Hasil untuk "Forestry"

L. Gustafsson, S. Baker, J. Bauhus et al.

F. Tubiello, M. Salvatore, A. Ferrara et al.

J. Baynes, J. Herbohn, Carl S. Smith et al.

Longxiang Shao, Ulrich Dahmen, Juergen Rossmann

Rigid body dynamics simulators are important tools for the design, analysis and optimization of mechanical systems in a variety of technical and scientific applications. This study examines four different simulation environments (Adams, Simscape, OpenModelica, and VEROSIM), focusing in particular on the comparison of the modeling methods, the numerical solvers, and the treatment of numerical problems that arise especially in closed-loop kinematics (esp. redundant boundary conditions and static equilibrium problem). A novel and complex crane boom of a real forestry machine serves as a practical benchmark application example. The direct comparison of the different solution approaches in the examined simulation tools supports the user in selecting the most suitable tool for his application.

ZHANG Lei, YU Ying, ZHAO Yixuan, CHEN Qiang, YANG Ruxing

This study aimed to evaluate the dynamic changes of non-volatile metabolites during green tea processing from the albino tea variety ‘Fuhuang 1’. Green tea was made from one bud with two leaves through three steps: natural drying, fixation and rolling. A total of 2 654 non-volatile metabolites were detected by ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) in the raw material, intermediate products and final product. The total content of non-volatile metabolites showed an upward trend during tea processing. Our analysis showed that fixation was crucial for the conversion of non-volatile metabolites in green tea processing. A total of 292 important differential metabolites were selected before and after fixation, including amino acids and their derivatives (40), flavonoids (37), lipids (101), nucleotides and their derivatives (28), and phenolic acids (21). These metabolites were significantly enriched in pathways such as the biosynthesis of secondary metabolites, carbon metabolism, cysteine and methionine metabolism, arginine biosynthesis, alanine, aspartic acid and glutamic acid metabolism. They were categorized into three clusters by K-Means analysis. The metabolites in the first cluster accumulated significantly during fixation. The metabolites in the second cluster accumulated significantly during fixation and also accumulated during drying, but to a lesser extent. However, the metabolites in the third cluster significantly decreased during fixation. Amino acids and their derivatives accumulated significantly during fixation, especially reduced glutathione, which might be a signature compound of ‘Fuhuang 1’ green tea. Lipids were the most active compounds during green tea processing; their relative contents significantly increased, with lysophosphatidylethanolamine showing the greatest accumulation. Some flavonoids, nucleotides and their derivatives accumulated only during fixation, whereas others accumulated during both fixation and drying. This study provides a theoretical basis for the innovative utilization of tea albino mutants.

Lizhi Wang, Yanli Zhao, Zhihui Jiao et al.

Ongoing climate change is increasing the frequency and magnitude of high-temperature events, and extreme weather events such as heatwaves are expected to become more common. The impacts of extreme temperatures are likely even more severe at higher trophic levels, which depend on the adaptive capacity of lower trophic levels. However, compared with parasitoids at the third trophic level, less is known about these effects on parasitoids at the fourth trophic level, which occupy the terminal end of food chains. This study investigates the effects of experimental heatwave duration variability on the development of two congeneric gregarious larval–pupal endoparasitoids, <i>Oomyzus scaposus</i> and <i>O. spiraculus</i>, parasitizing the seven-spot ladybird, <i>Coccinella septempunctata</i> L. Heatwave treatments negatively affected the brood size of both species. The heatwave also affected the sex ratio of <i>O. scaposus</i>, though it remained highly female-biased. Exposure to heatwaves for 1 h accelerated the development of <i>O. scaposus</i>. For <i>O. scaposus</i>, the body mass of both females and males was lowest under the 3 h heatwave treatment. In contrast, for <i>O. spiraculus</i>, heatwaves had a marginally negative effect on the body mass of both female and male adults, though this effect was not statistically significant. Our results indicate that both species respond similarly, and even daily heatwave exposure of a few hours can affect the performance of <i>O. scaposus</i> and <i>O. spiraculus</i>.

