scholarly journals Disease symptoms and their frequency of occurrence in sycamores (Acer pseudoplatanus L.) in the Rymanów Forest Unit stands

2012 ◽  
Vol 60 (1) ◽  
pp. 123-133
Author(s):  
Tadeusz Kowalski ◽  
Paulina Materniak
Keyword(s):  
Cross Sections ◽  
Riparian Forest ◽  
Field Studies ◽  
Mountain Forest ◽  
Forest Site ◽  
Acer Pseudoplatanus ◽  
Disease Symptoms ◽  
Cancer Symptoms ◽  
Dead Trees ◽  
Crown Thinning

Field studies were conducted in the years 2003 - 2005 in the Rymanów Forest Unit in 13 stands aged between 40 to 100 years, which had 10% - 60% of the sycamore in their species composition. They grew on a mountain forest site (12 stands) and mountain riparian forest (1 stand). In each of them 100 trees were examined, growing next to each other in the central part of the stands. The disease symptoms, on trunks and in the crown area of each tree, and their intensity were determined according to the predefined symptomatic - developmental code. More than 80 fragments of wood and bark were collected from trunks of living and dead trees with local cankers and bark peeling off exposing wood. From the samples, 798 isolations were made on 2% malt - agar medium. The examined sycamores in the Rymanów Forest Unit showed a large variation in the disease symptoms and their occurrence frequency. Among 1300 analyzed trees, only 13.7% did not show external, macroscopic disease symptoms. There was a relatively large share of dead trees (15.0%), which in individual stands ranged 4.0 - 32.0%. The most frequent symptoms in crowns were as follows: top dying (6.3% trees), entire branch dying (16.2%) or only their tops (9.6%), crown thinning (19.4%), leaf atrophy (10.8%) and leaf discoloration (11.6%). On sycamores trunks, the following symptoms were found: plate-like and strip-like necrosis of bark that was breaking, falling off and exposing wood (8.6% trees), local bark cankers (14.7%), among which healed ones dominated (10.3%), bark cracks (14.3%) and tree cancer symptoms (3.8%). Bark necrosis and wood exposure formed 1.5 times more frequently on the northern and western side than on the southern and eastern side, bark cracks appeared most frequently on the southern trunk side. On the cross sections of sycamore trunks, the following symptoms were found predominantly: T-shaped discolorations which appeared in the place of local healed cankers, dead wood regions in the places of local unhealed cankers and widespread bark cankers, sometimes taking the form of a sector reaching the part near the pith, and greyish - green or greenish - brown wood discolorations in the form of numerous stains, especially in the trunk periphery part. On the trunks of 184 (14.2%) sycamores, perithecia of <i>Nectria coccinea</i> were present. They formed in the area of cankers on bark and exposed wood alike. Fruiting bodies of <i>Nectria cinnabarina</i>, <i>Eutypa acharii</i>, <i>Melanomma pulvis-pyrius</i>, conidiomata of <i>Cytospora ambiens</i>, <i>Aposphaeria</i> cf. <i>pulviscula</i> and conidiomata of <i>Stegonsporium pyriforme</i> occurred sporadically. From wood, the following were isolated predominantly: <i>Basidiomycetes</i> sp. 1, <i>Chalara</i> sp. 1, <i>Cadophora fastigiata</i>, <i>Nectria cinnabarina</i> and <i>Cytospora ambiens</i>. <i>Chalara</i> sp.1, with its morphological features, best matched the anamorph of <i>Ceratocystis coerulescens sensu lato</i>.

scholarly journals Occurrence of disease symptoms and selected biotic factors connected with beech (Fagus sylvatica L.) dieback phenomenon in stands of The Magurski National Park

