scholarly journals Interacting environmental factors associated with the incidence of Hypoxylon canker on trembling aspen

1980 ◽  
Vol 10 (1) ◽  
pp. 17-24 ◽  
Author(s):  
Robert I. Bruck ◽  
Paul D. Manion

Twenty-three natural stands of trembling aspen (Populustremuloides Michx.) were surveyed for incidence of a canker caused by Hypoxylonmammatum (Wahl.) Miller. Canker incidence ranged from 0 to 70%. Horizonal soil samples were analyzed for their chemical and physical properties, and aspen leaf lamina tissue was analyzed for nutrient concentrations. A model accounting for 92% of the variation in canker incidence was constructed, utilizing 56 measured parameters, through the use of simple- and multi-correlation statistical analyses. Highly significant negative correlations were observed between canker frequency and each of aspen cover density, soil moisture, abundance of soil mottles, soil consistence, exchangeable soil Mn, Ca, and Na, and aspen tissue concentrations of Mn, Ca, and Na. Positive correlations were observed between canker incidence and each of soil temperature, soil depth, bulk density, rooting depth, and soil fractions over 2 and 10 mm. The association between exchangeable soil nutrients and aspen tissue concentrations was highly significant (p = 0.01). It is concluded that physical and chemical parameters of the soil which related most directly to moisture comprise a system of variables which are highly related to Hypoxylon canker incidence in trembling aspen.

Soil Research ◽  
1986 ◽  
Vol 24 (1) ◽  
pp. 95 ◽  
Author(s):  
ND Turvey ◽  
AB Rudra ◽  
J Turner

The objectives of the study were to determine whether selected soil physical and chemical parameters could be used as predictors of site and the productivity of Pinus radiata (D. Don). The study was carried out in the Lithgow district of New South Wales. Sixty plots were located in first-rotation unthinned stands of P. radiata of age 11 years. None of the stands had received fertilizer. The stands were selected to cover a wide range of merchantable volume production (0-175 m3 ha-1), and were located on a range of geological types including siltstone, medium-grained quartz sandstone, conglomerate, and rhyolitic tuff and lava. Soil depth was positively correlated, and per cent sand negatively correlated with all stand production variables. No other soil physical-or chemical variables were correlated consistently with stand variables. Discriminant analysis was used to test for the ability of a selected subset of soil physical and chemical variables to discriminate (a) between three volume production classes, and (b) between three geological groups. Soil depth, per cent sand, and total nitrogen contributed to two functions which discriminated between volume production groups. Cation exchange capacity, Bray phosphorus, per cent sand, exchangeable sodium, and total nitrogen contributed to two functions which discriminated between geological groups. Thus soil physical parameters were predominant in discriminating between volume production groups, and soil chemical parameters were predominant in discriminating between geological groups.


2012 ◽  
Vol 7 (4) ◽  
pp. 731-740 ◽  
Author(s):  
Iga Lewin ◽  
Krzysztof Szoszkiewicz

AbstractThe ecological drivers of macrophyte development in a lowland agricultural area were tested based on a 2008 survey on the Wkra River catchment. Our survey was carried out in the rivers of an agricultural area with relatively high concentrations of both nitrates and phosphates in the water. By using the Polish macrophyte method, we were able to calculate several botanical metrics. Canonical ordination analyses used to relate biological data to environmental variables such as physical and chemical parameters of water, surface water velocity or river width, were carried out using CANOCO for Windows. Redundancy analysis (RDA) showed that pH and alkalinity were the parameters best correlated with the distribution of macrophytes and values of macrophyte indices. The recorded values of the Macrophyte Index for River in the Wkra River and its tributaries reflected their good and moderate ecological status (the Water Framework Directive scale). Despite the fact that nutrient concentrations in the water were relatively high and that most of the sites represented eutrophic conditions, the results of this survey showed that non-nutrient parameters may play an important role in explaining aquatic plant occurrence in rivers that have been subjected to eutrophication.


2015 ◽  
Vol 16 (2) ◽  
pp. 432 ◽  
Author(s):  
S. TAS ◽  
I.N. YILMAZ

Distribution of potentially harmful microalgae and algal blooms were investigated at monthly and weekly time scales between October 2009 and September 2010 in the Golden Horn, a eutrophic estuary in the Sea of Marmara (Turkey). Several physical and chemical parameters were analysed together with phytoplankton composition and abundance. A total number of 23 potentially harmful and/or bloom-forming microalgae (14 dinoflagellates, 4 diatoms and 5 phytoflagellates) were identified throughout this study period, of which nine taxa have been confirmed to be toxic elsewhere in the world. Most harmful species and algal blooms were observed in late spring and summer particularly in the middle and upper estuaries, and nine taxa formed dense and successive algal blooms causing water discoloration. Nutrient concentrations increased significantly from the lower to the upper estuary. Additionally, high organic matter loads in the upper estuary could also have benefited by mixotrophic species. The increasing number of potentially harmful and bloom-forming species and algal blooms indicated that the GHE is a potential risk area for future HABs. 


2018 ◽  
Vol 6 (10) ◽  
pp. 123-130
Author(s):  
Yaroslava Zhukova ◽  
◽  
Pylyp Petrov ◽  
Olena Boloba ◽  
Tetiana Ohrimenko ◽  
...  

