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Little is known about the impact of exotic invasive plant species on soil invertebrate communities. The influence of highly productive invader Reynoutria sachalinensis on the soil microarthropods was studied. Three sites, with different coverage of the invader, have been selected in the mixed forest in the Jura Krakowsko-Częstochowska. The lowest abundance of microarthropods and the lowest oribatid species richness were noted in the monospecific Reynoutria infestation stand. The reduction of abundance of saprophagous mites (Oribatida, Acaridida) and springtails were observed at the totally invaded site, whereas gamasid and actinedid mites reacted positively to the presence of Reynoutria. Observed abundances and species richness of microarthropods at studied sites were in accordance with theories on biodiversity. Antifungal activity of phenolic compounds present in leaves of R. sachalinensis may negatively influence on saprophagous representatives of microarthropods. On the other hand, predacious mites profited from the simplified vegetation structure.
Gujarat has a coast line of approximately 1700 Km, varying in different habitat conditions. The state has two gulfs viz., gulf of Khambhat and gulf of Kachchh. Edaphic conditions of different habitats in ‘Bhal’ region of Gujarat state which falls in two districts viz. Ahmedabad and Bhavnagar district of Gujarat state. The coastal vegetation depends on the edaphic conditions of the region. The coastal flora of the ‘Bhal’ region belonging to Bhavnagar district has species like Suaeda nudiflora, Prosopis chilensis, Dichanthium annulatum, etc. The ‘Bhal’ region has marshy, wetland and semi-arid habitat. The present study investigates different physico-chemical parameters like Electrical Conductivity, pH and Sodium Adsorption Ratio, as well as mineral ion Sodium, Potassium, Calcium, Magnessium and Chloride concentration in the soil of ‘Bhal’ region.
Plantations of energy plants are the alternative form of post-agricultural and degraded land management. Particularly, small-area plantations of the tree species, including the willow Salix sp., raise local natural values of degraded habitats and are a dwelling place for numerous entomofauna, birds and mammals. Herbaceous vegetation accompanying short-rotation coppice (SRC) constitutes at the beginning a competition for energy species plantings and therefore is subject to chemical and mechanical control. In successive years, it may increase local biodiversity at the level of plant species and associations, both in ruderal habitats and extensively used agricultural lands. In the presented paper, results of the study referring to evaluation of the floristic and phytosociological diversity of herbaceous vegetation accompanying selected 4–5-year-old willow short-rotation coppices (SRC) situated on lands adjacent to the Odra River estuary (Western Pomerania) in different soil-habitat conditions are showed. Investigations were carried out in willow SRCs located on degraded sandy silts and sewage sludge-fertilised silts, fallow post-farmland and degraded grassland. The largest number of species onfirmed by the highest Shannon-Wiener’s diversity index (H) and species evenness index (J) was characteristic of SRCs set on sandy silt fertilised with sewage sludge, wet grassland and fallow post-farmland when compared to those on sandy silt and over-dried grassland. The analysis of vegetation showed a strong predominance of anthropogenic associations (synanthropic and seminatural) over autogenic (natural) ones.
In the 40 fir localities in the Sudety Mountains, varying in site conditions and the degree of natural regeneration development were taken soil samples from the mineral horizon and were subjected to particle size distribution analysis. The best regeneration of fir stands has been reported on medium-textured soils, containing a few percents of the clay fraction and from 50to 60% of sand.The poorest regeneration was reported on silty soils, located in the lower parts of slopes. In comparision with the Carpathians, spectrum of conditions in which firs grow in the Sudety Mountains is clearly shifted from coarse-textured soils to medium-textured soils.
Prokaryotic or gan isms are ex posed in the course of evo lu tion to var i ous im pacts, re­sult ing of ten in dras tic changes of their ge nome size. De pending on cir cum stances, the same lin eage may di verge into spe cies hav ing sub stan tially re duced genomes, or such whose genomes have un der gone con sid er able en large ment. Ge nome re duc tion is a con se quence of ob li gate intracellular life style ren der ing nu mer ous genes ex pend able. An other con se quence of intracellular life style is re duc tion of ef fec tive pop u la- tion size and lim ited pos si bil ity of gene ac quire mentvia lat eral trans fer. This causes a state of re laxed se lec tion re sult ing in ac cu mu la tion of mildly del e te ri ous mu ta tions that can not be cor rected by re com bi na tion with the wild type copy. Thus, gene loss is usually irreversible. Additionally, constant environment of the eukaryotic cell ren­ders that some bac te rial genes in volved in DNA re pair are ex pand able. The loss of these genes is a prob a ble cause of mutational bias re sult ing in a high A+T con tent. While causes of genome reduction are rather indisputable, those resulting in ge­nome ex pan sion seem to be less ob vi ous. Pre sum ably, the ge nome en large ment is an indirect consequence of adaptation to changing environmental conditions and re­quires the ac qui si tion and in te gra tion of nu mer ous genes. It seems that the need for a great number of capabilities is common among soil bacteria irrespective of their phylo gen etic re la tion ship. How ever, this would not be pos si ble if soil bac te ria lacked in dig e nous abil i ties to ex change and ac cu mu late ge netic in for ma tion. The lat ter are con sid er ably fa cil i tated when house keep ing genes are phys i cally sep a rated from adaptive loci which are useful only in certain circum stances.
Twelve physiographic regions, determined in Kraków province, were analysed using 1398 Braun- Blanquet phytosociological surveys of grain and root crops. The evaluation was made according to the Ellenberg method in which, weeds were considered to be indices of thermal (T), humidity (W), soil reaction (R), nitrogen content (N), and soil biological activity (G) conditions. The method proved to be useful to demonstrate differences between studied mesoregions.
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