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The effects of destruction of meadow which has been degraded as a result of the building of fishing pond in 1989. The directions of plant succession on those area during the last 10 years have been also evaluated. The study has taken the non-used former grassland and extensive but still used meadow located on the area of village Przyrownica, near Pisia river. In the year 1998 10 phytosociological records on the meadow and on the non-used area have been recorded. On the non-used area (the old fishing pond) 39 plant species have been recorded, the highest constancy was been observed for Carex gracilis, Juncus conglomeratus, Typha lalifolia, Sium latifolium and for appeared spontaneously grass species for Phragmites communis and Phalaris arundinacea. Majority of plant communities belonged to class Phragmitetea association of Phragmition and Magnocaricion. In more humid habitats class Molinio-Arrhenatheretea has been recorded. Besides grass species which appeared spontaneously the most important were Phalaris arundinacea. Phragmities communis, Poa trivialis, Poa palustris. On the comparison on the control extensive meadow appeared totally 62 plant species. Molinio-Arrhenatheretea class dominated (37 species), particularly from Molinietalia. Phragmitatea class has been represented only by two but very good adopted to the difficult environmental conditions grass species Phalaris arundinacea and Phragmites communis. Besides the other grass species the most important were Alopecurus pratensis, Holcus lanatus, Festuca arundinacea, and locally Deschampsia caespitosa, Poa trivialis, Poa palustris, Dactylis glomerata. The results show that this tested area does not suit to recultivation and it is not possible to come back to the former meadow. Plant repeated succession is going into the direction of forestry or bug communities. The degraded non-agricultural area has rather biological then agricultural value.
Based on 301 phytosociological records the 17 plant associations and following classes were destinguished: Phragmitetea (9), Molinio-Arrhenatheretea (6) and Plantaginetea (2). The changes of meadows plant communities in period 1956-1997 were also presented. The results confirmed that the areas were covered by poor plant communities substantially increased. During that time the association Cirsio-Polygonetum and species - Polemonium coeruleum, Molinia coerulea dissappeared. Presently the 170 species vascular flora were found on the area. The new rare specics: Euphorbia palustris, Sonchus paluster and Carex clisticha were appeared.
Content available Ocena zmian florystycznych runi trawnikow miejskich.
The experiments on the street lawns were conducted in the years 1986 and 1996-1997. The aim of the experiments was to investigate the changes in the composition of the street lawns sward during the 10 years by estimating the floral composition and the share of living as well as synantrophic forms. The number of plant species in the sward increased from 77% in 1986 to 91% ten years later. Within the same period of time the grass share in the sward cover composition decreased from 59% to 24%. The group of dicotyledonous species was the dominating one. The share of taxons increased considerably within both the leguminous plants group (from 3 to 14 species) as well as the cover composition (from 3,5% to 17%). During the ten years in question the share of lawn plants (of Molinio-Arrhenatheretea) decreased, whilst that of synanthropic plants increased. Among the sward cover composing plants the native species, that is apophytes, dominated. However their share in the sward cover decreased from 96% to 82% during the period under investigation. Both the synantrophic plants as well as the living forms share in the lawn sward influenced the sustainability of lawns. The negative influence is that of the considerable share of the one-year species. During the ten years their share in the sward cover composition increased from 8% in 1986 to 33% in 1996-97. The changes in the lawns composition during the ten-year period influenced the sustainability of lawns. They were positive on one hand - the sward cover increased due to the increased number of taxons. On the other hand they were negative as the share of the ruderal species and that of intruder species increased.
Content available Zalesienia a sukcesja wtórna
One of the result of human economy activity is the existence of expanse areas being post-industrial west lands - without plant cover and its surface is usually covered by specific substratum (e.g. coal dust) By means of transect system it has been investigated which species, and how fast manage to establish on those habitats. New data for species observed by such methods have been obtained. The investigation on primary succession on coal mine sedimentation pools (lagoons) has been carried out for seven years on 137 objects (few hectares each). The presented paper contains: the list of grass species observed on (all 137) objects; ecological characteristics of stated species; the frequency of the plants occurrence; the participation of grasses among species which establish first on the bare coal dust substratum; the grass participation in flora composition during the plant cover development; the grasses participation in plant communities. There are some grass species which occur quite often on the investigated objects such as: Agropyron repens, Agrostis stolonifera, Apera spica-venti, Calamagrostis epigejos, Dactylis glomerata, Deschampsia caespitosa, Festuca rubra, Holcus lanatus, Lolium perenne, Phragmites australis, Poa annua, Poa compressa subsp. compressa and Poa pratensis. Many aspects of the problem of plant cover creation on post-industrial wastelands still need to be explained.
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