Mats Hannerz

Effects on the flora in Norway spruce forests following clearcutting and shelterwood cutting

Abstract Clearcutting and shelterwood cutting of mature Norway spruce peatland forests were compared regarding the effects on the forest flora. Repeated observations of the field and bottom layer vegetation were made before and until 7 or 8 years after harvesting at four sites located along a gradient from southern to northern Sweden. Clearcutting resulted in a greater change of species composition compared with shelterwood cutting. Diversity, measured as Simpsons index, and species number per subplot were lower in the clearcut than in the shelterwood after 7 or 8 years. By applying Ellenbergs indicator values, it was concluded that shelterwood regimes may preserve species preferring shaded and moist conditions, whereas those species decreased after clearcutting. Species preferring high levels of nitrogen increased in the clearcut. According to both multivariate and univariate analyses, the vegetation changed in a similar direction at all sites, although the level of response differed considerably. Despite these similarities, there was a marked site effect, which was not surprising considering the large geographic variation between sites. It is concluded that shelterwood cutting might be a better alternative than clearcutting for forests on fertile peatland sites, with respect to conservation of vascular plants and bryophytes.

Genecology and Gene Resource Management Strategies for Conifer Cold Hardiness

It has long been recognized that considerable genetic variation exists within conifer species for cold hardiness and associated phenological traits. As early as 1759, Linnaeus reported that yew trees from France were less cold hardy than local ones in Sweden (Hesselman 1907) and in 1881, von Seckendorff observed differences in cold hardiness between provenances of Abies douglasii Lindl. [syn. Pseudotsuga menziesii (Mirb.) Franco] from Canada (summarized by Langlet 1971). Since these early observations, clinal patterns of variation have been documented at both relatively coarse and fine spatial scales, and some broad generalizations can be drawn from the extensive literature.

Changes in the vascular plant vegetation after different cutting regimes on a productive Peatland site in Central Sweden

We studied the changes in vascular plant vegetation in the first five years after final felling of a mature Norway spruce (Picea abies (L.) Karst.) forest on a productive peatland. Vegetation changes following clearcutting and selective cutting (shelterwoods with the density 140 and 200 stem ha‐1) were compared. The total cover of the understory increased three times on the clearcut and more than twice in the shelterwoods. The relative decrease of the three most common species was from 73% to 3% on the clearcut and 79 to 28% under the shelter trees. Six of the 16 most common species in the mature forest almost disappeared on the clearcut. In contrast, in the shelterwoods, few species decreased and twelve of the most common species remained the same or increased their cover.

Growth cessation and autumn-frost hardiness in one-year-old Picea abies progenies from seed orchards and natural stands.

One-year-old seedlings of Norway spruce [Picea abies (L.) Karst.] from seed orchards and natural stands were compared with respect to growth cessation and autumn-frost hardiness. The correlation among traits related to growth, growth cessation and frost hardiness on the same plants in two sets of environmental conditions was assessed. Total height, the degrees of shoot lignification and frost hardiness, and the timing of height growth cessation and budset were recorded at two nurseries in central and northern Sweden. Nine seed-orchard seed-lots were compared with seed from 26 natural stands originating from 56° N to 66° N in Sweden. Latitude explained 55-87% of the statistical variation among stands in the analysed traits at the central nursery and 49-84% at the northern nursery. On average, the seed-orchard progeny performed similarly to progeny from natural stands located 1-2° south of the origin of the seed-orchard clones. Reference material representing a geographical gradient was found to be a valuable aid when interpreting the results of growth cessation and frost-hardiness evaluations.

Research for a bio-based economy in the forest sector – a Nordic example

The global population continues to increase, and estimates suggest it will reach some nine billion people in 2050. An anticipated substantial rise in consumption will put further stress on the Earth’s ecological production systems. According to the Millennium Ecosystem Assessment, some planetary thresholds have already been passed, e.g. as regards climate change, eutrophication and biodiversity. The challenge is to produce more consumables for the growing population, but with a lower environmental impact. One constraint is that there is limited land to cultivate, meaning that production has to increase per unit land area. This is particularly the case for agricultural land, but in many parts of the world also applies to forest land. Part of the global solution is to replace fossil-based energy and products with renewable and environmentally friendly bio-based alternatives. Forest-related examples include biomass-based fuel replacing oil or coal and wood-based materials replacing oil-based plastics, concrete and steel in products and structures. This intention behind replacement or substitution is, in part, to drive a societal shift into a bio-based economy. The Nordic countries are rich in the natural resources that are prerequisites for this shift. Sweden, Norway and Finland together have over 60 million hectares of forest. Denmark and Iceland historically have lower forest acreage, but are taking actions to increase their production of wood. The Nordic Council of Ministers has taken several initiatives to strengthen the Nordic bioeconomy, as stressed in the Nidaros Declaration for green growth, adopted in 2012. The ongoing three-year programme NordBio is one example. This programme aims to improve the way we use our resources and minimise our generation of waste. Nordic Forest Research (SNS) is a collaborative body, financed with Nordic funds under the auspices of the Nordic Council of Ministers. SNS supports several cooperating networks and projects intended to strengthen the bio-based economy. The organisation initiated arranging a seminar on bioeconomy to be held at the IUFRO World Congress 2014 in Salt Lake City, USA. The seminar will give a broad overview of research in bioeconomy and will also be supported by a special issue of Scandinavian Journal of Forest Research. This issue is one outcome of the initiative from SNS. The articles span a broad range of topics from social science and biomass production to technological innovations. Two guest editors, alongside the chief editor, have taken part in the job of selecting and developing the papers. Anders Roos has been responsible for articles related to social science and economics. The articles have been selected from contributions to the SNS-funded conference “The forest sector in the biobased economy: perspectives from policy and economic sciences”, which took place in Uppsala, Sweden, in August 2013. HansÖrjan Nohrstedt is the editor of four invited articles reviewing methods to increase biomass production. Finally, two review articles giving examples of industrial innovations and the role of the wood mechanical industry have been commissioned. Together, the articles provide a broad overview of the concept of bioeconomy, mainly from a Nordic perspective. Biomass production is the foundation for the forestbased bioeconomy. Hedwall et al. (2014) present a review of fertiliser application and its constraints and opportunities from a biological, economic and environmental perspective. Helmisaari et al. (2014) summarise the current and future use of forest biomass for energy. Dahl Kjær et al. (2014) discuss the option of introduced tree species in relation to past, present and future situations. Native tree species could also be utilised more efficiently by means of genetic tree improvement. Ruotsalainen (2014) gives an overview of the history, methods and results of forest tree breeding worldwide. Technological advances open up new markets based on renewable resources from the forest. Lindström and Aulin (2014) review the major market and technical challenges and opportunities for using nanocellulosic materials. Sandberg et al. (2014) describe the importance

