{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,17]],"date-time":"2026-03-17T12:01:58Z","timestamp":1773748918036,"version":"3.50.1"},"reference-count":36,"publisher":"MDPI AG","issue":"5","license":[{"start":{"date-parts":[[2013,4,25]],"date-time":"2013-04-25T00:00:00Z","timestamp":1366848000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/3.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>Airborne remote sensing has an important role to play in mapping and monitoring biodiversity over large spatial scales. Techniques for applying this technology to biodiversity mapping have focused on remote species identification of individual crowns; however, this requires collection of a large number of crowns to train a classifier, which may limit the usefulness of this approach in many study regions. Based on the premise that the spectral variation among sites is related to their ecological dissimilarity, we asked whether it is possible to estimate the beta diversity, or turnover in species composition, among sites without the use of training data. We evaluated alternative methods using simulated communities constructed from the spectra of field-identified tree and shrub crowns from an African savanna. A method based on the k-means clustering of crown spectra produced beta diversity estimates (measured as Bray-Curtis dissimilarity) among sites with an average pairwise correlation of ~0.5 with the true beta  diversity, compared to an average correlation of ~0.8 obtained by a supervised species classification approach. When applied to savanna landscapes, the unsupervised clustering  method produced beta diversity estimates similar to those obtained from supervised classification. The unsupervised method proposed here can be used to estimate the spatial structure of species turnover in a landscape when training data (e.g., tree crowns) are unavailable, providing top-down information for science, conservation and ecosystem management applications.<\/jats:p>","DOI":"10.3390\/rs5052057","type":"journal-article","created":{"date-parts":[[2013,4,25]],"date-time":"2013-04-25T10:35:11Z","timestamp":1366886111000},"page":"2057-2071","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":56,"title":["Estimating Vegetation Beta Diversity from Airborne Imaging Spectroscopy and Unsupervised Clustering"],"prefix":"10.3390","volume":"5","author":[{"given":"Claire","family":"Baldeck","sequence":"first","affiliation":[{"name":"Department of Global Ecology, Carnegie Institution for Science, 260 Panama St., Stanford, CA 94305, USA"}]},{"given":"Gregory","family":"Asner","sequence":"additional","affiliation":[{"name":"Department of Global Ecology, Carnegie Institution for Science, 260 Panama St., Stanford, CA 94305, USA"}]}],"member":"1968","published-online":{"date-parts":[[2013,4,25]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"299","DOI":"10.1016\/S0169-5347(03)00071-5","article-title":"From space to species: Ecological applications for remote sensing","volume":"18","author":"Kerr","year":"2003","journal-title":"Trends Ecol. Evol"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"306","DOI":"10.1016\/S0169-5347(03)00070-3","article-title":"Remote sensing for biodiversity science and conservation","volume":"18","author":"Turner","year":"2003","journal-title":"Trends Ecol. Evol"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"203","DOI":"10.1177\/0309133308093606","article-title":"Measuring and modeling biodiversity from space","volume":"32","author":"Gillespie","year":"2008","journal-title":"Progr. Phys. Geogr"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"147","DOI":"10.1016\/S0304-3800(00)00354-9","article-title":"Predictive habitat distribution models in ecology","volume":"135","author":"Guisan","year":"2000","journal-title":"Ecol. Model"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"37","DOI":"10.1016\/j.ecolmodel.2005.11.007","article-title":"Mapping the species richness and composition of tropical forests from remotely sensed data with neural networks","volume":"195","author":"Foody","year":"2006","journal-title":"Ecol. Model"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"536","DOI":"10.1007\/s10021-007-9041-z","article-title":"Hyperspectral remote sensing of canopy biodiversity in Hawaiian