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Woody plants grown near the roads are force-fed by salt and this has negative effect on their growth and decorative value. The aim of the presented study was to investigate the effects of salinity on growth and nutrient composition of four trees species often planted along the roads and streets in Poland. Two years old seedlings (bare root) of four tree species: Acer negundo, A. platanoides, Quercus robur and Tilia cordata were potted and grown outside under four soil salinity levels maintained by drenching plants with tap water containing 0.25, 0.5, 1.5, and 3.3g NaCl/L H2O. Plant height, soil samples for electrical conductivity (EC) and pH determination as well as leaf samples for macroelements (N, P, K, Ca, Mg) content evaluation were collected after each growing season of two years of experiment. Electrical conductivity of the growing medium varied insignificantly between species, but salt concentration in the growing medium was distinctly higher in the upper than in the bottom part. Soil salinity had strong but variable effect on plant growth during the experiment. Only Acer negundo growth was not affected even by the highest concentration of NaCl solution. With increasing salinity of growing medium more Na+ was taken by all species but the biggest amount of sodium ions was accumulated in the leaves of Tilia cordata, while the lowest in Acer negundo. Than potassium ions content decreased with increasing medium salinity only in the leaves of Quercus robur and Tilia cordata. In the leaves of Acer platanoides and Tilia cordata calcium concentration was decreased at increased salinity, in two other tested species amount of Ca2+ in the leaves was elevated. The main conclusion that can be drown is that Acer negundo is highly tolerant to salinity stress while Acer platanoides was the most sensitive among tested species.
In the years 2003–2005 studies were conducted in the area of Lublin the aim of which was to study the population dynamics of aphids colonizing the trees of Juglans regia L. in the street and the park sites against the course of weather conditions. The weather in spring probably had no effect on the date of hatching of the larva of fundatrix, which was usually observed in the third 10-days’ period of May. On the other hand, the dry period, heat waves (above 30°C) and stormy rainfalls affected the break in the aphid population observed in July and August. The maximum population of P. juglandis was found in the second 10-days’ period of June, while that of Ch. juglandicola – at he turn of June and July. The highest number of P. juglandis was observed in 2004, while that of Ch. juglandicola in 2003. In 2003 the dominating species in both sites was Ch. juglandicola, while in the other years of studies it was P. juglandis.
The studies were conducted in the years 1999 - 2001 in the green area of the Lublin city in the street (A) and park (B) sites. The purpose of the studies was to determine the dynamics of the bean aphid population (Aphis fabae Scop.) and the effect of its feeding on the blooming of park roses (Rosa sp.). The presence of dwarf specimens of A. fabae was observed only on the crown petals and the sepals. Their feeding significantly affected the decorative character of roses, since the crown petals inhabited by them were faster to dry out and fall down. The presence of aphids on the shrubs was found throughout the period of about two months, and the aphids were more numerous in the street site.
The studies were conducted in Lublin in the years 1999-2001 in two sites (street and park ones) on the trees Crataegus x media Bechst. The purpose was to determine the domination and frequency of particular aphid species, their effect on the decorative character of plants as well as the occurrence of the aphidophagous in aphid colonies. It was found out that A. pami was the dominating species in both sites. The decorative character of the studied trees was lowered by aphids A. pami and aphids from the genus Dysaphis. Aphids from the genus Dysaphis also caused changes in the chemical composition of the injured plant parts. The presence of predatory arthropods was observed in aphid colonies occurring on hawthorn. The most numerous of these were the larvae of Syrphidae and Caccinellidae. The culture of parasitized aphids gave numerous flights of parasitoids and hyperparasitoids. Greater number of both predators and parasitoids of I and II grades were observed in the street site as compared to the park site.
W próbkach osadów ściekowych powstających w obiektach kanalizacji deszczowej głównych ulic Krakowa, pobranych w czterech sezonach 2002/03 oceniono zawartość Fe i Mn, oraz skład ziarnowy i mineralny a także zmiany wskaźników fizykochemicznych środowiska wodnego osadów, jak pH, potencjału oksydacyjno-redukcyjnego Eh i przewodności elektrolitycznej właściwej (PEW).
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