Jennifer E. Helm, Elizabeth G. Simpson, Lorelle I. Berkeley et al.

Abstract Understanding how vegetation management affects animals' habitat selection patterns is critical for comprehensive conservation planning. As part of a decade‐long study (2011–2019) of 486 adult female sage‐grouse in central Montana, we investigated how a conservation‐based grazing program (CGP) affected greater sage‐grouse (Centrocercus urophasianus) habitat selection at two temporal scales: (a) the seasonal scale (four biologically relevant seasons) and (b) the annual scale. We used resource selection functions to assess sage‐grouse selection for pastures enrolled in a CGP as well as plant functional type and topography. We found that sage‐grouse strongly selected shrub cover, flatter slopes, and less tree cover. They selected CGP‐enrolled pastures (Pre‐, During‐, and Post‐grazing system implementation) over Non‐CGP pastures during all seasons except the summer–fall. During the summer–fall, they selected pastures where CGP implementation was complete. Future research is needed to determine whether selection for CGP‐enrolled pastures was due to unmeasured, underlying differences between CGP and non‐CGP pastures or CGP enrollment patterns rather than effects of different grazing systems, as well as whether these habitat selection differences are linked to demographic rates or population dynamics.

Yawen Lu, Zhuoyang Sun, Jinyuan Shao et al.

The popularity of LiDAR devices and sensor technology has gradually empowered users from autonomous driving to forest monitoring, and research on 3D LiDAR has made remarkable progress over the years. Unlike 2D images, whose focused area is visible and rich in texture information, understanding the point distribution can help companies and researchers find better ways to develop point-based 3D applications. In this work, we contribute an unreal-based LiDAR simulation tool and a 3D simulation dataset named LiDAR-Forest, which can be used by various studies to evaluate forest reconstruction, tree DBH estimation, and point cloud compression for easy visualization. The simulation is customizable in tree species, LiDAR types and scene generation, with low cost and high efficiency.

Fabrice Mayran de Chamisso, Loïc Cotten, Valentine Dhers et al.

With the advent of multispectral imagery and AI, there have been numerous works on automatic plant segmentation for purposes such as counting, picking, health monitoring, localized pesticide delivery, etc. In this paper, we tackle the related problem of automatic and selective plant-clearing in a sustainable forestry context, where an autonomous machine has to detect and avoid specific plants while clearing any weeds which may compete with the species being cultivated. Such an autonomous system requires a high level of robustness to weather conditions, plant variability, terrain and weeds while remaining cheap and easy to maintain. We notably discuss the lack of robustness of spectral imagery, investigate the impact of the reference database's size and discuss issues specific to AI systems operating in uncontrolled environments.

Johanna Engman, Karl Åström, Magnus Oskarsson

In this paper we present a method for line segment detection in images, based on a semi-supervised framework. Leveraging the use of a consistency loss based on differently augmented and perturbed unlabeled images with a small amount of labeled data, we show comparable results to fully supervised methods. This opens up application scenarios where annotation is difficult or expensive, and for domain specific adaptation of models. We are specifically interested in real-time and online applications, and investigate small and efficient learning backbones. Our method is to our knowledge the first to target line detection using modern state-of-the-art methodologies for semi-supervised learning. We test the method on both standard benchmarks and domain specific scenarios for forestry applications, showing the tractability of the proposed method.

Lars Nieradzik, Henrike Stephani, Jördis Sieburg-Rockel et al.

Wood species identification plays a crucial role in various industries, from ensuring the legality of timber products to advancing ecological conservation efforts. This paper introduces WoodYOLO, a novel object detection algorithm specifically designed for microscopic wood fiber analysis. Our approach adapts the YOLO architecture to address the challenges posed by large, high-resolution microscopy images and the need for high recall in localization of the cell type of interest (vessel elements). Our results show that WoodYOLO significantly outperforms state-of-the-art models, achieving performance gains of 12.9% and 6.5% in F2 score over YOLOv10 and YOLOv7, respectively. This improvement in automated wood cell type localization capabilities contributes to enhancing regulatory compliance, supporting sustainable forestry practices, and promoting biodiversity conservation efforts globally.

