52 research outputs found

    The origin of pine pollen grains captured from air at Calypsobyen, Svalbard

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    Spitsbergen is the largest island in the Svalbard Archipelago (Norway) that has been permanently populated. The harsh Arctic climate prevents development of large vascular plants such as trees. A two-year aerobiological survey was conducted within the framework of two consecutive polar expeditions (2014 and 2015) in Spitsbergen (Calypsobyen, Bellsund). The air quality was measured continuously from June/July to August using a 7-day volumetric air sampler, Tauber trap and moss specimens. Collected air samples and gravimetric pollen deposits were processed following transfer to sterile laboratory conditions and analyzed with the aid of light microscopy. Days when pine pollen grains were detected in the air were selected for further analysis. Clusters of back-trajectories, computed using the Hybrid Single Particle Lagrangian Integrated Trajectory model in combination with ArcGIS software as well as the Flextra trajectory model, showed the movement of air masses to the sampling location at Hornsund, and thus indicated the likely origin of pollen grains. The GlobCover 2009 and CORINE Land Cover 2012 datasets were employed to establish the distribution of coniferous forests in the areas of interest. Conclusions were drawn based on the analyses of the circulation of air masses, using visualization of global weather conditions forecast to supercomputers. For the first time, we have demonstrated that pine pollen grains occurring in pine-free Spitsbergen, could originate from numerous locations, including Scandinavia, Iceland, Siberia and northern Canada. Pollen grains were transported via air masses for distances exceeding ~2000 km. Both air samples and gravimetric pollen deposits revealed the same pattern of Pinus pollen distributio

    Wpływ deszczów ulewnych i roztopów na rozwój wąwozu lessowego

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    Water erosion and supply of material for fluvial transport under episodic surface flow conditions in the semi-arid zone on Boa Vista (Cabo Verde)

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    This paper presents the effects of the natural conditions of the semi-arid zone on the tem-poral and spatial variability of production and supply of material for fluvial transport under conditions of episodic surface flow. Based on measurements of water runoff, concentration of suspension and dissolved material in the course of a one-hour rainfall, it has been determined that the catchments under study have a considerable resistance to the effects of water erosion. Some protection is supplied by the ablation pavement, which reduces rainsplash and slopewash and prevents flow concentration. Consid-erably more erosion has been noted on unpaved roads concentrating water flow even on plateaux and gently inclined slopes. Obviously the potential for leaching rock material in short-duration flow is limited. Large proportions of the dissolved material carried away from the catchments are salts of marine and aeolian provenance. The high intensity of erosional processes in the early phase of runoff is evidence of the role of physical weathering between rainfalls, which supplies the material for fluvial transport

    Rozwój i funkcjonowanie lessowej skarpy uprawowej w okresie zwiększonej częstości wysokich opadów

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    Rozwój procesów erozyjnych na lessowej skarpie uprawowej koło Garbowa na Wyżynie Lubelskiej obserwowano w obfitujących w opady ulewne latach 1995-2001. Badana skarpa powstała przy dnie doliny nieckowatej w miejscu, gdzie biegnąca prawie równolegle do jej osi miedza, podcina garb na zboczu. Analiza profilu glebowego dowodzi, że utworzenie skarpy spowodowała głównie erozja pod miedzą, uwarunkowana jej położeniem. W okresie badań kilkakrotnie, z 2-2,5 cm przed 1995 r., do 8-10 cm, zwiększyło się średnie roczne tempo erozji pod skarpą, powodując jej wzrost z 1,7-1,8 m do 2,4 m. Uniemożliwia to akumulację w dnie doliny i powoduje „ściąganie” pod miedzę jej osi, co zagraża stabilności skarpy. Skarpa ulega również bezpośredniej degradacji poprzez rozcinanie i sufozję. Wynika to z możliwości koncentracji nad nią wody w bruzdach i zagłębieniach, szczególnie w uprawach okopowych oraz zbożach jarych. Przed degradacją nie chroni skarpy również obsianie pola trawą, gdyż intensywna infiltracja wywołuje ruchy masowe. Procesy grawitacyjne są szczególnie aktywne poniżej pola trawy, zasianej na gruncie wcześniej naruszonym przez sufozję. W takich warunkach, najwłaściwsze wydają się uprawy, zapewniające jednocześnie umiarkowaną infiltrację oraz powierzchniowe, rozproszone odprowadzanie nadmiaru wody, jak np. oziminy (zwłaszcza żyto) i rośliny motylkowe (zwłaszcza koniczyna).The erosion processes on a loessy agricultural scarp near Garbów in the Lublin Upland were studied in the years 1995-2001, when heavy rainfalls were frequent. The examined scarp developed near the bottom of a trough-like valley, where a balk almost parallel to the valley axis occurs. This balk undercuts a small ridge-like slope. The investigations of a soil profile indicate that the scarp was formed mainly by erosion below the balk, conditioned by its situation. Mean erosion rate, which was calculated as 2-2.5 cm/year before 1995, increased several times (up to 8-10 cm/year) during the mentioned period, and resulted in the increase of the scarp height from 1.7-1.8 m to 2.4 m. This makes the accumulation in the valley bottom impossible, and shifts the valley axis towards the scarp. That is why the scarp stability is endangered. The scarp is also directly degraded by dissection and piping. This results from the concentration of water flow in the rills and small depressions above the scarp, especially when root plants or spring crops are cultivated. Grassing does not prevent the scarp degradation, because intensive infiltration initiates mass movements. These processes are especially active on the scarp below the grass field which was earlier affected by piping. Therefore, crops which provide a moderate infiltration and scatter the flow of water surplus, e.g. winter crops (especially rye) and papilionaceous plants (especially clover), seem to be the best in these circumstances

    Genetic interpretation of micromorphological features of gully less - soil deposits (case study : Kolonia Celejów, E Poland)

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    Five complex soil profiles in gully system on Nałeczów Plateau (E Poland) were examined. They represent the loess sediments modified by soil processes and postpedogenic transformations. Two examined profiles represent natural and mature Luvisols with diagnostic illuvial horizon (Bt argillic) developed on the edge of plateau geomorphologic level and in the relict valley bottom. The other soil profiles reflects postpedogenic soil degradation, redeposition and secondary accumulation (deluvia, colluvia and/or proluvia). Record of these processes are the micromorphological features created by lithological processes (=primary loess and secondary pedoliths) or by pedogenesis (mainly bioturbation, illuviation, de- and recalcification). The important group of microfeatures are pedorelicts which clearly confirm genetic dependences of pedoliths (deluvia and proluvia) and soils developed in situ and located in higher hypsometric levels in the catchment

    Natężenie procesów niweo-eolicznych w okolicy Lublina w lutym 2007 r.

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    Natężenie procesów niweo - eolicznych w okolicy Lublina w lutym 2007 r.

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    Influence of field and road pattern change on gully development in the Bug River valley side (E Poland)

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    Causes of dynamic development of a permanent gully dissected in sandy river valley side were presented in this paper. Road and field pattern change conditioned the gully forming during one downpour. A new pattern and crop structure caused fast surface flow on the side. Flow concentration along the road and balks causes dissections of gully escarpments and development of the gully branches
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