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  • 1.
    Dynesius, Mats
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Åström, Marcus
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Nilsson, Christer
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Microclimatic buffering by logging residues and forest edges reduces clear-cutting impacts on forest bryophytes2008Inngår i: Applied Vegetation Science, ISSN 1402-2001, E-ISSN 1654-109X, Vol. 11, nr 3, s. 345-354Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Question: The practice of extracting logging residues after clear-cutting for bioenergy purposes is spreading. Logging residues constitute a shelter in clear-cut areas and therefore concerns have been expressed that their removal could make the ground and its vegetation more exposed to extreme micro¬climatic conditions. We asked whether logging residues and forest edges can protect ground-dwelling forest bryophytes from fatal microclimate events following clear-cutting.

    Location: Boreal forests of central Sweden.

    Methods: Using transplants of eight forest floor bryophyte species we experimentally analysed the sheltering effect (less solar radiation and less wind) of logging residues and forest edges in seven clear-cut areas. Transplants were placed in two contrasting positions in each area; near a north-facing forest edge and in the centre of the clear-cut area. In each position, half of the transplants were covered by a layer of spruce branches and the other half was left uncovered. We estimated proportion of apparently living shoots (apparent vitality) and measured radial growth of transplants during one growing season.

    Results: Position in the clear-cut area, but not cover of spruce branches, clearly influenced radial growth. Vitality scores were higher among transplants covered with branches and the lowest apparent vitality was observed in uncovered transplants in the middle of clear-cut areas. The change in area of apparently liv¬ing shoots during the course of the experiment (growth minus mortality) was unaffected by branch cover close to the edge but positively affected in the centre of the clear-cut area. In general, the effect of branch cover on bryophytes was higher in the centre of clear-cut areas. Here, climatic measurements showed that branch cover buffers during periods of extreme microclimates.

    Conclusions: Extraction of logging residues after clear-felling may reduce the survival of some ground-dwelling forest organisms. The additional sheltering provided by branches was unimportant close to forest edges. We suggest smaller clear-cut areas, green-tree retention and other ways to make logged areas shadier and less windy to mitigate the reduced shelter caused by harvest of logging residues.

    Fulltekst (pdf)
    Dynesius et al_AVS2008
  • 2.
    Herberg, Erik R.
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap. Kiel School of Sustainability, Christian-Albrechts-Universitat zu Kiel, Kiel, Germany.
    Sarneel, Judith M.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap. Ecology & Biodiversity Group and Plant Ecophysiology Group, Utrecht University, CH Utrecht, The Netherlands.
    Recruitment of riparian plants after restoration of geomorphic complexity in northern Sweden2017Inngår i: Applied Vegetation Science, ISSN 1402-2001, E-ISSN 1654-109X, Vol. 20, nr 3, s. 435-445Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Question: Restoration of channelized streams increases geomorphic complexity but it remains unclear how this interacts with processes that drive future vegetation changes (dispersal, germination and establishment). This study asks if increased geomorphic complexity increases recruitment conditions of sown seeds or affects post-dispersal natural seedling densities. Location: Vindel River catchment, northern Sweden. Methods: We selected seven study streams with paired reaches that differed in the degree to which geomorphic complexity was restored. Basic reaches used simple restoration methods while enhanced reaches additionally added large boulders and woody debris. We sowed seeds of six species at ten locations in each reach in 2014 and counted the number of seedlings after 8wk and the number of naturally occurring seedlings in a plot adjacent to the sowing locations in 2013 and 2014. Using factor analysis based on 34 complexity measurements, overall geomorphic complexity was quantified for eight of the 14 reaches. Results: Total numbers of sown (2014) and natural seedlings (2013 and 2014) summed per reach did not differ between restoration types when tested pair-wise. Enhanced restoration did not always significantly increase geomorphic complexity, which differed considerably between the streams. More complex reaches were steeper, had larger size sediment and more nutrient-poor soils. Total recruitment of sown species significantly decreased with increasing complexity. Numbers of natural seedlings differed considerably from 2013 to 2014, but were not related to complexity. In 2014, a potential parent plant of the same species occurred within the same plot for 71.8% of the natural seedlings that could be identified. Conclusions: The recruitment of sown seeds was affected by overall geomorphic complexity rather than by the enhanced restoration. The absence of a correlation between geomorphic complexity and natural seedlings could indicate that natural seedling dynamics are not solely determined by recruitment conditions, but also by dispersal.

    Fulltekst (pdf)
    fulltext
  • 3. Walker, Donald A.
    et al.
    Epstein, Howard E.
    Šibík, Jozef
    Bhatt, Uma
    Romanovsky, Vladimir E.
    Breen, Amy L.
    Chasníková, Silvia
    Daanen, Ronald
    Druckenmiller, Lisa A.
    Ermokhina, Ksenia
    Forbes, Bruce C.
    Frost, Gerald V.
    Geml, Jozsef
    Kaarlejärvi, Elina
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Khitun, Olga
    Khomutov, Artem
    Kumpula, Timo
    Kuss, Patrick
    Matyshak, Georgy
    Moskalenko, Natalya
    Orekhov, Pavel
    Peirce, Jana
    Raynolds, Martha K.
    Timling, Ina
    Vegetation on mesic loamy and sandy soils along a 1700-km maritime Eurasia Arctic Transect2019Inngår i: Applied Vegetation Science, ISSN 1402-2001, E-ISSN 1654-109X, Vol. 22, nr 1, s. 150-167Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Questions: How do plant communities on zonal loamy vs. sandy soils vary across the full maritime Arctic bioclimate gradient? How are plant communities of these areas related to existing vegetation units of the European Vegetation Classification? What are the main environmental factors controlling transitions of vegetation along the bioclimate gradient?

    Location: 1700-km Eurasia Arctic Transect (EAT), Yamal Peninsula and Franz Josef Land (FJL), Russia.

    Methods: The Braun-Blanquet approach was used to sample mesic loamy and sandy plots on 14 total study sites at six locations, one in each of the five Arctic bioclimate subzones and the forest-tundra transition. Trends in soil factors, cover of plant growth forms (PGFs) and species diversity were examined along the summer warmth index (SWI) gradient and on loamy and sandy soils. Classification and ordination were used to group the plots and to test relationships between vegetation and environmental factors.

    Results: Clear, mostly non-linear, trends occurred for soil factors, vegetation structure and species diversity along the climate gradient. Cluster analysis revealed seven groups with clear relationships to subzone and soil texture. Clusters at the ends of the bioclimate gradient (forest-tundra and polar desert) had many highly diagnostic taxa, whereas clusters from the Yamal Peninsula had only a few. Axis 1 of a DCA was strongly correlated with latitude and summer warmth; Axis 2 was strongly correlated with soil moisture, percentage sand and landscape age.

    Conclusions: Summer temperature and soil texture have clear effects on tundra canopy structure and species composition, with consequences for ecosystem properties. Each layer of the plant canopy has a distinct region of peak abundance along the bioclimate gradient. The major vegetation types are weakly aligned with described classes of the European Vegetation Checklist, indicating a continuous floristic gradient rather than distinct subzone regions. The study provides ground-based vegetation data for satellite-based interpretations of the western maritime Eurasian Arctic, and the first vegetation data from Hayes Island, Franz Josef Land, which is strongly separated geographically and floristically from the rest of the gradient and most susceptible to on-going climate change.

    Fulltekst (pdf)
    fulltext
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