scholarly journals Sensitivity of Landsat-8 OLI and TIRS Data to Foliar Properties of Early Stage Bark Beetle (Ips typographus, L.) Infestation

2019 ◽  
Vol 11 (4) ◽  
pp. 398 ◽  
Author(s):  
Haidi Abdullah ◽  
Roshanak Darvishzadeh ◽  
Andrew Skidmore ◽  
Marco Heurich
Keyword(s):  
Bark Beetle ◽  
Early Stage ◽  
Statistical Significance ◽  
Principal Component ◽  
Leaf Traits ◽  
Ips Typographus ◽  
Landsat 8 ◽  
Least Squares Regression ◽  
Infrared Band ◽  
The Impact

In this study, the early stage of European spruce bark beetle (Ips typographus, L.) infestation (so-called green attack) is investigated using Landsat-8 optical and thermal data. We conducted an extensive field survey in June and the beginning of July 2016, to collect field data measurements from several infested and healthy trees in the Bavarian Forest National Park (BFNP), Germany. In total, 157 trees were selected, and leaf traits (i.e. stomatal conductance, chlorophyll fluorescence, and water content) were measured. Three Landsat-8 images from May, July, and August 2016 were studied, representing an early stage, advanced stage, and post-infestation, respectively. Spectral vegetation indices (SVIs) sensitive to the measured traits were calculated from the optical domain (VIS, NIR, and SWIR), and canopy surface temperature (CST) was calculated from the thermal infrared band using the mono-window algorithm. The leaf traits were used to examine the impact of bark beetle infestation on the infested trees and to explore the link between these traits and remote sensing data (CST and SVIs). The differences between healthy and infested samples regarding measured leaf traits were assessed using Student’s t test. The relative importance of the CST and SVIs for estimating measured leaf traits was evaluated based on the variable importance in projection (VIP) obtained from the partial least squares regression (PLSR) analysis. A temporal comparison was then made for SVIs with a VIP > 1, including CST, using statistical significance tests. The clustering method using a principal components analysis (PCA) was used to examine visually how well the two groups of sample plots (healthy and infested) are separated in 2-D space based on principal component scores. Finally, linear regression (LR) was used to generate the leaf traits maps using the SVI that have highest VIP score and then used to produce a stress map for the study area. The results revealed that all measured leaf traits were significantly different (p < 0.05) between healthy versus infested samples. Moreover, the study showed that CST was superior to the SVIs in detecting subtle canopy changes due to bark beetle infestation for the three months considered in this study. The results showed that CST is an essential variable for estimating measured leaf traits with VIP > 1, improving the results of clustering when used with other SVIs. Likewise, the stress map produced by CST and leaf traits well presented the infestation areas at the green attacked stage. The new insight offered by this study is that the stress induced by the early stage of bark beetle infestation is more pronounced by Landsat-8 thermal bands than the SVIs calculated from its optical bands. The potential of CST in detecting the green attack stage would have positive implications for forest practice.

The urban areas classification methodology according to multi-zone images of Sentinel 2 and Landsat 8 (on the example of the city of Thanh Hoa, Vietnam)

2020 ◽  
Vol 956 (2) ◽  
pp. 40-49
Author(s):  
Le Hung Trinh ◽  
Dinh Sinh Mai ◽  
V.R. Zablotskii
Keyword(s):  
Land Cover ◽  
Urban Areas ◽  
Satellite Images ◽  
Near Infrared ◽  
Landsat 8 ◽  
Land Use Classification ◽  
Infrared Band ◽  
The Status ◽  
The Impact ◽  
Sentinel 2

In recent years, land cover changes very quickly in urban areas due to the impact of population growth and socio-economic development. The authors present the method of land cover/land use classification based on the combination of Sentinel 2 and Landsat 8 multi-resolution satellite images. A middle infrared band (band 11), a near infrared (band 8) of Sentinel 2 image and a thermal infrared one (band 10) of Landsat 8 image were used to calculate EBBI (Enhanced Built-up and Barreness Index). The EBBI index and Sentinel 2 spectral bands with spatial resolution 10 m (band 2, 3, 4, 8) were used to classify the land cover. The obtained results showed that, the method of land cover classification based on combination of Sentinel 2 and Landsat 8 satellite images improves the overall accuracy by about 5 % compared with the one using only Sentinel 2 data. The results obtained at the study can be used for the management, assessment and monitoring the status and dynamics of land cover in urban areas.

