Article
Plant Sciences
Xiaofeng Wang, Yi Wang, Chaowei Zhou, Lichang Yin, Xiaoming Feng
Summary: Fine monitoring of tree species using UAV data and object-oriented classification at the single tree scale achieved high accuracy in detecting surface fragments, improving classification effects, and avoiding salt and pepper noise compared to traditional methods.
URBAN FORESTRY & URBAN GREENING
(2021)
Article
Ecology
Sercan Gulci, Abdullah E. Akay, Nese Gulci, Inanc Tas
Summary: The use of unmanned aerial vehicles (UAVs) as a useful tool in forestry studies is increasing rapidly, showing an increasing level of precision in the field of forestry. By using UAV-supported measurement data to calculate tree information in three dimensions, forest parameters at plot levels in stands can be quickly revealed.
ECOLOGICAL INFORMATICS
(2021)
Article
Environmental Sciences
Luiz Felipe Ramalho de Oliveira, H. Andrew Lassiter, Ben Wilkinson, Travis Whitley, Peter Ifju, Stephen R. Logan, Gary F. Peter, Jason G. Vogel, Timothy A. Martin
Summary: Unmanned aircraft systems (UAS) have rapidly advanced in technology, allowing for low-cost capture of high-resolution images for deriving three-dimensional photogrammetric point clouds. This study evaluates the quality of three-dimensional datasets from two cameras and one lidar sensor collected over a managed pine stand with different planting densities. The results show that the higher-quality camera photogrammetric data is sufficient for individual tree detection and height determination, but lidar data is best overall. The automated tree detection algorithm performed well with lidar data, but slightly fell short in comparison to manual mensuration within the lidar point cloud.
Article
Multidisciplinary Sciences
Yuta Matsuura, Heming Zhang, Kousuke Nakao, Chang Qiong, Iman Firmansyah, Shin Kawai, Yoshiki Yamaguchi, Tsutomu Maruyama, Hisayoshi Hayashi, Hajime Nobuhara
Summary: This study proposes a high-precision measurement method for conventional crop height measurements using aerial drone images. The method utilizes a drone equipped with a monocular camera and real-time kinematic global navigation satellite system (RTK-GNSS) for real-time processing, and performs high-precision stereo matching based on long-baseline lengths. A new calibration method is also proposed to improve accuracy and speed. The method demonstrated a significant reduction in error rates compared to conventional methods in natural world environments.
SCIENTIFIC REPORTS
(2023)
Article
Plant Sciences
Longfei Zhou, Ran Meng, Yiyang Tan, Zhengang Lv, Yutao Zhao, Binyuan Xu, Feng Zhao
Summary: This study compares the performances of UAV-LiDAR and UAV-DAP approaches in measuring crown-level forest canopy height (FCH) in the urban environment. The results show that non-ground coverage is the main factor affecting the accuracy of the DAP approach in measuring urban FCH.
URBAN FORESTRY & URBAN GREENING
(2022)
Article
Environmental Sciences
Seyed Arvin Fakhri, Hooman Latifi, Kyumars Mohammadi Samani, Zahed Shakeri, Hamed Naghavi, Fabian Ewald Fassnacht
Summary: This study combines UAV photogrammetry and field inventories to assess the relationship between diameter at breast height (DBH) and tree height (H) in pollarded oak trees. The results show that both linear and nonlinear allometric models can accurately describe this relationship, which is stable across oak species. This finding is important for biomass inventory and DBH estimation in stands dominated by pollarded, multi-stem coppice structures.
Article
Forestry
Heather Grybas, Russell G. Congalton
Summary: Unmanned aerial systems (UASs) and structure-from-motion (SfM) image processing can be important tools for sustainable forest management. This study investigated the impact of flight parameters on the accuracy of estimated forest structure and found that flying height does not significantly affect accuracy, while increasing forward overlap can significantly reduce errors.
Article
Ecology
Adrian Pascual, Frederico Tupinamba-Simoes, Tiago de Conto
Summary: The global monitoring of forest structure is supported by satellite data, but different canopy height models may have discrepancies. This study analyzed tree-level data from eucalypt plantations in Brazil and found that certain models did not provide accurate estimates, highlighting the need for further validation and improvement.