From the editor: On the stage in a week

Scandinavian Journal of Forest Research, in cooperation with Taylor & Francis, is continuing its efforts to speed up the publication process. With the implementation of Accepted Manuscript Online (AMO), an author will see his or her paper online within only one week after the manuscript is accepted by the editor. This version is the submitted manuscript, not yet copy-edited or type-set, but still possible to download in full html-format. The manuscript is also possible to cite. A DOI†-number (Digital Object Identifier) is assigned when the article is registered in the production system. The DOI number is a unique identifier that will be associated with the manuscript through the various parts of the production process and after publication. Speed of publication is one of the prerequisites for success in a researcher’s world. In ‘‘the old days’’, there was sometimes a long lag-phase before a paper was finally printed and distributed to libraries, often a frustrating process for the researcher who wants to disseminate their findings as quickly as possible. With the online publication system, an article is quickly available also in the case of a printing queue. Once the manuscript is type-set, copy-edited and approved by the author, it will move from AMO to a fully edited, but non-paginated copy in iFirst. All accepted articles will appear in iFirst within eight weeks. iFirst articles are also available for reading, downloading and being cited. The final step is when the paper is assigned to a printed issue. This is when the article receives it final page numbers. All papers not yet printed are found under Forthcoming articles on the journal website (www. tandfonline.com/sfor). The list starts with the fully edited iFirst articles, and continues with Accepted Author Version. iFirst or AMO article can be cited in the following way: Bjørn Økland, Robert A. Haack & Gunnar Wilhelmsen (2011): Detection probability of forest pests in current inspection protocols A case study of the bronze birch borer, Scandinavian Journal of Forest Research, DOI:10.1080/02827581.2011. 632782 Being the editor of Scandinavian Journal of Forest Research, I am really proud of the service we now offer our authors.

Scandinavian Journal of Forest Research – 25 years supporting forest science

The Scandinavian Journal of Forest Research has served the needs of the forest science community since 1986. So 2010 sees the publication of the 25th consecutive volume. The journal has evolved from one with an applied, regional profile, to an international journal with global contributions. The changes to the journal also reflect the development of the field of forest science. This short article gives some insight into the story of the Scandinavian Journal of Forest Research.

Rooting Success of Cuttings from Young Picea abies in Transition to Flowering Competent Phase

Abstract Abundant flowering occurred in a central Swedish trial with 10-yr-old Picea abies L. (Karst.) cuttings, taken on 4-yr-old seedlings. Large deviations in cone-set between clones were assumed to reflect different stages in transition from juvenile to flowering competent phase. Rooting success and first-yr growth performance (leader length, leader origin and plagiotropic growth) were studied on cuttings originating from the upper and lower parts of the crown in 15 clones with heavy cone-set and 15 clones without cones. Twigs from the lower part of the crown had a significantly higher rooting percentage. Cone-set did not have an effect on any of the variables analysed. The results suggest that flowering ability and rooting capacity are independent age-related processes, implying that selection for high rooting capacity in clonal forestry does not reduce flowering competence. The results will have a great impact on breeding of P. abies, since both early flowering and high rooting ability are important...

News and views: Editor's summary

The first two papers report results from genetic experiments with Norway spruce performed in climate chambers, and provide comparisons with results from the field. Johan Sonesson and Gosta Eriksson found that families varied with respect to drought tolerance. Drought tolerance was also genetically correlated with early budset. However, no correlation between drought tolerance and growth was detected, either in the climate chamber or in the field.

Top downloaded article focuses on management strategies

A conceptual article on strategies to adapt forest management to climate warming was the most popular article being read in 2010, at least when measured with download statistics. A long time has passed since researchers went to the university library to collect a paper copy of a scientific article. Today, the library has moved into each computer’s web browser. This change allows for a faster and more detailed follow-up of how abstracts and full papers are downloaded, and hopefully also read. In 2010, altogether 18,988 full text papers from Scandinavian Journal of Forest Research were downloaded via the Informaworld standard platform. Downloads via the EBSCO database added another 6810 papers. The downloads have increased quickly over the last few years, from a total of 10,631 in 2005. This list shows the top 10 downloaded articles in 2010. Papers ranking from 11 to 20 are not shown, but they include several papers published in the second half of 2010. These could be expected to climb higher on the list in 2011. It is worth noting that a paper from 1999 (Kozlowski, 1999) was still the sixteenth most downloaded article.