Natural regeneration and vegetation changes in wet spruce forests after natural and artificial disturbances

2007 ◽  
Vol 37 (10) ◽  
pp. 1907-1914 ◽  
Author(s):  
Magda Jonášová ◽  
Ivona Matějková
Keyword(s):  
Norway Spruce ◽  
Bark Beetle ◽  
Natural Regeneration ◽  
Ips Typographus ◽  
Tree Regeneration ◽  
Vegetation Changes ◽  
Natural Disturbances ◽  
Spruce Forests ◽  
The Impact

An extensive area of Norway spruce ( Picea abies (L.) Karst.) forests in the Šumava Mountains, Central Europe, has been affected by a massive bark beetle ( Ips typographus L.) outbreak since the mid-1990s. One part of the area was left without intervention and two types of intervention have been applied in other parts: (1) the classical forest approach, based on the logging of attacked trees and (2) “sanitation”, in which attacked trees were cut down, debarked, and left lying in the stand. The main goal of our research was to test the impact of nonintervention and both types of intervention on the regeneration of the Norway spruce forests. The Norway spruce forests influenced by natural disturbances (bark beetle outbreak and windfalls) regenerated very well if left without intervention. The bark beetle outbreaks and windfalls do not represent a threat to the long-term persistence of the forests. Clearcuts resulted in formation of pioneer stages with a postponed spruce regeneration. In sanitation plots, the reduction of both previous vegetation and tree regeneration was obvious. Generally, both interventions against bark beetle delayed the recovery of Norway spruce forests.

Mite communities (Acari, Mesostigmata) associated with Ips typographus (Coleoptera, Scolytidae) in managed and natural Norway spruce stands in Central Europe

2012 ◽  
Vol 7 (5) ◽  
pp. 910-916 ◽  
Author(s):  
Dariusz Gwiazdowicz ◽  
Jacek Kamczyc ◽  
Ewa Teodorowicz ◽  
Jerzy Błoszyk
Keyword(s):  
Norway Spruce ◽  
Bark Beetle ◽  
Bark Beetles ◽  
Management Practices ◽  
Mite Species ◽  
Ips Typographus ◽  
Ne Poland ◽  
Set Up ◽  
Mite Communities ◽  
The Impact

AbstractPrevious studies have suggested that forest management practices can influence bark beetle populations as well as those of some associated insects. However, the impact on bark beetle-associated mites, which occur in bark beetle galleries in large numbers, have not yet been studied. The objective of this study was to compare mesostigmatid mite communities associated with the Norway spruce pest Ips typographus in managed and natural forest stands separated by spruce-free belt. The study sites were located in Białowieża National Park (NE Poland) as well as in the Izery Mountains (Szklarska Poręba Forest District — SW Poland), which were destroyed in 1981–1987 by an ecological disaster. In total, 30 Borregard pipe traps containing the commercial attractant Ipsodor W (Chemipan, Poland) were set up at each study site and collected in August 2010. In total, 7214 bark beetles and 1804 mites were collected which were classified into 16 species. We observed differences in the total abundance of mites as well as the total number of recorded mite species. The communities were quite similar, and were generally dominated by populations of Trichouropoda polytricha, Dendrolaelaps quadrisetus and Uroobovella ipidis. The Shannon and Evenness indexes as well as the mean number of mites per sample were not significantly different between forests.

Performance of shariah-compliant firms and non-shariah-compliant firms in the MENA region

2016 ◽  
Vol 7 (4) ◽  
pp. 268-281 ◽  
Author(s):  
Omar Farooq ◽  
Amal Alahkam
Keyword(s):  
United Arab Emirates ◽  
Stock Price ◽  
Statistical Significance ◽  
Ordinary Least Squares ◽  
Business Networks ◽  
Least Squares Regression ◽  
Sampling Errors ◽  
Mena Region ◽  
Content Type ◽  
The Impact

Purpose This paper aims to document the relative performance of non-financial shariah-compliant firms and non-financial non-shariah-compliant firms in the MENA (Morocco, Egypt, Saudi Arabia, United Arab Emirates, Jordan, Kuwait and Bahrain) region during the period between 2005 and 2009. Design/methodology/approach This paper uses pooled ordinary least squares regression analysis to document the effect of shariah compliance on stock price performance in the MENA region on a sample of non-financial firms that consists of shariah- and non-shariah-compliant firms. Findings Using market-adjusted returns as a proxy for performance, this paper shows that shariah-compliant firms underperform non-shariah-compliant firms. The results also show that underperformance of shariah-compliant firms holds in the civil law and in the common law countries. Interestingly, this paper also shows that difference between the performance of shariah-and non-shariah-compliant firms disappears during the crisis period. Research limitations/implications This paper argues that the characteristics of shariah-compliant firms are such that these firms are at a disadvantage relative to their non-shariah-compliant counterparts. For example, high leverage of their counterpart firms can act as a disciplining mechanism and positively affect performance of these firms. Similarly, high account receivables and high cash allow non-shariah-compliant firms to make more effective business networks than shariah-compliant firms and fund large capital expenditures. Consequently, shariah-compliant firms underperform non-shariah-compliant firms. This study’s results, however, should be read with caution, as they are mainly based upon the performance of large volume, statistical significance, sampling errors and possible labeling miss-specification. Further research on this topic with different research methodology is essential. Originality/value This paper takes a financial view rather than religious view while highlighting the impact of shariah characteristics on firm performance.

