scholarly journals Fungal colonization of soil-buried plasticized polyvinyl chloride (pPVC) and the impact of incorporated biocides

Microbiology ◽  
2006 ◽  
Vol 152 (6) ◽  
pp. 1731-1739 ◽  
Author(s):  
H. A. Sabev ◽  
P. S. Handley ◽  
G. D. Robson
Keyword(s):  
Forest Soil ◽  
Polyvinyl Chloride ◽  
Soil Fungi ◽  
Dioctyl Phthalate ◽  
Fungal Colonization ◽  
Penicillium Janthinellum ◽  
Grassland Soil ◽  
Plastic Surface ◽  
The Impact ◽  
Dioctyl Adipate

Plasticized polyvinyl chloride (pPVC) with or without incorporated biocides was buried in grassland and forest soil for up to 10 months. The change with time in viable counts of fungi on the plastic surface was followed, together with the percentage capable of clearing the two plasticizers dioctyl adipate (DOA) and dioctyl phthalate (DOP). With time fungal total viable counts (TVC) on control pPVC increased and the fraction able to clear DOA was considerably higher than the average estimated in both soil types. A total of 92 fungal morphotypes were isolated from grassland soil and 42 from forest soil with the greatest variety of fungal isolates observed on control pPVC. The incorporation of biocides into pPVC affected both fungal TVC and the richness of species isolated. The biocides NCMP [n-(trichloromethylthio)phthalimide], OBPA (10,10′-oxybisphenoxarsine) and OIT (2-n-octyl-4-isothiazolin-3-one) were the most effective in grassland soil, and TCMP [2,3,5,6-tetrachloro-4-(methylsulphonyl)pyridine] and NCMP the most effective in forest soil. In grassland soil, Penicillium janthinellum established as a principal colonizer and was recovered from all pPVC types. DOP clearers were found at much lower levels than DOA clearers, with Doratomyces spp. being the most efficient. At the end of 10 months the physical properties of the pPVC were altered; changes in stiffness were the most significant for heavily colonized grassland-buried pPVC samples, whereas in forest soil, the extensibility of the pPVC was affected more than the stiffness. These results suggest that fungi are important colonizers of pPVC buried in soil and that enrichment of soil fungi capable of clearing DOA occurs during colonization of the plastic surface. The results also demonstrate that incorporated biocides have a marked impact on the richness of species colonizing the pPVC surface.

A Predictive Model of the Impact of the Skidding System on Forest Soil in Severe Climatic Conditions

2020 ◽  
pp. 131-144
Author(s):  
S.E. Rudov ◽  
◽  
V.Ya. Shapiro ◽  
O.I. Grigoreva ◽  
I.V. Grigorev ◽  
...  
Keyword(s):  
Forest Soil ◽  
Warm Season ◽  
Climatic Conditions ◽  
Soil Freezing ◽  
Class Iii ◽  
Freezing And Thawing ◽  
Metal Structures ◽  
Rapid Adjustment ◽  
Soil Freezing And Thawing ◽  
The Impact

In the Russian Federation logging operations are traditionally carried out in winter. This is due to the predominance of areas with swamped and water-logged (class III and IV) soils in the forest fund, where work of forestry equipment is difficult, and sometimes impossible in the warm season. The work of logging companies in the forests of the cryolithozone, characterized by a sharply continental climate, with severe frosts in winter, is hampered by the fact that forest machines are not recommended to operate at temperatures below –40 °C due to the high probability of breaking of metal structures and hydraulic system. At the same time, in the warm season, most of the cutting areas on cryosolic soils become difficult to pass for heavy forest machines. It turns out that the convenient period for logging in the forests of the cryolithozone is quite small. This results in the need of work in the so-called off-season period, when the air temperature becomes positive, and the thawing processes of the soil top layer begin. The same applies to the logging companies not operating in the conditions of cryosolic soils, for instance, in the Leningrad, Novgorod, Pskov, Vologda regions, etc. The observed climate warming has led to a significant reduction in the sustained period of winter logging. Frequent temperature transitions around 0 °C in winter, autumn and spring necessitate to work during the off-season too, while cutting areas thaw. In bad seasonal and climatic conditions, which primarily include off-season periods in general and permafrost in particular, it is very difficult to take into account in mathematical models features of soil freezing and thawing and their effect on the destruction nature. The article shows that the development of long-term predictive models of indicators of cyclic interaction between the skidding system and forest soil in adverse climatic conditions of off-season logging operations in order to improve their reliability requires rapid adjustment of the calculated parameters based on the actual experimental data at a given step of the cycles.

scholarly journals Insect herbivory facilitates the establishment of an invasive plant pathogen

