Karol Bronisz, Michał Zasada. (2020). Taper models for black locust in west Poland. Silva Fennica vol. 54 no. 5 article id 10351. https://doi.org/10.14214/sf.10351

Keywords: taper; Robinia pseudoacacia; mixed-effects models; section diameter over and under bark; volume prediction

Highlights: Seven taper models with different numbers of estimated parameters were analysed; Section diameter and volume was modelled using fixed and mixed-effects modelling approaches; The variable-form taper model with eight estimated parameters fitted the data the best; The lowest error for volume prediction was achieved for the fixed-effects taper model.

Abstract | Full text in HTML | Full text in PDF | Author Info

The diameter at any point on a stem and tree volume are some of the most important types of information used in forest management planning. One of the methods to predict the diameter at any point on a stem is to develop taper models. Black locust (Robinia pseudoacacia L.) occurs in almost all forests in Poland, with the largest concentration in the western part of the country. Using empirical data obtained from 13 black locust stands (48 felled trees), seven taper models with different numbers of estimated parameters were analysed for section diameters both over and under bark using fixed and mixed-effects modelling approaches. Assuming a lack of additional measurements, the best fitted taper models were used for the prediction of over bark volume using both methods. The predicted volume was compared with the results from different volume equations available for black locust. The variable-form taper model with eight estimated parameters fitted the data the best. The lowest root mean square error for volume prediction was achieved for the elaborated fixed-effects taper model (0.0476), followed by the mixed-effects taper model (0.0489). At the same time, the difference between the volume relative errors achieved based on the taper models does not differ significantly from the results obtained using the volume equations already available for black locust (two of the three analysed).

Bronisz, Institute of Forest Sciences, Warsaw University of Life Sciences-SGGW, Nowoursynowska 159, PL 02-776 Warsaw, Poland E-mail: karol.bronisz@wl.sggw.pl
Zasada, Institute of Forest Sciences, Warsaw University of Life Sciences-SGGW, Nowoursynowska 159, PL 02-776 Warsaw, Poland https://orcid.org/0000-0002-4881-296X E-mail: Michal.Zasada@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 (R²for 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
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
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

Click this link to register to Silva Fennica.

If you are a registered user, log in to save your selected articles for later access.

Contents alert

Your selected articles

Follow @SilvaFennica