Using high-resolution images to analyze the importance of crown size and competition for the growth of tropical trees
The influence of canopy structure on tropical tree growth has been scantly studied because of the difficulties making field measurements in these dense multi-layered ecosystems. The recent advent of unmanned aerial vehicles (UAVs), has made it easier to collect canopy data, so offering a way to gain a better understanding of forest productivity and thereby improve forest management. In this study, we assessed tree growth prediction using UAV-derived crown measurements as an alternative for field data. Four experimental 9 ha plots were sampled in two forest sites, Yoko in the Democratic Republic of the Congo and Loundoungou in the Republic of Congo. Field inventories were made between 2015 and 2020. For each tree, we computed the diameter increment (DBHI) using censuses and diameter-based competition indices (diameter-based CIs) using the first census. High-resolution orthoimages and digital surface models were acquired with UAVs in 2016 and 2018 in the two sites. They gave estimates of crown characteristics (size, relative elevation, shape) and crown-based competition indices (crown-based CIs). Co-recorded UAV and field measurements were obtained for 1558 trees. The diameter increment of these trees was then modelled using supervised component generalized linear regression, and 20 % of trees were kept for cross-validation. Combined field and UAV data predicted tree DBHI twice better than either taken separately. Diameter at breast height (DBH) and crown area (CA) were found to be complementary predictors. Crown-based CIs significantly improved predictions of models already containing DBH and CA. Adding diameter-based CIs to models containing DBH, CA, and crown-based CIs only marginally improved growth predictions, showing that tree competition can be well-described with UAV data. The model calibrated at one site predicted the growth at the other site well, suggesting that a general model could be devised for multiple sites. Growth variance was better explained in the site (Yoko) where the crown density was higher and the crown smaller. Further data are now needed from multiple sites with ranging stand structures and compositions to build a general model.
Main Authors: | , , , , , , , , , |
---|---|
Format: | article biblioteca |
Language: | eng |
Subjects: | K01 - Foresterie - Considérations générales, U30 - Méthodes de recherche, accroissement du diamètre, Houppier, croissance, aménagement forestier, mesure (activité), forêt tropicale, structure du peuplement, analyse d'image, écologie forestière, http://aims.fao.org/aos/agrovoc/c_34812, http://aims.fao.org/aos/agrovoc/c_16172, http://aims.fao.org/aos/agrovoc/c_3394, http://aims.fao.org/aos/agrovoc/c_16129, http://aims.fao.org/aos/agrovoc/c_4668, http://aims.fao.org/aos/agrovoc/c_24904, http://aims.fao.org/aos/agrovoc/c_34911, http://aims.fao.org/aos/agrovoc/c_36762, http://aims.fao.org/aos/agrovoc/c_3044, http://aims.fao.org/aos/agrovoc/c_8500, |
Online Access: | http://agritrop.cirad.fr/607179/ http://agritrop.cirad.fr/607179/1/ndamiyehe23.pdf |
Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
id |
dig-cirad-fr-607179 |
---|---|
record_format |
koha |
institution |
CIRAD FR |
collection |
DSpace |
country |
Francia |
countrycode |
FR |
component |
Bibliográfico |
access |
En linea |
databasecode |
dig-cirad-fr |
tag |
biblioteca |
region |
Europa del Oeste |
libraryname |
Biblioteca del CIRAD Francia |
language |
eng |
topic |
