Accuracy and limitations for spectroscopic prediction of leaf traits in seasonally dry tropical environments

dc.contributor.authorStreher, Annia Susin [UNESP]
dc.contributor.authorTorres, Ricardo da Silva
dc.contributor.authorMorellato, Leonor Patrícia Cerdeira [UNESP]
dc.contributor.authorSilva, Thiago Sanna Freire
dc.contributor.institutionUniversidade Estadual Paulista (Unesp)
dc.contributor.institutionNTNU - Norwegian University of Science and Technology
dc.contributor.institutionUniversity of Stirling. Stirling
dc.date.accessioned2020-12-12T02:39:40Z
dc.date.available2020-12-12T02:39:40Z
dc.date.issued2020-07-01
dc.description.abstractGeneralized assessments of the accuracy of spectroscopic estimates of ecologically important leaf traits such as leaf mass per area (LMA) and leaf dry matter content (LDMC) are still lacking for most ecosystems, and particularly for non-forested and/or seasonally dry tropical vegetation. Here, we tested the ability of using leaf reflectance spectra to estimate LMA and LDMC and classify plant growth forms within the cerrado and campo rupestre seasonally dry non-forest vegetation types of Southeastern Brazil, filling an existing gap in published assessments of leaf optical properties and plant traits in such environments. We measured leaf reflectance spectra from 1648 individual plants comprising grasses, herbs, shrubs, and trees, developed partial least squares regression (PLSR) models linking LMA and LDMC to leaf spectra (400–2500 nm), and identified the spectral regions with the greatest discriminatory power among growth forms using Bhattacharyya distances. We accurately predicted leaf functional traits and identified different growth forms. LMA was overall more accurately predicted (RMSE = 8.58%) than LDMC (RMSE = 9.75%). Our model including all sampled plants was not biased towards any particular growth form, but growth-form specific models yielded higher accuracies and showed that leaf traits from woody plants can be more accurately estimated than for grasses and forbs, independently of the trait measured. We observed a large range of LMA values (31.80–620.81 g/m2) rarely observed in tropical or temperate forests, and demonstrated that values above 300 g/m2 could not be accurately estimated. Our results suggest that spectroscopy may have an intrinsic saturation point, and/or that PLSR, the current approach of choice for estimating traits from plant spectra, is not able to model the entire range of LMA values. This finding has very important implications to our ability to use field, airborne, and orbital spectroscopic methods to derive generalizable functional information. We thus highlight the need for increasing spectroscopic sampling and research efforts in drier non-forested environments, where environmental pressures lead to leaf adaptations and allocation strategies that are very different from forested ecosystems. Our findings also confirm that leaf reflectance spectra can provide important information regarding differences in leaf metabolism, structure, and chemical composition. Such information enabled us to accurately discriminate plant growth forms in these environments regardless of lack of variation in leaf economic traits, encouraging further adoption of remote sensing methods by ecologists and allowing a more comprehensive assessment of plant functional diversity.en
dc.description.affiliationUniversidade Estadual Paulista (Unesp) Instituto de Biociências Departamento de Biodiversidade
dc.description.affiliationDepartment of ICT and Natural Sciences NTNU - Norwegian University of Science and Technology
dc.description.affiliationUniversidade Estadual Paulista (Unesp) Instituto de Biociências Departamento de Biodiversidade Phenology Lab
dc.description.affiliationBiological and Environmental Sciences Faculty of Natural Resources University of Stirling. Stirling
dc.description.affiliationUnespUniversidade Estadual Paulista (Unesp) Instituto de Biociências Departamento de Biodiversidade
dc.description.affiliationUnespUniversidade Estadual Paulista (Unesp) Instituto de Biociências Departamento de Biodiversidade Phenology Lab
dc.description.sponsorshipConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
dc.description.sponsorshipFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
dc.description.sponsorshipIdFAPESP: 2009/54208-6
dc.description.sponsorshipIdFAPESP: 2013/50155-0
dc.description.sponsorshipIdFAPESP: 2015/17534-3
dc.description.sponsorshipIdFAPESP: 2016/00757-2
dc.description.sponsorshipIdFAPESP: 2017/01912-4
dc.description.sponsorshipIdCNPq: 307560/2016-3
dc.description.sponsorshipIdCNPq: 310144/2015-9
dc.description.sponsorshipIdCNPq: 310761/2014-0
dc.description.sponsorshipIdCNPq: 311820/2018-2
dc.description.sponsorshipIdCNPq: 400717/2013-1
dc.identifierhttp://dx.doi.org/10.1016/j.rse.2020.111828
dc.identifier.citationRemote Sensing of Environment, v. 244.
dc.identifier.doi10.1016/j.rse.2020.111828
dc.identifier.issn0034-4257
dc.identifier.scopus2-s2.0-85083648546
dc.identifier.urihttp://hdl.handle.net/11449/201704
dc.language.isoeng
dc.relation.ispartofRemote Sensing of Environment
dc.sourceScopus
dc.subjectCerrado
dc.subjectLDMC
dc.subjectLeaf spectroscopy
dc.subjectLMA
dc.subjectPartial least squares regression (PLSR)
dc.subjectPlant functional traits, campo rupestre
dc.titleAccuracy and limitations for spectroscopic prediction of leaf traits in seasonally dry tropical environmentsen
dc.typeArtigo
unesp.author.orcid0000-0002-9276-7289[1]

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