{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,27]],"date-time":"2026-01-27T13:38:06Z","timestamp":1769521086921,"version":"3.49.0"},"reference-count":43,"publisher":"MDPI AG","issue":"20","license":[{"start":{"date-parts":[[2020,10,13]],"date-time":"2020-10-13T00:00:00Z","timestamp":1602547200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100006697","name":"Maa- ja Mets\u00e4talousministeri\u00d6","doi-asserted-by":"publisher","award":["project number 188\/03.02.02.00\/2016"],"award-info":[{"award-number":["project number 188\/03.02.02.00\/2016"]}],"id":[{"id":"10.13039\/501100006697","id-type":"DOI","asserted-by":"publisher"}]},{"name":"undefined &lt;span style=&quot;color:gray;font-size:10px;&quot;&gt;undefined&lt;\/span&gt;","award":["project number 307362"],"award-info":[{"award-number":["project number 307362"]}]},{"DOI":"10.13039\/100007797","name":"Helsingin Yliopisto","doi-asserted-by":"publisher","award":["Doctoral Program in Sustainable Use of Renewable Natural Resources (AGFOREE)"],"award-info":[{"award-number":["Doctoral Program in Sustainable Use of Renewable Natural Resources (AGFOREE)"]}],"id":[{"id":"10.13039\/100007797","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>Information from seedling stands in time and space is essential for sustainable forest management. To fulfil these informational needs with limited resources, remote sensing is seen as an intriguing alternative for forest inventorying. The structure and tree species composition in seedling stands have created challenges for capturing this information using sensors providing sparse point densities that do not have the ability to penetrate canopy gaps or provide spectral information. Therefore, multispectral airborne laser scanning (mALS) systems providing dense point clouds coupled with multispectral intensity data theoretically offer advantages for the characterization of seedling stands. The aim of this study was to investigate the capability of Optech Titan mALS data to characterize seedling stands in leaf-off and leaf-on conditions, as well as to retrieve the most important forest inventory attributes, such as distinguishing deciduous from coniferous trees, and estimating tree density and height. First, single-tree detection approaches were used to derive crown boundaries and tree heights from which forest structural attributes were aggregated for sample plots. To predict tree species, a random forests classifier was trained using features from two single-channel intensities (SCIs) with wavelengths of 1550 (SCI-Ch1) and 1064 nm (SCI-Ch2), and multichannel intensity (MCI) data composed of three mALS channels. The most important and uncorrelated features were analyzed and selected from 208 features. The highest overall accuracies in classification of Norway spruce, birch, and nontree class in leaf-off and leaf-on conditions obtained using SCI-Ch1 and SCI-Ch2 were 87.36% and 69.47%, respectively. The use of MCI data improved classification by up to 96.55% and 92.54% in leaf-off and leaf-on conditions, respectively. Overall, leaf-off data were favorable for distinguishing deciduous from coniferous trees and tree density estimation with a relative root mean square error (RMSE) of 37.9%, whereas leaf-on data provided more accurate height estimations, with a relative RMSE of 10.76%. Determining the canopy threshold for separating ground returns from vegetation returns was found to be critical, as mapped trees might have a height below one meter. The results showed that mALS data provided benefits for characterizing seedling stands compared to single-channel ALS systems.<\/jats:p>","DOI":"10.3390\/rs12203328","type":"journal-article","created":{"date-parts":[[2020,10,14]],"date-time":"2020-10-14T21:24:39Z","timestamp":1602710679000},"page":"3328","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":13,"title":["Using Leaf-Off and Leaf-On Multispectral Airborne Laser Scanning Data to Characterize Seedling Stands"],"prefix":"10.3390","volume":"12","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-6240-077X","authenticated-orcid":false,"given":"Mohammad","family":"Imangholiloo","sequence":"first","affiliation":[{"name":"Department of Forest Sciences, University of Helsinki, P.O. Box 27, 00014 Helsinki, Finland"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2730-8892","authenticated-orcid":false,"given":"Ninni","family":"Saarinen","sequence":"additional","affiliation":[{"name":"Department of Forest Sciences, University of Helsinki, P.O. Box 27, 00014 Helsinki, Finland"},{"name":"School of Forest Sciences, University of Eastern Finland, P.O. Box 111, 80101 Joensuu, Finland"}]},{"given":"Markus","family":"Holopainen","sequence":"additional","affiliation":[{"name":"Department of Forest Sciences, University of Helsinki, P.O. Box 27, 00014 Helsinki, Finland"},{"name":"Department of Remote Sensing and Photogrammetry, Finnish Geospatial Research Institute (FGI), National Land Survey of Finland (NLS), Geodeetinrinne 2, 02430 Masala, Finland"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5545-0613","authenticated-orcid":false,"given":"Xiaowei","family":"Yu","sequence":"additional","affiliation":[{"name":"Department of Remote Sensing and Photogrammetry, Finnish Geospatial Research Institute (FGI), National Land Survey of Finland (NLS), Geodeetinrinne 2, 02430 Masala, Finland"}]},{"given":"Juha","family":"Hyypp\u00e4","sequence":"additional","affiliation":[{"name":"Department of Remote Sensing and Photogrammetry, Finnish Geospatial Research Institute (FGI), National Land Survey of Finland (NLS), Geodeetinrinne 2, 02430 Masala, Finland"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6552-9122","authenticated-orcid":false,"given":"Mikko","family":"Vastaranta","sequence":"additional","affiliation":[{"name":"School of Forest Sciences, University of Eastern Finland, P.O. Box 111, 80101 Joensuu, Finland"}]}],"member":"1968","published-online":{"date-parts":[[2020,10,13]]},"reference":[{"key":"ref_1","unstructured":"Tapio (2006). Hyv\u00e4n Mets\u00e4nhoidon Suositukset. (Recommendations for Forest Management in Finland), Forest Development Centre Tapio. Mets\u00e4kustannus oy. (In Finnish)."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"645","DOI":"10.14214\/sf.320","article-title":"Timing and intensity of precommercial thinning and their effects on the first commercial thinning in Scots pine stands","volume":"40","author":"Huuskonen","year":"2006","journal-title":"Silva Fenn."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"111","DOI":"10.1080\/02827581.2013.869349","article-title":"Effects of early cleaning on young Picea abies stands","volume":"29","author":"Uotila","year":"2014","journal-title":"Scand. J. For. 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