scholarly journals 157 Spectroscopic analysis of tissues collected from male goats differing in genetic propensity to consume juniper

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 119-120
Author(s):  
Douglas R Tolleson ◽  
Nick Garza ◽  
Kaylee Hollingsworth ◽  
Jose M Diaz ◽  
Thomas H Welsh
Keyword(s):  
Near Infrared ◽  
Statistical Significance ◽  
Spectral Characteristics ◽  
Principal Component ◽  
Breeding Value ◽  
Capra Hircus ◽  
Strongly Correlated ◽  
Least Squares Regression ◽  
Tissue Samples ◽  
Physico Chemical

Abstract Juniper (Juniperus spp.) foliage is consumed by free-ranging goats in the southwestern US. Junipers contain monoterpenes which have toxicological and pharmacological effects. We sampled 20 male Spanish goats (Capra hircus; 10 young [2-year-old] and 10 old [3-5-year-old]) from a herd selected for their propensity to consume a high (estimated breeding value [EBV] = 13.01 ± 0.20) or low (EBV = -14.76 ± 0.48) proportion of juniper in the diet to determine the ability of near infrared spectroscopy (NIRS) in detecting physico-chemical differences in animal tissues. Heart (ventricle; interior and exterior surfaces), liver (caudate lobe), and muscle (longissimus dorsi) samples as well as an entire kidney and testicle, were collected at harvest (n = 5 of each age [i.e. length of exposure to monoterpenes] and juniper EBV combination). Tissue samples were stored in whirl-pac bags at -20o C and later thawed to ~24o C for NIRS analysis. Spectra (400–2500 nm) were obtained with an ASD Field Spec using a contact probe directly through the whirl-pac sample bag. Principal component and partial least squares regression procedures were accomplished in SAS; P &lt; 0.05 indicated statistical significance. Both age (RSQ, 0.2 to 0.6; P &lt; 0.05) and juniper EBV (RSQ, 0.2 to 0.65; P &lt; 0.05) were correlated with near infrared (NIR) spectral characteristics. Propensity to consume juniper was most strongly correlated with NIR spectra in testicular tissue (RSQ = 0.65, MSE = 0.25, P &lt; 0.01), and least strongly correlated in the heart interior surface (RSQ = 0.21, MSE = 0.21, P &lt; 0.05). Spectral correlations with propensity to consume juniper were stronger in tissues from old (RSQ ~ 0.68) than young (RSQ ~ 0.52) goats, especially in liver, kidney, muscle, and testicle. Physico-chemical differences in goat tissues were affected by genetic propensity to consume juniper, and these were detected by NIRS.

Phenolic predictors for Norway spruce resistance to the bark beetle Ips typographus (Coleoptera: Scolytidae) and an associated fungus, Ceratocystis polonica

1998 ◽  
Vol 28 (5) ◽  
pp. 720-728 ◽  
Author(s):  
Franck Brignolas ◽  
François Lieutier ◽  
Daniel Sauvard ◽  
Erik Christiansen ◽  
Alan A Berryman
Keyword(s):  
Norway Spruce ◽  
Bark Beetle ◽  
Bark Beetles ◽  
Phenolic Content ◽  
Principal Component ◽  
Ips Typographus ◽  
Phenolic Composition ◽  
Relative Resistance ◽  
Induced Reaction ◽  
Ceratocystis Polonica

Changes in phloem phenolic content of Norway spruce (Picea abies (L.) Karst.) clones were followed during the first 12 days of the reaction induced by phloem artificial inoculation with Ceratocystis polonica Siem., a bark beetle (Ips typographus L.) associated fungus. The aim was to confirm our previous results concerning the mechanisms of this reaction and the possible predictors of Norway spruce resistance to bark beetles and their associated fungi. The induced reaction was characterized by a slight decrease of tanning ability and an increase of (+)-catechin concentration, which confirmed our previous observations. The relative resistance of the clones was first predicted using the predictors previously proposed. In addition, the first axis of the principal component analysis describing the phenolic content of all clones was used as a synthetic predictor (resistance axis). Related variables were also tested as predictors. Actual resistance of each clone was then measured, using mass inoculations of C. polonica, and was compared with the predictions. Four predictors were so validated: the resistance axis, tanning ability and isorhapontin concentration in uninoculated phloem, and (+)-catechin concentration in the phloem 6 days after its inoculation. Phloem phenolic composition could thus be used to predict Norway spruce resistance to bark beetles and their associated fungi.

