Dorota Wrońska-Pilarek

The optimal sample size in pollen morphological studies using the example of Rosa canina L. (Rosaceae)

This study undertook an investigation of an important problem, so far completely overlooked in the palynological literature — to determine the optimal sample size for pollen grain morphological studies. In other words, we investigated the number of pollen grains which should be measured in order to obtain a representative mean value of a given quantitative feature which, in consequence, would make it possible to more accurately describe the pollen of a given taxon. Investigations were conducted on a sample comprising 3850 Rosa canina L. pollen grains on the basis of the length of the polar axis (P), the equatorial diameter (E) and the P/E ratio, at the flower, specimen and population levels. The size of the pollen samples analysed reflected common sample numbers employed in previous pollen morphology studies, namely from five through 10, 20, 30, 50, 100 up to 200 pollen grains. The statistical analyses performed revealed a relatively low variability in pollen grain biometric features at the levels of flower, specimen and population. At the lowest level of variability analysed, it is sufficient to take measurements of several grains to obtain values satisfactorily representing the variability within the flower level. At the level of a specimen or population, the number of grains necessary to secure representative mean values should range from 15 to 20. However, when the research objective is not only information regarding mean values of pollen grain biometric features but also the analysis of their variability (min—max), then the sample size should include approximately 30 grains. The results obtained, apart from their significance in taxonomic studies, also possess important practical significance; measurements of pollen grain biometric features are very labour-intensive and costly and, sometimes, because of difficulties in obtaining satisfactory quantities of plant material (e.g. herbarium specimens, rare species, paleopalynological collections), also very sparse.

Morphological studies of pollen grains of the Polish endemic species of the genus Rubus (Rosaceae)

The pollen of six taxa of the genus Rubus endemic to Poland (R. capitulatus, R. chaerophylloides, R. ostroviensis, R. posnaniensis, R. seebergensis and R. spribillei)was studied using light and scanning electron microscopy. The study objective was to extend the knowledge of the species pollen morphology and to investigate whether pollen morphology may help to taxonomically distinguish a very rare bramble species. Study material was derived from six natural localities where the species occur in the Wielkopolska region (Poland). Ten quantitative pollen grain features were analysed as well as the following qualitative ones: outline, shape, type of bridge and exine sculpture. Only mature, correctly formed pollen grains (30 per specimen) were measured and 180 pollen grains were examined in total. It was found that R. capitulatus and R. seebergensis had the highest mean values of P, E and Le features. In addition, pollen grains of R. capitulatus were most flattened (mean P/E ratio equals 1.14), while those of R. seebergensis were most elongated (mean P/E ratio equals 1.27). R. spribillei was the only species with striae of similar width as muri, whereas striae in the remaining species were wider. R. chaerophylloides and R. posnaniensis were characterised by specific, similar exine sculpture. Nevertheless, it should be stated that differences between pollen features of the species studied are so small and the variability of these features are so large that it is difficult to clearly identify the species studied. Therefore, pollen grain morphology can serve only as an auxiliary feature for the determination of these species.

Ecological lands for conservation of vascular plant diversity in the urban environment

Conservation of biodiversity in urban areas has become crucial to urban green area management. There are several legislative solutions for preservation of species and habitats in cities. One of them is ‘ecological lands’ – a low-restrictive form of protected areas in Poland. We aimed to assess their efficiency in vascular flora biodiversity conservation in the urban environment in Poznań (W Poland; 550,000 inhabitants). We hypothesized that ecological lands which cover <2% of the city area comprise over 50% of taxonomic diversity and over 90% of functional trait-level range of the vascular flora. Analysis of five ecological lands, which covered 1.8% of the whole city area confirmed our hypothesis. In ecological lands studied, we found 564 species of vascular plants, which is 52.9% of the whole city flora. These species belonged to 23 of 29 phytosociological classes represented in the whole city (73.9%). Functional trait distributions in ecological lands studied comprised from 95.8 to 100% of trait distributions in the flora of the whole city. Ecological lands seem to be a good way for conservation of biodiversity in urban areas. The legislative simplicity and low restrictiveness for both land management and recreational utility make ecological lands a much easier form of nature conservation which may be adapted to other cities for more efficient biodiversity management.