2012 ◽  
Vol 58 (2) ◽  
pp. 441-452
Author(s):  
Piotr Rojek
Keyword(s):  
Fagus Sylvatica ◽  
National Park ◽  
Forest Site ◽  
Age Classes ◽  
Similar Frequency ◽  
Disease Symptoms ◽  
Age Class ◽  
Leaf Chlorosis ◽  
Cryptococcus Fagisuga ◽  
Crown Thinning

The studies were carried out in 12 beech stands, growing on mountain fresh forest site in Magurski National Park. Stands differed in respect of exposition (northern and southern) and age - lower age classes (21-60 years old) and higher age classes (81-120 years old). This paper presents evaluation of frequency of disease symptoms occurrence in the crowns and on the trunks of beeches. The presence and the place of occurrence of fungus <i>Ascodichaena rugosa</i> and insects <i>Cryptococcus fagisuga</i> and <i>Ectoedemia liebwerdella</i>, which could be connected with beech bark necrosis on the trunks were noted down. In each stand 50 trees, growing side by side in center of the stand, were analyzed. Among 600 analyzed trees of <i>Fagus sylvatica</i>, 2.6% had a dead top. Crown thinning were present on 51.8% of trees. It appeared frequently in higher age class stands and didn't cover more than ¼ of the crown. Moreover, in crowns of 4.1% of trees the leaf chlorosis appeared. The most frequent symptom on trunks of beeches were local necroses (98% of trees), that were sometimes connected with slime fluxing (3.3%). Necroses were the most number in stands growing on the southern exposition and on south parts of the trunks. <i>Cryptococcus fagisuga</i> appeared mostly in high age class stands. Intensity of its appearance was similar on the trees growing on the southern and northern exposition (respectively, 48.3% and 53.3%). Particular parts of the trunks were colonized with similar frequency by <i>C. fagisuga</i> irrespective of cardinal points (N-29.3%; S-21.7%; W-22.7%; E-26.2%) and number of necroses on the trunks. <i>Ascodichaena rugosa</i> appeared on 8.6% of trees, more frequently on their north parts of the trunks (7.3%). In the places colonized by fungi <i>A. rugosa</i>, insect <i>C. fagisuga</i> was absent. Occurrence of larvae of <i>Ectoedemia liebwerdella</i> was mostly found on trunks of beeches growing on the southern exposition (43.0%), on 35.3% of trees they colonized south parts of trunks. There wasn't observed any connection between the occurrence of these larvae and symptoms of local necroses.

Preadaptation and spatial effects on retention-tree survival in cut areas in Estonia

2008 ◽  
Vol 38 (10) ◽  
pp. 2616-2625 ◽  
Author(s):  
Raul Rosenvald ◽  
Asko Lõhmus ◽  
Andres Kiviste
Keyword(s):  
Natural Disturbance ◽  
Forest Edge ◽  
Forest Site ◽  
Spatial Effects ◽  
Forest Edges ◽  
Dead Trees ◽  
Tree Survival ◽  
Tree Retention ◽  
Standing Dead ◽  
Retention Trees

Survival of live retention trees is a key issue for stand-scale applications of natural-disturbance-based silviculture. We explored the survival of 3255 trees in 102 cut areas (mean size 2.3 ha) in Estonia for 6 years, focusing on spatial variation and preadaptation of the trees. Altogether, 35% of the trees died during the study period, contributing 4.4 m3 of downed dead trunks and 1 m3 of standing dead trees per hectare. The annual mortality rates declined over time. The main survival determinants were tree species (higher for hardwood deciduous trees), diameter (species dependent), position relative to forest edge (higher for trees near current or former forest edges), retention density (positive), and exposure (negative). The results suggest that (1) green-tree retention can effectively increase the abundance of large shade-tolerant trees, but it is equally important for producing deadwood; (2) larger individuals, former interior-forest trees near current forest edges, and preadapted trees in open conditions should be preferably retained; (3) there is no obvious necessity to modify tree-retention techniques for tree survival according to geographical region or forest site type.

