Almost five thousand allotment gardens divided into one million plots are used by roughly 10% of Polish society. Several studies have emphasized their social importance and significance for enlargement of the area and the integrity of urban spatial greenery systems. However, the area of allotment gardens in Polish cities has been decreasing since the changes in the post-communist country in the 1990s. There is a lack of a simple method of classification and valuation of allotment gardens in relation to their significance in urban green space systems that could be used by officials and city planners. Hence, this study aims to examine the significance of allotment gardens in the spatial development of the green space system of Poznań and classify them with a simple and universal method of valuation which could be used in urban planning. The location of allotment gardens in the urban green space system in Poznań was examined with the classification method elaborated here. It was based on the valuation of several internal and external features of individual allotment gardens. The results showed that allotment gardens are important areas and spatial elements of the green space system in Poznań. Over 30% of allotment gardens are of high significance in the green space system of the city. Nevertheless, according to urban planning documentation, there are plans to reduce the area of allotments in Poznań. Even gardens indicated in the research to be of high significance to the integrity and enlargement area of the urban green space system are planned to be liquidated. Use of the developed classification could influence the decision-making process regarding the liquidation of allotment gardens and preserve the most valuable objects.

Sorbus torminalis is a rare forest tree species in Poland. Allelic and genotypic structures at 25 isozyme gene loci were observed in 20 populations from Poland, situated mainly along a latitudinal gradient. Levels of genetic diversity were high both at the species level (P = 44%, He = 0.435) and within populations (mean P = 40.8%, mean H_e= 0.373). Levels of differentiation among populations were relatively high (F_ST= 0.17) and a noticeable geographic structure of this differentiation was detected. The population in the ‘Brekinia’ reserve had a unique genetic structure of a clonal population and was the most distinct from the other populations.

The paper presents the results of the study on seed morphology of eight following Allium species: A. pyrenaicum Costa & Vayr., A. rotundum L., A. sphaerocephalon L., A. vineale L., A. moly L., A. karataviense Regel, A. fistulosum L. and A. nutans L. The study confirmed the substantial diversity in testa characters, especially curvature and relief of anticlinal walls as well as microsculpture of outer periclinal walls. The occurrence of raised anticlinal walls - an unusually rare feature in Allium seeds, previously observed only in a few species, was found in A. karataviense. It was also found that the testa type in A. pyrenaicum did not match the typical character combination, described before for subg. Allium sect. Allium.

The aim of the study was to analyse the quality of soil in urban allotment gardens in the context of the production of home-grown vegetables. The study was conducted on six allotment gardens (31 individual plots) in Gorzów Wielkopolski, a medium-sized Polish city with an average level of industrialisation. The following soil characteristics were analysed: pH, electric conductivity, organic matter, organic carbon, humus, total nitrogen, C:N ratio, NH₄⁺-N, NO₃-N⁻, P, K, Ca, Mg, SO₄⁻-S, Cl, Na, Fe, Cu, Zn, Mn, Ni, Cr, Cd, Pb. The analyses showed that the soils were abundant in necessary nutrients for vegetable growing. They had high content of calcium, magnesium, and phosphorus. However, the soil pH in areas of vegetable cropping was too high. The content of toxic heavy metals—cadmium (0.22–0.59 mg∙kg⁻¹ d.m.) and lead (3.46–16.89 mg∙kg⁻¹ d.m.)—was within the acceptable limits. Nevertheless, the chemical analysis of carrots used as test vegetables showed that the permissible limits of cadmium and lead content in their roots were exceeded. The excessive uptake of these toxic metals can be reduced by lowering the soil pH and applying organic carbon to the soil.