Current issue: 58(4)

Under compilation: 58(5)

Scopus CiteScore 2023: 3.5
Scopus ranking of open access forestry journals: 17th
PlanS compliant
Select issue
Silva Fennica 1926-1997
1990-1997
1980-1989
1970-1979
1960-1969
Acta Forestalia Fennica
1953-1968
1933-1952
1913-1932

Articles by Rafał Wojtan

Category : Research article

article id 9968, category Research article
Hubert Lachowicz, Anna Bieniasz, Rafał Wojtan. (2019). Variability in the basic density of silver birch wood in Poland. Silva Fennica vol. 53 no. 1 article id 9968. https://doi.org/10.14214/sf.9968
Keywords: Betula pendula; tree age; forest habitat type; thickness of trees; geographical location; physical properties of wood
Highlights: Location, tree age and forest habitat type, and the interactions between those factors, have a statistically significant impact on the basic density of silver birch wood; The average basic density of silver birch wood increases with the age of the tree.
Abstract | Full text in HTML | Full text in PDF | Author Info

This work presents the findings of a study concerning variability in the basic density of silver birch (Betula pendula Roth) wood, depending on the geographical location of tree stands, the age and thickness of the trees, the forest habitat type, and interactions between some of these factors. The study was carried out on wood from trees aged approximately 30, 50 and 70 years in 12 forest districts located throughout Poland. In total 4777 wood samples, taken from 306 trees from 51 test plots, were measured. The location, the age of the trees, the thickness of the trees and the forest habitat type, as well as interactions between these factors, proved to have a significant influence on the basic density of silver birch wood. The highest mean values of the basic density of the birch wood were found in Sokołów forest district on the FBF habitat type (549 kg m–3) and in Giżycko forest district on the FMBF habitat type (548 kg m–3). For the entire set of examined material, the average values of the basic density of wood increase with tree age. For the examined material originating in FBF and FMBF habitats the average values of basic density showed no significant differences; however, in the cases of the forest districts of Giżycko, Łobez and Rudziniec, significant differences in the analysed property were observed.

  • Lachowicz, Department of Forest Utilization, Warsaw University of Life Sciences SGGW, Nowoursynowska 159 02-787 Warsaw, Poland E-mail: hubert.lachowicz@wl.sggw.pl
  • Bieniasz, Department of Forest Utilization, Warsaw University of Life Sciences SGGW, Nowoursynowska 159 02-787 Warsaw, Poland E-mail: anna.bieniasz@wl.sggw.pl (email)
  • Wojtan, Laboratory of Dendrometry and Forest Productivity, Warsaw University of Life Sciences SGGW, Nowoursynowska 159 02-787 Warsaw, Poland E-mail: rwojtan@wl.sggw.pl
article id 1559, category Research article
Karol Bronisz, Mike Strub, Chris Cieszewski, Szymon Bijak, Agnieszka Bronisz, Robert Tomusiak, Rafał Wojtan, Michał Zasada. (2016). Empirical equations for estimating aboveground biomass of Betula pendula growing on former farmland in central Poland. Silva Fennica vol. 50 no. 4 article id 1559. https://doi.org/10.14214/sf.1559
Keywords: silver birch; simplified and expanded models; seemingly unrelated regression
Highlights: We developed equations for aboveground biomass components of young silver birch stands on post-agricultural lands in central Poland for single tree level; Simplified equations were based exclusively on diameter at ground level or breast height, while expanded ones were based on the appropriate diameter and tree height; For large trees, diameter at breast height is a more appropriate explanatory variable than diameter at ground level; Biomass estimations based on models from neighboring countries were consistent with our results.
Abstract | Full text in HTML | Full text in PDF | Author Info

We determined empirical models for estimating total aboveground as well as stem, branches, and foliage dry biomass of young (age up to 16 years) silver birch (Betula pendula Roth.) growing on the post-agricultural lands. Two sets of allometric models for trees with a height below or above 1.3 m (small and large trees respectively) were developed. Simplified models were elaborated based exclusively on appropriate tree diameter (diameter at ground level for small trees, diameter at breast height for large trees), while expanded models also included tree height. Total aboveground biomass was estimated as the sum of biomass of all tree components. To assure additivity of the developed equations, the seemingly unrelated regression approach for the final model fitting was used. Expanded models in both tree groups were characterized by a better fit to the data (R2 for total aboveground biomass for small and large trees equaled 0.8768 and 0.9752, respectively). Diameter at breast height appeared to be a better predictor than diameter at ground level – simplified models had better fit for large trees (R2 for total aboveground biomass equals 0.9611) than for small ones (R2 = 0.7516). The developed equations provide biomass predictions consistent with available Latvian, Estonian, Finnish, Swedish, and Norwegian models for silver birch.