ECOLOGICAL INFORMATICS
(2022)
Article
Environmental Sciences
Mei Li, Zengyuan Li, Qingwang Liu, Erxue Chen
Summary: By using ULS and USP data, four kinds of stand heights in plantation forests were estimated using different models. The prediction accuracy of stand heights using USP was comparable to ULS, with Lorey's height having the highest accuracy. The correlation between metrics from ULS and USP increased with height, and canopy height model-based metrics performed slightly better than normalized point cloud-based metrics.
Article
Forestry
Siwen Chen, Yanyun Nian, Zeyu He, Minglu Che
Summary: This study investigated the influence of flight height and point cloud density on tree height estimation in alpine mountainous regions. The results showed that a flight height of 85 m achieved the highest accuracy in tree height estimation, while the lowest accuracy was observed at a height of 175 m. The accuracy of tree height estimation decreased as the point cloud density decreased. A flight height of 145 m was more applicable for maintaining accuracy and safety. A point cloud density of 125-185 pts/m(2) can guarantee tree height estimation accuracy.
Article
Green & Sustainable Science & Technology
Arun Gyawali, Mika Aalto, Jussi Peuhkurinen, Maria Villikka, Tapio Ranta
Summary: Estimating tree height in young forests using remote sensing methods such as LiDAR and DAP is a viable alternative to traditional field measurement approaches, with acceptable error and comparable accuracy.
Article
Environmental Sciences
Qingda Chen, Tian Gao, Jiaojun Zhu, Fayun Wu, Xiufen Li, Deliang Lu, Fengyuan Yu
Summary: Accurate individual tree segmentation is important for forest management and the study of forest ecosystems. This study introduced a new UAV-LiDAR dataset, FULD, which fused leaf-off and leaf-on point clouds, to assess its benefits for tree segmentation and height estimation in dense deciduous forests. The results showed that the combination of FULD and the layer stacking segmentation algorithm produced the highest accuracies across all forest types and improved tree height estimation.
Article
Geography, Physical
Zhenbang Hao, Lili Lin, Christopher J. Post, Elena A. Mikhailova, Minghui Li, Yan Chen, Kunyong Yu, Jian Liu
Summary: This study developed a Mask R-CNN model to automatically detect tree crown and height of Chinese fir in a plantation, achieving high accuracy. Results showed that CHM input images outperformed DSM images for tree crown delineation and height assessment, highlighting the potential of Mask R-CNN in assisting remote sensing applications in forests.
ISPRS JOURNAL OF PHOTOGRAMMETRY AND REMOTE SENSING
(2021)
Article
Environmental Sciences
Xu Tang, Haotian You, Yao Liu, Qixu You, Jianjun Chen
Summary: By using UAV-derived digital elevation models (DEMs) and light detection and ranging (LiDAR) data, the height growth of trees can be accurately estimated on a monthly scale. The study found close correlations between the DEMs based on UAV stereo images and UAV LiDAR, as well as between the canopy height models (CHMs) based on UAV images and measured tree heights. The analysis of monthly height growth estimates revealed significant differences among tree species. These results provide valuable data for correcting growth differences and offer guidance for the time difference correction of other forest structure parameters.
Article
Environmental Sciences
Neal C. Swayze, Wade T. Tinkham, Jody C. Vogeler, Andrew T. Hudak
Summary: This study investigated the use of unmanned aerial system (UAS) imagery for modeling individual tree and stand-level metrics in dry conifer forests. It found that tree extraction accuracy was maximized for nadir crosshatch UAS flight designs, while extracted tree height accuracy was high for all UAS flight parameters. Additionally, stand density estimates were most accurate with off-nadir or crosshatch flight designs at lower altitudes.
