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Field experiments were conducted to evaluate the efficacy of glyphosate (H1) and fluazifop-P-butyl (H2) herbicides with adjuvants on the common reed without cutting and at two different cutting levels (10 and 30 cm). The adjuvants were urea, nitric acid and sulfonic acid. The relative importance value (RIV), leaf chlorophyll content and plant density were determined to assay the efficacy of herbicides. Glyphosate treatment only (H1 a) was more effective than fluazifop-P-butyl (H2 a) on reeds without cutting and at the 10 cm cutting level. However, no significant difference was observed between them at the 30 cm cutting level. A positive effect of plant cutting occurred on the efficacy of all herbicides applied alone or in a tank mix with adjuvants. Furthermore, the 10 cm cutting level was more effective in eradication of reeds than the 30 cm cutting level. The adjuvants significantly improved the efficacy of the recommended (Hb) and half recommended (Hc) herbicide rates in comparison to being used alone on uncut reeds. The reduction percentages were 94.5, 86.99, 76.61 and 69.94 for H1 b, H1 c, H2 b and H2 c treatments, respectively. However, the adjuvants did not improve the glyphosate effect at different levels of cutting. Conversely the reduction percentage of reeds was improved by the recommended rate of fluazifop-P-butyl with adjuvants (H2 b) to 92.77% and 84.62% at 10 and 30 cm cutting levels, respectively.
Differences between 13 common reed (Phragmites australis) populations, growing in urban conditions within the town of Poznań (western Poland), are described by 8 morphological traits of panicles' variability and the frequency of peroxidase (dimeric and monomeric) allozymes. Values of morphological characters were processed statistically using agglomerative clustering by the closest neighbours (UPGMA) method based on Euclidean distances. Proteins were separated in the starch gel electrophoretic procedure, showing cathodic migration. Populations are polymorphic and have a certain level of heterozygosity. The level of populations' diversity (DST = 0.097) is lower than the intra-population variability (GST = 0.187). The gene flow between populations is rather low (Nm = 1.090).
W strefie zalewowej Jeziora Kwiecko, powstałej na skutek pracy elektrowni szczytowo-pompowej, wytyczono stałe transekty o różnym poziomie zatapiania. Badano wpływ zatapiania w cyklu dobowym na strukturę przestrzenną i morfologię populacji trzciny pospolitej. Stwierdzono, że wzrost intensywności zatapiania wpływa bezpośrednio na zwiększenie zagęszczenia i redukcję architektury pędów. Ograniczeniu ulega wysokość i średnica pędów, ich powierzchnia asymilacyjna oraz długość wiech. Wysiłek cenopopulacji zatapianych skierowany jest na powiększenie areałów osobniczych, a dominujące rozmnażanie wegetatywne potwierdza stabilność populacji.
Analyses of three macroelements and six microelements in reed stems, accompanied by investigation of periphyton density were carried out in two reservoirs: Żarnowieckie Lake and Puck Bay. To reveal the influence of chemical composition of biotic substrate on periphyton qualitative and quantitative characteristics, ordination methods were applied (PCA, CCA, DCA, RDA). The results indicated that Copoepoda (Harpacticoida) and Chlorophyta preferred reed substrate with relatively high zinc, sulfur and chromium but low manganese and carbon content. In turn, Nematoda reached the highest density on a substrate rich in manganese. Mercury in reed limited density of Arachnidae-Hydrachnella and Chironomidae larvae, an effect which was not observed for Ciliata libera. Copepoda (Harpacticoida) preferred low chromium and lead content and high carbon/nitrogen ratio, which meant low nitrogen concentration in the reed substrate. Moreover, preferences of Nematoda and Bacillariophyta for freshwaters and Copepoda for brackish waters were indicated. The results presented in this paper should be treated as a contribution to more detailed research on interactions between reed chemical composition and periphyton density.
Results of the survey into expansive growth of the common reed (Phragmites australis (Cav.) Trin. ex Steud.) carried out in the upper Narew River valley (NE Poland) within the whole area of Narew National Park (6810 ha) (NNP) are presented in the paper. The Narew River is an anastomosing river in the part subjected to the analysis and an open swampy bog ecosystem has formed within its valley. Sedge communities and to a lesser degree meadow communities are typical plant communities in the study area. Till the end of the 1970’s, the area was agriculturally used. Since the beginning of the 1980’s when grassland mowing was discontinued, expansion of reed communities has been recorded. The analysis of reed expansion has been based upon data on its range originating from interpretation of aerial NIR photos made in 1987 and 1997. The field survey and analysis of the air photos have shown that the reed expansion rate differs depending on the location in the study area. Assessment showed that in 1987 the total area of the common reed stands equalled 1214.75 ha (18% of the NNP area), and in 1997 – 2300.6 ha (34%). Due to considerable homogeneity of habitat features within the valley and habitat requirements of reed, a basic hypothesis has been put forward that the rate of reed expansion in terms of the increase of reed community area is related to bankline density and length. The material obtained and statistical analysis have confirmed that assumption. Besides, it was mentioned that cessation of mowing sedge grasslands along with a change in character of spring surface flooding also contributed to reed expansion.
Using a transect technique, each of 12 reed Phragmites australis (Cav.) Trin ex Steud. populations collected in middle part of Odra River-basin, represented by more than 30 plants, were compared with 3 populations from other part of the country and 1 from France. Each panicle was examined according to 15 morphological traits. Results of measurements were subjected to multivariate analysis of variance, to analysis of canonical variables and used for construction of a minimum spanning tree (= dendrite) on the basis of the shortest Mahalanobis distances. The obtained results indicate that populations are generally similar. One population from France (Orleans) shows visible separateness. It may suggest that morphological traits of panicles may be useful in investigations of the reed P. australis populations of a larger geographical distribution.
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