  • Bronisz, Laboratory of Dendrometry and Forest Productivity, Faculty of Forestry, Warsaw University of Life Sciences – SGGW, Nowoursynowska 159, 02-787 Warsaw, Poland E-mail: karol.bronisz@wl.sggw.pl (email)
  • Strub, Warnell School of Forestry and Natural Resources, University of Georgia, Athens, GA, 30605, USA E-mail: strub@mcfns.com
  • Cieszewski, Warnell School of Forestry and Natural Resources, University of Georgia, Athens, GA, 30605, USA E-mail: thebiomat@gmail.com
  • Bijak, Laboratory of Dendrometry and Forest Productivity, Faculty of Forestry, Warsaw University of Life Sciences – SGGW, Nowoursynowska 159, 02-787 Warsaw, Poland E-mail: szymon.bijak@wl.sggw.pl
  • Bronisz, Laboratory of Dendrometry and Forest Productivity, Faculty of Forestry, Warsaw University of Life Sciences – SGGW, Nowoursynowska 159, 02-787 Warsaw, Poland E-mail: agnieszka.bronisz@wl.sggw.pl
  • Tomusiak, Laboratory of Dendrometry and Forest Productivity, Faculty of Forestry, Warsaw University of Life Sciences – SGGW, Nowoursynowska 159, 02-787 Warsaw, Poland E-mail: robert.tomusiak@wl.sggw.pl
  • Wojtan, Laboratory of Dendrometry and Forest Productivity, Faculty of Forestry, Warsaw University of Life Sciences – SGGW, Nowoursynowska 159, 02-787 Warsaw, Poland E-mail: rafal.wojtan@wl.sggw.pl
  • Zasada, Laboratory of Dendrometry and Forest Productivity, Faculty of Forestry, Warsaw University of Life Sciences – SGGW, Nowoursynowska 159, 02-787 Warsaw, Poland E-mail: michal.zasada@wl.sggw.pl
article id 963, category Research article
Szymon Bijak, Michał Zasada, Agnieszka Bronisz, Karol Bronisz, Maciej Czajkowski, Łukasz Ludwisiak, Robert Tomusiak, Rafał Wojtan. (2013). Estimating coarse roots biomass in young silver birch stands on post-agricultural lands in central Poland. Silva Fennica vol. 47 no. 2 article id 963. https://doi.org/10.14214/sf.963
Keywords: abandoned farmland; belowground biomass; allometric equations; root-to-shoot ratio
Highlights: Age and size of the tree are the most important factors that influence the amount of belowground biomass; Allocation of the biomass to the coarse roots also depends on age and size of the tree
Abstract | Full text in HTML | Full text in PDF | Author Info
Study analyses coarse (d>2 mm of diameter) roots biomass dynamics in young succession stands of silver birch (Betula pendula Roth) growing on abandoned farmlands in central Poland. Research material based on 181 sample trees, which were gathered in 20 pure silver birch stands in 5 locations. The age of the trees varied from 1 to 16 years. Coarse roots biomass of the investigated trees ranged from 0.7 to 4305.5 g/tree (422.6 g/tree on average) showing great variability (coefficient of variation equals 185%). A clear dependence of belowground biomass on the age and size of a tree was observed. Root-to-shoot ratio values vary from 0.1 to 1.0 with evidence of a tendency to decrease with increasing age, diameter at the breast height and height of analysed trees. An allometric equation was elaborated for the estimation of belowground biomass based on height or diameter at breast height of young silver birches. The suitability of this formula should be considered for the estimation of biomass accumulation and carbon sequestration by young successional silver birch stands growing on abandoned agricultural lands.
  • Bijak, Warsaw University of Life Sciences – SGGW, Faculty of Forestry, Laboratory of Dendrometry and Forest Productivity, Nowoursynowska 159, 02-776 Warszawa, Poland E-mail: szymon.bijak@wl.sggw.pl (email)
  • Zasada, Warsaw University of Life Sciences – SGGW, Faculty of Forestry, Laboratory of Dendrometry and Forest Productivity, Nowoursynowska 159, 02-767 Warszawa, Poland E-mail: michal.zasada@wl.sggw.pl
  • Bronisz, Warsaw University of Life Sciences – SGGW, Faculty of Forestry, Laboratory of Dendrometry and Forest Productivity, Warszawa, Poland E-mail: agnieszka.bronisz@wl.sggw.pl
  • Bronisz, Warsaw University of Life Sciences – SGGW, Faculty of Forestry, Laboratory of Dendrometry and Forest Productivity, Warszawa, Poland E-mail: karol.bronisz@wl.sggw.pl
  • Czajkowski, Warsaw University of Life Sciences – SGGW, Faculty of Forestry, Laboratory of Dendrometry and Forest Productivity, Warszawa, Poland E-mail: maciej.czajkowski@wl.sggw.pl
  • Ludwisiak, Warsaw University of Life Sciences – SGGW, Faculty of Forestry, Laboratory of Dendrometry and Forest Productivity, Warszawa, Poland E-mail: lukasz.ludwisiak@wl.sggw.pl
  • Tomusiak, Warsaw University of Life Sciences – SGGW, Faculty of Forestry, Laboratory of Dendrometry and Forest Productivity, Warszawa, Poland E-mail: robert.tomusiak@wl.sggw.pl
  • Wojtan, Warsaw University of Life Sciences – SGGW, Faculty of Forestry, Laboratory of Dendrometry and Forest Productivity, Warszawa, Poland E-mail: rafal.wojtan@wl.sggw.pl

Register
Click this link to register to Silva Fennica.
Log in
If you are a registered user, log in to save your selected articles for later access.
Contents alert
Sign up to receive alerts of new content
Your selected articles