{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,18]],"date-time":"2026-03-18T18:31:41Z","timestamp":1773858701021,"version":"3.50.1"},"reference-count":62,"publisher":"MDPI AG","issue":"7","license":[{"start":{"date-parts":[[2016,6,28]],"date-time":"2016-06-28T00:00:00Z","timestamp":1467072000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100005416","name":"Research Council of Norway","doi-asserted-by":"publisher","award":["184636\/S30"],"award-info":[{"award-number":["184636\/S30"]}],"id":[{"id":"10.13039\/501100005416","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>It has been shown that height measurements obtained by airborne laser scanning (ALS) with high point density (&gt;7\u20138 m\u22122) can be used to detect small trees in the alpine tree line\u2014an ecotone sensitive to climate change. Because the height measurements do not discriminate between trees and other convex structures with positive height values, this study aimed at assessing the contribution of ALS backscatter intensity to classification of trees and non-trees. The study took place in a boreal-alpine ecotone in southeastern Norway and was based on 500 precisely georeferenced small trees and non-tree objects for which ALS height and intensity were derived from four different ALS acquisitions, representing different sensors, pulse repetition frequencies (PRF), and flying altitudes. The sensors operated at 1064 nm. Based on logistic regression modeling, it was found that classification into three different tree species ((1) spruce; (2) pine; and (3) birch)) and two different non-tree object types (objects with: (1) vegetated surface; and (2) rock) was significantly better (p &lt; 0.001\u20130.05) than a classification based on models with trees and non-trees as binary response. The cause of the improved classification is mainly diverse reflectivity properties of non-tree objects. No effect of sensor, PRF, and flying altitude was found (p &gt; 0.05). Finally, it was revealed that in a direct comparison of the contribution of intensity backscatter to improve classification models of trees and non-trees beyond what could be obtained by using the ALS height information only, the contribution of intensity turned out to be far from significant (p &gt; 0.05). In conclusion, ALS backscatter intensity seems to be of little help in classification of small trees and non-trees in the boreal-alpine ecotone even when a more detailed discrimination on different species and different non-tree structures is applied.<\/jats:p>","DOI":"10.3390\/rs8070548","type":"journal-article","created":{"date-parts":[[2016,6,29]],"date-time":"2016-06-29T06:20:33Z","timestamp":1467181233000},"page":"548","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":5,"title":["Discrimination between Ground Vegetation and Small Pioneer Trees in the Boreal-Alpine Ecotone Using Intensity Metrics Derived from Airborne Laser Scanner Data"],"prefix":"10.3390","volume":"8","author":[{"given":"Erik","family":"N\u00e6sset","sequence":"first","affiliation":[{"name":"Department of Ecology and Natural Resource Management, P.O. Box 5003, N-1432 \u00c5s, Norway"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2016,6,28]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Maltamo, M., N\u00e6sset, E., and Vauhkonen, J. (2014). Forestry Applications of Airborne Laser Scanning. Concepts and Case Studies, Springer.","DOI":"10.1007\/978-94-017-8663-8"},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Maltamo, M., N\u00e6sset, E., and Vauhkonen, J. (2014). Forestry Applications of Airborne Laser Scanning. Concepts and Case Studies, Springer.","DOI":"10.1007\/978-94-017-8663-8"},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Maltamo, M., N\u00e6sset, E., and Vauhkonen, J. (2014). Forestry Applications of Airborne Laser Scanning. Concepts and Case Studies, Springer.","DOI":"10.1007\/978-94-017-8663-8"},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Maltamo, M., N\u00e6sset, E., and Vauhkonen, J. (2014). Forestry Applications of Airborne Laser Scanning. Concepts and Case Studies, Springer.","DOI":"10.1007\/978-94-017-8663-8"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"299","DOI":"10.1016\/j.rse.2012.10.008","article-title":"Model-assisted estimation of change in forest biomass over an 11 year period in a sample survey supported by airborne LiDAR: A case study with post-stratification to provide \u201cactivity data\u201d","volume":"128","author":"Gobakken","year":"2013","journal-title":"Remote Sens. Environ."},{"key":"ref_6","doi-asserted-by":"crossref","unstructured":"Maltamo, M., N\u00e6sset, E., and Vauhkonen, J. (2014). Forestry Applications of Airborne Laser Scanning. Concepts and Case Studies, Springer.","DOI":"10.1007\/978-94-017-8663-8"},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Maltamo, M., N\u00e6sset, E., and Vauhkonen, J. (2014). Forestry Applications of Airborne Laser Scanning. Concepts and Case Studies, Springer.","DOI":"10.1007\/978-94-017-8663-8"},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Maltamo, M., N\u00e6sset, E., and Vauhkonen, J. (2014). Forestry Applications of Airborne Laser Scanning. Concepts and Case Studies, Springer.","DOI":"10.1007\/978-94-017-8663-8"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"357","DOI":"10.1016\/j.rse.2007.03.004","article-title":"Using airborne laser scanning to monitor tree migration in the boreal-alpine transition zone","volume":"110","author":"Nelson","year":"2007","journal-title":"Remote Sens. Environ."