lowland rainforests","volume":"10","author":"Carlson","year":"2007","journal-title":"Ecosystems"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"423","DOI":"10.1016\/j.rse.2007.03.018","article-title":"Effects of spatial and spectral resolution in estimating ecosystem \u03b1-diversity by satellite imagery","volume":"111","author":"Rocchini","year":"2007","journal-title":"Remote Sens. Environ"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"2000","DOI":"10.1016\/j.rse.2008.01.008","article-title":"Modeling distribution of Amazonian tree species and diversity using remote sensing measurements","volume":"112","author":"Saatchi","year":"2008","journal-title":"Remote Sens. Environ"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"352","DOI":"10.1890\/1051-0761(2003)013[0352:LFPWSH]2.0.CO;2","article-title":"Linking floristic patterns with soil heterogeneity and satellite imagery in Ecuadorian Amazonia","volume":"13","author":"Tuomisto","year":"2003","journal-title":"Ecol. Appl"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"429","DOI":"10.1111\/j.1654-109X.2009.01037.x","article-title":"Mapping continuous fields of forest alpha and beta diversity","volume":"12","author":"Feilhauer","year":"2009","journal-title":"Appl. Veg. Sci"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"2635","DOI":"10.1080\/01431160600954712","article-title":"Distance decay in spectral space in analyzing ecosystem \u03b2-diversity","volume":"28","author":"Rocchini","year":"2007","journal-title":"Int. J. Remote Sens"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"279","DOI":"10.2307\/1943563","article-title":"Vegetation of the Siskiyou mountains, Oregon and California","volume":"30","author":"Whittaker","year":"1960","journal-title":"Ecol. Monogr"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"252","DOI":"10.1111\/j.1472-4642.2007.00341.x","article-title":"Using generalized dissimilarity modelling to analyse and predict patterns of beta diversity in regional biodiversity assessment","volume":"13","author":"Ferrier","year":"2007","journal-title":"Divers. Distrib"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"375","DOI":"10.1016\/j.rse.2005.03.009","article-title":"Hyperspectral discrimination of tropical rain forest tree species at leaf to crown scales","volume":"96","author":"Clark","year":"2005","journal-title":"Remote Sens. Environ"},{"key":"ref_15","first-page":"1","article-title":"Tree species discrimination in tropical forests using airborne imaging spectroscopy","volume":"99","author":"Asner","year":"2012","journal-title":"IEEE Trans. Geosci. Remote. Sens"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"167","DOI":"10.1016\/j.isprsjprs.2012.03.005","article-title":"Classification of savanna tree species, in the Greater Kruger National Park region, by integrating hyperspectral and LiDAR data in a random forest data mining environment","volume":"69","author":"Naidoo","year":"2012","journal-title":"ISPRS J. Photogramm"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"3462","DOI":"10.3390\/rs4113462","article-title":"Mapping savanna tree species at ecosystem scales using support vector machine classification and BRDF correction on airborne hyperspectral and LiDAR data","volume":"4","author":"Colgan","year":"2012","journal-title":"Remote Sens"},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"Baldeck, C.A., Colgan, M.S., F\u00e9ret, J.-B., Levick, S.R., Martin, R.E., and Asner, G.P. (2013). Landscape-scale variation in plant community composition of an African savanna from airborne species mapping. Ecol. Appl., in review.","DOI":"10.1890\/13-0307.1"},{"key":"ref_19","unstructured":"Palmer, M.W., Wohlgemuth, T., Earls, P., Ar\u00e9valo, J.R., and Thompson, S.D. (1999, January 22\u201329). Opportunities for Long-Term Ecological Research at the Tallgrass Prairie Preserve, Oklahoma. Budapest, Hungary."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"121","DOI":"10.1002\/env.516","article-title":"Quantitative tools for perfecting species lists","volume":"13","author":"Palmer","year":"2002","journal-title":"Environmetrics"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"013536","DOI":"10.1117\/1.2794018","article-title":"Carnegie Airborne Observatory: In-flight fusion of hyperspectral imaging and waveform light detection and ranging for three-dimensional studies of ecosystems","volume":"1","author":"Asner","year":"2007","journal-title":"J. Appl. Remote Sens."