REMOTE SENSING OF ENVIRONMENT
(2021)
Article
Forestry
Sophia Etzold, Marco Ferretti, Gert Jan Reinds, Svein Solberg, Arthur Gessler, Peter Waldner, Marcus Schaub, David Simpson, Sue Benham, Karin Hansen, Morten Ingerslev, Mathieu Jonard, Per Erik Karlsson, Antti-Jussi Lindroos, Aldo Marchetto, Miklos Manninger, Henning Meesenburg, Paivi Merila, Pekka Nojd, Pasi Rautio, Tanja G. M. Sanders, Walter Seidling, Mitja Skudnik, Anne Thimonier, Arne Verstraeten, Lars Vesterdal, Monika Vejpustkova, Wim de Vries
FOREST ECOLOGY AND MANAGEMENT
(2020)
Review
Ecology
Fabio Berzaghi, Ian J. Wright, Koen Kramer, Sylvie Oddou-Muratorio, Friedrich J. Bohn, Christopher P. O. Reyer, Santiago Sabate, Tanja G. M. Sanders, Florian Hartig
TRENDS IN ECOLOGY & EVOLUTION
(2020)
Article
Multidisciplinary Sciences
Songhan Wang, Yongguang Zhang, Weimin Ju, Jing M. Chen, Philippe Ciais, Alessandro Cescatti, Jordi Sardans, Ivan A. Janssens, Mousong Wu, Joseph A. Berry, Elliott Campbell, Marcos Fernandez-Martinez, Ramdane Alkama, Stephen Sftch, Pierre Friedlingstein, William K. Smith, Wenping Yuan, Wei He, Danica Lombardozzi, Markus Kautz, Dan Zhu, Sebastian Lienert, Etsushi Kato, Benjamin Poulter, Tanja G. M. Sanders, Inken Kruger, Rong Wang, Ning Zeng, Hanqin Tian, Nicolas Vuichard, Atul K. Jain, Andy Wiltshire, Vanessa Haverd, Daniel S. Goll, Josep Penuelas
Article
Engineering, Civil
Rui Liu, Klaus Greve, Pengyu Cui, Nan Jiang
Summary: This study introduces a method of multi-source data fusion for collaborative navigation, which improves the stability and accuracy of the navigation service. Experimental results demonstrate the advantages of this method in positioning efficiency and precision.
Article
Engineering, Marine
Rui Liu, Klaus Greve, Nan Jiang, Pengyu Cui
Summary: This paper addresses the importance of spatial distribution of collaborative targets and the information collaboration process in real-time collaborative navigation efficiency. By designing a collaborative communication process and analyzing the spatial distribution conditions of collaborative targets, a method based on CGDOP value is proposed for evaluation. A simulated experiment is conducted to evaluate the collaboration effect in different spatial shapes, optimizing navigation data efficiency and improving stability and reliability of real-time navigation service.
JOURNAL OF NAVIGATION
(2021)
Article
Remote Sensing
Ayman Abdel-Hamid, Olena Dubovyk, Klaus Greve
Summary: This study found that InSAR coherence can be used for grasslands monitoring, with higher variability in coherence during non-drought season and higher backscattering coefficient. The regularity of Sentinel-1 data is beneficial for InSAR applications, and the potential will be improved with the availability of Sentinel-1B data.
INTERNATIONAL JOURNAL OF APPLIED EARTH OBSERVATION AND GEOINFORMATION
(2021)
Article
Environmental Sciences
Arun K. Bose, Daniel Scherrer, J. Julio Camarero, Daniel Ziche, Flurin Babst, Christof Bigler, Andreas Bolte, Isabel Dorado-Linan, Sophia Etzold, Patrick Fonti, David I. Forrester, Jordane Gavinet, Antonio Gazol, Ester Gonzalez de Andres, Dirk Nikolaus Karger, Francois Lebourgeois, Mathieu Levesque, Elisabet Martinez-Sancho, Annette Menzel, Burkhard Neuwirth, Manuel Nicolas, Tanja G. M. Sanders, Tobias Scharnweber, Jens Schroder, Roman Zweifel, Arthur Gessler, Andreas Rigling
Summary: Recent studies have shown a strong relationship between delayed recovery of tree growth after drought and subsequent tree mortality, especially with the projected increase in drought frequency and intensity. The growth of trees is more influenced by precipitation and climatic water balance rather than temperature, and the recovery after drought varies depending on the season and climatic factors.
SCIENCE OF THE TOTAL ENVIRONMENT
(2021)
Article
Multidisciplinary Sciences
Jan-Peter George, Tanja G. M. Sanders, Volkmar Timmermann, Nenad Potocic, Mait Lang
Summary: European ash and narrow-leafed ash are important forest tree species that are currently under threat from an invasive fungal pathogen. Studies have shown an increase in crown defoliation and mortality, with differences in survival rate among regions. Excessive water regime and extreme precipitation events have a significant impact on ash survival. Urgent cross-border action is needed to rescue the ash trees.
