Article
Forestry
Heloisa Guimaraes Santos, Flavia Maria Avelar Goncalves, Jose Luis Lima, Aurelio Mendes Aguiar, Gabriel Dehon Sampaio Pecanha Rezende, Bruno Marco de Lima, Magno Antonio Patto Ramalho
Summary: The study analyzed seven eucalyptus trials in four Brazilian states to determine the influence of neighboring plants on clone performance in single-tree plots. The research found that clone performances were not affected by neighboring plants. Adjustments for missing and dominated trees did not increase experimental accuracy or alter clone ranking, suggesting their use was not justified.
JOURNAL OF FORESTRY RESEARCH
(2021)
Article
Plant Sciences
Joannes Guillemot, Veronica Asensio, Bruno Bordron, Yann Nouvellon, Guerric le Maire, Jean-Pierre Bouillet, Jean-Christophe Domec, Juan Sinforiano Delgado Rojas, Cassio Hamilton Abreu-Junior, Patricia Battie-Laclau, Ivan Cornut, Amandine Germon, Jose Leonardo De Moraes Goncalves, Agnes Robin, Jean-Paul Laclau
Summary: The application of potassium fertilization in tropical plantations can increase tree growth, but it may also reduce the hydraulic compensation to growth, potentially increasing the risk of drought-induced dieback under climate change.
PLANT CELL AND ENVIRONMENT
(2021)
Article
Forestry
Carlos A. Gonzalez-Benecke, M. Paulina Fernandez, Jorge Gayoso, Matias Pincheira, Maxwell G. Wightman
Summary: Accurate estimation of tree diameter, height, volume, and biomass is crucial for economic and ecological applications. This study presents exponential equations for predicting these parameters in planted stands of different tree species using varying levels of input data. The models perform well, especially when height and crown area are known, and can be applied across a wide range of ages and densities.
Article
Agriculture, Multidisciplinary
Alessandra Morais Melo, Cristiano Rodrigues Reis, Bruno Ferraz Martins, Tamires Mousslech Andrade Penido, Luiz Carlos Estraviz Rodriguez, Eric Bastos Gorgens
Summary: This study developed an approach to discriminate the presence or absence of understory in eucalyptus plantations based on airborne laser scanning surveys. The bimodal canopy height profile accurately distinguished the presence or absence of understory, with a logistic model showing high values of accuracy and kappa. Weibull parameters were effective in identifying the presence and absence of understory in eucalyptus plantations.
Article
Environmental Sciences
Jinlong Zang, Wenjian Ni, Yongguang Zhang
Summary: Oil palm is an efficient oil-producing crop, but its expansion leads to deforestation. Estimating the height of oil palm is crucial for understanding forest damage and carbon stock. This study proposes a method that combines ICESat-2 footprint data with stand age to map oil palm height at a regional scale. The results show significant increases in oil palm height over the past two decades in Peninsular Malaysia.
REMOTE SENSING OF ENVIRONMENT
(2023)
Article
Forestry
Rui Yang, Jinghui Meng
Summary: This study applied non-parametric machine learning methods to model the site index of Masson pine and compared the performance of different modeling approaches and variables. The results indicated that the LightGBM model had the highest accuracy and that soil physicochemical properties were the most important factors affecting the site index.
Article
Forestry
Guillermo Federico Olmedo, Horacio Gilabert, Horacio Bown, Rebeca Sanhueza, Pia Silva, Carlos Jorquera-Stuardo, Francisco Sierra
Summary: Forest plantations play a significant role in carbon sequestration and greenhouse gas mitigation, but forest fires can greatly reduce their capability. This study aims to estimate the carbon loss factor for major plantation species in Chile, namely Pinus radiata, Eucalyptus nitens, and Eucalyptus globulus, across different ages and fire severities. By assessing biomass loss after forest fires in 2018-2019, a model was developed to predict biomass loss and associated emissions.
Article
Forestry
Wagner Squizani, Betania Vahl de Paula, Lincon Stefanello, Danilo Eduardo Rozane, Elias Frank de Araujo, William Natale, Gustavo Brunetto
Summary: This study aimed to investigate the nutritional status of Eucalyptus plantations in Brazil using the CND method. Nutrient concentration in leaves and the diameter at breast height (DBH) were measured, and the nutritional status of E. saligna was calculated. The CND method provided more accurate recommendations compared to univariate and bivariate methods, leading to a reduced use of fertilizers.
CANADIAN JOURNAL OF FOREST RESEARCH
(2023)
Article
Ecology
Qiyu Guo, Shouhang Du, Jinbao Jiang, Wei Guo, Hengqian Zhao, Xuzhe Yan, Yinpeng Zhao, Wanshan Xiao
Summary: This study proposes a new approach to map forest canopy mean height (CMH) and aboveground biomass (AGB) using field measurement data, GEDI LiDAR, sentinel, and terrain data. The CMH and AGB models achieved high accuracy in the study area and showed good transferability to other areas. This method has the potential to be used for large-scale forest mapping.