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"1682","DOI":"10.1139\/b86-225","article-title":"Late holeocene reproductional patterns of Pinus sylvestris and Picea abies at the forest limit in central Sweden","volume":"64","author":"Kullman","year":"1986","journal-title":"Can. J. Bot."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"41","DOI":"10.1111\/j.1365-2745.2006.01190.x","article-title":"Tree line population monitoring of Pinus sylvestris in the Swedish Scandes, 1973\u20132005: Implications for tree line theory and climate change ecology","volume":"95","author":"Kullman","year":"2007","journal-title":"J. Ecol."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"352","DOI":"10.1111\/j.1365-2745.2006.01200.x","article-title":"Variability, contigency and rapid change in recent subarctic alpine tree line dynamics","volume":"95","author":"Danby","year":"2007","journal-title":"J. Ecol."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"345","DOI":"10.1017\/S0032247407006511","article-title":"Characterisation of arctic treelines by LiDAR and multispectral imagery","volume":"43","author":"Rees","year":"2007","journal-title":"Polar Rec."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"271","DOI":"10.1016\/j.rse.2012.03.008","article-title":"Prediction of tree biomass in the forest-tundra ecotone using airborne laser scanning","volume":"123","author":"Holmgren","year":"2012","journal-title":"Remote Sens. Environ."},{"key":"ref_15","first-page":"753","article-title":"Appraisal of seedling stand vegetation with airborne imagery and discrete-return LiDAR\u2014An explanatory analysis","volume":"42","author":"Korpela","year":"2008","journal-title":"Silv. Fenn."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"4702","DOI":"10.3390\/rs70404702","article-title":"Vertical height errors in digital terrain models derived from airborne laser scanner data in a boreal-alpine ecotone in Norway","volume":"7","year":"2015","journal-title":"Remote Sens."},{"key":"ref_17","unstructured":"Kvaalen, H., Solberg, S., and May, J. (2015). Aldersuavhengig Bonitering Med Laserscanning av Enkelttr\u00e6r (Age-Independent Site Quality Classification of Individual Trees Using Laser Scanning), Norwegian Institute of Bioeconomy Research. Available online: http:\/\/www.hdl.handle.net\/11250\/2375817."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"68","DOI":"10.1016\/S0924-2716(99)00011-8","article-title":"Airborne laser scanning\u2014An introduction and overview","volume":"54","author":"Wehr","year":"1999","journal-title":"ISPRS J. Photogramm. Remote Sens."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"101","DOI":"10.1080\/01431168508948427","article-title":"Automated measurements of terrain reflection and height variations using an airborne infrared laser system","volume":"6","author":"Schreier","year":"1985","journal-title":"Int. J. Remote Sens."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"255","DOI":"10.1109\/LGRS.2005.850534","article-title":"Study of surface brightness from backscattered laser intensity: Calibration of laser data","volume":"2","author":"Kaasalainen","year":"2005","journal-title":"IEEE Geosci. Remote Sens. Lett."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"325","DOI":"10.1016\/j.isprsjprs.2006.10.006","article-title":"Classifying individual tree species under leaf-off and leaf-on conditions using airborne LiDAR","volume":"61","author":"Brandtberg","year":"2007","journal-title":"ISPRS J. Photogramm. Remote Sens."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"290","DOI":"10.1016\/S0034-4257(03)00008-7","article-title":"Detection and analysis of individual leaf-off tree crowns in small footprint, high sampling density LiDAR data from the eastern deciduous forest in North America","volume":"85","author":"Brandtberg","year":"2003","journal-title":"Remote Sens. Environ."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"415","DOI":"10.1016\/S0034-4257(03)00140-8","article-title":"Identifying species of individual trees using airborne laser scanner","volume":"90","author":"Holmgren","year":"2004","journal-title":"Remote Sens. Environ."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"1537","DOI":"10.1080\/01431160701736471","article-title":"Species identification of individual trees by combining high resolution LiDAR data with multi-spectral images","volume":"29","author":"Holmgren","year":"2008","journal-title":"Int. J. Remote Sens."