The article provides an analysis of life forms of 9 floristic complexes of the Ketpen ridge on the basis of many years of research materials, where life forms were studied in each floristic complex according to the systems of K. Raunkiaer and I.G. Serebryakov. An analysis of life forms according to the system of K. Raunkiaer established the dominance of hemicryptophytes in cryophilic-meadow (74.8%), petrophilic (72.5%) and deciduous-forest (80.3%) floristic complexes of the Ketpen ridge, which accounted for the total number of species of complexes. The second large group in terms of the number of species corresponded to cryptophytes, which predominate in the cryophilic-meadow (65.3%) and psammophilic (45.9%) floristic complexes. Distribution of species according to life forms according to I.G. Serebryakov demonstrated a clear predominance of polycarpic in the meadow complex amounting to 82.5%, deciduous-forest – 81.7%, psammophilous – 75.9% and steppe – 79.4% floristic complexes of the total number of species of complexes. An analysis of the meadow floristic complex of the Ketpen ridge according to Serebryakov showed that taproot plants account for 128 species or 20.5%, short-rhizome – 18.4%, long-rhizome – 11.3%, turf-rhizomatous – 4.8%. An analysis of the life forms of the psammophilic floristic complex revealed the prevalence of therophytes (40.7%). It was found that the spectrum of life forms according to Raunkiaer and Serebryakov emphasizes the peculiarities of the floristic complexes of the Ketpen ridge.
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Life form spectrum is an informative parameter in a comparative analysis of ecological structure of Collembola communities, and a valuable indicator of conditions of soil environment. This suggests a search of adequate methods of its determination. In the present study, two methods of evaluation of life form spectra in springtail communities are compared. A usual approach is a determination of the species composition and abundance, with a subsequent formal distribution of the species present among the life form categories of a chosen system, e.g. among epedaphic, hemiedaphic and euedaphic life forms considered as dwellers of litter surface and upper horizon, of litter depth and topsoil, and of soil horizon, respectively (Hopkin 1997). By this method (A) all the specimens of a given species are attributed to the same life form. However, species populations contain juveniles with smaller body size, thinner cuticle and weaker pigmentation, which tend to be more sensitive to environmental constraints and to dwell deeper in soil than adults. Therefore the attribution of juveniles and adults of a given species to the same life form may not be accurate. Another approach is a direct attribution of a life form category to each collembolan individual during the determination process, according to the visual assessment of its morphological characters (body size and development of pigmentation, number and pigmentation of ommatidia). In that case representatives of a given species might be attributed to more than one life form category, e.g. adults to epedaphic whereas juveniles to hemiedaphic life form, or to hemi- and euedaphic life form, respectively (method B). To compare both methods, mass collembolan material of a microcosm experiment carried out in a beech-oak forest at Mikolajki Research Station (NE Poland) and aimed at investigation of mesofauna/earthworm interactions, was used. The comparison showed a statistically significant bias between the spectra of Collembola life forms estimated by methods A and B: the latter spectrum was shifted to the favour of euedaphic forms. The range of the bias was larger in soil than in litter horizon. Method B is suggested to be closer to a real life form distribution in a collembolan community and may be used for corrections of the data obtained by the traditional taxonomic method A.
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The paper presents: a) the general differentiation of the pine forests of Europe, and b) the floristic differentiation of the study sites, located along the transect stretching between 50 stopni 28 minut and 70 stopni 09 minut N, as well as c) the relations between the geographical location and the climatic characteristics on the hand, and the selected features of the richness and species diversity of the herb layer on the other. One can observe a dependence (p<0.05) between the temperature and latitude on the one hand, and the number of species from some groups on the other. For the vascular plants, the indicators of linear correlation amount to, respectively, 0.64 and -0.63 (the number of the vascular species of the herb layerr increases with the warming of climate and the movement towards the South), and for the numbers of lichen species: -0.81 and 0.78 (the dependencies have the opposite directions to the previous ones). The variability of the relative shares of the particular species groups is correlated with geographical location and climatic variables. Three basic patterns of spatial variability can in this context be identified. The first of these is represented by the share of the lignified chamaephytes (dwarfshrubs). In accordance with this pattern, the minimum shares are observed at the latitudes of Lithuania, Latvia, and Estonia. The second pattern of variability is represented by the shares of hemicryptophytes. In accordance with this pattern the maximum shares are observed between 53 stopnie and 56 stopni N. The third pattern of variability is represented, in particular, by the share of the evergreen species which is proporrtional to the latitude.
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The purposes of the present paper are: a) to show the synusial structure of the herb layer of ten sites, located in Norway, Finland, Estonia, Latvia, Lithuania and Poland, along the transect stretching between 50 stopni 28 minut and 70 stopni 09 minut N, and b) to characterise the species-area curves for all the sites studied. The number of types of synusiae on the particular sites ranges from three to ten, though only one or two have the dominating character, that is, occupy at least 20% of surface. From the point of view of synusial differentiation three geographical groups of sites could be established: the most distinctly different are the northern sites. The second subset of sites, though featuring relatively weak internal mutual similarities, encompasses the sites located in the middle part of the transect. The third subset of sites, represents a more southern character. For each of the sites separately the dependence between the number of vascular species of the herb layer and the area of the site considered (the species-area relationship) is described by the formula y=ax^b. Correlation coefficients between the model and the actual number of species are very high, from 0.902 to 0.998.
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Bioparameters of selected herb species were studied on five control (undamaged) and five bark beetles damaged parallel plots established in form of two vertical transects in the spruce ecosystems of Bielovodska valley (High Tatra Mts.). The most abundant life forms in the studied phytocoenoses were hemicryptophytes (65%), the least abundant geophytes (5%). According to significance of differences in the average length of shoots the sensitivity of herb species to different ecological conditions and calamitous changes of the spruce stands density is a follows: Homogyne alpina > Luzula sylvatica = Dryopteris dilatata > Oxalis acetosella. According to significance of differences in energy content the sensitivity of species was following: Luzula sylvatica > Oxalis acetosella > Dryopteris dilatata > Homogyne alpina > Vaccinum myrtillus. However, the mean values calculated for undamaged and for damaged plots were significantly different (P<0.05) only in the case of weight of Luzula sylvatica shoots.
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