K01 - Foresterie - Considérations générales U30 - Méthodes de recherche accroissement du diamètre Houppier croissance aménagement forestier mesure (activité) forêt tropicale structure du peuplement analyse d'image écologie forestière http://aims.fao.org/aos/agrovoc/c_34812 http://aims.fao.org/aos/agrovoc/c_16172 http://aims.fao.org/aos/agrovoc/c_3394 http://aims.fao.org/aos/agrovoc/c_16129 http://aims.fao.org/aos/agrovoc/c_4668 http://aims.fao.org/aos/agrovoc/c_24904 http://aims.fao.org/aos/agrovoc/c_34911 http://aims.fao.org/aos/agrovoc/c_36762 http://aims.fao.org/aos/agrovoc/c_3044 http://aims.fao.org/aos/agrovoc/c_8500 K01 - Foresterie - Considérations générales U30 - Méthodes de recherche accroissement du diamètre Houppier croissance aménagement forestier mesure (activité) forêt tropicale structure du peuplement analyse d'image écologie forestière http://aims.fao.org/aos/agrovoc/c_34812 http://aims.fao.org/aos/agrovoc/c_16172 http://aims.fao.org/aos/agrovoc/c_3394 http://aims.fao.org/aos/agrovoc/c_16129 http://aims.fao.org/aos/agrovoc/c_4668 http://aims.fao.org/aos/agrovoc/c_24904 http://aims.fao.org/aos/agrovoc/c_34911 http://aims.fao.org/aos/agrovoc/c_36762 http://aims.fao.org/aos/agrovoc/c_3044 http://aims.fao.org/aos/agrovoc/c_8500 |
spellingShingle |
K01 - Foresterie - Considérations générales U30 - Méthodes de recherche accroissement du diamètre Houppier croissance aménagement forestier mesure (activité) forêt tropicale structure du peuplement analyse d'image écologie forestière http://aims.fao.org/aos/agrovoc/c_34812 http://aims.fao.org/aos/agrovoc/c_16172 http://aims.fao.org/aos/agrovoc/c_3394 http://aims.fao.org/aos/agrovoc/c_16129 http://aims.fao.org/aos/agrovoc/c_4668 http://aims.fao.org/aos/agrovoc/c_24904 http://aims.fao.org/aos/agrovoc/c_34911 http://aims.fao.org/aos/agrovoc/c_36762 http://aims.fao.org/aos/agrovoc/c_3044 http://aims.fao.org/aos/agrovoc/c_8500 K01 - Foresterie - Considérations générales U30 - Méthodes de recherche accroissement du diamètre Houppier croissance aménagement forestier mesure (activité) forêt tropicale structure du peuplement analyse d'image écologie forestière http://aims.fao.org/aos/agrovoc/c_34812 http://aims.fao.org/aos/agrovoc/c_16172 http://aims.fao.org/aos/agrovoc/c_3394 http://aims.fao.org/aos/agrovoc/c_16129 http://aims.fao.org/aos/agrovoc/c_4668 http://aims.fao.org/aos/agrovoc/c_24904 http://aims.fao.org/aos/agrovoc/c_34911 http://aims.fao.org/aos/agrovoc/c_36762 http://aims.fao.org/aos/agrovoc/c_3044 http://aims.fao.org/aos/agrovoc/c_8500 Ndamiyehe Ncutirakiza, Jean-Baptiste Gourlet-Fleury, Sylvie Lejeune, Philippe Bry, Xavier Trottier, Catherine Mortier, Frédéric Fayolle, Adeline Muhashy Habiyaremye, François Ndjele Mianda-Bungi, Léopold Ligot, Gauthier Using high-resolution images to analyze the importance of crown size and competition for the growth of tropical trees |
description |
The influence of canopy structure on tropical tree growth has been scantly studied because of the difficulties making field measurements in these dense multi-layered ecosystems. The recent advent of unmanned aerial vehicles (UAVs), has made it easier to collect canopy data, so offering a way to gain a better understanding of forest productivity and thereby improve forest management. In this study, we assessed tree growth prediction using UAV-derived crown measurements as an alternative for field data. Four experimental 9 ha plots were sampled in two forest sites, Yoko in the Democratic Republic of the Congo and Loundoungou in the Republic of Congo. Field inventories were made between 2015 and 2020. For each tree, we computed the diameter increment (DBHI) using censuses and diameter-based competition indices (diameter-based CIs) using the first census. High-resolution orthoimages and digital surface models were acquired with UAVs in 2016 and 2018 in the two sites. They gave estimates of crown characteristics (size, relative elevation, shape) and crown-based competition indices (crown-based CIs). Co-recorded UAV and field measurements were obtained for 1558 trees. The diameter increment of these trees was then modelled using supervised component generalized linear regression, and 20 % of trees were kept for cross-validation. Combined field and UAV data predicted tree DBHI twice better than either taken separately. Diameter at breast height (DBH) and crown area (CA) were found to be complementary predictors. Crown-based CIs significantly improved predictions of models already containing DBH and CA. Adding diameter-based CIs to models containing DBH, CA, and crown-based CIs only marginally improved growth predictions, showing that tree competition can be well-described with UAV data. The model calibrated at one site predicted the growth at the other site well, suggesting that a general model could be devised for multiple sites. Growth variance was better explained in the site (Yoko) where the crown density was higher and the crown smaller. Further data are now needed from multiple sites with ranging stand structures and compositions to build a general model. |
