Forests 2016, 7(4), 87; doi:10.3390/f7040087
Deriving Merchantable Volume in Poplar through a Localized Tapering Function from Non-Destructive Terrestrial Laser Scanning
1
College of Forestry, Nanjing Forestry University, Nanjing 210037, China
2
Department of Remote Sensing and Photogrammetry, Finnish Geospatial Research Institute (FGI, formerly Finnish Geodetic Institute), Masala 02431, Finland
3
Department of Forest Resources Management, Faculty of Forestry, University of British Columbia, 2045-2424 Main Mall, Vancouver, BC V6T 1Z4, Canada
4
Advanced Analysis and Testing Center, Nanjing Forestry University, Nanjing 210037, China
†
These authors contributed equally to this work.
*
Author to whom correspondence should be addressed.
Academic Editor: Eric J. Jokela
Received: 19 October 2015 / Revised: 24 March 2016 / Accepted: 9 April 2016 / Published: 20 April 2016
(This article belongs to the Special Issue Forest Ground Observations through Terrestrial Point Clouds)
Abstract
Timber volume is an important ecological component in forested landscapes. The application of terrestrial laser scanning (TLS) to volume estimation has been widely accepted though few species have well-calibrated taper functions. This research uses TLS technology in poplar (Populus × canadensis Moench cv. ‘I-72/58’) to extract stem diameter at different tree heights and establish the relationship between point cloud data and stem curve, which constitutes the basis for volume estimation of single trees and the stand. Eight plots were established and scanned by TLS. Stem curve functions were then fitted after extraction of diameters at different height, and tree heights from the point cloud data. Lastly, six functions were evaluated by R2 and RMSE. A modified Schumacher equation was the most suitable taper function. Volume estimates from the TLS-derived taper function were better than those derived using the stem-analysis data. Finally, regression analysis showed that predictions of stem size were similar when data were based on TLS versus stem analysis. Its high accuracy and efficiency indicates that TLS technology can play an important role in forest inventory assessment. View Full-TextKeywords:
TLS; taper function; stem curve; merchantable volume; point cloud; plot level
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Sun, Y.; Liang, X.; Liang, Z.; Welham, C.; Li, W. Deriving Merchantable Volume in Poplar through a Localized Tapering Function from Non-Destructive Terrestrial Laser Scanning. Forests 2016, 7, 87.
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