scholarly journals Detection of Bark Beetle Disturbance at Tree Level Using UAS Multispectral Imagery and Deep Learning

2021 ◽  
Vol 13 (23) ◽  
pp. 4768
Author(s):  
Robert Minařík ◽  
Jakub Langhammer ◽  
Theodora Lendzioch

This study aimed to examine the potential of convolutional neural networks (CNNs) for the detection of individual trees infested by bark beetles in a multispectral high-resolution dataset acquired by an unmanned aerial system (UAS). We compared the performance of three CNN architectures and the random forest (RF) model to classify the trees into four categories: pines, sbbd (longer infested trees when needles turn yellow), sbbg (trees under green attack) and non-infested trees (sh). The best performance was achieved by the Nez4c3b CNN (kappa 0.80) and Safaugu4c3b CNN (kappa 0.76) using only RGB bands. The main misclassifications were between sbbd and sbbg because of the similar spectral responses. Merging sbbd and sbbg into a more general class of infested trees made the selection of model type less important. All tested model types, including RF, were able to detect infested trees with an F-score of the class over 0.90. Nevertheless, the best overall metrics were achieved again by the Safaugu3c3b model (kappa 0.92) and Nez3cb model (kappa 0.87) using only RGB bands. The performance of both models is comparable, but the Nez model has a higher learning rate for this task. Based on our findings, we conclude that the Nez and Safaugu CNN models are superior to the RF models and transfer learning models for the identification of infested trees and for distinguishing between different infestation stages. Therefore, these models can be used not only for basic identification of infested trees but also for monitoring the development of bark beetle disturbance.

2006 ◽  
Vol 32 (5) ◽  
pp. 247-252
Author(s):  
Christopher Fettig ◽  
Tom DeGomez ◽  
Kenneth Gibson ◽  
Christopher Dabney ◽  
Robert Borys

Bark beetles (Coleoptera: Scolytidae) are commonly recognized as the most important mortality agent in western North American coniferous forests. High-value trees such as those located in residential, recreational, or administrative sites are particularly susceptible to attack. Regardless of landowner objectives, tree losses in these unique environments generally have a catastrophic impact. The value of these individual trees, the cost of removal, and the loss of aesthetics may justify protection until the main thrust of a bark beetle infestation subsides. This situation emphasizes the need for assuring that effective insecticides are available for individual tree protection. In this study, we assessed the efficacy of permethrin plus-C (Masterline®) and carbaryl (Sevin SL®) for protecting ponderosa, Pinus ponderosa Dougl. ex. Laws., lodgepole, P. contorta Dougl. ex Loud., and pinyon, P. edulis Engelm., pines from bark beetle attack during two field seasons. Masterline® was effective for protecting P. contorta from mountain pine beetle, Dendroctonus ponderosae Hopkins, attack for one field season. However, Sevin SL® was efficacious for two field seasons. An insufficient number of P. ponderosa and P. edulis control trees were killed to make definitive conclusions regarding efficacy in those systems. The data reported here regarding Masterline® is the first published report on its effectiveness for preventing bark beetle attack on standing trees. Masterline® appears to be an effective individual tree protection tool, but repeated applications will be necessary if multiyear control is desired.


2020 ◽  
Vol 15 ◽  
Author(s):  
Deeksha Saxena ◽  
Mohammed Haris Siddiqui ◽  
Rajnish Kumar

Background: Deep learning (DL) is an Artificial neural network-driven framework with multiple levels of representation for which non-linear modules combined in such a way that the levels of representation can be enhanced from lower to a much abstract level. Though DL is used widely in almost every field, it has largely brought a breakthrough in biological sciences as it is used in disease diagnosis and clinical trials. DL can be clubbed with machine learning, but at times both are used individually as well. DL seems to be a better platform than machine learning as the former does not require an intermediate feature extraction and works well with larger datasets. DL is one of the most discussed fields among the scientists and researchers these days for diagnosing and solving various biological problems. However, deep learning models need some improvisation and experimental validations to be more productive. Objective: To review the available DL models and datasets that are used in disease diagnosis. Methods: Available DL models and their applications in disease diagnosis were reviewed discussed and tabulated. Types of datasets and some of the popular disease related data sources for DL were highlighted. Results: We have analyzed the frequently used DL methods, data types and discussed some of the recent deep learning models used for solving different biological problems. Conclusion: The review presents useful insights about DL methods, data types, selection of DL models for the disease diagnosis.


