{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,3]],"date-time":"2026-06-03T22:56:06Z","timestamp":1780527366193,"version":"3.54.1"},"reference-count":46,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2019,1,7]],"date-time":"2019-01-07T00:00:00Z","timestamp":1546819200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001807","name":"Funda\u00e7\u00e3o de Amparo \u00e0 Pesquisa do Estado de S\u00e3o Paulo","doi-asserted-by":"publisher","award":["(#2017\/03867-6"],"award-info":[{"award-number":["(#2017\/03867-6"]}],"id":[{"id":"10.13039\/501100001807","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001807","name":"Funda\u00e7\u00e3o de Amparo \u00e0 Pesquisa do Estado de S\u00e3o Paulo","doi-asserted-by":"publisher","award":["#2016\/05219-9"],"award-info":[{"award-number":["#2016\/05219-9"]}],"id":[{"id":"10.13039\/501100001807","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>Airborne Laser Scanning (ALS) has been considered as a primary source to model the structure and function of a forest canopy through the indicators leaf area index (LAI) and vertical canopy profiles of leaf area density (LAD). However, little is known about the effects of the laser pulse density and the grain size (horizontal binning resolution) of the laser point cloud on the estimation of LAD profiles and their associated LAIs. Our objective was to determine the optimal values for reliable and stable estimates of LAD profiles from ALS data obtained over a dense tropical forest. Profiles were compared using three methods: Destructive field sampling, Portable Canopy profiling Lidar (PCL) and ALS. Stable LAD profiles from ALS, concordant with the other two analytical methods, were obtained when the grain size was less than 10 m and pulse density was high (&gt;15 pulses m\u22122). Lower pulse densities also provided stable and reliable LAD profiles when using an appropriate adjustment (coefficient K). We also discuss how LAD profiles might be corrected throughout the landscape when using ALS surveys of lower density, by calibrating with LAI measurements in the field or from PCL. Appropriate choices of grain size, pulse density and K provide reliable estimates of LAD and associated tree plot demography and biomass in dense forest ecosystems.<\/jats:p>","DOI":"10.3390\/rs11010092","type":"journal-article","created":{"date-parts":[[2019,1,9]],"date-time":"2019-01-09T03:06:06Z","timestamp":1547003166000},"page":"92","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":110,"title":["Optimizing the Remote Detection of Tropical Rainforest Structure with Airborne Lidar: Leaf Area Profile Sensitivity to Pulse Density and Spatial Sampling"],"prefix":"10.3390","volume":"11","author":[{"given":"Danilo Roberti Alves de","family":"Almeida","sequence":"first","affiliation":[{"name":"Department of Forest Sciences, \u201cLuiz de Queiroz\u201d College of Agriculture (USP\/ESALQ), University of S\u00e3o Paulo, Av. P\u00e1dua Dias, 11, Piracicaba 13418-900, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Scott C.","family":"Stark","sequence":"additional","affiliation":[{"name":"Department of Forestry, Michigan State University, East Lansing, MI 48824, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3198-966X","authenticated-orcid":false,"given":"Gang","family":"Shao","sequence":"additional","affiliation":[{"name":"Department of Forestry, Michigan State University, East Lansing, MI 48824, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Juliana","family":"Schietti","sequence":"additional","affiliation":[{"name":"National Institute for Amazon Research (INPA), Av. Andr\u00e9 Ara\u00fajo, 2936, Manaus 69067-375, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0488-6895","authenticated-orcid":false,"given":"Bruce Walker","family":"Nelson","sequence":"additional","affiliation":[{"name":"National Institute for Amazon Research (INPA), Av. Andr\u00e9 Ara\u00fajo, 2936, Manaus 69067-375, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7844-3560","authenticated-orcid":false,"given":"Carlos Alberto","family":"Silva","sequence":"additional","affiliation":[{"name":"US Forest Service (USDA), Rocky Mountain Research Station, RMRS, 1221 South Main Street, Moscow, ID 83843, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2517-0279","authenticated-orcid":false,"given":"Eric Bastos","family":"Gorgens","sequence":"additional","affiliation":[{"name":"Department of Forestry, Federal University of Vales do Jequitinhonha e Mucuri\u2014Campus JK, Rodovia MGT 367\u2014Km 583, n\u00b0 5000, Te\u00f3filo Otoni CEP 69900-056, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ruben","family":"Valbuena","sequence":"additional","affiliation":[{"name":"Department of Plant Sciences, Forest Ecology and Conservation, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK"},{"name":"School of Forest Sciences, University of Eastern Finland, P.O. Box 111, Joensuu, Finland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Daniel de Almeida","family":"Papa","sequence":"additional","affiliation":[{"name":"Department of Forest Sciences, \u201cLuiz de Queiroz\u201d College of Agriculture (USP\/ESALQ), University of S\u00e3o Paulo, Av. P\u00e1dua Dias, 11, Piracicaba 13418-900, Brazil"},{"name":"Embrapa Acre, Rodovia BR-364, km 14, Rio Branco CEP 69900-056, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8245-4062","authenticated-orcid":false,"given":"Pedro Henrique Santin","family":"Brancalion","sequence":"additional","affiliation":[{"name":"Department of Forest Sciences, \u201cLuiz de Queiroz\u201d College of Agriculture (USP\/ESALQ), University of S\u00e3o Paulo, Av. P\u00e1dua Dias, 11, Piracicaba 13418-900, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2019,1,7]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"185","DOI":"10.2307\/2387827","article-title":"Liana biomass and leaf area of a \u201cTierra Firme\u201d forest in the Rio Negro Basin, Venezuela","volume":"15","author":"Putz","year":"1983","journal-title":"Biotropica"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"2403","DOI":"10.1093\/jxb\/erg263","article-title":"Ground-based measurements of leaf area index: A review of methods, instruments and current controversies","volume":"54","year":"2003","journal-title":"J. Exp. Bot."},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Tymen, B., Vincent, G., Courtois, E.A., Heurtebize, J., Dauzat, J., Marechaux, I., and Chave, J. (2017). 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