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Martin M. Gossner ◽  
Ludwig Beenken ◽  
Kirstin Arend ◽  
Dominik Begerow ◽  
Derek Peršoh
Keyword(s):  
Invasive Plant ◽  
Pathogenic Fungus ◽  
Feeding Activity ◽  
Insect Herbivory ◽  
Forest Health ◽  
Mechanical Damage ◽  
Pathogenic Fungi ◽  
Fungal Colonization ◽  
Feeding Damage ◽  
The Impact

AbstractPlants can be severely affected by insect herbivores and phytopathogenic fungi, but interactions between these plant antagonists are poorly understood. We analysed the impact of feeding damage by the abundant herbivore Orchestes fagi on infection rates of beech (Fagus sylvatica) leaves with Petrakia liobae, an invasive plant pathogenic fungus. The fungus was not detected in hibernating beetles, indicating that O. fagi does not serve as vector for P. liobae, at least not between growing seasons. Abundance of the fungus in beech leaves increased with feeding damage of the beetle and this relationship was stronger for sun-exposed than for shaded leaves. A laboratory experiment revealed sun-exposed leaves to have thicker cell walls and to be more resistant to pathogen infection than shaded leaves. Mechanical damage significantly increased frequency and size of necroses in the sun, but not in shade leaves. Our findings indicate that feeding damage of adult beetles provides entry ports for fungal colonization by removal of physical barriers and thus promotes infection success by pathogenic fungi. Feeding activity by larvae probably provides additional nutrient sources or eases access to substrates for the necrotrophic fungus. Our study exemplifies that invasive pathogens may benefit from herbivore activity, which may challenge forest health in light of climate change.

Effect of the morphology of polyvinyl chloride on the impact strength of materials based on it

1986 ◽  
Vol 28 (11) ◽  
pp. 2715-2722 ◽  
Author(s):  
T.G. Monakhova ◽  
D.N. Bort ◽  
L.I. Batuyeva ◽  
V.G. Marinin ◽  
T.B. Zavarova ◽  
...  
Keyword(s):  
Impact Strength ◽  
Polyvinyl Chloride ◽  
Strength Of Materials ◽  
The Impact

scholarly journals TRANSFORMATION OF OPEN SOIL SURFACE UNDER THE IMPACT OF RAINFALL IN MODEL EXPERIMENT

2018 ◽  
pp. 23-40 ◽  
Author(s):  
G. V. Vindeker ◽  
E. Yu. Prudnikova ◽  
I. Yu. Savin
Keyword(s):  
Forest Soil ◽  
Model Experiment ◽  
Soil Surface ◽  
Significant Rise ◽  
Leached Chernozem ◽  
Surface Image ◽  
Average Reflectance ◽  
Grey Forest Soil ◽  
Surface Drying ◽  
The Impact

During the model experiment we exposed samples from surface layer of leached chernozem, grey forest and soddy-podzolic soils to study the impact of raindrop action on their surface. According to our results, surface of leached chernozem and grey forest soil transformed similarly forming the crust separated by the cracks. The crust consisted of light (washed silt fraction) and dark (compacted fine material) areas. As for the soddy-podzilic soil, we observed surface accumulation of sand and washed mineral grains. Surface image classification showed that cracks generally tended to increase in area during the surface drying. However, leached chernozem cracked quicker and heavier compared to grey forest soil. In addition, the proportion between light and dark areas of the crust for these two types of soil changed differently as well. In conditions of different transformation cycles divided by heavy rainfalls, the changes of cracks position and the increase of light crust area was observed, while dark area moved to the cracks. Such spatial rearrangement resulted in the increase of average reflectance in RGB channels. The inequality between reflectance in different channels increased as well. During the experiment significant surface lightening occurred. It mainly affected the light area of crust and led to significant rise in reflectance in red channel.

scholarly journals Re-Evaluating the Age of Deep Biosphere Fossils in the Lockne Impact Structure

Geosciences ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 202 ◽  
Author(s):  
Mikael Tillberg ◽  
Magnus Ivarsson ◽  
Henrik Drake ◽  
Martin J. Whitehouse ◽  
Ellen Kooijman ◽  
...  
Keyword(s):  
Hydrothermal Activity ◽  
Crystalline Rock ◽  
Hydrothermal Systems ◽  
Fungal Colonization ◽  
Precambrian Basement ◽  
Impact Event ◽  
Deep Biosphere ◽  
Microbial Ecosystems ◽  
The Impact