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"325","DOI":"10.2307\/1942268","article-title":"An ordination of upland forest communities of southern Wisconsin","volume":"27","author":"Bray","year":"1957","journal-title":"Ecol. Monogr."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"1530","DOI":"10.1109\/TGRS.2004.827262","article-title":"Robust support vector method for hyperspectral data classification and knowledge discovery","volume":"42","author":"Moreno","year":"2004","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"1778","DOI":"10.1109\/TGRS.2004.831865","article-title":"Classification of hyperspectral remote sensing images with support vector machines","volume":"42","author":"Melgani","year":"2004","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"247","DOI":"10.1016\/j.isprsjprs.2010.11.001","article-title":"Support vector machines in remote sensing: A review","volume":"66","author":"Mountrakis","year":"2011","journal-title":"ISPRS J. Photogramm."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"9","DOI":"10.4102\/koedoe.v26i1.591","article-title":"Landscapes of the Kruger National Park","volume":"26","author":"Gertenbach","year":"1983","journal-title":"Koedoe"},{"key":"ref_27","unstructured":"Du Toit, J.T., Rogers, K.H., and Biggs, H.C. (2003). The Kruger Experience: Ecology and Management of Savanna Heterogeneity, Island Press."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"125","DOI":"10.1007\/BF02289630","article-title":"The analysis of proximities: Multidimensional scaling with an unknown distance function. I","volume":"27","author":"Shepard","year":"1962","journal-title":"Psychometrika"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1007\/BF02289565","article-title":"Multidimensional scaling by optimizing goodness of fit to a nonmetric hypothesis","volume":"29","author":"Kruskal","year":"1964","journal-title":"Psychometrika"},{"key":"ref_30","unstructured":"Dimitriadou, E., Hornik, K., Leisch, F., Meyer, D., and Weingessel, A. E1071: Miscellaneous Functions of the Department of Statistics (e1071). Available online: http:\/\/CRAN.R-project.org\/package=e1071."},{"key":"ref_31","unstructured":"Oksanen, J., Blanchet, F.G., Kindt, R., Legendre, P., Minchin, P.R., O'Hara, R.B., Simpson, G.L., Solymos, P., Stevens, M.H.H., and Wagner, H. Vegan: Community Ecology Package. R Package version 2.0\u20134. Available online: http:\/\/CRAN.R-project.org\/package=vegan."},{"key":"ref_32","unstructured":"Hijmans, R.J., and van Etten, J. Raster: Geographic Analysis and Modeling with Raster Data. R Package Version 2.0\u201312. Available online: http:\/\/CRAN.R-project.org\/package=raster."},{"key":"ref_33","unstructured":"R Development Core Team Available online: http:\/\/www.R-project.org\/."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"269","DOI":"10.1890\/070152","article-title":"Airborne spectranomics: Mapping canopy chemical and taxonomic diversity in tropical forests","volume":"7","author":"Asner","year":"2009","journal-title":"Front. Ecol. Environ."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"2136","DOI":"10.1111\/j.1365-2699.2011.02585.x","article-title":"Geological control of floristic composition in Amazonian forests","volume":"38","author":"Higgins","year":"2011","journal-title":"J. Biogeogr."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"243","DOI":"10.1038\/35012251","article-title":"Systematic conservation planning","volume":"405","author":"Margules","year":"2000","journal-title":"Nature"}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/5\/5\/2057\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T21:46:23Z","timestamp":1760219183000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/5\/5\/2057"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2013,4,25]]},"references-count":36,"journal-issue":{"issue":"5","published-online":{"date-parts":[[2013,5]]}},"alternative-id":["rs5052057"],"URL":"https:\/\/doi.org\/10.3390\/rs5052057","relation":{},"ISSN":["2072-4292"],"issn-type":[{"value":"2072-4292","type":"electronic"}],"subject":[],"published":{"date-parts":[[2013,4,25]]}}}