Harish Karunakaran, Gopeshh Raaj Subbaraj

Mobile manipulator systems are comprised of a mobile platform with one or more manipulators and are of great interest in a number of applications such as indoor warehouses, mining, construction, forestry etc. We present an approach for computing actuator commands for such systems so that they can follow desired end-effector and platform trajectories without the violation of the nonholonomic constraints of the system in an indoor warehouse environment. We work with the Fetch robot which consists of a 7-DOF manipulator with a differential drive mobile base to validate our method. The major contributions of our project are, writing the dynamics of the system, Trajectory planning for the manipulator and the mobile base, state machine for the pick and place task and the inverse kinematics of the manipulator. Our results indicate that we are able to successfully implement trajectory control on the mobile base and the manipulator of the Fetch robot.

Sylvain Ambayi Bienu, Tolerant K. Lubalega, Damase P. Khasa et al.

Tropical rainforests play an important role in the global Eco-climatic balance and its sustainable management is a major concern that has attracted the attention of researchers. The Luki biosphere reserve, while under a status of protected area, experiences anthropic pressures without spare. In order to control the activities of local populations and particularly to implement the principles of natural resources management enacted by the Man and Biosphere program of the United Education, Scientific, and Cultural Organization, a zoning plan has been implemented in the Luki biosphere reserve since 1979. The aim of this study was to evaluate the floristic composition, the diversity and structural parameters on floristic groupings of forest tree species in the Luki Biosphere Reserve (LBR) to evaluate whether the implemented zoning has an effect on plant diversity and population structure of forest trees species in the Luki Biosphere Reserve. Floristic data were collected on a set of 15 plots of 1 hectare (ha) each following the management zoning, in which tree species with diameter at breast height (dbh) ≥ 10 cm were measured and identified. Floristic diversity analysis was carried out and the relationship between within plots species richness and physical and chemical properties of soil was established. In total, 6497 individual trees were inventoried belonging to a total of 218 species grouped in 41 families making an average tree density of 433 ± 13 individual per hectare. Two floristic groups emerged from the ordination of species and cluster analysis. Prioria balsamifera and Dialium pachyphyllum were among the most represented and characteristic tree species in the floristics groups. The families Sterculiaceae, Fabaceae, Ebenaceae, Olacaceae, Rubiaceae, Annonaceae, Myristicaceae, Meliaceae and Sapotaceae displayed high values of specific important index. Tree populations from the three zoning displayed an ''inverted J'' shape in an axil distribution of classes of diameters while the horizontal distribution of tree height displayed a bell structure. A significant difference exists in species richness among zones and floristic groupings. The floristics groupings were distributed following the soil texture. This work provides the basic elements for a sustainable management plan adapted with the current zoning plan in the Luki Biosphere Reserve.

Keisuke Toba, Takahisa Nakai, Tomoya Murano

Wood drying, such as boxed-heart square timber, often involves surface checks, which spoils the appearance of wood products and reduces their market value. Pretreatments are performed to avoid the surface checks, but detailed information about surface strain during timber drying remains unclear. In this study, surface strain detections were performed using two types of strain sensors (strain gauge and optical fiber strain sensor) to understand the surface dimensional changes during a series of pretreatments, consisting of steaming and high temperature and low humidity treatment. Simultaneous strain measurements based on the optical fiber sensor grasped the surface strain distributions in each lateral surface during timber drying; contraction behaviors were observed in the middle part of most surfaces in the early steaming stage, while one surface showed expansion. A remarkable expansion was detected in one surface during the high temperature and low humidity treatment, although most of the other surfaces showed gradual contraction behaviors. It was also discovered that the above detected behaviors were gradually reduced with the progress of each pretreatment.

Min Chen, Zhongyu Yan, Lu Han et al.

In the original publication, there is a mistake in Figure 1: A duplication error between 1B and 1C, which occurred due to the similarity of the images of the three nanoparticles [...]

