Wyniki wyszukiwania

1

The conditions of spatial variation in throughfall in a fir-beech forest stand in Swietokrzyskie Mountains

100%

Kozlowski R.

Rocznik Świętokrzyski. Seria B. Nauki Przyrodnicze. Kieleckie Towarzystwo Naukowe

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2013

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tom 34

2

Studying soil salinity and its relations with microtopography and vegetation at field scale

86%

Zhao C.-W., Xu L., Wang Z.-C., Wang Y.-H., Chi C.-M.

Polish Journal of Environmental Studies

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2013

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tom 22

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nr 4

Spatial variation of soil salinity and sodicity is a typical characteristic of Songnen Plain grasslands in northeast China. Best management practices and grassland productivity improvement require further understanding of the relationships among the causal factors at field scale. A field soil survey for the interactions among salinity, microtopography, and vegetation was conducted on a 2.8 hectare saline sodic grassland at Da’an Sodic Land Experimental Station, Chinese Academy of Sciences, northeast China. Salinity of the soil decreases by depth increment with Na+ and HCO-3 as the dominant ions. Soil salinity and sodicity parameters measured include pH, electrical conductivity for 1 to 5 soil-water extracts (EC1:5), apparent electrical conductivity (ECa), sodium adsorption ratio, and exchangeable sodium percentage. Soil salinity is in an order of slope > mound > depression for microtopography and soil under S. corniculata community is in severe salinity, while there is no significant difference under P. australis-A. mongolica and P. australis communities. The water and salt regime in various microtopographical conditions also is discussed.

3

Spatial variation of winter wheat cultivars yields in the Lower Silesian area, South-West Poland

86%

Weber R., Bujak H., Zalewski D.

Electronic Journal of Polish Agricultural Universities. Series Agronomy

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2016

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tom 19

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nr 3

4

Intra-urban migration in the Warsaw urban region

86%

Potrykowska A.

Geographia Polonica

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1993

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tom 61

5

The usefulness of some soil properties and plant traits for the estimation of spatial variation in the 35 field experiment with pea (Pisum sativum L. sensu lato)

72%

Golaszewski J., Zaluski D., Stawiana-Kosiorek A., Sulima P.

Electronic Journal of Polish Agricultural Universities. Series Agronomy

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2009

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tom 12

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nr 2

6

Could meadow passerine distribution within a grassland system be influenced by spatial variation in the mowing schedule?

72%

Broyer J., Curtet L., Chazal R.

Acta Ornithologica

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2018

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tom 53

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nr 2

This study explored meadow passerine capacity to select habitat conditions likely to preserve their breeding success. We observed the variation in bird abundance, assessed with the point count method, over a 25-year period (1993-2017) within two phytosociological facies of the hay-meadows in the lower Saône Valley (3.000 ha), eastern France: a meso-hygrophilic facies characterized by increasingly early mowing, and a hygrophilic facies mown later, with thereby a lower risk of nesting failure. At the beginning of the monitoring (1993-2001), birds were evenly distributed within the two facies. Later on, as more than 90% of meso-hygrophilic meadows were already mown by July 1, birds became more abundant in the hygrophilic facies. This trend was observed in each of the two most abundant species, the Whinchat Saxicola rubetra and the Corn Bunting Emberiza calandra. In two hygrophilic areas (55 and 76 ha) and two meso-hygrophilic areas (49 and 116 ha), passerine territories were mapped in 2011 with the territory mapping method and invertebrates were captured weekly on transects with colour plates and Barber traps. In spite of substantially higher invertebrate abundance, passerine territory density was lower in meso-hygrophilic study sites (6.4 territories/10 ha vs. 10.6). Within each study site however, captured invertebrates were more abundant in the areas selected by territorial birds. In fact, bird abundance estimated from point counts in 2011 varied negatively with the percentage mown by July 1 within a 200m-radius in 2010. This apparently adaptive behaviour leading to a selection of later mown fields seemed to be successful since bird abundance increased until 2010. However, after a succession of extreme climatic events (droughts, late floods), passerine abundance declined thereafter in both facies.