scholarly journals Resources of dead wood in the municipal forests in Warsaw

2015 ◽  
Vol 76 (4) ◽  
pp. 322-330 ◽  
Author(s):  
Konrad Skwarek ◽  
Szymon Bijak
Keyword(s):  
National Parks ◽  
Coarse Woody Debris ◽  
Forest Ecosystems ◽  
Dead Wood ◽  
Woody Debris ◽  
Forest Site ◽  
Natural Forests ◽  
Dead Trees ◽  
Standing Dead ◽  
High Degree

Abstract Dead wood plays an important role for the biodiversity of forest ecosystems and influences their proper development. This study assessed the amount of coarse woody debris in municipal forests in Warsaw (central Poland). Based on the forest site type, dominant tree species and age class, we stratified all complexes of the Warsaw urban forests in order to allocate 55 sample plots. For these plots, we determined the volume of dead wood including standing dead trees, coarse woody debris and broken branches as well as uprooted trees. We calculated the amount of dead wood in the distinguished site-species-age layers and for individual complexes. The volume of dead matter in municipal forests in Warsaw amounted to 38,761 m3, i.e. 13.7 m3/ha. The obtained results correspond to the current regulations concerning the amount of dead organic matter to be left in forests. Only in the Las Bielański complex (northern Warsaw) volume of dead wood is comparable to the level observed in Polish national parks or nature reserves, which is still far lower than the values found for natural forests. In general, municipal forests in Warsaw stand out positively in terms of dead wood quantity and a high degree of variation in the forms and dimensions of dead wood.

scholarly journals Efficacy of Silver Dihydrogen Citrate and Steam Vapor against a Human Norovirus Surrogate, Feline Calicivirus, in Suspension, on Glass, and on Carpet

2018 ◽  
Vol 84 (12) ◽  
Author(s):  
David Buckley ◽  
Muthu Dharmasena ◽  
Angela Fraser ◽  
Charles Pettigrew ◽  
Jeffery Anderson ◽  
...  
Keyword(s):  
Prevention And Control ◽  
Field Studies ◽  
Feline Calicivirus ◽  
Human Norovirus ◽  
Disease Symptoms ◽  
Hard Surface ◽  
Color Changes ◽  
The Government ◽  
And Control ◽  
A Current

ABSTRACTCarpets and other soft surfaces have been associated with prolonged and reoccurring human norovirus (HuNoV) outbreaks. Environmental hygiene programs are important to prevent and control HuNoV outbreaks. Despite our knowledge of HuNoV transmission via soft surfaces, no commercially available disinfectants have been evaluated on carpets. Our aim was to adapt a current standardized method for virucidal testing by assessing two disinfection technologies, silver dihydrogen citrate (SDC) and steam vapor, against one HuNoV surrogate, feline calicivirus (FCV), on wool and nylon carpets. First, we evaluated the effect of both technologies on the appearance of carpet. Next, we evaluated the efficacy of SDC in suspension and the efficacy of SDC and steam vapor against FCV on a glass surface, each with and without serum. Lastly, we tested both technologies on two types of carpet, wool and nylon. Both carpets exhibited no obvious color changes; however, SDC treatments left a residue while steam vapor left minor abrasions to fibers. SDC in suspension and on glass reduced FCV by 4.65 log10and >4.66 log10PFU, respectively, but demonstrated reduced efficacy in the presence of serum. However, SDC was only efficacious against FCV on nylon (3.62-log10PFU reduction) and not wool (1.82-log10PFU reduction). Steam vapor reduced FCV by >4.93 log10PFU on glass in 10 s and >3.68 log10PFU on wool and nylon carpet carriers in 90 s. There was a limited reduction of FCV RNA under both treatments compared to that of infectivity assays, but RNA reductions were higher in samples that contained serum.IMPORTANCEHuman noroviruses (HuNoV) account for ca. 20% of all diarrheal cases worldwide. Disease symptoms may include diarrhea and vomit, with both known to contribute to transmission. The prevention and control of HuNoV are difficult because they are environmentally resilient and resistant to many disinfectants. Several field studies have linked both hard and soft surfaces to HuNoV outbreaks. However, many disinfectants efficacious against HuNoV surrogates are recommended for hard surfaces, but no commercially available products have demonstrated efficacy against these surrogates on soft surfaces. Our research objectives were to evaluate liquid and steam-based technologies in suspension and on hard surface carriers in addition to adapting and testing a protocol for assessing the virucidal effects of disinfection technologies on carpet carriers. These results will inform both the government and industry regarding a standard method for evaluating the virucidal effects of disinfectants on carpet while demonstrating their efficacy relative to suspension and hard-surface tests.

