Effects of sample tree selection and calculation methods on the accuracy of field plot values in area-based forest inventories
Accurate field plot data on forest attributes are crucial in area-based forest inventories assisted by airborne laser scanning, providing an essential reference for calibrating predictive models. This study assessed how sample tree selection methods and plot data calculation methods affect the accur...
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| Format: | Article |
| Language: | English |
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Finnish Society of Forest Science
2025-06-01
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| Series: | Silva Fennica |
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| Online Access: | https://www.silvafennica.fi/article/25003 |
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| author | Lennart Noordermeer Terje Gobakken Johannes Breidenbach Rune Eriksen Erik Næsset Hans Ole Ørka Ole M. Bollandsås |
| author_facet | Lennart Noordermeer Terje Gobakken Johannes Breidenbach Rune Eriksen Erik Næsset Hans Ole Ørka Ole M. Bollandsås |
| author_sort | Lennart Noordermeer |
| collection | DOAJ |
| description | Accurate field plot data on forest attributes are crucial in area-based forest inventories assisted by airborne laser scanning, providing an essential reference for calibrating predictive models. This study assessed how sample tree selection methods and plot data calculation methods affect the accuracy of field plot values of timber volume, Lorey’s mean height, and dominant height. We used data obtained from 12 420 circular sample plots of 250 m2, measured as part of the Norwegian national forest inventory and 45 local forest management inventories. We applied Monte Carlo simulations by which we tested various numbers of sample trees, methods to select sample trees, and methods to calculate plot-level values from tree-level measurements. Accuracies of plot values were statistically significantly affected by the number of sample trees, sample tree selection method, and calculation method. Obtained values of root mean square error ranged from 5% to 16% relative to the mean observed values, across the factors studied. Accuracy improved with increasing numbers of sample trees for all forest attributes. We obtained greatest accuracies by selecting sample trees with a probability proportional to basal area, and by retaining field-measured heights for sample trees and using heights predicted with a height-diameter model for non-sample trees. This study highlights the importance of appropriate sample tree selection methods and calculation methods in obtaining accurate field plot data in area-based forest inventories. |
| format | Article |
| id | doaj-art-b9864cfa1a6c447da6445d451f5fd9de |
| institution | Kabale University |
| issn | 2242-4075 |
| language | English |
| publishDate | 2025-06-01 |
| publisher | Finnish Society of Forest Science |
| record_format | Article |
| series | Silva Fennica |
| spelling | doaj-art-b9864cfa1a6c447da6445d451f5fd9de2025-08-20T03:25:59ZengFinnish Society of Forest ScienceSilva Fennica2242-40752025-06-0159210.14214/sf.25003Effects of sample tree selection and calculation methods on the accuracy of field plot values in area-based forest inventoriesLennart Noordermeer0https://orcid.org/0000-0002-8840-0345Terje Gobakken1https://orcid.org/0000-0001-5534-049XJohannes Breidenbach2Rune Eriksen3Erik Næsset4Hans Ole Ørka5Ole M. Bollandsås6https://orcid.org/0000-0002-1231-7692Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, NMBU, P.O. Box 5003, NO-1432 Ås, NorwayFaculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, NMBU, P.O. Box 5003, NO-1432 Ås, NorwayDivision of Forest and Forest Resources, Norwegian Institute of Bioeconomy Research (NIBIO), P.O. Box 115, NO-1431 Ås, NorwayDivision of Forest and Forest Resources, Norwegian Institute of Bioeconomy Research (NIBIO), P.O. Box 115, NO-1431 Ås, NorwayFaculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, NMBU, P.O. Box 5003, NO-1432 Ås, Norway Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, NMBU, P.O. Box 5003, NO-1432 Ås, NorwayFaculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, NMBU, P.O. Box 5003, NO-1432 Ås, NorwayAccurate field plot data on forest attributes are crucial in area-based forest inventories assisted by airborne laser scanning, providing an essential reference for calibrating predictive models. This study assessed how sample tree selection methods and plot data calculation methods affect the accuracy of field plot values of timber volume, Lorey’s mean height, and dominant height. We used data obtained from 12 420 circular sample plots of 250 m2, measured as part of the Norwegian national forest inventory and 45 local forest management inventories. We applied Monte Carlo simulations by which we tested various numbers of sample trees, methods to select sample trees, and methods to calculate plot-level values from tree-level measurements. Accuracies of plot values were statistically significantly affected by the number of sample trees, sample tree selection method, and calculation method. Obtained values of root mean square error ranged from 5% to 16% relative to the mean observed values, across the factors studied. Accuracy improved with increasing numbers of sample trees for all forest attributes. We obtained greatest accuracies by selecting sample trees with a probability proportional to basal area, and by retaining field-measured heights for sample trees and using heights predicted with a height-diameter model for non-sample trees. This study highlights the importance of appropriate sample tree selection methods and calculation methods in obtaining accurate field plot data in area-based forest inventories.https://www.silvafennica.fi/article/25003forest inventory methodsfield plot accuracyheight-diameter modelingsample tree selection |
| spellingShingle | Lennart Noordermeer Terje Gobakken Johannes Breidenbach Rune Eriksen Erik Næsset Hans Ole Ørka Ole M. Bollandsås Effects of sample tree selection and calculation methods on the accuracy of field plot values in area-based forest inventories Silva Fennica forest inventory methods field plot accuracy height-diameter modeling sample tree selection |
| title | Effects of sample tree selection and calculation methods on the accuracy of field plot values in area-based forest inventories |
| title_full | Effects of sample tree selection and calculation methods on the accuracy of field plot values in area-based forest inventories |
| title_fullStr | Effects of sample tree selection and calculation methods on the accuracy of field plot values in area-based forest inventories |
| title_full_unstemmed | Effects of sample tree selection and calculation methods on the accuracy of field plot values in area-based forest inventories |
| title_short | Effects of sample tree selection and calculation methods on the accuracy of field plot values in area-based forest inventories |
| title_sort | effects of sample tree selection and calculation methods on the accuracy of field plot values in area based forest inventories |
| topic | forest inventory methods field plot accuracy height-diameter modeling sample tree selection |
| url | https://www.silvafennica.fi/article/25003 |
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