scholarly journals Epicuticular wax on stomata of damaged silver fir trees (Abies alba Mili.)

2011 ◽  
Vol 74 (2) ◽  
pp. 159-166 ◽  
Author(s):  
Tomislav Bačić ◽  
Ljiljana Krstin ◽  
Jadranka Roša ◽  
Željko Popović

Condition of epistomatal wax on the abaxial surface of the current and previous-year needles of damaged silver fir trees (<em>Abies alba</em> Mill.), both from the polluted Risnjak and "clean" Donja Dobra sites in Gorski Kotar region, both influenced by pollutants coming from Europe, during two years, three times a year, were examined with Scanning Electron Microscope. In the course of time the wax tubules on the epistomatal rims of stomata in polluted, but also in "clean" needles surface, become fused and agglomerated rapidly to various extents of morphologically different types of amorphous wax crusts, primarily compact and particulate ones. This process begins very early, especially in polluted Risnjak site, and may be interpreted as a possible result of air pollution. However, the recrystalization, or production of new tubules, also appears relatively quickly in mostly cases. Quantitative estimations indicate a very large total amount of amorphous wax crusts in the current-year needles, and a very high percentage of the same wax in previous-year needles. Amorphous wax crusts cover stomatal pores, as well as the rims, disturbing the normal gas exchange. Statistically there is a signicant tendency of increase in wax degradation in the needles of the polluted site in comparison with those of the unpolluted one, but there is an insignificant wax degradation among the needles of damaged trees within each site. These results confirmed most of the research done in our preliminary report.

1988 ◽  
Vol 66 (1) ◽  
pp. 125-129 ◽  
Author(s):  
E. Bermadinger ◽  
D. Grill ◽  
P. Golob

The difference in vigour between Picea abies (L.) Karst. and Abies alba Mill, in an area exposed to fine dust containing MgO is reflected in scanning electron microscope studies of the needle surfaces. The greater vitality of the silver fir is correlated with intact wax structures and a somewhat lower dust load. In contrast, the spruce reveals a marked effect on the epicuticular wax by a heavy fine-dust load. Possible causes and physiological consequences are discussed.


Forests ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 640
Author(s):  
Cristian Gheorghe Sidor ◽  
Radu Vlad ◽  
Ionel Popa ◽  
Anca Semeniuc ◽  
Ecaterina Apostol ◽  
...  

The research aims to evaluate the impact of local industrial pollution on radial growth in affected Norway spruce (Picea abies (L.) Karst.) and silver fir (Abies alba Mill.) stands in the Tarnița study area in Suceava. For northeastern Romania, the Tarnița mining operation constituted a hotspot of industrial pollution. The primary processing of non-ferrous ores containing heavy metals in the form of complex sulfides was the main cause of pollution in the Tarnița region from 1968 to 1990. Air pollution of Tarnița induced substantial tree growth reduction from 1978 to 1990, causing a decline in tree health and vitality. Growth decline in stands located over 6 km from the pollution source was weaker or absent. Spruce trees were much less affected by the phenomenon of local pollution than fir trees. We analyzed the dynamics of resilience indices and average radial growth indices and found that the period in which the trees suffered the most from local pollution was between 1978 and 1984. Growth recovery of the intensively polluted stand was observed after the 1990s when the environmental condition improved because of a significant reduction in air pollution.


2011 ◽  
Vol 361-363 ◽  
pp. 288-295
Author(s):  
De Wei Chen ◽  
Xiao Ling Ge ◽  
Quen Tin Shi ◽  
Jiu Wang Tian

Using scanning electron microscope, the microscopic pictures of the surface on sediment have been obtained from the sub-micron titanium dioxide suspensions without dispersant or adding different types of dispersants. Deposits of titanium dioxide suspension have been observed and the mechanism of the dispersant has been analyzed. Meanwhile, deposits of titanium dioxide gray distribution figure have been gained by self-compiled Matlab program, which proved that the surface sediments is fractal, and the fractal dimension has been calculated under different conditions. The rules between suspension stability and fractal dimension have been achieved.


2010 ◽  
Vol 92 ◽  
pp. 283-288 ◽  
Author(s):  
Ming Shan Yang

The wollastonite/PP composites were manufactured by twin-screw extruder and the effects of compatabilizer, feeding method and screw configuration on the properties of wollastonite/PP composites were investigated in this paper. The dispersion of fibrous wollastonite in PP matrix was determined by scanning electron microscope (SEM). The results showed that the strength, toughness and flowability of the composite were simultaneously guaranteed by using three different types of PP resins, and the interfacial adhesion was improved greatly by adding the compatabilizer of PP-g-MAH, which increases the comprehensive properties of wollastonite/PP composite. The fibrous dispersion of wollastonite in PP matrix was achieved by using of side feeding and the weak-shear screw configuration, which reaches the good reinforcing effect.