2021 ◽  
Vol 23 (4) ◽  
pp. 2742-2752
Author(s):  
Tamar L. Greaves ◽  
Karin S. Schaffarczyk McHale ◽  
Raphael F. Burkart-Radke ◽  
Jason B. Harper ◽  
Tu C. Le

Machine learning models were developed for an organic reaction in ionic liquids and validated on a selection of ionic liquids.


Forests ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1290
Author(s):  
Branislav Hroššo ◽  
Pavel Mezei ◽  
Mária Potterf ◽  
Andrej Majdák ◽  
Miroslav Blaženec ◽  
...  

Research Highlights: Bark beetles are important agents of disturbance regimes in temperate forests, and specifically in a connected wind-bark beetle disturbance system. Large-scale windthrows trigger population growth of the European spruce bark beetle (Ips typographus L.) from endemic to epidemic levels, thereby allowing the killing of Norway spruce trees over several consecutive years. Background and Objectives: There is a lack of evidence to differentiate how outbreaks are promoted by the effects of environmental variables versus beetle preferences of trees from endemic to outbreak. However, little is known about how individual downed-tree characteristics and local conditions such as tree orientation and solar radiation affect beetle colonization of downed trees. Materials and Methods: To answer this question, we investigated the infestation rates and determined tree death categories (uprooted, broken, and stump) in wind-damaged areas in Western Tatra Mts. in Carpathians (Slovakia) from 2014–2016, following a windthrow in May 2014. In total, we investigated 225 trees over eight transects. For every tree, we measured its morphological (tree height, crown characteristics), environmental (solar radiation, terrain conditions, trunk zenith), temporal (time since wind damage), and beetle infestation (presence, location of attack, bark desiccation) parameters. We applied Generalized Additive Mixed Models (GAMM) to unravel the main drivers of I. typographus infestations. Results: Over the first year, beetles preferred to attack broken trees and sun-exposed trunk sides over uprooted trees; the infestation on shaded sides started in the second year along with the infestation of uprooted trees with lower desiccation rates. We found that time since wind damage, stem length, and incident solar radiation increased the probability of beetle infestation, although both solar radiation and trunk zenith exhibited nonlinear variability. Our novel variable trunk zenith appeared to be an important predictor of bark beetle infestation probability. We conclude that trunk zenith as a simple measure defining the position of downed trees over the terrain can anticipate beetle infestation. Conclusions: Our findings contribute to understanding of the bark beetle’s preferences to colonize windthrown trees in the initial years after the primary wind damage. Further, our findings can help to identify trees that are most susceptible to beetle infestation and to prioritize management actions to control beetle population while maintaining biodiversity.


1980 ◽  
Vol 112 (7) ◽  
pp. 725-730 ◽  
Author(s):  
D. J. Goheen ◽  
F. W. Cobb

AbstractThe relationship between bark beetle infestation of ponderosa pine and severity of infection by Ceratocystis wageneri was investigated by closely monitoring 256 trees (136 apparently healthy, 60 moderately diseased, and 60 severely diseased at initiation of study) for beetle infestation from summer 1972 to fall 1975. Disease ratings were updated by periodic examination, and some trees changed disease category during the study. Ninety trees were infested by Dendroctonus brevicomis, D. ponderosae, or both, five by buprestids alone, and one tree died from effects of the pathogen alone. Sixty-two of the beetle-infested trees were severely diseased at time of infestation, 25 were moderately diseased, and only three were apparently healthy. Thus, the results showed that bark beetles were much more likely to infest infected than healthy trees. Among diseased trees, those with advanced infections were most likely to be infested. There was evidence that buprestids (especially Melanophila spp.) and possibly Ips spp. attacked diseased trees prior to Dendroctonus spp. infestation.