7

Temporal fluctuations of the phytoplankton community in an isolated floodplain lake (North Mollakoy Lake) of the Sakarya River (Northern Turkey)

72%

Sevindik T. O., Tunca H., Onem B., Tamer S. A.

Oceanological and Hydrobiological Studies

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2014

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tom 43

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nr 4

8

Biomass of underbrush and conditions for its occurrence in stands of the Niepolomice Forest

72%

Orzel S., Socha J., Forgiel M., Ochal W.

Electronic Journal of Polish Agricultural Universities. Series: Forestry

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2005

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tom 08

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nr 1

9

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Spatial and interannual variations of seasonal sea surface temperature patterns in the Baltic Sea

72%

Bradtke K., Herman A., Urbanski J. A.

Oceanologia

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2010

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tom 52

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nr 3

345-362

On the basis of monthly averaged satellite data, this study examined how the annual cycle of the Baltic Sea surface temperature (SST) varied spatially and temporally during the period 1986–2005. We conclude that there are two main thermal seasons in the Baltic Sea separated only by short transitional periods – spring lasting about one month, and autumn lasting two months. Generally speaking, summer covers the part of the year from June to October with the highest monthly mean SST in August. Winter, with a minimum monthly mean SST in February in shallow waters or in March in deeper areas, lasts from December to April. As a result of climate changes over the Baltic Sea region, strong positive trends in SST occur in the summer months. In consequence, the period with extremely high sea surface water temperatures has become slightly longer in the central Baltic. In the last decade winter changes in SST display zero or even negative tendencies. The investigated period was characterized by an annual increase in mean temperatures of about 0.03–0.07◦C. However, the rates of monthly mean SST changes were sometimes more than three times as high.

10

Estimation of diatom and dinoflagellate cell volumes from surface waters of the Northern Indian Ocean

72%

Chitari R. R., Anil A. C.

Oceanologia

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2017

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tom 59

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nr 3

Phytoplankton samples collected from the Northern Indian Ocean (Bay of Bengal, northern Arabian Sea, and Dona Paula Bay Goa, west coast of India), were utilized to quantify changes in cell size, cell volume and carbon per cell of diatoms and dinoflagellates. The dataset from the Bay of Bengal also provides inter- and intra-annual variations (April 2008 to March 2010). The variations in cell size and volume were large in regions influenced by the riverine influx or terrigenous inputs. An interregional comparison of commonly available forms (8 species) points out that cell volumes are highest in the North Atlantic and lowest in the Mediterranean. The information provided will be useful in estimation of carbon biomass and biogeochemical studies.

11

Spatial and seasonal variations of large tintinnid ciliates in Shenhu Bay of China

72%

Wang Y., Zhang W., Lin Y., Zheng L., Yang J.

Oceanological and Hydrobiological Studies

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2014

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tom 43

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nr 3

12

Spatiotemporal variation of alkaline phosphatase activity in coastal waters off Trivandrum

72%

Shivaramu M. S., Randive A. K., Kumari R., Gauns M., Ponnapakkam L. A.

Oceanologia

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2019

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tom 61

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nr 1

13

Grain-size characteristics and net transport patterns of surficial sediments in the Zhejiang nearshore area, East China Sea

72%

Liang J., Liu J., Xu G., Chen B.

Oceanologia

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2020

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tom 62

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nr 1

14

Clutch size variation in agile frog Rana dalmatina on post-mining areas

72%

Solsky M., Smolova D., Dolezalova J., Sebkova K., Vojar J.