scholarly journals Mapping European Spruce Bark Beetle Infestation at Its Early Phase Using Gyrocopter-Mounted Hyperspectral Data and Field Measurements

2021 ◽  
Vol 13 (22) ◽  
pp. 4659
Author(s):  
Florian M. Hellwig ◽  
Martyna A. Stelmaszczuk-Górska ◽  
Clémence Dubois ◽  
Marco Wolsza ◽  
Sina C. Truckenbrodt ◽  
...  
Keyword(s):  
Bark Beetle ◽  
Early Stage ◽  
Field Measurements ◽  
Ips Typographus ◽  
Hyperspectral Data ◽  
Spruce Bark ◽  
Attack Phase ◽  
Preliminary Study ◽  
Very High

The prolonged drought of recent years combined with the steadily increasing bark beetle infestation (Ips typographus) is causing enormous damage in Germany’s spruce forests. This preliminary study investigates whether early spruce infestation by the bark beetle (green attack) can be detected using indices based on airborne spatial high-resolution (0.3 m) hyperspectral data and field spectrometer measurements. In particular, a new hyperspectral index based on airborne data has been defined and compared with other common indices for bark beetle detection. It shows a very high overall accuracy (OAA = 98.84%) when validated with field data. Field measurements and a long-term validation in a second study area serve the validation of the robustness and transferability of the index to other areas. In comparison with commonly used indices, the defined index has the ability to detect a larger proportion of infested spruces in the green attack phase (60% against 20% for commonly used indices). This index confirms the high potential of the red-edge domain to distinguish infested spruces at an early stage. Overall, our index has great potential for forest preservation strategies aimed at the detection of infested spruces in order to mitigate the outbreaks.

scholarly journals Breast – conserving Surgery in Early – Stage Triple – Negative Breast Cancer: Is There a Higher Risk of Locoregional Recurrence?

2012 ◽  
Vol 12 (1) ◽  
pp. 11-14
Author(s):  
Jelena Maksimenko ◽  
Arvids Irmejs ◽  
Genadijs Trofimovics ◽  
Edvins Miklasevics
Keyword(s):  
Breast Cancer ◽  
Triple Negative Breast Cancer ◽  
Locoregional Recurrence ◽  
Triple Negative ◽  
Early Stage ◽  
Statistical Significance ◽  
Group Versus ◽  
Significant Difference ◽  
The Impact ◽  
Mastectomy Group

SummaryIntroduction.Triple- negative breast cancer (TNBC) is an aggressive disease with poor prognosis and high risk of locoregional recurrence (LRR).Aim of the Study.Is to examine the impact of type of surgery on locoregional recurrence in women with early- stage invasive triplenegative breast cancer (TNBC).Materials and Methods.A total of 68 women with stage I- II (T1N0M0, T2N0M0, T1N1M0, or T2N1M0) invasive, unifocal TNBC with hitologically tumor- free surgical margins were included. Patients were stratified into two groups according to surgical treatment, breast- conserving therapy (BCT) in 36 of 68 patients versus mastectomy in 32 of 68 patients. The two common founder mutations in BRCA1 (4153delA and 5382insC) in Latvia were tested using a multiplex- specific polymerase chain reaction(PCR) assay. Clinicopathological data and survival outcomes were analyzed.Results.There were no statistically significant differences in relation to age, stage, tumor size, histological type, tumor grade and nodal status between two groups. 24 patients (77.4%) in the mastectomy group and 27(75%) patients in the BCT group received chemotherapy, these difference was not statistically significant. 10(32.2%) of 32 patients in the mastectomy group and 34(94%) of 36 patients in the BCT group received postoperative radiation (P< 0.0001). There was no statistically significant difference noted in rates of distant metastases (5 cases (16.1%) in the mastectomy group versus 4 cases (11.1%) in the BCT group; P < 0.725)). A higher proportion of patients in the BCT group experienced locoregional recurrence compared with patients in the mastectomy group (3 cases (8.3%) versus 0 case (0%), respectively), but this did not reach statistical significance (P< 0.241). It was found that the tumor histology, grade, age at presentation and BRCA1 mutation status were not significant predictors of local recurrence. There was no significant difference in 5- year breast cancer- related survival between two groups (P>0.05).Conclusions.Patients after BCT have a higher locoregional recurrence rates compared to mastectomy, but this did not reach statistical significance. According to our study data BCT is not a contraindication in the TNBC.

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