1990 ◽  
Vol 122 (3) ◽  
pp. 423-427 ◽  
Author(s):  
Thomas W. Phillips

AbstractResults of a field experiment indicate that adults of the pine weevil Hylobius pales (Herbst) respond to pheromones of bark beetles. Each sex of H. pales was more attracted to traps baited with the combination of a pine bolt infested with male Ips calligraphus Germar plus the synthetic Dendroctonus Erichson pheromones frontalin and exo-brevicomin, than to traps baited with pine bolts alone. The combined numbers of male and female H. pales caught in traps baited only with Ips calligraphus-infested bolts were significantly greater than numbers caught in traps baited with uninfested control bolts. The attraction of H. pales to bark beetle pheromones may represent a kairomonal response in which weevils exploit semiochemicals from other species that signify a suitable host resource.


2021 ◽  
Author(s):  
Erica Jaakkola ◽  
Anna Maria Jönsson ◽  
Per-Ola Olsson ◽  
Maj-Lena Linderson ◽  
Thomas Holst

<p>Tree killing by spruce bark beetles (<em>Ips typographus</em>) is one of the main disturbances to Norway spruce (<em>Picea abies</em>) forests in Europe and the risk of outbreaks is amplified by climate change with effects such as increased risk of storm felling, tree drought stress and an additional generation of spruce bark beetles per year<sup>[1]</sup>. The warm and dry summer of 2018 triggered large outbreaks in Sweden, the increased outbreaks are still ongoing and affected about 8 million m<sup>3</sup> forest in 2020<sup>[2]</sup>. This is the so far highest record of trees killed by the spruce bark beetle in a single year in Sweden<sup>[2]</sup>. In 1990-2010, the spruce bark beetle killed on average 150 000 m<sup>3</sup> forest per year in southern Sweden<sup>[3]</sup>. Bark beetles normally seek and attack Norway spruces with lowered defense, i.e. trees that are wind-felled or experience prolonged drought stress<sup>[4]</sup>. However, as the number of bark beetle outbreaks increase, the risk of attacks on healthy trees also increase<sup>[5]</sup>. This causes a higher threat to forest industry, and lowers the possibilities to mitigate climate change in terms of potential decreases in carbon uptake if the forests die<sup>[4,5]</sup>. Norway spruce trees normally defend themselves by drenching the beetles in resin<sup>[6]</sup>. The resin in turn contains different biogenic volatile organic compounds (BVOCs), which can vary if the spruce is attacked by bark beetles or not<sup> [4,6]</sup>. The most abundant group of terpenoids (isoprene, monoterpenes and sesquiterpenes), is most commonly emitted from conifers, such as Norway spruce<sup>[7,8]</sup>. The aim of this study was to enable a better understanding of the direct defense mechanisms of spruce trees by quantifying BVOC emissions and its composition from individual trees under attack</p><p>To analyze the bark beetles’ impact on Norway spruce trees a method was developed using tree trunk chambers and adsorbent tubes. This enables direct measurements of the production of BVOCs from individual trees. Three different sites in Sweden, with different environmental conditions were used for the study and samples were collected throughout the growing season of 2019. After sampling, the tubes were analyzed in a lab using automated thermal desorption coupled to a gas chromatograph and a mass spectrometer to identify BVOC species and their quantity.</p><p>The preliminary results show a strong increase in BVOC emissions from a healthy tree that became infested during the data collection. The finalized results expect to enable better understanding of how spruce trees are affected by insect stress from bark beetles, and if bark beetle infestation will potentially result in increased carbon emission in the form of BVOCs.</p><p><strong>References</strong></p><p>[1] Jönsson et al. (2012). Agricultural and Forest Meteorology 166: 188–200<br>[2] Skogsstyrelsen, (2020). https://via.tt.se/pressmeddelande/miljontals-granar-dodades-av-granbarkborren-2020?publisherId=415163&releaseId=3288473<br>[3] Marini et al. (2017). Ecography, 40(12), 1426–1435.<br>[4] Raffa (1991). Photochemical induction by herbivores. pp. 245-276<strong><br></strong>[5] Seidl, et al. (2014). Nature Climate Change, 4(9), 806-810. <br>[6] Ghimire, et al. (2016). Atmospheric Environment, 126, 145-152.<br>[7] Niinemets, U. and Monson, R. (2013). ISBN 978-94-007-6606-8<br>[8] Kesselmeier, J. and Staudt, M. (1999). Journal of Atmospheric Chemistry, 33(1), pp.23-88</p>