Wenqi Zhang, Dan Jin, Ruizhi Yang

In this paper, a diffusive predator–prey model with a memory effect in predator and anti-predator behaviour in prey is studied. The stability of the coexisting equilibrium and the existence of Hopf bifurcation are analysed by analysing the distribution of characteristic roots. The property of Hopf bifurcation is investigated by the theory of the centre manifold and normal form method. Through the numerical simulations, it is observed that the anti-predator behaviour parameter <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>η</mi></semantics></math></inline-formula>, the memory-based diffusion coefficient parameter <i>d</i>, and memory delay <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>τ</mi></semantics></math></inline-formula> can affect the stability of the coexisting equilibrium under some parameters and cause the spatially inhomogeneous oscillation of prey and predator’s densities.

Romeo Bandinelli, Gabriele Scozzafava, Bianca Bindi et al.

The importance of traceability in food products in regard to consumer preferences, the difficulty of certifications in communicating credence attributes, and concerns about food safety, have led consumers to ask for more information about the credibility of information reported on the label with the product itself, due to the importance of traceability in food products. An objective of this study is to analyze the benefits of implementing blockchain technology in the supply chain for ancient wheat, as a technology capable of sharing reliable information about the products easily along the entire value chain. In particular, the aim is to evaluate how the consumer reacts when confronted with a package of ancient wheat pasta for which all the information on its origin and processing methods is available. In order to achieve these results, a survey based on the Technology Acceptance Model has been developed and conducted in the Italian country. Result indicates the importance of identifying an independent variable that represents the degree of security when faced with a threat that creates a circumstance, condition or event that can lead to economic hardship, for example, data destruction, disclosure, modification, fraud, waste, and abuse. The strength of blockchain lies precisely in its ability to guarantee the immutability of data throughout the supply chain, providing the end consumer with a high-quality product.

XIONG Wen-yu, HE Jun-qiang, DAI Wan-zhen et al.

The main functional components and biological activities of <i>Grifola frondosa</i> were reviewed, and the existing problems and future research directions were also discussed.

Dan-Dan Wang, Wen Zhao, Mumin Reyila et al.

Soil microorganisms play an indispensable role in the forest ecosystem. It is necessary to study the soil microorganisms in <i>Pinus sylvestris</i> var. <i>mongolica</i>, which is one of the afforestation species widely planted in the northern sandy region of China. We collected soil samples of <i>P. sylvestris</i> at large spatial scales and analyzed bacterial and fungal community composition differences using high-throughput sequencing techniques. The results showed that: (1) the richness index of different sandy lands was significantly different. The α-diversity of bacteria was the highest in Mu Us Sandy Land, and the α-diversity of fungi was the highest in Horqin Sandy Land. (2) The dominant phyla of bacteria were Actinobacteria, Proteobacteria, Chloroflexi and Acidobacteria, while the dominant phyla of fungi were Ascomycota and Basidiomycota. The relative abundance of dominant phyla was different. (3) Temperature and precipitation were the main driving factors of bacterial and fungal community change at large spatial scale. In addition, bacteria were also affected by total nitrogen, soil organic carbon and pH content; fungal community was affected by pH. The microorganisms showed obvious differences in geographical distribution, which could provide ideas for promoting sustainable management of <i>P. sylvestris</i> stand.

Muhammad Salman Pathan, Jiantao Wu, Yee Hui Lee et al.

Rainfall is a climatic factor that affects many human activities like agriculture, construction, and forestry. Rainfall is dependent on various meteorological features and its prediction is a very complex task due to the dynamic climatic nature. A detailed study of different climatic features associated with the occurrence of rainfall should be made in order to understand the influence of each parameter in the context of rainfall. In this paper, we propose a methodical approach to analyze the affect of various parameters on rainfall. Our study uses $5$ years of meteorological data from a weather station located in the United States. The correlation and interdependence among the collected meteorological features were obtained. Additionally, we identified the most important meteorological features for rainfall prediction using a machine learning-based feature selection technique.