Impact-generated hydrothermal systems have been suggested as favourable environments for deep microbial ecosystems on Earth, and possibly beyond. Fossil evidence from a handful of impact craters worldwide have been used to support this notion. However, as always with mineralized remains of microorganisms in crystalline rock, certain time constraints with respect to the ecosystems and their subsequent fossilization are difficult to obtain. Here we re-evaluate previously described fungal fossils from the Lockne crater (458 Ma), Sweden. Based on in-situ Rb/Sr dating of secondary calcite-albite-feldspar (356.6 ± 6.7 Ma) we conclude that the fungal colonization took place at least 100 Myr after the impact event, thus long after the impact-induced hydrothermal activity ceased. We also present microscale stable isotope data of 13C-enriched calcite suggesting the presence of methanogens contemporary with the fungi. Thus, the Lockne fungi fossils are not, as previously thought, related to the impact event, but nevertheless have colonized fractures that may have been formed or were reactivated by the impact. Instead, the Lockne fossils show similar features as recent findings of ancient microbial remains elsewhere in the fractured Swedish Precambrian basement and may thus represent a more general feature in this scarcely explored habitat than previously known.

scholarly journals The Impact of Nickel Mining on Soil Properties and Growth of Two Fast-Growing Tropical Trees Species

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Ricksy Prematuri ◽  
Maman Turjaman ◽  
Takumi Sato ◽  
Keitaro Tawaraya
Keyword(s):  
Forest Soil ◽  
Dry Weight ◽  
Natural Forest ◽  
Total Carbon ◽  
Available Phosphorus ◽  
Shoot Height ◽  
Fast Growing ◽  
Shoot Dry Weight ◽  
Nickel Mining ◽  
The Impact

Opencast nickel mining is common in natural forests of Indonesia. However, rehabilitation of postmining degraded land is difficult. We investigated the effect of opencast nickel mining on soil chemical properties and the growth of two fast-growing tropical tree species, Falcataria moluccana and Albizia saman. Soil was collected from post-nickel mining land and a nearby natural forest. Soil pH, available phosphorus (P) concentration, total carbon (TC) and total nitrogen (TN) concentration, C/N ratio, cation exchange capacity (CEC), and exchangeable K, Na, Mg, Ca, Fe, and Ni concentrations were determined. Falcataria moluccana and A. saman were then grown in the collected soils for 15 weeks in a greenhouse. Shoot height and shoot and root dry weights of the seedlings were measured. The post--nickel mining soils TN, TC, available P, CEC, and exchangeable Ca and Na concentrations decreased by 98%, 93%, 11%, 62%, 85%, and 74%, respectively, in comparison with the natural forest soils. The pH of postmining soil was higher than natural forest soil. Shoot dry weight of F. moluccana seedlings grown in postmining soil was significantly ( P < 0.05 ) lower than that of seedlings grown in natural forest soil. However, there was no difference in shoot dry weight between A. saman seedlings grown in natural forest soil and postmining soil, as well as root dry weights of both species. The results indicate that opencast nickel mining decreased soil fertility, which subsequently inhibited the growth of F. moluccana and A. saman seedlings.

Changes in the properties and productivity of leached chernozem and gray forest soil under the impact of ameliorants

2015 ◽  
Vol 48 (10) ◽  
pp. 1149-1158 ◽  
Author(s):  
A. Kh. Yapparov ◽  
L. M.-Kh. Bikkinina ◽  
I. A. Yapparov ◽  
Sh. A. Aliev ◽  
A. M. Ezhkova ◽  
...  
Keyword(s):  
Forest Soil ◽  
Gray Forest Soil ◽  
Leached Chernozem ◽  
The Impact

The Mechanisms of Material Removal in the Fluidized Bed Machining of Polyvinyl Chloride Substrates

2013 ◽  
Vol 135 (1) ◽  
Author(s):  
M. Barletta ◽  
V. Tagliaferri ◽  
F. Trovalusci ◽  
F. Veniali ◽  
A. Gisario
Keyword(s):  
Fluidized Bed ◽  
Polyvinyl Chloride ◽  
Process Parameters ◽  
Material Removal ◽  
High Speed ◽  
Mesh Size ◽  
Main Process ◽  
Machining Time ◽  
Polymeric Substrates ◽  
The Impact

In this paper, the mechanisms of material removal during the fluidized bed machining (FBM) of polymeric substrates are analyzed. Cylindrical components composed of polyvinyl chloride (PVC) were exposed to the impact of abrasives while rotating at high speed within a fluidization column. The interaction between the Al2O3 abrasive media and the PVC surfaces was studied to identify the effect of the main process parameters, such as the machining time, the abrasive mesh size, and the rotational speed. The change in the surface morphology as a function of the process parameters was evaluated using field emission gun—scanning electron microscopy (FEG-SEM) and contact gauge profilometry. An improvement in the finishing of the processed surfaces was achieved, and the related mechanisms were identified. The roles of the impact speed and the contact conditions between the abrading particles and the substrate were also investigated.

Sign in / Sign up

Export Citation Format

Share Document