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Spatial Diversification of the Balance on the Labour Market in Rural areas in Poland

100%

Stanny M.

Bulletin of Geography. Socio-economic Series

2010

tom 14

nr 14

103-111

The purpose of the study is to present the spatial diversification of the level of the balance on the local labour market in the rural areas. The spatial unit of the analysis is constituted by rural communes (gminas) and the rural areas of the urban-rural communes in Poland according to the administrative division into town and village. This means that the research concerns the spatial diversification observed according to 2,171 units. It was accepted in the research that a balanced labour market occurs where favourable demographic structures are located around the largest regional centres in Poland. This is connected with the development of the communes' non-agricultural economic functions and a strong dependence on urban markets.

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

100%

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

Oceanologia

2008

tom No. 50 (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.