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We compiled a global database for leaf, stem and root biomass representing c. 11 000 records for c. 1200 herbaceous and woody species grown under either controlled or field conditions. We used this data set to analyse allometric relationships and fractional biomass distribution to leaves, stems and roots. We tested whether allometric scaling exponents are generally constant across plant sizes as predicted by metabolic scaling theory, or whether instead they change dynamically with plant size. We also quantified interspecific variation in biomass distribution among plant families and functional groups. Across all species combined, leaf vs stem and leaf vs root scaling exponents decreased from c. 1.00 for small plants to c. 0.60 for the largest trees considered. Evergreens had substantially higher leaf mass fractions (LMFs) than deciduous species, whereas graminoids maintained higher root mass fractions (RMFs) than eudicotyledonous herbs. These patterns do not support the hypothesis of fixed allometric exponents. Rather, continuous shifts in allometric exponents with plant size during ontogeny and evolution are the norm. Across seed plants, variation in biomass distribution among species is related more to function than phylogeny. We propose that the higher LMF of evergreens at least partly compensates for their relatively low leaf area : leaf mass ratio. © 2015 New Phytologist Trust.

The royal fern (Osmunda regalis L.) is a threatened species, which reaches the northeastern border of its natural range in Poland. The number of royal fern stands is decreasing due to decline of its natural habitat - alder carrs. The main aim of this paper was to compare features of stands in habitats representing different levels of anthropogenic transformation and to investigate all stands of the royal fern in the ‘Baszków’ nature reserve (3.76 ha; Krotoszyn Forest District, Poland). We distinguished four plant communities within the nature reserve: Carici elongatae-Alnetum, Molinio-Pinetum, Leucobryo-Pinetum and Pinus-Padus. In total, we found 144 royal fern specimens within the nature reserve area growing in 20 stands: 97 specimens in Carici-Alnetum (9 stands), 32 specimens in Molinio-Pinetum (4 stands) and 15 specimens along a drainage ditch (7 stands). Specimens from Carici-Alnetum had the highest proportion of sporophylles (41%), which shows the habitat preferences of the royal fern. Low proportion of sporophylles and the low number of specimens in the stands in ditches prove lower vitality of royal ferns and possibility of local extirpation in these stands. Royal fern populations in secondary habitats such as ditches and borders of forest divisions should be particularly monitored. Passive royal fern protection in the nature reserve gave positive results due to better availability of light, connected with mortality of some trees.

The ‘Czmoń’ nature reserve (23.65 ha) was established in 1998 to protect one of the best-retained areas of natural oak-hornbeam forest (Galio-Carpinetum) in the center of the Wielkopolska Region. Apart from oak-hornbeam forest, the ash-elm riparian forest (Querco-Ulmetum) and alder riparian forest (Fraxino-Alnetum) are found in the reserve. These plant communities, both natural and degenerated as a consequence of previous forest management, have created the convenient conditions for assessment the phytocoenoses’ regeneration potential. The aim of this study was to assess the age and species structure of woody species natural regeneration of the whole area of the nature reserve. To achieve that target, during August and September 2012, 142 sample plots were established with the total area 3550 m2 on which tree and shrub composition and densities were calculated. Woody species regeneration created various diverse communities among individual sub-units, however oak-hornbeam forest species were predominant in the whole regeneration layer. The character of a ‘natural’ forest was retained on a part of the stands. Moreover, regeneration in degenerated parts of the ‘Czmoń’ nature reserve stands is changing according to potential vegetation. Whereas, the establishment of gaps in the Scots pine stands using artificial regeneration was not worthwhile. The natural regeneration structure under the canopy layer of Scots pine stands unambiguously supports the claim that phytocoenoses can regenerate on their own. In spite of the oak regeneration being infrequent, all stands within the ‘Czmoń’ nature reserve retain substantial rejuvenation potential.

The Balkan pine (Pinus peuce) is a Balkan Peninsula endemic tree species, growing in high mountains of Bulgaria, Macedonia, Serbia, Montenegro, Kosovo, Albania, and Greece and forming pure and mixed stands in subalpine forests. The paper gives a survey of biodiversity of Balkan pine stands in the Rogów Arboretum in reference to environmental data. In the plots examined, 29 taxa of vascular plants, 29 taxa of macrofungi and 127 taxa of invertebrates were recorded. The revealed diversity is discussed with regard to the data from Pinus peuce natural habitats.

Established vegetation can facilitate the ectomycorrhizal infection of seedlings, but it is not known whether this interaction is limited by the phylogenetic relatedness of trees and seedlings. We use a series of bioassay experiments to test whether soil modification by different ectomycorrhizal tree species causes different levels of seedling infection, whether the extent of seedling infection is a function of the relatedness of tree and seedling, and whether the effect of trees on seedlings is mediated by biotic or abiotic soil factors. We found that soils from under different tree species do vary in their mycorrhizal infectiveness. However, this variation is not related to the genetic relatedness of trees and seedlings but instead, appears to be an attribute of the overstory species, irrespective of seedling species, mediated through a suite of humus- and base-cation-related abiotic effects on soils. Modification of abiotic soil properties by overstory trees should be considered as an important factor in the effect of different overstory trees on the extent of seedling mycorrhizal infection.