1971 ◽  
Vol 49 (7) ◽  
pp. 1021-1024 ◽  
Author(s):  
T. S. Sahota

The failure of ovarian development in Douglas-fir bark beetles denied of their natural gallery environment and maintained on host bark chips was investigated. Such insects possessed a high activity of proteolytic enzymes in their guts but relatively small amounts of female-specific proteins both in haemolymph and the oocytes. Topical application of farnesyl methyl ether did not increase the activity of gut proteases but resulted in increased amounts of female-specific proteins in haemolymph and ovaries. Thus it appears that the Douglas-fir bark beetles maintained on bark chips do not suffer from an inability to break down the ingested proteins, but synthesize and transfer less than normal amounts of female-specific proteins to the developing oocytes.


Author(s):  
Gonca Ece Özcan ◽  
Korhan Enez ◽  
Burak Arıcak

Forest roads are important transportation equipment through forested areas in the rugged, mountainous terrain of northern Turkey. Forest roads harm forest ecosystems due to both the manner in which they are established and how they are used afterwards. Damage to trees that occur during road construction through forests stresses trees, which facilitates outbreaks of bark beetle populations. Bark beetles are significant risk to the health and productivity of Turkish pine forests and to pine forests worldwide. In particular, Ips sexdentatus (Boerner) (Coleoptera, Curculionidae, Scolytinae) is a particularly destructive species of bark beetle in Turkish forests. Their damage to coniferous trees threatens the sustainability of the forest ecosystems. This study primarily aims to assess the intensity of damage that I. sexdentatus inflicts on Pinus nigra J.F.Arnold stands relative to several parameters: the distance to the nearest forest road, aspect (shady - sunny), slope (0–15% or >15%), and other stand characteristics. In this study, we show how damage by an I. sexdentatus infestation in pure black pine stands varies with distance to forest roads and in situ edaphic factors. We sampled 45 plots (400 m2 each), slope, aspect and distances to the nearest forest road was determined using ArcGIS software and the region’s road network overlays. Results showed that trees located within 100 m from the nearest forest road were the most severely damaged ones. The intensity of I. sexdentatus damage was about 16% in a hectare. Trees that were in 16–20 cm diameter class were damaged more often. I. sexdentatus damage did not show any significant correlation with the slope, aspect or degree of canopy closure.


2020 ◽  
Vol 2 (2) ◽  
pp. 94-104
Author(s):  
Yusuf Budi Prasetya Santosa ◽  
Fahmi Hidayat

The use of varied learning models by history teachers will facilitate teachers and students in implementing and following the learning process. This study aims to determine the learning process and the use of learning models used by history teachers. This study uses a qualitative methodology with an observation and interview approach conducted at two high schools, Dian Didaktika High School and SMA Negeri 2 Depok. From the results of the study it can be seen, that the history teacher at the two schools has carried out the learning process using a scientific approach. There is no difference in the selection of learning strategies, both of them use the contextual teaching learning model. The difference between the two is in the selection of learning methods, where the history teacher Dian Didaktika uses the method of learning project base learning and the history teacher of SMA Negeri 2 Depok uses a method of learning outside the classroom by visiting museums.


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