format |
article |
topic_facet |
K01 - Foresterie - Considérations générales U30 - Méthodes de recherche accroissement du diamètre Houppier croissance aménagement forestier mesure (activité) forêt tropicale structure du peuplement analyse d'image écologie forestière http://aims.fao.org/aos/agrovoc/c_34812 http://aims.fao.org/aos/agrovoc/c_16172 http://aims.fao.org/aos/agrovoc/c_3394 http://aims.fao.org/aos/agrovoc/c_16129 http://aims.fao.org/aos/agrovoc/c_4668 http://aims.fao.org/aos/agrovoc/c_24904 http://aims.fao.org/aos/agrovoc/c_34911 http://aims.fao.org/aos/agrovoc/c_36762 http://aims.fao.org/aos/agrovoc/c_3044 http://aims.fao.org/aos/agrovoc/c_8500 |
author |
Ndamiyehe Ncutirakiza, Jean-Baptiste Gourlet-Fleury, Sylvie Lejeune, Philippe Bry, Xavier Trottier, Catherine Mortier, Frédéric Fayolle, Adeline Muhashy Habiyaremye, François Ndjele Mianda-Bungi, Léopold Ligot, Gauthier |
author_facet |
Ndamiyehe Ncutirakiza, Jean-Baptiste Gourlet-Fleury, Sylvie Lejeune, Philippe Bry, Xavier Trottier, Catherine Mortier, Frédéric Fayolle, Adeline Muhashy Habiyaremye, François Ndjele Mianda-Bungi, Léopold Ligot, Gauthier |
author_sort |
Ndamiyehe Ncutirakiza, Jean-Baptiste |
title |
Using high-resolution images to analyze the importance of crown size and competition for the growth of tropical trees |
title_short |
Using high-resolution images to analyze the importance of crown size and competition for the growth of tropical trees |
title_full |
Using high-resolution images to analyze the importance of crown size and competition for the growth of tropical trees |
title_fullStr |
Using high-resolution images to analyze the importance of crown size and competition for the growth of tropical trees |
title_full_unstemmed |
Using high-resolution images to analyze the importance of crown size and competition for the growth of tropical trees |
title_sort |
using high-resolution images to analyze the importance of crown size and competition for the growth of tropical trees |
url |
http://agritrop.cirad.fr/607179/ http://agritrop.cirad.fr/607179/1/ndamiyehe23.pdf |
work_keys_str_mv |
AT ndamiyehencutirakizajeanbaptiste usinghighresolutionimagestoanalyzetheimportanceofcrownsizeandcompetitionforthegrowthoftropicaltrees AT gourletfleurysylvie usinghighresolutionimagestoanalyzetheimportanceofcrownsizeandcompetitionforthegrowthoftropicaltrees AT lejeunephilippe usinghighresolutionimagestoanalyzetheimportanceofcrownsizeandcompetitionforthegrowthoftropicaltrees AT bryxavier usinghighresolutionimagestoanalyzetheimportanceofcrownsizeandcompetitionforthegrowthoftropicaltrees AT trottiercatherine usinghighresolutionimagestoanalyzetheimportanceofcrownsizeandcompetitionforthegrowthoftropicaltrees AT mortierfrederic usinghighresolutionimagestoanalyzetheimportanceofcrownsizeandcompetitionforthegrowthoftropicaltrees AT fayolleadeline usinghighresolutionimagestoanalyzetheimportanceofcrownsizeandcompetitionforthegrowthoftropicaltrees AT muhashyhabiyaremyefrancois usinghighresolutionimagestoanalyzetheimportanceofcrownsizeandcompetitionforthegrowthoftropicaltrees AT ndjelemiandabungileopold usinghighresolutionimagestoanalyzetheimportanceofcrownsizeandcompetitionforthegrowthoftropicaltrees AT ligotgauthier usinghighresolutionimagestoanalyzetheimportanceofcrownsizeandcompetitionforthegrowthoftropicaltrees |
_version_ |
1807170493794484224 |
spelling |