Comparative Pollen Morphological Analysis and Its Systematic Implications on Three European Oak (Quercus L., Fagaceae) Species and Their Spontaneous Hybrids

Pollen morphology of three parental Quercus species (Q. robur L., Q. petraea (Matt) Liebl, Q. pubescens Willd.) and two spontaneous hybrids of these species (Q. ×calvescens Vuk. = Q. petraea × Q. pubescens and Q. ×rosacea Bechst. = Q. robur × Q. petraea) was investigated in this study. The pollen originated from 18 natural oak sites and 67 individuals (oak trees). Each individual was represented by 30 pollen grains. In total, 2010 pollen grains were measured. They were analysed for nine quantitative and four qualitative features. Pollen size and shape were important features to diagnosing Quercus parental species and hybrids. On the basis of exine ornamentation, it was possible to identify only Q. pubescens, while the remaining species and hybrids did not differ significantly with respect to this feature. The determination of the diagnostic value of endoaperture features requires further palynological studies. On the basis of pollen size and shape Q. robur × Q. petraea was clearly separated. Grouping of 67 oak trees on the basis of pollen grain features has shown that individuals from different as well as same taxa occurred in the same groups. Likewise, with respect to natural sites, oak trees originating from the same places as well as from geographically distant ones, grouped together. Pollen morphological features allow to distinguish a part of the studied Quercus taxa. Therefore, it can be used as an auxiliary feature in the taxonomy.

Trees with monumental dimensions in the south-western part of the Poznań agglomeration

The research was carried out within three forest-park complexes located in the south-western part of the Poznań city, which once had the status of ecological uses. The aim of the work was to inventory a dendroflora for the selection of trees with monumental dimensions. In addition, changes in the participation of monumental trees in local vegetation over the last 12 years had been analysed. During the current inventory, 58 monumental specimens were recorded in three afforestation complexes. Most of them grew at Leszczyńska street (31 specimens), and the least at Tyniecka street (6). Since 2004 tree trunk perimeters had increased on average of 18.5 cm. All activities, including conservation works, undertaken in the three described afforestation complexes, or in the immediate vicinity, should lead to the preservation of these objects, their protection against devastation and to expose their most valuable fragments.

Systematic importance of morphological features of pollen grains of species from Erica (Ericaceae) genus

The Erica genus has as yet not been investigated satisfactorily in terms of palynology. Its complicated taxonomic system, large number of species, as well as its extensive but disrupted range of occurrence, all contribute to the fact that few researchers have undertaken investigations of this species. It was assumed that the research results would be representative thanks to a complex comparative analysis of all diagnostical, morphological pollen features performed on properly selected plant material, representing the most important distinguished intrageneric taxons at the present time (45 species from all five subgenera and 22 sections), both discriminated pollen dispersal units (tetrads and monads) as well as the main centres of genus occurrence and diversification (species from Europe, the Republic of South Africa (RSA) and Madagascar). The study revealed that the diagnostic features of the pollen grains studied were: pollen dispersal unit, exine ornamentation, P/E ratio, tetrad diameter (D) and length of polar axis (P). On the basis of these traits, 14 Erica species (six creating monads and eight—tetrads) were distinguished which, in the case of pollen features, constitutes a significant number. Other heaths created small groups, usually containing two or three species, but up to seven species. The present study, based on the highest number of Erica species (45) analysed so far, corroborated the view that an examination of palynological features may assist in clarifying classification systems for the large and taxonomically very difficult Erica genus, in particular, at the level of the subgenus and section, but also at species level. The results obtained indicate the need to continue palynological investigations on the Erica genus.

