Site Index Models for Main Forest-Forming Tree Species in Poland

Jarosław Socha , Luiza Tymińska-Czabańska , Ewa Grabska , Stanisław Orzeł


Site index is the most commonly used measure of potential site productivity, providing key information for forest management practices. It is determined using species-specific site index models that take into account climatic and edaphic factors. To reliably estimate the site index, appropriate models are necessary. In Poland, however, outdated guidelines, i.e., yield tables, are used to determine site classes, which result in the inappropriate estimation of height growth and increments of stands. Therefore, the aim of this study is to develop new site index models for the main forest forming tree species in Poland, in a total of eight species. For the development of site index models, we used growth trajectories of 3052 sample trees, representing the whole range of geographic locations and site conditions. Five dynamic models were selected and parametrized to develop the site index models. The models were evaluated using quantitative measures of goodness of fit (MAE, R2, and AIC), the analysis of residuals, and the assessment of how the model reflects the biological phenomena of height growth. Results showed that depending on the species, different models have the highest predictive ability. There are significant differences in results using traditional yield tables and developed site index models. For most of the species, the largest differences characterized either the youngest or the oldest age classes. These differences can be attributed to the changes in growth conditions from the time when yield tables were developed. Growth dynamics of forest stands may also show spatial variability, thus, in future research additional site variables and, regional variability should be taken into account.
Author Jarosław Socha (FoF / IoFRM / DoBaPoF)
Jarosław Socha,,
, Luiza Tymińska-Czabańska
Luiza Tymińska-Czabańska ,,
, Ewa Grabska
Ewa Grabska ,,
, Stanisław Orzeł (FoF / IoFRM / DoBaPoF)
Stanisław Orzeł,,
Journal seriesForests, ISSN 1999-4907, (N/A 100 pkt)
Issue year2020
Publication size in sheets0.9
Article number301
Keywords in Englishheight growth; GADA; site productivity; site index model
ASJC Classification1107 Forestry
Languageen angielski
LicenseJournal (articles only); published final; Uznanie Autorstwa (CC-BY); with publication
Score (nominal)100
Score sourcejournalList
Publication indicators WoS Citations = 0; Scopus SNIP (Source Normalised Impact per Paper): 2018 = 0.943; WoS Impact Factor: 2018 = 2.116 (2) - 2018=2.453 (5)
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FinansowanieThis work was supported by the project I-MAESTRO. Project Innovative forest MAnagEment STrategies for a Resilient biOeconomy under climate change and disturbances (I-MAESTRO) is supported under the umbrella of ForestValue ERA-NET Cofund by the National Science Centre, Poland and French Ministry of Agriculture, Agrifood, and Forestry; French Ministry of Higher Education, Research and Innovation, German Federal Ministry of Food and Agriculture (BMEL) via Agency for Renewable Resources (FNR), Slovenian Ministry of Education, Science and Sport (MIZS). ForestValue has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement N◦ 773324. Data collection was supported by the project “Actual and potential site productivity in Poland for the main forest forming tree species”, financed by the General Direction of State Forests [agreement no. ER-2717-11/14, 15th April 2014].
Wkład autorówConceptualization, J.S.; Methodology, J.S.; Validation, J.S., L.T.-C.; Formal Analysis, J.S.; Investigation, J.S. and L.T.-C.; Resources, J.S.; Data Curation, J.S., S.O.; Writing—Original Draft Preparation, J.S., L.T.-C., E.G., S.O.; Writing—Review & Editing, J.S. and L.T.-C.; Visualization, J.S. and L.T.-C.; Funding Acquisition, J.S. All authors have read and agreed to the published version of the manuscript.
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* presented citation count is obtained through Internet information analysis and it is close to the number calculated by the Publish or Perish system.
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