dig-cirad-fr-6071792024-08-05T07:09:36Z http://agritrop.cirad.fr/607179/ http://agritrop.cirad.fr/607179/ Using high-resolution images to analyze the importance of crown size and competition for the growth of tropical trees. Ndamiyehe Ncutirakiza Jean-Baptiste, Gourlet-Fleury Sylvie, Lejeune Philippe, Bry Xavier, Trottier Catherine, Mortier Frédéric, Fayolle Adeline, Muhashy Habiyaremye François, Ndjele Mianda-Bungi Léopold, Ligot Gauthier. 2024. Forest Ecology and Management, 552:121553, 21 p.https://doi.org/10.1016/j.foreco.2023.121553 <https://doi.org/10.1016/j.foreco.2023.121553> Using high-resolution images to analyze the importance of crown size and competition for the growth of tropical trees Ndamiyehe Ncutirakiza, Jean-Baptiste Gourlet-Fleury, Sylvie Lejeune, Philippe Bry, Xavier Trottier, Catherine Mortier, Frédéric Fayolle, Adeline Muhashy Habiyaremye, François Ndjele Mianda-Bungi, Léopold Ligot, Gauthier eng 2024 Forest Ecology and Management K01 - Foresterie - Considérations générales U30 - Méthodes de recherche accroissement du diamètre Houppier croissance aménagement forestier mesure (activité) forêt tropicale structure du peuplement analyse d'image écologie forestière http://aims.fao.org/aos/agrovoc/c_34812 http://aims.fao.org/aos/agrovoc/c_16172 http://aims.fao.org/aos/agrovoc/c_3394 http://aims.fao.org/aos/agrovoc/c_16129 http://aims.fao.org/aos/agrovoc/c_4668 http://aims.fao.org/aos/agrovoc/c_24904 http://aims.fao.org/aos/agrovoc/c_34911 http://aims.fao.org/aos/agrovoc/c_36762 http://aims.fao.org/aos/agrovoc/c_3044 République démocratique du Congo http://aims.fao.org/aos/agrovoc/c_8500 The influence of canopy structure on tropical tree growth has been scantly studied because of the difficulties making field measurements in these dense multi-layered ecosystems. The recent advent of unmanned aerial vehicles (UAVs), has made it easier to collect canopy data, so offering a way to gain a better understanding of forest productivity and thereby improve forest management. In this study, we assessed tree growth prediction using UAV-derived crown measurements as an alternative for field data. Four experimental 9 ha plots were sampled in two forest sites, Yoko in the Democratic Republic of the Congo and Loundoungou in the Republic of Congo. Field inventories were made between 2015 and 2020. For each tree, we computed the diameter increment (DBHI) using censuses and diameter-based competition indices (diameter-based CIs) using the first census. High-resolution orthoimages and digital surface models were acquired with UAVs in 2016 and 2018 in the two sites. They gave estimates of crown characteristics (size, relative elevation, shape) and crown-based competition indices (crown-based CIs). Co-recorded UAV and field measurements were obtained for 1558 trees. The diameter increment of these trees was then modelled using supervised component generalized linear regression, and 20 % of trees were kept for cross-validation. Combined field and UAV data predicted tree DBHI twice better than either taken separately. Diameter at breast height (DBH) and crown area (CA) were found to be complementary predictors. Crown-based CIs significantly improved predictions of models already containing DBH and CA. Adding diameter-based CIs to models containing DBH, CA, and crown-based CIs only marginally improved growth predictions, showing that tree competition can be well-described with UAV data. The model calibrated at one site predicted the growth at the other site well, suggesting that a general model could be devised for multiple sites. Growth variance was better explained in the site (Yoko) where the crown density was higher and the crown smaller. Further data are now needed from multiple sites with ranging stand structures and compositions to build a general model. article info:eu-repo/semantics/article Journal Article info:eu-repo/semantics/publishedVersion http://agritrop.cirad.fr/607179/1/ndamiyehe23.pdf text Cirad license info:eu-repo/semantics/restrictedAccess https://agritrop.cirad.fr/mention_legale.html https://doi.org/10.1016/j.foreco.2023.121553 10.1016/j.foreco.2023.121553 info:eu-repo/semantics/altIdentifier/doi/10.1016/j.foreco.2023.121553 info:eu-repo/semantics/altIdentifier/purl/https://doi.org/10.1016/j.foreco.2023.121553 info:eu-repo/grantAgreement/////(EU) FOrmation, Recherche, Environnement dans la TShopo/FORETS |