THE MOST VALUABLE TREES OF THE ECOLOGICAL LANDS ‘DĘBINA I’ AND ‘DĘBINA II’ IN POZNAŃ

The aim of the study was to approximate the empirical distribution of diameter at breast height, height and crown length using theoretical distributions: normal, log-normal, Weibull, Gaussian mixture and Johnson’s SB. For the distribution of all characteristics in the stands in the fresh mixed forest site and additionally for crown length in the fresh mixed coniferous forest site, the distribution of the Gaussian mixture was best matched, in other cases the most accurate approximation was provided by Johnson’s SB distribution. The obtained relationships may be helpful in predicting stand development and in forest management planning, while in the future they may be an important step in the development of a local model of pine stand growth.Several hydrological objects have been erected in the Nadwarciański Landscape Park as ecological compensation measures to mitigate the effect of habitat destruction caused by the construction of the A2 highway. In permanent experimental plots established in those objects a vegetation cover survey was performed in 2010, 2011 and 2016 and ecological indicators were calculated. The effectiveness of these measures to restore nature value was analysed, showing the hydrological objects to be ineffective. Water conditions in the Warta river valley have not improved, while a decrease in species richness and simplification of plant communities have been observed.The work presents a review of the literature concerning the industrial use of the Paulownia genus. The purpose of the study was to analyse the current state of knowledge and potential for planting industrial hybrids of Paulownia. The paper presents botanical affiliation, a brief historical outline, the use of wood, climate requirements and experience with young hybrid crops. Based on the literature review, it may be concluded that the main purpose of cultivation in short cycles is to produce wood pulp for the needs of the pulp and energy industry rather than the other branches of the wood industry. It is worth noting that the provided technical parameters, chemical composition, requirements for growing conditions and biomass production, differ for the other species of Paulownia as well as various hybrids. It cannot be definitely stated that Paulownia is a universal species and gives the same effects under various conditions, but an attempt should be taken to determine the suitability of selected species or their hybrids for specific purposes.

Verification of a survey of the most valuable trees in the city of Częstochowa

In the city of Częstochowa a total of 122 valuable trees of 25 species from 12 families were inventoried. The most numerous group comprises trees with circumferences of natural monuments (55), followed by already registered natural monuments (25), trees with circumferences comparable to those of natural monuments and impressive trees (18 specimens each) and the category of “other trees” (6). The status of natural monuments presently found in the city of Częstochowa was confirmed. Described trees are typically native deciduous species, of which the most numerous are Acer platanoides (18 trees) and Tilia cordata (16 trees). Approximately 60% of them have circumferences from 201 to 300 cm. The health condition of surveyed trees is usually very good (84%). A total of 45 trees were selected with circumferences of natural monuments and characterised by a very good health condition, which may be proposed as worthy of protection as natural monuments. Key worDs: natural monuments, most valuable trees, dendrological survey, Częstochowa

The amount of carbon in the undergrowth biomass of main types of forests stands in Poland

Abstract The sequestration of carbon in biomass of herb and moss layers of forest ecosystems is relatively less studied, than analogical processes in trees biomass and soil organic mass. The paper presents mean values of carbon concentration and mean amounts of dry mass of plant material in the herb and moss layer of phytocoenoses formed under canopy of stands of main forest-forming species of trees in Poland. The parameters were studied for beech, birch, oak, alder, pine, fir and spruce forest stands, for most of the particular age classes. The studied plots were contained in following plant associations and communities: Ribo nigri-Alnetum, Fraxino-Alnetum, Galio odorati-Fagetum, Luzulo luzuloidis-Fagetum, Molinio caeruleae-Quercetum roboris, Calamagrostio-Quercetum petraeae, Abietetum polonicum, Abieti-Piceetum montanum, Calamagrostio villosae-Piceetum, as well as anthropogenic communities: Betula pendula comm. on Leucobryo-Pinetum habitat, Larix decidua comm. on Tilio-Carpinetum habitat, Pinus sylvestris comm. on Tilio-Carpinetum habitat, Picea abies comm. on Luzulo pilosae-Fagetum habitat (in lowland) and Picea abies comm. on Luzulo luzuloidis-Fagetum habitat (in lower mountain localities). The relatively highest carbon amount was observed in oak forests, pine forests and in older age classes of lowland beech forest, where the carbon concentration in dry mass reaches from 60 to 81%. The lowest concentrations were determined for lowland spruce forests, highland fir forests and for alder forests. The carbon concentration reached in these types of ecosystems from 39 to 41%.