Effect of season, trash and fungicides on fungi associated with subterranean clover

1986 ◽  
Vol 26 (4) ◽  
pp. 431 ◽  
Author(s):  
MJ Barbetti
Keyword(s):  
Subterranean Clover ◽  
Growing Season ◽  
Field Studies ◽  
Population Changes ◽  
Fusarium Spp ◽  
Fungal Population ◽  
Trichoderma Spp ◽  
Disease Symptoms ◽  
Previous Season ◽  
Clover Pasture

In field studies we monitored the effects of time of season, trash and fungicides on the populations of fungi associated with leaves and petioles of newly sown subterranean clover, particularly in relation to the development of disease symptoms. These effects were compared with the fungal population changes occurring in a nearby established subterranean clover pasture. A range of fungi, notably Leptosphaerulina trifolii, Phoma medicaginis and Stemphylium globuliferum, were found to colonise subterranean clover cotyledons, leaves and petioles readily throughout the growing season from as early as 1 week after emergence. The incidence of L. trifolii and S. globuliferum was reasonably consistent throughout the growing season. Alternaria spp., Cladosporium spp., Myrothecium verrucaria, P. medicaginis and Trichoderma spp. were more prevalent later in the season. Fusarium avenaceum and other Fusarium spp. were more prevalent early in the season, while Pithomyces chatarum and S. botryosum were more prevalent midseason. The fungi isolated showed no ability, under the conditions of this investigation, to cause disease, and there was no correlation between fungi isolated and disease symptoms observed. The incidence of several fungi, especially L. trifolii and P. medicaginis, was greatly increased by the presence of trash from the previous season but was greatly decreased by regular applications of fungicide.

scholarly journals Challenges for Managing Candidatus Liberibacter spp. (Huanglongbing Disease Pathogen): Current Control Measures and Future Directions

2018 ◽  
Vol 108 (4) ◽  
pp. 424-435 ◽  
Author(s):  
Ryan A. Blaustein ◽  
Graciela L. Lorca ◽  
Max Teplitski
Keyword(s):  
Broad Spectrum ◽  
Field Studies ◽  
Current Control ◽  
Control Measures ◽  
In Planta ◽  
Citrus Industry ◽  
Future Directions ◽  
Disease Symptoms ◽  
Citrus Greening Disease ◽  
Candidatus Liberibacter

Huanglongbing (HLB; “citrus greening” disease) has caused significant damages to the global citrus industry as it has become well established in leading citrus-producing regions and continues to spread worldwide. Insecticidal control has been a critical component of HLB disease management, as there is a direct relationship between vector control and Candidatus Liberibacter spp. (i.e., the HLB pathogen) titer in HLB-infected citrus trees. In recent years, there have been substantial efforts to develop practical strategies for specifically managing Ca. Liberibacter spp.; however, a literature review on the outcomes of such attempts is still lacking. This work summarizes the greenhouse and field studies that have documented the effects and implications of chemical-based treatments (i.e., applications of broad-spectrum antibiotics, small molecule compounds) and nonchemical measures (i.e., applications of plant-beneficial compounds, applications of inorganic fertilizers, biological control, thermotherapy) for phytopathogen control. The ongoing challenges associated with mitigating Ca. Liberibacter spp. populations at the field-scale, such as the seasonality of the phytopathogen and associated HLB disease symptoms, limitations for therapeutics to contact the phytopathogen in planta, adverse impacts of broad-spectrum treatments on plant-beneficial microbiota, and potential implications on public and ecosystem health, are also discussed.