SCIENTIFIC REPORTS
(2022)
Article
Plant Sciences
Anne Gnilke, Tanja G. M. Sanders
Summary: Capturing forest disturbances over time is crucial for ecosystem recovery and providing timely information to foresters. Large satellite imagery spanning more than two decades represents a valuable data source, but challenges exist in obtaining reliable information and standardizing processing routines. This study investigates forest disturbances using ground validated occurrences in Germany and proposes a workflow based on MODIS EVI time series data.
FRONTIERS IN PLANT SCIENCE
(2022)
Article
Plant Sciences
J-P George, P-C Burkner, T. G. M. Sanders, M. Neumann, C. Cammalleri, J. V. Vogt, M. Lang
Summary: European forests have experienced exceptional droughts in the last two decades, leading to increasing mortality rates in trees and species-specific impacts. Analysis of extensive observational data shows that previous-year soil moisture anomaly is the primary driver of mortality patterns in conifers.
Article
Environmental Studies
Salamatu J. Tannor, Girma Kelboro, Klaus Greve, Christian Borgemeister, Bernhard Tischbein
Summary: The resilience of African rural livelihoods is at risk due to over-reliance on rain-fed agriculture and the impacts of climate variability. This study highlights the interconnectedness of climate variability and extractivism on rural livelihoods, and how contextual factors influence individuals' perceptions of these impacts. It emphasizes the need for policy-makers to include mining landscapes in national adaptation programs.
EXTRACTIVE INDUSTRIES AND SOCIETY
(2022)
Review
Forestry
Shah Rukh, Tanja G. M. Sanders, Inken Krueger, Tobias Schad, Andreas Bolte
Summary: A severe heatwave and drought in 2018 and subsequent years have resulted in significant growth reductions, leaf senescence, browning, and diebacks of European beech trees in Central Europe. These impacts may have long-term consequences, including reduced vitality and potential tree death. It is important to study the short- and long-term effects of defoliation on post-drought growth, and evaluate adaptive forest management strategies to better understand the future of beech trees in Central Europe.
Article
Environmental Sciences
Marian Adan, Henri E. Z. Tonnang, Klaus Greve, Christian Borgemeister, Georg Goergen
Summary: This study utilized time series data and NDVI computed from Landsat 8 imagery to monitor and quantify the damage caused by Fall armyworm in Western and Southern African countries. The results showed a correlation between FAW infestation and a decrease in vegetation productivity. NDVI can be used as a proxy to measure pest damage to vegetation productivity.
GEOCARTO INTERNATIONAL
(2023)
Article
Geosciences, Multidisciplinary
Christopher P. O. Reyer, Ramiro Silveyra Gonzalez, Klara Dolos, Florian Hartig, Ylva Hauf, Matthias Noack, Petra Lasch-Born, Thomas Roetzer, Hans Pretzsch, Henning Meesenburg, Stefan Fleck, Markus Wagner, Andreas Bolte, Tanja G. M. Sanders, Pasi Kolari, Annikki Makela, Timo Vesala, Ivan Mammarella, Jukka Pumpanen, Alessio Collalti, Carlo Trotta, Giorgio Matteucci, Ettore D'Andrea, Lenka Foltynova, Jan Krejza, Andreas Ibrom, Kim Pilegaard, Denis Loustau, Jean-Marc Bonnefond, Paul Berbigier, Delphine Picart, Sebastien Lafont, Michael Dietze, David Cameron, Massimo Vieno, Hanqin Tian, Alicia Palacios-Orueta, Victor Cicuendez, Laura Recuero, Klaus Wiese, Matthias Buechner, Stefan Lange, Jan Volkholz, Hyungjun Kim, Joanna A. Horemans, Friedrich Bohn, Joerg Steinkamp, Alexander Chikalanov, Graham P. Weedon, Justin Sheffield, Flurin Babst, Iliusi Vega del Valle, Felicitas Suckow, Simon Martel, Mats Mahnken, Martin Gutsch, Katja Frieler
EARTH SYSTEM SCIENCE DATA
(2020)
Article
Biology
Josep Penuelas, Marcos Fernandez-Martinez, Helena Vallicrosa, Joan Maspons, Paolo Zuccarini, Jofre Carnicer, Tanja G. M. Sanders, Inken Krueger, Michael Obersteiner, Ivan A. Janssens, Philippe Ciais, Jordi Sardans
COMMUNICATIONS BIOLOGY
(2020)