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"289","DOI":"10.1016\/j.isprsjprs.2005.05.002","article-title":"Airborne laser scanning: Exploratory data analysis indicates potential variables for classification of individual trees or forest stands according to species","volume":"59","author":"Moffiet","year":"2005","journal-title":"ISPRS J. Photogramm. Remote Sens."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"1407","DOI":"10.1080\/01431160701736448","article-title":"Analysis of full waveform LiDAR data for the classification of deciduous and coniferous trees","volume":"29","author":"Reitberger","year":"2008","journal-title":"Int. J. Remote Sens."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"1163","DOI":"10.1016\/j.rse.2009.02.002","article-title":"Classifying species of individual trees by intensity and structure features derived from airborne laser scanner data","volume":"113","year":"2009","journal-title":"Remote Sens. Environ."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"3891","DOI":"10.1016\/j.rse.2008.06.007","article-title":"Mapping of understory lichens with airborne discrete-return LiDAR data","volume":"112","author":"Korpela","year":"2008","journal-title":"Remote Sens. Environ."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"1549","DOI":"10.1016\/j.foreco.2009.07.007","article-title":"Airborne small-footprint discrete-return LiDAR data in the assessment of boreal mire surface patterns, vegetation, and habitats","volume":"258","author":"Korpela","year":"2009","journal-title":"For. Ecol. Manag."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"655","DOI":"10.5589\/m12-053","article-title":"Classifying tree and non-tree echoes from airborne laser scanning in the forest-tundra ecotone","volume":"38","author":"Stumberg","year":"2012","journal-title":"Can. J. Remote Sens."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"264","DOI":"10.5589\/m11-041","article-title":"Detection of small single trees in the forest-tundra ecotone using height values from airborne laser scanning","volume":"37","author":"Thieme","year":"2011","journal-title":"Can. J. Remote Sens."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"4582","DOI":"10.3390\/rs6054582","article-title":"Improving classification of airborne laser scanning echoes in the forest-tundra ecotone using geostatistical and statistical measures","volume":"6","author":"Stumberg","year":"2014","journal-title":"Remote Sens."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"148","DOI":"10.1016\/j.rse.2008.09.001","article-title":"Effects of different sensors, flying altitudes, and pulse repetition frequencies on forest canopy metrics and biophysical stand properties derived from small-footprint airborne laser data","volume":"113","year":"2009","journal-title":"Remote Sens. Environ."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"2210","DOI":"10.1016\/j.rse.2009.06.003","article-title":"Influence of terrain model smoothing and flight and sensor configurations on detection of small pioneer trees in the boreal-alpine transition zone utilizing height metrics derived from airborne scanning lasers","volume":"113","year":"2009","journal-title":"Remote Sens. Environ."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"677","DOI":"10.1080\/02827581.2013.793386","article-title":"Characterizing forest species composition using multiple remote sensing data and inventory approaches","volume":"28","author":"Dalponte","year":"2013","journal-title":"Scand. J. For. Res."},{"key":"ref_36","doi-asserted-by":"crossref","unstructured":"Hauglin, M., and N\u00e6sset, E. (2016). Detection and segmentation of small trees in the forest-tundra ecotone using airborne laser scanning. Remote Sens.","DOI":"10.3390\/rs8050407"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"451","DOI":"10.2307\/1930167","article-title":"The use of distance measures in phytosociological sampling","volume":"37","author":"Cottam","year":"1956","journal-title":"Ecology"},{"key":"ref_38","unstructured":"Terrasolid (2014). TerraMatch User\u2019s Guide, Terrasolid Ltd.. Available online: http:\/\/www.terrasolid.com\/download\/tmatch.pdf."},{"key":"ref_39","unstructured":"Blom (2007). Rapport BNO07757, Veggli, Blom Geomatics As. (Project Report to Client, Unpublished)."},{"key":"ref_40","unstructured":"Terrasolid TerraScan User\u2019s Guide. Available online: https:\/\/www.terrasolid.com\/download\/tscan.pdf."},{"key":"ref_41","first-page":"111","article-title":"Dem generation from laser scanner data using adaptive tin models","volume":"33","author":"Axelsson","year":"2000","journal-title":"Int. Arch. Photogramm. Remote Sens. Spat. Inf. Sci."},{"key":"ref_42","first-page":"77","article-title":"Calibration of the Optech ALTM 3100 laser scanner intensity data using brightness targets","volume":"36","author":"Ahokas","year":"2006","journal-title":"Int. Arch. Photogramm. Remote Sens. Spat. Inf. Sci."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"369","DOI":"10.1016\/j.isprsjprs.2010.04.003","article-title":"Range and AGC normalization in airborne discrete-return LiDAR intensity data for forest canopies","volume":"65","author":"Korpela","year":"2010","journal-title":"ISPRS J. Photogramm. Remote Sens."