scholarly journals Molecular composition of biogenic secondary organic aerosols using ultrahigh-resolution mass spectrometry: comparing laboratory and field studies

2014 ◽  
Vol 14 (4) ◽  
pp. 2155-2167 ◽  
Author(s):  
I. Kourtchev ◽  
S. J. Fuller ◽  
C. Giorio ◽  
R. M. Healy ◽  
E. Wilson ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Boreal Forest ◽  
Laboratory Experiments ◽  
Field Studies ◽  
Molecular Composition ◽  
Forest Site ◽  
Ultrahigh Resolution ◽  
Urban Sample ◽  
Kendrick Mass Defect ◽  
Resolution Mass

Abstract. Numerous laboratory experiments have been performed in an attempt to mimic atmospheric secondary organic aerosol (SOA) formation. However, it is still unclear how close the aerosol particles generated in laboratory experiments resemble atmospheric SOA with respect to their detailed chemical composition. In this study, we generated SOA in a simulation chamber from the ozonolysis of α-pinene and a biogenic volatile organic compound (BVOC) mixture containing α- and β-pinene, Δ3-carene, and isoprene. The detailed molecular composition of laboratory-generated SOA was compared with that of background ambient aerosol collected at a boreal forest site (Hyytiälä, Finland) and an urban location (Cork, Ireland) using direct infusion nanoelectrospray ultrahigh-resolution mass spectrometry. Kendrick mass defect and van Krevelen approaches were used to identify and compare compound classes and distributions of the detected species. The laboratory-generated SOA contained a distinguishable group of dimers that was not observed in the ambient samples. The presence of dimers was found to be less pronounced in the SOA from the BVOC mixtures when compared to the one component precursor system. The molecular composition of SOA from both the BVOC mixture and α-pinene represented the overall composition of the ambient sample from the boreal forest site reasonably well, with 72.3 ± 2.5% (n = 3) and 69.1 ± 3.0% (n = 3) common ions, respectively. In contrast, large differences were found between the laboratory-generated BVOC samples and the ambient urban sample. To our knowledge this is the first direct comparison of molecular composition of laboratory-generated SOA from BVOC mixtures and ambient samples.

scholarly journals Controls over N<sub>2</sub>O, NO<sub>x</sub> and CO<sub>2</sub> fluxes in a calcareous mountain forest soil

2005 ◽  
Vol 2 (5) ◽  
pp. 1423-1455 ◽  
Author(s):  
B. Kitzler ◽  
S. Zechmeister-Boltenstern ◽  
C. Holtermann ◽  
U. Skiba ◽  
K. Butterbach-Bahl
Keyword(s):  
Forest Soil ◽  
Co2 Emissions ◽  
Temporal Variations ◽  
Beech Forest ◽  
N Deposition ◽  
Measuring System ◽  
Mountain Forest ◽  
N2o Emissions ◽  
Minor Importance ◽  
Forest Site

Abstract. We measured nitrogen oxides (N2O and NOx), dinitrogen (N2) and carbon dioxide (CO2) emissions from a spruce-fir-beech forest soil in the North Tyrolean limestone Alps in Austria. The site received 12.1 kg nitrogen via wet and dry deposition. Fluxes of nitric oxide (NO) were measured by an automatic dynamic chamber system on an hourly basis over a two year period. Daily N2O emissions were obtained by a semi-automatic gas measuring system. In order to cover spatial variability biweekly manual measurements of N2O and CO2 emissions were carried out, additionally. For acquiring information on the effects of soil and meteorological conditions and of N-deposition on N-emissions we chose the autoregression procedure (time-series analysis) as our means of investigation. Hence, we could exclude the data's autocorrelation in the course of the time. We found that soil temperature, soil moisture and wet N-deposition followed by air temperature and precipitation were the most powerful influencing parameters effecting N-emissions. With these variables up to 89% of observed temporal variations of N-emissions could be explained. During the two-year investigation period between 2.5 and 3.5% of deposited N was reemitted in form of N2O whereas only 0.2% were emitted as NO. At our mountain forest site the main end-product of microbial activity processes was N2 and trace gases (N2O and NO) were only of minor importance.

