneration was evaluated after four harvests at 5-year intervals. Prior to harvests, the overstory of all the treated stands was dominated by Tsuga canadensis (L.) Carr., Picea spp. A Dietr., and Abies balsamea (L.) Mill. Eleven species or species groups were identified among the regeneration: A. balsamea, T. canadensis, Picea spp., Thuja occidentalis L., Pinus spp. L., Betula papyrifera Marsh., Acer rubrum L., Betula populifolia Marsh., Populus spp. L., Fagus grandifolia Ehrh. and Prunus serotina Ehrh. Regeneration abundance was measured as counts of seedlings or sprouts taller than 15 cm but with diameters less than 1.3 cm at breast height (1.37 m). Regardless of harvest treatment, total regeneration was profuse, ranging from over 25,000 to nearly 80,000 trees ha-1. Regeneration was dominated by conifers with a total angiosperm component of 10 to 52 percent approximately 5 years after harvest and 11 to 33 percent after 10 years. Consequently, in forests of similar species composition, tree regeneration following partial harvests should be sufficiently abundant with an array of species to meet a variety of future management objectives.

  • Brissette, ORCID ID:E-mail:
article id 5595, category Article
R.A. Fleming. (1996). A mechanistic perspective of possible influences of climate change on defoliating insects in North America's boreal forests. Silva Fennica vol. 30 no. 2–3 article id 5595. https://doi.org/10.14214/sf.a9240

There is no doubt that tree survival, growth, and reproduction in North America's boreal forests would be directly influenced by the projected changes in climate if they occur. The indirect effects of climate change may be of even greater importance, however, because of their potential for altering the intensity, frequency, and perhaps even the very nature of the disturbance regimes which drive boreal forest dynamics. Insect defoliator populations are one of the dominating disturbance factors in North America's boreal forests and during outbreaks trees are often killed over vast forest areas. If the predicted shifts in climate occur, the damage patterns caused by insects may be considerably changed, particularly those of insects whose temporal and spatial distributions are singularly dependent on climatic factors. The ensuing uncertainties directly affect depletion forecasts, pest hazard rating procedures, and long-term planning for pest control requirements. Because the potential for wildfire often increases in stands after insect attack, uncertainties in future insect damage patterns also lead to uncertainties in fire regimes. In addition, because the rates of processes key to biogeochemical and nutrient recycling are influenced by insect damage, potential changes in damage patterns can indirectly affect ecosystem resilience and the sustainability of the multiple uses of the forest resource.

In this paper, a mechanistic perspective is developed based on available information describing how defoliating forest insects might respond to climate warming. Because of its prevalence and long history of study, the spruce budworm, Choristoneura fumiferana Clem. (Lepidoptera: Tortricidae), is used for illustrative purposes in developing this perspective. The scenarios that follow outline the potential importance of threshold behaviour, historical conditions, phenological relationships, infrequent but extreme weather, complex feedbacks, and natural selection. The urgency of such considerations is emphasized by reference to research suggesting that climate warming may already be influencing some insect lifecycles.

  • Fleming, ORCID ID:E-mail:
article id 4704, category Article
V. A. Kolehmainen. (1960). Lehtikuusenviljelys Tuomarniemellä. Silva Fennica no. 108 article id 4704. https://doi.org/10.14214/sf.a9139
English title: Cultivation of larch in Tuomarniemi, Finland.

Foreign tree species have been planted in Finland since 1900s, the most famous being Larix sibirica plantations in Raivola in Karelia, which now belongs to Soviet Union. One of the largest larch plantations of Finland today is situated in Tuomarniemi, in Central Finland. Ten larch stands were established in Tuomarniemi between 1912 and 1937 mainly by planting. The stand established in 1937 was sown. The trees represent five larch species: Larix sibirica Ledeb. (5 stands), Larix gmelinii var. kurilensis (2 stands, current name probably Larix gmelinii var. gmelinii), Larix americana Michx. (1 stand, now Larix laricina), Larix decidua Mill. (1 stand) and Larix occidentalis Nutt. (1 stand). The total area of the larch stands is 82.5 ha. This paper reports the studies made in the plantations in 1958.

In Tuomarniemi larch grows well in many types of soil from Vaccinium type sites to fresh mineral soil sites. The age of the stands varies from 19 to 48, height from 12 to 24 metres and annual growth from 5 to 12 m3/ha. Larix sibirca has the best stem form of the species, followed by L. gmelinii var. kuriliensis. Easiest to split is the straight-grained L. gmelinii var. kuriliensis. L. sibirica is almost as easy to process. The wood of L. decidua, on the other hand, is often spiral-grained and tough. The trees are seldom infected with decay fungi.

The PDF includes a summary in German.

  • Kolehmainen, ORCID ID:E-mail:
article id 7608, category Article
Peitsa Mikola. (1969). Comparative observations on the nursery technique in different parts of the world. Acta Forestalia Fennica no. 98 article id 7608. https://doi.org/10.14214/aff.7608

This paper is a report of the authors visits to over 80 forestry nurseries in 20 countries mostly in the tropics or subtropics. The article aim is to describe the methods used in the various countries and compares them to the conventional methods of cool and temperate countries. The article introduces nurseries of Africa south of the Sahara, Mediterranean area, Australian and New Zealand and Latin America.

A complete revolution has taken place in the Finnish nursery practice, which used to raise the seedlings in natural field soil in open-air nurseries. The seedlings were usually transplanted into transplant beds at the age of two years. Now the use of plastic greenhouses of light construction and an artificial soil substrate (fertilized peat) are essential. The new technique has some similarities to the practises of the tropical and subtropical nurseries. In Finland cultivation in greenhouses has hastened the development of the seedlings and shortened the nursery rotation from four to two years, and provided better control of watering and fertilization.

Peat beds in greenhouses are used also in Swaziland. The advantage of peat is that it is free of weed seeds, which eliminates weeding. Peat substrate gives also better yield of seedlings, which decreases the need of seeds, which is important in Finland. Another technique common with tropical silviculture is the production of potted seedlings, which are easy to handle and transport. In tropics, peat pots (jiffy pots) have made it possible to grow plantable seedlings in one season without transplanting. The present Finnish technique means a decreased degree of mechanization compared to the conventional technique of modern European and American nurseries.

  • Mikola, ORCID ID:E-mail:
article id 4445, category Article
Aimo Kaarlo Cajander. (1927). The scientific foundation of forestry as exemplified by Forest Research Work in Suomi. Silva Fennica no. 4 article id 4445. https://doi.org/10.14214/sf.a8393

The article is a lecture given by A.K. Cajander in the International Congress of Plant Science. The lecture describes results of Finnish forest research that might be regarded significant also for North America. Because of similarities in nature and forest management, forest research may use similar methods in both areas.

For instance, line plot survey in the form used in Finland could well be applied in North America. In Finland, lines were drawn at 26 kilometer intervals. Visual estimates about, for instance, species, tree growth and productivity class, were made along the lines and sample plots were taken every other kilometer. To gain full advantage of the method, a productivity classification and yield tables are needed. When these are known, it is possible to find out how to increase the productivity of forests with suitable tree species and proper forest management. This kind of inventory of forest resources and the state of forests provides reliable information for forest policy. Another important issue for forest research is forest management, which requires understanding on their biology. At the same time, research must provide methods for practical forestry.

A summary in Finnish is included in the PDF.

  • Cajander, ORCID ID:E-mail:

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