Oro tarša yra viena svarbiausių žmonijos problemų Lietuvoje ir pasauliniu mąstu. Oro taršos poveikis kelia didžiulį pavojų aplinkai ir visų gyvų organizmų tolimesniam egzistavimui. Viena pagrindinių problemų daugumoje didesnių miestų yra užterštumas kietosiomis dalelėmis. Šiame darbe pateikiami tyrimų duomenys apie kietųjų dalelių ir sunkiųjų metalų koncentracijų kiekius Šiaulių miesto aplinkos ore 2007 m. Darbe įvertinti atliktų kietųjų dalelių koncentracijų tyrimai gyvenamųjų mikrorajonų aplinkos ore šildymo sezonu, iš kurių paaiškėjo, kad labiausiai kietosiomis dalelėmis užterštas Medelyno mikrorajonas, o KD10 koncentracija kito nuo 0,4 iki 1,16 DLK. Įvertinus sunkiųjų metalų koncentracijas miesto aplinkos ore buvo nustatyta, kad jais labiausiai užterštas miesto centras, kur didžiausi autotransporto srautai. Iš Medelyne atliktų kietųjų dalelių dispersinės sudėties tyrimų buvo nustatyta, kad pavojingiausių dalelių (KD2,5) yra ~60%, KD10 ~15%, 20-60 µm dalelių ~25%. Taip pat darbe buvo sumodeliuota, programų paketu „Varsa“, pietinio pramoninio rajono ���monių išmetamų kietųjų dalelių emisijų sklaida. Paaiškėjo, kad šie teršalai dažniausiai vėjo nešami centro link, į šiaurinę miesto dalį, o aplink taršos šaltinius jų kiekiai siekia 0,3 mg/m3. / Air polution is one of the most important problems in Lithuania and all over the world. Air polution causes hudge harm to environment and to all egzisting organizms. Particulate air polution is one of hazardous part especialy in the bigger citys. This master degree‘s work represents the research data on the concentration volumes of the solid particles and heavy metals in the environmental air in Šiauliai city in 2007. The concentration analysis of solid particles in the environmental air, at housing/residential areas, during winter seasons, research proved that Medelynas district is mostly pulluted district in Šiauliai and the PM10 concentration varyed from 0.4 to 1.16 MPC. Due to the biggest flow of transport, the town centre is mostly polluted with heavyweight metals. A result of a solid particle dispersional analysis showed the size of solid particules,and that the most dangerous amount of particles (PM2,5) is about 60%, PM10 ~15%, 20-60 microns size ~ 25%. The simulation of emmision from the stationary polluting sources of solid particles at industrial enterprises in the south of the town gets carried by the wind towards the center of the city and it reaches the amount of 0.3 mg/m3 concentration of solid particles around the industrial enterprise district.

The study deals with first telemetry observations of Black-Crowned Night Herons (Nycticorax nycticorax) in the Czech Republic. The main aim was to describe post-fledging dispersal abilities and evaluate influence of chosen factors to dispersion of young birds. The study also deals with population trends, variability of reproductive parameters and factors affecting these traits.

<p>Meiofauna, and especially marine nematodes are common in sediments around the world. Despite very wide ranging distributions in many nematode species, little is presently known about their dispersal mechanisms shaping these patterns. Rafting, and perhaps ballast water transport has been suggested as viable means for nematode long-range transport. On a much smaller scale other processes have been suggested for their dispersal. They generally include some form of passive suspension into the water column and later on a passive, haphazard settling back towards the bottom.</p><p>Small-scale phenomena in nematode dispersal were studied by conducting a series of studies at Askö field station, Trosa Archipelago, Baltic proper. Studied aspects were one case of macrofaunal influence on nematode dispersal rate, using an amphipod, <i>Monoporeia affinis</i> as disturbing agent, and three different studies on mechanisms related to settling. The experiments were conducted both in laboratory and field settings.</p><p>The amphipod <i>Monoporeia affinis</i> did not exert any influence on the dispersal rate in the nematodes. The nematode dispersal was only an effect of time, in the aspect that the more time that past, the more nematodes dispersed from their place of origin. The settling experiments revealed that nematodes do have an active component in their settling behaviour, as they were able to exert influence on the spot where they were to settle. They were able to choose settling spot in response to the food quality of the sediment. It also became evident that contrary to common belief, nematodes are able to extend their presence in the water column far beyond the times that would be predicted considering settling velocities and hydrodynamic conditions alone.</p>

Meiofauna, and especially marine nematodes are common in sediments around the world. Despite very wide ranging distributions in many nematode species, little is presently known about their dispersal mechanisms shaping these patterns. Rafting, and perhaps ballast water transport has been suggested as viable means for nematode long-range transport. On a much smaller scale other processes have been suggested for their dispersal. They generally include some form of passive suspension into the water column and later on a passive, haphazard settling back towards the bottom. Small-scale phenomena in nematode dispersal were studied by conducting a series of studies at Askö field station, Trosa Archipelago, Baltic proper. Studied aspects were one case of macrofaunal influence on nematode dispersal rate, using an amphipod, Monoporeia affinis as disturbing agent, and three different studies on mechanisms related to settling. The experiments were conducted both in laboratory and field settings. The amphipod Monoporeia affinis did not exert any influence on the dispersal rate in the nematodes. The nematode dispersal was only an effect of time, in the aspect that the more time that past, the more nematodes dispersed from their place of origin. The settling experiments revealed that nematodes do have an active component in their settling behaviour, as they were able to exert influence on the spot where they were to settle. They were able to choose settling spot in response to the food quality of the sediment. It also became evident that contrary to common belief, nematodes are able to extend their presence in the water column far beyond the times that would be predicted considering settling velocities and hydrodynamic conditions alone.