ECOLOGICAL INFORMATICS
(2023)
Article
Forestry
Cecilia Alonso-Rego, Paulo Fernandes, Juan Gabriel Alvarez-Gonzalez, Stefano Arellano-Perez, Ana Daria Ruiz-Gonzalez
Summary: This study developed equation systems to estimate dead ladder fuels in Pinus radiata stands based on tree-level and stand-level models. The estimates were found to be robust and accurate, providing valuable information for reducing crown-fire hazards in pine forests.
Article
Plant Sciences
Yu Yan, Shengqiang Wang, Yuhong Cui, Chenyang Jiang, Jiazhen Deng, Mingye Lin, Shaoming Ye
Summary: Studying the impacts of pure Eucalyptus forests and mixed artificial forests on the stability of aggregates and the stoichiometric characteristics of organic carbon, total nitrogen, and total phosphorus is important for understanding the distribution and cycling of soil C-N-P. The results showed that mixed forests had higher stability, OC, TN, and TP contents and stocks compared to pure Eucalyptus forests. Aggregates > 2 mm in size had the greatest contribution to the soil OC, TN, and TP stocks.
JOURNAL OF SOIL SCIENCE AND PLANT NUTRITION
(2023)
Article
Forestry
Yuanchun Li, Huipeng Li, Wei Zhang, Baolin Chen, Lei Yang, Mengfan Li, Jianxiao Zhu, Qiong Cai
Summary: In Chinese pine plantations on the Loess Plateau, thinning was found to promote tree growth, particularly radial growth, while it had no effect on stand biomass. These findings provide valuable guidance for forest management and highlight the importance of reasonable thinning treatments.
Article
Environmental Sciences
Kim Penglase, Tom Lewis, Sanjeev K. Srivastava
Summary: Increased demand for sustainable timber products has led to large investments in agroforestry in Australia. To mitigate the risk of fire in juvenile Pinus plantations, an accurate assessment of understory profiles is needed. current assessment protocols are time-consuming and expensive, therefore, this research project investigates the use of geospatial analysis of drone-derived photographic data as a cost-saving alternative. The method used proved highly applicable to immature forest environments, but less reliable for close canopied older plantations.
Article
Forestry
Joni Waldy, John A. Kershaw, Aaron Weiskittel, Mark J. Ducey
Summary: The study compared two stand-level growth modeling approaches for Eucalyptus hybrid species on Sumatra Island using both time-based and state-space methods. Results showed that dynamic models using either time-based or state-space approaches are adequate for predicting stand parameters to rotation age. Although both methods produced reliable and biologically reasonable predictions, the time-based approach outperformed the state-space approach on various equivalence tests and goodness-of-fit statistics.
CANADIAN JOURNAL OF FOREST RESEARCH
(2021)
Article
Forestry
Wenhua Xiang, Linhua Li, Shuai Ouyang, Wenfa Xiao, Lixiong Zeng, Liang Chen, Pifeng Lei, Xiangwen Deng, Yelin Zeng, Jiangping Fang, David I. Forrester
Summary: The study found that stand age significantly impacts allometric models, with branches and leaves being more sensitive to the environment and most affected by stand age. Stand age-specific allometric equations fit well using DBH and the combined form (DBH*H^2) as predictor variables, and including stand age as a complementary variable improved the fit of generalized allometric equations.
EUROPEAN JOURNAL OF FOREST RESEARCH
(2021)
Article
Biology
Kasper Kansanen, Petteri Packalen, Matti Maltamo, Lauri Mehtatalo
Summary: This study introduces an estimator for population totals in forest surveys based on circular plot sampling, using distance-based detection probabilities derived from stochastic geometry. The estimator is shown to be unbiased for Poisson forests and provides variance estimates and approximate confidence intervals, with simulation results demonstrating lower error values compared to existing methods.
Article
Environmental Sciences
Syed Adnan, Matti Maltamo, Lauri Mehtatalo, Rhei N. L. Ammaturo, Petteri Packalen, Ruben Valbuena
Summary: This study introduces a new mathematical approach by using the Gini coefficient to replace the traditional FHD method in describing the vertical complexity of LiDAR height profiles, with extensions to higher-dimensional variables. The research found differences in the accuracy of LiDAR models in different forest structural types, with implications for estimating forest aboveground biomass.
REMOTE SENSING OF ENVIRONMENT
(2021)
Article
Geochemistry & Geophysics
Janne Raty, Petri Varvia, Lauri Korhonen, Pekka Savolainen, Matti Maltamo, Petteri Packalen
Summary: This study compared single-photon and linear-mode airborne LiDAR for predicting species-specific volumes in forests, and found that the linear-mode Riegl VQ-1560i performed the best.
IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING
(2022)
Article
Forestry
Annika Kangas, Timo P. Pitkanen, Lauri Mehtatalo, Juha Heikkinen
Summary: The volume models used in Finland for the last four decades exhibit illogical behavior for small trees. In recent studies, changes in tree stem form over time and space have been observed, potentially influenced by environmental factors. This research aims to develop new models for volume and taper curves to examine the effects of management and environmental factors, and improve the understanding of stem form changes. The results indicate spatial trends in stem form and significant changes in Lapland, particularly in the lowest part of the stem of large pines.