Polish Journal of Ecology

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2014

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tom 62

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nr 4

Clutch size is an important life history trait in amphibians, and it varies among and within species, populations and individuals. Within a population, its variation has been attributed to a positive relationship between females’ age or size and their fecundity as well as to spatio-temporal differences in environmental conditions. Therefore, clutch size has been shown to be both spatially and seasonally variable. We examined spatial and seasonal clutch size variation based upon two years of study involving 160 clutches of the Agile Frog Rana dalmatina Bonaparte, 1840 in 14 ponds within one spoil bank in the Czech Republic’s North Bohemian brown coal basin. The overall mean clutch size was 1295 (SD 596), which is one of the largest that has been reported. However, both clutch size and its variance differed considerably between the years. Clutch size also varied among the ponds. We found no relationship between clutch size and the distance of a breeding pond from alluvial forest, a typical wintering habitat. Despite existence at the site of many suitable reproduction habitats, the spoil bank does not offer the complex of all habitats needed for persistence of the R. dalmatina population. To protect that population, it is necessary to preserve not only breeding ponds on the spoil bank but also alluvial forest and, most importantly, the connectivity between these two crucial habitats.

15

Primary productivity off Western and Southern Portuguese waters

72%

Cavaco M. H., Cabecadas G.

Bulletin of the Sea Fisheries Institute

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2003

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nr 1

16

Spatial variation of air temperature in the Arctic in 1951-1990

72%

Przybylak R.

Polish Polar Research

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1997

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tom 18

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nr 1

17

Seasonal variability of benthic ammonium release in the surface sediments of the Gulf of Gdańsk (Southern Baltic Sea)

72%

Maksymowska-Brossard D., Piekarek-Jankowska H.

Oceanologia

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2001

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tom 43

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nr 1

This paper describes the seasonal and spatial variations of diffusive sediment– water ammonium fluxes in the western part of the Gulf of Gdańsk (southern Baltic). It assesses the potential environmental controls of these fluxes, such as the inflow of organic matter to bottom sediments and its quality, temperature-induced degradation of organic matter, and the redox potential of sediments. Ammonium fluxes, calculated using Fick’s first law, were always in the direction from the sediment into the water column and differed significantly with respect to sediment type. Fluxes were most intensive in sediments with the highest silt-clay fraction located in the deepest parts of the study area. The mean annual diffusive fluxes of ammonium from sediments to near-bottom water were estimated at 5.24 tonnes km−2 year−1 for silty-clays, 1.85 tonnes km−2 year−1 for silty-sands and 1.03 tonnes km−2 year−1 for sandy sediments. There was a high seasonal variation, with the greatest ammonium release in summer and early autumn, when the temperature of near-bottom water was the highest. On the basis of the calculated diffusive ammonium fluxes, we estimated that approximately 2700 tonnes of N–NH+4 are released annually from the surface sediments of the western part of the Gulf of Gdańsk, providing a minimum of 10% of the mineral nitrogen essential for primary production in surface waters. Our results are undoubtedly underestimated, as we disregarded advective ammonium fluxes, which in some areas of the Gulf of Gdańsk could well be comparable to diffusive fluxes.

18

Geostatistical approach to data from field experiments with check plots

72%

Golaszewski J.

Electronic Journal of Polish Agricultural Universities. Series Agronomy

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2002

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tom 05

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nr 2

The paper suggests some indicators for the application of spatial methods in field experimentation. The indicators were based on the data from two field-breeding experiments with pea and field bean. Partially balanced square lattice designs were applied. The Smiths index of soil heterogeneity b, chemical properties of the soil e.g. pH, Mg, P and K contents as well as data obtained from check plots sown with a single variety were used to evaluate spatial variation across the experiments. The Smiths index of soil variability b showed a potential as a convenient tool to assess the purposefulness of background variation analysis by applying spatial methods. When b<0.6 one can expect a significantly increased efficiency of the experiment. Therefore the application of the nearest neighbour analysis or kriging to the data obtained from a net of check plots can produce the concomitant variable which can reduce the experimental error effectively.

19

Spatial variation in long-term trends in a metapopulation of the globally threatened Aquatic Warbler Acrocephalus paludicola in Poland

58%

Zmihorski M., Lawicki L., Marchowski D., Wylegala P., Part T.