},{"key":"ref_44","unstructured":"Oveland, I. Personal communication."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"125","DOI":"10.5589\/m12-021","article-title":"Simultaneously acquired airborne laser scanning and multispectral imagery for individual tree species identification","volume":"38","author":"Gobakken","year":"2012","journal-title":"Can. J. Remote Sens."},{"key":"ref_46","unstructured":"SAS (2007). SAS OnlineDoc\u00ae, Version 9.2, SAS Institute Inc."},{"key":"ref_47","unstructured":"Hosmer, D.W., and Lemeshow, S. (1989). Applied Logistic Regression, John Wiley & Sons, Inc."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"37","DOI":"10.1177\/001316446002000104","article-title":"A coefficient of agreement for nominal scales","volume":"20","author":"Cohen","year":"1960","journal-title":"Educ. Psychol. Meas."},{"key":"ref_49","unstructured":"Bishop, Y.M.M., Fienberg, S.S., and Holland, P.W. (1975). Discrete Multivariate Analysis: Theory and Practice, The MIT Press."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"35","DOI":"10.1016\/0034-4257(91)90048-B","article-title":"A review of assessing the accuracy of classifications of remotely sensed data","volume":"37","author":"Congalton","year":"1991","journal-title":"Remote Sens. Environ."},{"key":"ref_51","doi-asserted-by":"crossref","unstructured":"Miller, R.G. (1981). Simultaneous Statistical Inference, Springer-Verlag. [2nd ed.].","DOI":"10.1007\/978-1-4613-8122-8"},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"71","DOI":"10.1002\/(SICI)1521-4036(199903)41:1<71::AID-BIMJ71>3.0.CO;2-O","article-title":"An improved goodness-of-fit statistic for probability prediction models","volume":"41","author":"Pigeon","year":"1999","journal-title":"Biom. J."},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"980","DOI":"10.1111\/j.1541-0420.2006.00581.x","article-title":"A goodness-of-fit test for multinomial logistic regression","volume":"62","author":"Goeman","year":"2006","journal-title":"Biometrics"},{"key":"ref_54","first-page":"69","article-title":"A quantitative method to test for consistency and correctness in photointerpretation","volume":"49","author":"Congalton","year":"1983","journal-title":"Photogramm. Eng. Remote Sens."},{"key":"ref_55","first-page":"300","article-title":"Utilizing airborne laser intensity for tree species classification","volume":"36","year":"2007","journal-title":"Int. Arch. Photogramm. Remote Sens. Spat. Inf. Sci."},{"key":"ref_56","doi-asserted-by":"crossref","first-page":"522","DOI":"10.1016\/j.foreco.2006.09.072","article-title":"A new empirical approach for estimation in k-tree sampling","volume":"237","author":"Kleinn","year":"2006","journal-title":"For. Ecol. Manag."},{"key":"ref_57","doi-asserted-by":"crossref","first-page":"2994","DOI":"10.1139\/x06-189","article-title":"Poisson mixture models for regression analysis of stand-level mortality","volume":"36","author":"Afflec","year":"2006","journal-title":"Can. J. For. Res."},{"key":"ref_58","doi-asserted-by":"crossref","first-page":"461","DOI":"10.1139\/cjfr-2015-0384","article-title":"Predicting the occurrence of large-diameter trees using airborne laser scanning","volume":"46","author":"Korhonen","year":"2016","journal-title":"Can. J. For. Res."},{"key":"ref_59","doi-asserted-by":"crossref","first-page":"1030","DOI":"10.1111\/j.0006-341X.2000.01030.x","article-title":"Zero-inflated Poisson and binomial regression with random effects: A case study","volume":"56","author":"Hall","year":"2000","journal-title":"Biometrics"},{"key":"ref_60","doi-asserted-by":"crossref","first-page":"2152","DOI":"10.1016\/j.rse.2009.05.019","article-title":"Assessing forest structural and physiological information content of multi-spectral LiDAR waveforms by radiative transfer modelling","volume":"113","author":"Morsdorf","year":"2009","journal-title":"Remote Sens. Environ."},{"key":"ref_61","unstructured":"Van Genechten, B., Caner, H., Heine, W., Garsia, J.L.L., Poelman, R., and Quintero, M.S. (2008). Theory and Practice on Terrestrial Laser Scanning, Flemish Agency of the European Leonardo Da Vinci Program."},{"key":"ref_62","doi-asserted-by":"crossref","first-page":"2229","DOI":"10.1016\/j.rse.2010.04.025","article-title":"Simultaneous measurements of plant structure and chlorophyll content in broadleaf saplings with a terrestrial laser scanner","volume":"114","author":"Eitel","year":"2010","journal-title":"Remote Sens. Environ."}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/8\/7\/548\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T19:25:01Z","timestamp":1760210701000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/8\/7\/548"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2016,6,28]]},"references-count":62,"journal-issue":{"issue":"7","published-online":{"date-parts":[[2016,7]]}},"alternative-id":["rs8070548"],"URL":"https:\/\/doi.org\/10.3390\/rs8070548","relation":{},"ISSN":["2072-4292"],"issn-type":[{"value":"2072-4292","type":"electronic"}],"subject":[],"published":{"date-parts":[[2016,6,28]]}}}