scholarly journals Quantitative and qualitative characteristics of forests in the Baikal Mountain Forest region

2021 ◽  
Vol 875 (1) ◽  
pp. 012091
Author(s):  
N Kochetkova ◽  
M Bakhanova ◽  
S Zhan ◽  
N Yakovenko
Keyword(s):  
Field Studies ◽  
Mountain Forest ◽  
Coniferous Species ◽  
Grass Roots ◽  
Sanitary Condition ◽  
Forest Region ◽  
Irkutsk Region ◽  
Class 1 ◽  
The Republic ◽  
Total Stock

Abstract The article considers modern approaches to the study of the state of forests of the Baikal Mountain Forest region. All the obtained results of field studies are confirmed by a 13-year period of observations of the changes in the quantitative and qualitative indicators of growth and development of forests, the selected object. During the research, about 17 thousand ha of forest area were surveyed, 1570 permanent test areas were laid. According to the sanitary condition, the share of healthy plantings (class 1) accounts for 76.5%, the 2nd class of resistance (with the presence of small damage and signs of weakening) – 11.1% the indicators of other classes of resistance of plantings vary from 0.5% to 2.6%. The main sign of damage and weakening of forests are grass-roots fires – 60.3%. The total stock of wood according to the GIL is 2568.9 million m3. Coniferous species have the largest share of the stock of business trees – 94.3%, a smaller share of the stock – soft-leaved – 5.6%. The obtained data allow us to develop measures for rational forest management for part of the forests of the Republic of Buryatia, the Trans-Baikal Territory and the Irkutsk Region.

scholarly journals Precision and accuracy of modal analysis methods for clastic deposits and rocks: A statistical and numerical modeling approach

Geosphere ◽  
2021 ◽  
Author(s):  
Pierre-Simon Ross ◽  
Bernard Giroux ◽  
Benjamin Latutrie
Keyword(s):  
Modal Analysis ◽  
Cross Sections ◽  
Statistical Models ◽  
Normal Approximation ◽  
Numerical Models ◽  
Field Studies ◽  
Point Counts ◽  
Clastic Rocks ◽  
Analysis Methods ◽  
Precision And Accuracy

Quantifying the proportions of certain components in rocks and deposits (modal analysis or componentry) is important in earth sciences. Relevant methods for cross-sections (two- dimensional exposures) of clastic rocks include point counts or line counts. The accuracy of these methods has been supposed to be good in the literature but not necessarily verified empirically. Natural materials are inappropriate for assessing accuracy because the true proportions of each component are unknown. The precision of modal analysis methods has traditionally been evaluated from statistical models (primarily the normal approximation to the binomial distribution) but again rarely verified in practice because it is also extremely difficult to obtain different slices through the same material at outcrop scale. Here we create a set of numerical models of red and blue spheres with different proportions and sizes and cut 60 slices through the models, on which we perform point counts and line counts. We show that both of these methods are indeed able to retrieve the correct volumetric proportions of components, on average, when enough fragments are counted or intersected. As already known, precision is controlled by component abundance and the number of points counted or clasts intersected. However, we show that other important factors include differences between slices, which are relevant for our unequal-size models, and the proportion of voids, matrix, and/or cement in the rock. We present empirical precision charts for clast counts and line counts based on our models and make recommendations for future field studies.

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