Acta Ornithologica

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2016

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tom 51

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nr 2

The Polish breeding population (3,200-3,250 males) of the globally threatened Aquatic Warbler Acrocephalus paludicola represents almost 25% of the global population. Except for the relatively stable large population in the Biebrza valley in north-east Poland less is known about population trends of peripheral populations in western, central and south-eastern regions of the country and whether trends differ depending on region. We investigated the long-term population dynamics in 38 small populations between 1969-2013 in the four Polish regions. Summarizing the trends of all small populations of Aquatic Warblers showed a significant decline in total number of individuals and declining number of populations over time. However, population trends were distinctly different in the different regions, with stable dynamics in south-east, moderate decline in north-east and sharp decline in the central and western regions. During the study period 19 out of 38 populations became extinct (11 populations in the western region, two in central region, four in north-east region and none in the south-east region). Five of these populations were later recolonised thus suggesting a pattern of metapopulation dynamics. To mitigate the negative trends and increased risk of local and regional extinction in the western and central parts of Poland effort should be put to increasing dispersal among populations by increasing the number of stepping stone patches between the viable large eastern populations and the smaller central and western ones.

20

Impact of prey field variability on early cod larval survival: a sensitivity study of a Baltic cod Individual-based Model

58%

Schmidt J. O., Hinrichsen H.-H.

Oceanologia

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2008

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tom 50

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nr 2

205-220

Existing coupled biophysical models for Baltic larval cod drift, growth and survival use idealised constructed mean prey fields of nauplius distributions. These simulations revealed the best feeding conditions for Baltic cod larvae longer than 6 mm. For shorter, first feeding larvae (between 4.5 and 6 mm) pronounced differences in growth and survival were observed, which depend on food availability and to a lesser degree on ambient temperature. We performed runs with an Individual-based Model (IBM) for Baltic cod larvae in order to demonstrate how natural variability in prey abundance influences the survival success of first feeding larvae. In the Baltic, this larval stage lives mainly between 20 and 40 m depth and feeds exclusively on the nauplii of different calanoid copepods (Acartia spp., Pseudocalanus acuspes, Temora longicornis and Centropages hamatus). Prey data obtained from vertically stratified samples in the Bornholm Basin (Baltic Sea) in 2001 and 2002 indicate a strong variability at spatial and temporal scales. We calculated larval survival and growth in relation to natural variation of prey fields, i.e. species-specific nauplius abundance. The results of the model runs yielded larval survival rates from 60 to 100% if the mean size of nauplii species was taken and lower survival if prey consisted of early nauplius stages only.

Ograniczanie wyników

The conditions of spatial variation in throughfall in a fir-beech forest stand in Swietokrzyskie Mountains

Studying soil salinity and its relations with microtopography and vegetation at field scale

Spatial variation of winter wheat cultivars yields in the Lower Silesian area, South-West Poland

Intra-urban migration in the Warsaw urban region

The usefulness of some soil properties and plant traits for the estimation of spatial variation in the 35 field experiment with pea (Pisum sativum L. sensu lato)

Could meadow passerine distribution within a grassland system be influenced by spatial variation in the mowing schedule?

Temporal fluctuations of the phytoplankton community in an isolated floodplain lake (North Mollakoy Lake) of the Sakarya River (Northern Turkey)

Biomass of underbrush and conditions for its occurrence in stands of the Niepolomice Forest

Spatial and interannual variations of seasonal sea surface temperature patterns in the Baltic Sea

Estimation of diatom and dinoflagellate cell volumes from surface waters of the Northern Indian Ocean

Spatial and seasonal variations of large tintinnid ciliates in Shenhu Bay of China

Spatiotemporal variation of alkaline phosphatase activity in coastal waters off Trivandrum

Grain-size characteristics and net transport patterns of surficial sediments in the Zhejiang nearshore area, East China Sea

Clutch size variation in agile frog Rana dalmatina on post-mining areas

Primary productivity off Western and Southern Portuguese waters

Spatial variation of air temperature in the Arctic in 1951-1990

Seasonal variability of benthic ammonium release in the surface sediments of the Gulf of Gdańsk (Southern Baltic Sea)

Geostatistical approach to data from field experiments with check plots

Spatial variation in long-term trends in a metapopulation of the globally threatened Aquatic Warbler Acrocephalus paludicola in Poland

Impact of prey field variability on early cod larval survival: a sensitivity study of a Baltic cod Individual-based Model