2013 ◽  
Vol 664 ◽  
pp. 473-476 ◽  
Author(s):  
Xiao Li Zhang ◽  
Ai Fen Xu ◽  
Xiao Fan Chen ◽  
Ruo Lei Li ◽  
Chun Yan Yang

The production cost of amorphous alloys by vacuum induction melting (VIM) was very high. In order to reduce the cost, in this paper, alloys were prepared in alkaline crucible protected with different slags by Air induction melting (AIM). The comparison was found out between VTM and ATM in the research by using optical microscope (OM), scanning electron microscope (SEM), EDS, etc. Experimental results showed that Fe-Si-B alloys can be prepared by AIM with economic and technical feasibility.


Mechanik ◽  
2018 ◽  
Vol 91 (4) ◽  
pp. 322-324
Author(s):  
Wojciech Kacalak ◽  
Katarzyna Tandecka ◽  
Filip Szafraniec ◽  
Łukasz Rypina ◽  
Thomas G. Mathia

Micro-finishing with abrasive foils is characterized by a single use of the tool, which makes it necessary to optimally fill the space between the grains of the processing products. Microscopy research with the use of scanning electron microscopy enables a more complete evaluation of the machining process. Based on the structure of micro-chips, the phenomena occurring in the micro-finishing zone with foils with electrocorunded abrasive grains with a nominal size of 15 μm have been described. It has been shown that the analysis of micro-chips, the bottoms of machining marks and the size of micro-chips with segmentation construction allows to estimate the frequency of process discontinuities. Different types of spherical chips, created as a result of very high temperatures, are also presented as a phenomenon unfavorable for the process.


2019 ◽  
Vol 41 (4) ◽  
pp. 452-460
Author(s):  
Rubiene Neto Soares ◽  
Ronaldo Oliveira dos Santos ◽  
Breno Marques da Silva e Silva

Abstract: The aim of this study was to describe the morphology of fruit, seeds and seedlings, as well as the anatomy of the seed and the seedling of Pentaclethra macroloba (Willd.) Kuntze. Morpho-biometry was performed on fifty fruit samples and one hundred seeds. To describe the sequences of the morphological events of the germination stages, ten seeds were placed to germinate. Anatomical analysis was performed in a scanning electron microscope with seed samples and seedling leaves. The species has leguminous type fruit of 16.1 to 45.2 cm length and 4.1 to 7.3 cm width; seeds have a pleurogram and are eurispermic, ovoid, deltoid to elliptical and measure from 3.8 to 6.1 cm length and 2.5 to 5.7 cm width. Anatomically, the cotyledons are composed of thin-walled parenchyma cells with various oil cells. The seedlings have bipinnate leaves, with waxes and simple trichomes at the margins of the adaxial surface and paracytic stomata on the abaxial surface. The epicotyl is slightly twisted, with caducous cataphylls and a first pair of alternate eophylls. Germination is of the phanero-hypogean-reserve type. Taxonomic recognition of this species is possible in the field through the external morphological traits and can help in identification of saplings.


1981 ◽  
Vol 59 (5) ◽  
pp. 683-688 ◽  
Author(s):  
R. W. Rose Jr. ◽  
C. Gerald Van Dyke ◽  
C. B. Davey

Three different types of ectomycorrhizae found in the Southeastern United States on Eucalyptus nova-anglica and identified as being formed by Cenococcum geophilum, Pisolithus tinctorius, and Scleroderma geaster were examined with a scanning electron microscope (SEM). In overall appearance the three types of mycorrhizae could be distinguished easily from each other, particularly C. geophilum, which had a relatively smooth, undulate surface in comparison with the other two types. Detailed descriptions and comparisons of these ectomycorrhizae are given and the value of SEM in characterizing ectomycorrhizae is discussed


Minerals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1435
Author(s):  
Olev Vinn

Aragonite plays an important role in the biomineralization of serpulid polychaetes. Aragonitic structures are present in a wide range of serpulid species, but they mostly belong to one clade. Aragonitic structures are present in a wide range of marine environments, including the deep ocean. Aragonitic tube microstructures were studied using a scanning electron microscope. X-ray powder diffraction was used to identify the aragonite. Aragonite is used to build five different types of microstructures in serpulid tubes. The most common aragonitic irregularly oriented prismatic structure (AIOP) is also, evolutionarily, the most primitive. Some aragonitic microstructures, such as the spherulitic prismatic (SPHP) structure, have likely evolved from the AIOP structure. Aragonitic microstructures in serpulids are far less numerous than calcitic microstructures, and they lack the complexity of advanced calcitic microstructures. The reason why aragonitic microstructures have remained less evolvable than calcitic microstructures is currently unknown, considering their fit with the current aragonite sea conditions (Paleogene–recent).


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