2000 ◽  
Vol 31 (4-5) ◽  
pp. 411-422 ◽  
Author(s):  
Gísli Már Gíslason ◽  
Jón S. Ólafsson ◽  
Hákon Adalsteinsson

The characteristics of stream and river ecosystems in arctic and alpine areas are determined mainly by the relative contribution of glacial meltwater, snowmelt, rainfall and groundwater. Each source generates a particular seasonal hydrological signature, affecting physical and chemical properties, and hence biological communities. The relative contribution of each source is sensitive to climate change. The study was concentrated on the glacial River W-Jökulsá and some non-glacial rivers in the central highlands of Iceland. The water in the glacial river was entirely glacial meltwater at the glacier margin, but the glacial contribution was about 20% 40 km downstream. However, its tributaries and non-glacial reference rivers were mainly springfed. The invertebrate fauna was confined to Chironomidae of the genus Diamesa close to the glacier, but other taxa (species and groups of species) occupied the river further downstream, where their diversity was close to that found in the reference rivers.


Membranes ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 221
Author(s):  
Rafał Tytus Bray ◽  
Katarzyna Jankowska ◽  
Eliza Kulbat ◽  
Aneta Łuczkiewicz ◽  
Aleksandra Sokołowska

The paper presents the results of research on the use of ultrafiltration, using membranes of 200 and 400 kDa separation, for disinfection of municipal treated wastewater. The research was conducted on a fractional technical scale using real municipal treated wastewater from two large wastewater treatment plants treating most of the wastewater over the one-million polycentric Gdańsk agglomeration (1.2 million inhabitants). UF 200 kDa and UF 400 kDa processes enabled further improvement of the physical and chemical parameters of treated wastewater. Total phosphorus (to below 0.2 mg/L–UF 200 kDa, 0.13 mg/L–UF 400 kDa) and turbid substances (to below 0.2 mg/L, both membranes) were removed in the highest degree. COD was reduced efficiently (to below 25.6 mgO2/L–UF 200 kDa, 26.8 mgO2/L–UF 400 kDa), while total nitrogen was removed to a small extent (to 7.12 mg/L–UF 200 kDa and 5.7 mg/L–UF 400 kDa. Based on the reduction of indicator bacteria; fecal coliforms including E. coli (FC) and fecal enterococci (FE) it was found that the ultrafiltration is an effective method of disinfection. Not much indicator bacterial were observed in the permeate after processes (UF 200 kDa; FC—5 CFU/L; FE—1 CFU/L and UF 400 kDa; FC—70 CFU/L; FE—10 CFU/L. However, microscopic analysis of prokaryotic cells and virus particles showed their presence after the application of both membrane types; TCN 3.0 × 102 cells/mL–UF 200 kDa, 5.0 × 103 cells/mL–UF 400 kDa, VP 1.0 × 105/mL. The presence of potentially pathogenic, highly infectious virus particles means that ultrafiltration cannot be considered a sufficient disinfection method for treated wastewater diverted for reuse or discharged from high load wastewater treatment plants to recreational areas. For full microbiological safety it would be advisable to apply an additional disinfection method (e.g., ozonation).


Environments ◽  
2021 ◽  
Vol 8 (6) ◽  
pp. 49
Author(s):  
Markéta Šourková ◽  
Dana Adamcová ◽  
Jan Winkler ◽  
Magdalena Daria Vaverková

Illegal dumps and landfills with disposed of tires are a fact of today, which should not be neglected as they represent a great ecological burden for the environment, affect the surrounding nature and disturb the landscape. This research was focused on testing the phytotoxicity of aqueous leachates from the fractions of tires in two sets of experiments—to simulate laboratory conditions (tire leaching in distilled water) and natural conditions (tire leaching in water from a recipient) using the Phytotoxkit testing kit (kit for the establishment of inhibition/stimulation effect on the root development) and the watercress test of phytotoxicity (biological method for the assessment of leachate phytotoxicity). Plants whose seeds were selected for the test were watercress (Lepidium sativum L.) and white mustard (Sinapis alba L.). The aqueous leachate was tested for 38 weeks. During the experiment, physical and chemical parameters were measured at intervals of 14 days by the testing instrument HACH TEST KIT: electric conductivity (EC), amount of dissolved oxygen (LDO) and pH. Results of root growth inhibition (IR) on the seeds of Lepidium sativum L. and Sinapis alba L. exhibited values ranging from 11.73% to 47.74% in the tested samples. Results of germination index (GI) on the seeds of Lepidium sativum L. exhibited values below 66% in the tested samples, which indicated the leachate phytotoxicity. In spite of the fact that similar studies are tackling the acute toxicity of leachates from tires (particularly to algae, embryos and animals), this research brings complementary information in testing the acute phytotoxicity of tire leachates to higher plants.


2020 ◽  
Vol 10 (2) ◽  
pp. 335-346
Author(s):  
Arnold Landry Fotseu Kouam ◽  
Gideon Aghaindum Ajeagah

Abstract The aim of this study is to determine the effectiveness of disinfectant on the viability of eggs from three nematode species (Ascaris, Trichuris, Ankylostoma). It was conducted in a microcosm from June 2018 to June 2019. The wastewater scan was sampled using 5 L sterile containers, the sample was arranged in four replicas, three tests and one control. The test samples received three disinfectants (Moringa, calcium hypochlorite and Moringa associated with calcium hypochlorite) at varying concentrations. The physical and chemical parameters were measured before and after the application of each disinfectant. The samples were then observed under an optical microscope. The viability of the eggs was determined by incubating the Petri dish samples at 30 °C for 30 days. The analyses show that some physicochemical parameters can significantly influence the efficacy of disinfectant on the eggs. The calcium hypochlorite associated with Moringa at 0.6 g/L showed greater efficacy on reducing viability and inactivation of eggs with 100% efficacy yield rates on Ankylostoma and Trichuris trichiuria and 97% on Ascaris lumbricoides eggs; this efficacy is significantly different from that observed on samples treated with Moringa and simple calcium hypochlorite. Of the three parasites tested, A. lumbricoides showed greater resistance to the disinfectant.


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