Article
Forestry
Petteri Packalen, Jacob Strunk, Matti Maltamo, Mari Myllymaki
Summary: In airborne laser scanning (ALS)-based forest inventories, there is often a discrepancy between the circular plot shape used for model fitting and the square shape of population elements used for predictions. This study found that for equal area square and circular plots, there was no evidence of systematic prediction error when a model fitted to one shape was used to predict for the other shape. However, using a model fitted to circular plots to predict for square plots slightly underestimated the root mean square error (RMSE) value.
Article
Forestry
Roope Ruotsalainen, Timo Pukkala, Veli-Pekka Ikonen, Petteri Packalen, Heli Peltola
Summary: This study aimed to reduce the risk of wind damage in forested landscapes by utilizing stand neighbourhood information and terrain elevation information. The results showed that minimizing the differences in canopy height between adjacent stands resulted in homogeneous landscapes and continuous cover management was economically beneficial. The best weighting scheme for calculating the mean canopy height difference between adjacent stands was the deviation between the mean elevation of the boundary and the mean elevation of the terrain within 100 m of the boundary.
Article
Forestry
Parvez Rana, Ulla Mattila, Lauri Mehtaetalo, Jouni Siipilehto, Zhengyang Hou, Qing Xu, Timo Tokola
Summary: In this study, a novel fusion approach combining remote sensing-based models and National Forest Inventory (NFI)-based models was used to predict seedling stand characteristics. The NFI-based models were found to be unreliable, while the RS-based models provided higher accuracy. The fusion procedure improved the accuracy of prediction, and the tending needs of seedling stands were successfully classified and predicted.
CANADIAN JOURNAL OF FOREST RESEARCH
(2023)
Article
Remote Sensing
Fangting Chen, Zhengyang Hou, Svetlana Saarela, Ronald E. McRoberts, Goran Stahl, Annika Kangas, Petteri Packalen, Bo Li, Qing Xu
Summary: Remote sensing has improved forest inventory by using model-based inference to estimate parameters of interest from fine to coarse spatial resolution, facilitating decision making for natural resource management.
INTERNATIONAL JOURNAL OF APPLIED EARTH OBSERVATION AND GEOINFORMATION
(2023)
Article
Forestry
Mari Myllymaki, Sakari Tuominen, Mikko Kuronen, Petteri Packalen, Annika Kangas
Summary: This study investigates the value of metrics computed from tree locations and tree sizes for characterizing the structural naturalness of forests. The study finds that forests evaluated as structurally natural have larger variations in tree size and species composition, as well as a more clustered spatial pattern of trees. However, the link between the inspected metrics and naturalness evaluated in the field is weak.
Article
Forestry
Jouni Siipilehto, Sakari Sarkkola, Yrjo Nuutinen, Lauri Mehtatalo
Summary: Rotation forestry has been the main management practice in Finland, but the existing models are mainly applicable to even-aged stands. With the increasing demand for continuous cover forestry, there is a need for models that can be applied to uneven-aged stands. However, the new height-dbh models have shown less accurate performance compared to the existing models for even-aged stands.
FOREST ECOLOGY AND MANAGEMENT
(2023)
Article
Forestry
Annika Kangas, Mari Myllymaki, Lauri Mehtatalo
Summary: Maps of forest resources and ecosystem services are crucial for decision making at various levels. However, these maps often fail to address uncertainties, leading to vague understanding and potentially incorrect conclusions. This article reviews and tests methods for addressing and visualizing map uncertainties to improve decision making.
Article
Environmental Sciences
J. Kostensalo, L. Mehtatalo, S. Tuominen, P. Packalen, M. Myllymaki
Summary: This study developed a framework for building structurally representative tree maps using airborne laser scanning data and ground measurements, which can accurately map the attributes of forests. Compared to other methods, this approach improves the accuracy of mapping forest attributes.
REMOTE SENSING OF ENVIRONMENT
(2023)
Article
Remote Sensing
Lauri Mehtatalo, Adil Yazigi, Kasper Kansanen, Petteri Packalen, Timo Lahivaara, Matti Maltamo, Mari Myllymaki, Antti Penttinen
Summary: This study discusses methods for estimating tree-level characteristics using a Horvitz-Thompson-like estimator and a new method based on a sequential spatial point process model. The new method showed comparable performance to the HT-like estimator, with lower computational demands, making it attractive for practical use.
INTERNATIONAL JOURNAL OF APPLIED EARTH OBSERVATION AND GEOINFORMATION
(2022)
Article
Forestry
Mikko Kukkonen, Eetu Kotivuori, Matti Maltamo, Lauri Korhonen, Petteri Packalen
Summary: The study proposes a method for predicting tree volumes by species using photogrammetric UAS data and Sentinel-2 images, fitted with models based on airborne laser scanning data. The approach shows promise for species-specific small area forest management inventories in Finland and similar forest conditions where suitable field plots are available.