Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 20

Liczba wyników na stronie
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych:  urban green area
help Sortuj według:

help Ogranicz wyniki do:
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
The vegetation of allotment gardens is an important element of urban green areas and constitutes a habitat where many groups of insects exist, including aphids. This research involved the monitoring of winged morphs of aphids in allotment gardens in the area of Poznań with the use of Moericke traps. The fauna structure of aphids in two large allotment gardens was demonstrated by comparing the activity of winged morphs of aphids in 2000–2001 and 2014–2015. The vegetation of these gardens was accompanied by the rich fauna of aphids. For four growing seasons, 113 species or groups of aphid species were captured with the traps. Major changes were reported in the structure of the collected fauna in the period of time when the research was conducted. The differences concerned particular positions of collected species in aphid communities. The abundance of Anoecia corni, Aphis sambuci, Phorodon humuli and Periphyllus testudinaceus increased, and now hold the position of subdominants of the communities, whereas Myzus persicae and Hyalopterus pruni decreased in comparison with the situation more than ten years ago. Rhopalosiphum padi still remains an eudominant in the communities. The main reason for this phenomenon is thought to be due to changes in the vegetation composition of gardens because the gardens are being used differently. The production function has changed to recreation.
This study was carried out in Rome city from 1991 to 1999. In a total of 47 urban parks and suburban woods, 22 wooded areas were occupied by Great Spotted Woodpeckers during the breeding period. All woods greater than 50 ha in area were occupied by woodpeckers. On a five year scale, territorial stability was positively correlated with woodland size. The requirement of wooded area per territory was slightly higher in urban parks (6.7 ± 2.7 ha, n = 10 wooded areas) than in suburban woods (5.7 ± 1.3 ha, n = 5), and was negatively correlated to the vegetation cover. The area of woodland per territory in Rome was higher than in neighbouring deciduous oak woods. This suggests that urban habitats are of inferior quality for breeding Great Spotted Woodpeckers, probably owing to features of their vegetation and their isolation from other woodland patches. Maintaining mature stands of natural vegetation with old and dead trees in larger urban parks could be useful to encourage the occurrence of Great Spotted Woodpecker in cities.
The antifungal activity of two fungicides, i.e. Rovral Flo 255 SC and Sportak Alpha 380 EC was determined by in vitro tests to 12 fungal species isolated from blue spruce (Picea pungens) and its cultivar Glauca. It was found that Sportak Alpha 380 EC has the highest antifungal activity and the widest range of application to all fungi under examination. Rovral Flo 255 SC has shown significantly poorer activity.
We investigated the spatiotemporal dynamics of a breeding bird community in the urbanized landscape of Lublin city (150 km2, 0.5 million inhabitants, SE Poland). We conducted 211 separate territory mapping surveys during 26 years (1982–2007) in 24 green areas (0.2–30.1 ha in size), distributed along an urbanization gradient. We recorded a total of 16,151 territories of 65 species. According to the estimated species richness, we detected all the species present in the studied plots. The three species community indices (species richness, Shannon-Wiener index and abundance – number of breeding pairs in census plot) increased with increasing tree stand age and area of the site, while it decreased as the proportion of biologically inactive areas increased. The three indices showed significant negative trends as the study period progressed. The mean decreasing rate was 0.2 species and 2.3 territories per year. Distance to the city centre and understorey cover negatively affected bird abundance, while they positively affected species richness and the Shannon index. Tree stand age seems to be the most important of the three indices among the analyzed explanatory variables. Our results show that the diversity of breeding avifauna in an urbanized landscape can be significantly shaped by the proper management of vegetation and size of green areas in the city. The long term decline of the three diversity indices seems to be the most important outcome of our study and requires further research and monitoring.
The breeding (in 1991–1996) and wintering (1991/1992–1993/1994) avian community were surveyed in a suburban wood (29.27 ha) in Wrocław city (SW Poland). The 1992 breeding season began together with a drastic clearance of the compact undergrowth with the use of heavy machinery. A slump of abundance of the species nesting on the ground and small shrubs (≤1.5 m) followed, coupled with some modifications to their breeding behaviour, such as clustering of several singing males on the remaining bushes (Blackcap Sylvia atricapilla L.) and nesting in the piles of cut branches (Blackbird Turdus merula L.). As a result of the removal of 52% of the whole undergrowth the density of species nesting on the ground and small shrubs in 1992 was by 26% lower than in 1991 (decrease from 61.8 to 46.3 pairs 10 ha⁻¹). After 1993 a spontaneous regeneration of the bushy vegetation took place, with the ground and shrub-nesting species’ density recovering to 49.4 pairs 10 ha⁻¹ in 1996. After 1991 the park was colonized by 9 new hole-nester species, which was accompanied by the increase of density of this group (from 21.9 in 1991 to 37.9 pairs 10 ha⁻¹ in 1996). Throughout the entire study period a slight rise of density of birds nesting in tree canopies was visible (21.3 pairs 10 ha⁻¹ in 1991 and 33.8 pairs 10 ha⁻¹ in 1996). A year after the shrub clearance the wintering bird abundance was significantly lower (half of the previous numbers), with plant-eaters and insectivores hardest hit, especially Great Tit Parus major L. (average number of inidividuals per one count amounted to 59.2 in 1991/1992 and 21.9 in 1992/1993) and Blue Tit Parus caeruleus L. (respectively 37.0 and 16.0 ind.). An adequate timetable of vegetation clearance must be set up in the course of any decision-making process regarding green areas management to ensure the environmental issues are addressed properly
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.
A total of 3478 specimens, representing 47 aphid species, were collected in a green urban area of Poznań in 1998.
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.