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 Poznan (W Poland; 550,000 inhabitants). We hypothesized that ecological lands which cover

The aim of this study is verification of the taxonomic usefulness of the pollen grain features studied, based on pollen morphology of 32 wild species from all 4 subgenera and all 10 sections of the genus Rosa, mainly for delimitation of subgenera, sections, and species. The measurements and observations were carried out with both light microscopy and scanning electron microscopy. Only correctly formed pollen grains (30 per specimen) were measured, and 960 pollen grains were examined in total. They were analyzed for 14 quantitative features of pollen grains and exine sculpturing and the following qualitative ones: outline, shape, and operculum structure. Our study revealed that the diagnostic features of pollen grains studied were: exine sculpture, length of polar axis, and pollen shape (P/E ratio). On the basis of the above characters, five species were isolated and the remaining ones were included in several groups isolated on the basis of exine sculpture types. The following three exine sculpture types occurred in the species studied: granular-verrucate (in R. stellata), striate-psilate (in R. multibracteata and R. multiflora), and striate (the remaining species). R. banksiae is characterized by small pollen grains, while R. setigera has strongly elongated pollen with P/E ratio >1.5. Exine sculpture features considered to be diagnostic should be treated as auxiliary because they fail to differentiate individual species, although they can be helpful in distinguishing groups of species of similar exine sculpture. The arrangement of the species examined on a dendrogram only slightly corroborates division of the Rosa genus into subgenera and sections currently adopted in taxonomy (Rehder 1940). An interesting result was reported for the species studied from the Caninae (R. agrestis, R. canina, R. dumalis, R. jundzillii, and R. rubiginosa) section which, despite hybrid nature, with the exception of R. villosa, grouped in the same, most separated group of species.

Seed size and shape, seed coat surface pattern, seed coat thickness, and endosperm structure were investigated in Androsace septentrionalis, Cortusa matthioli, Hottonia palustris, Primula elatior, Soldanella carpatica (Primulaceae), Anagallis arvensis, A. minima, Cyclamen purpurascens, Glaux maritima, Lysimachia nemorum, L. vulgaris, Trientalis europaea (Myrsinaceae), and Samolus valerandi (Theophrastaceae). Three seed size categories were distinguished on the basis of biometric measurements. Almost all seeds examined were found to be small with an angular shape classified as sectoroid or polyhedral. A new type of seed shape, suboval, was identified for H. palustris. Cyclamen purpurascens seeds differed from seeds of all other species examined because of their large size, subglobose shape, and concave hilar area. Despite the different shape types, the length/width ratio of the seeds examined was constant, while their hilum length/width ratio was a highly variable feature. Three types of seed surface patterns were observed: (1) reticulate, (2) tuberculate with secondary striations, and (3) poroid-alveolate with the presence of a spongy outer layer. For seeds of Anagallis arvensis, A. minima, Cortusa matthioli, Lysimachia nemorum, and Soldanella carpatica, secondary seed sculpture was described. The seed coats of all species examined were two-layered, and great differences in testa thickness were found (9.9–128.6 μm). In general, seeds of the Myrsinaceae species were more often characterized by thick testa. Different proportions in thickness of the inner and outer testa layers were observed. In seeds with reticulate seed patterns, the inner testa layer was twice to several times thicker than the outer layer, while the opposite proportions were observed in seeds with the tuberculate or poroid-alveolate seed sculpture pattern. In seeds of all species examined, oxalate crystals were present on the surface of the inner testa layer. Thus, the presence or absence of oxalate crystals in testa is not a feature distinguishing species with angular or subglobose seeds. Four types of endosperm structure were identified according to the thickness of the endosperm cell walls and the relief of their inner surface: (1) with evenly thickened and smooth cell walls, (2) with evenly thickened cell walls and circular or helical thickenings on their inside surfaces, (3) with very thick, but not evenly thickened cell walls with constrictions (“pitted”), and (4) with very thin papery and undulate cell walls. There is no rule concerning the seed shape, type of the seed sculpture, testa thickness, or endosperm structure that corresponds to the family affiliation of the species examined.

The aim of this study was to investigate seed morphology and intra- and inter-population variation of seeds of Trollius europaeus L. and Trollius altissimus Crantz., two controversial species regarding their taxonomical position. We analyzed seed-coat microsculpture and some biometrical traits (length and width, width/length ratio, volume and projected perimeter). Seed sculpture did not differ between species, but seeds of T. altissimus were usually larger than seeds of T. europaeus. Although species differed significantly in seed morphology, it was possible to show the populations of both species that were similar regarding the analyzed seed traits. We noted a significant inter-population differentiation of seeds in both species with respect to seed-coat microornamentation and biometrical traits. We conclude that T. europaeus and T. altissimus are probably not two distinct species, but T. europaeus should be divided into two lower taxa in the rank of variety or subspecies.