Folia Geobotanica最新文献

Bryophytes comprise an important element of temperate forest biodiversity and functioning. Although numerous studies reported impacts of alien tree species on understorey vegetation, few focused on impacts on bryophytes. Here we checked whether three invasive tree species in Europe (Prunus serotina Ehrh., Quercus rubra L. and Robinia pseudoacacia L.) influence terricolous bryophyte communities, alpha and beta diversity, and cover. We used a set of 186 study plots in western Poland with data on the cover of bryophytes species, as well as light availability, soil C:N ratio and pH. We found that light availability was the main driver of bryophyte species richness, cover and composition. Poor Pinus sylvestris L. forests invaded by P. serotina hosted more species and higher species richness than non-invaded P. sylvestris forests, while forests invaded by Q. rubra and R. pseudoacacia hosted fewer species than native forest types. Low differences among forest types studied resulted from small pools of species and the presence of generalist species. Fagus sylvatica L. forest, Q. rubra and R. pseudoacacia forests hosted the smallest number of species, while the most species rich stands were poor P. sylvestris forest invaded by P. serotina and non-invaded P. sylvestris forests. We concluded that light limitation by invasive species might be more important than dominant tree species identity in limiting terricolous bryophyte species richness and abundance. This requires further studies, accounting for varied abundances of invasive tree species. Therefore, the conservation of sites with high terricolous bryophyte biodiversity needs to be focused on canopy cover.

Species’ responses to climatic gradients are constrained by multiple internal (e.g. trait plasticity and genetics) and external (local habitat) factors and may vary considerably between co-occurring species. This study examines morphological trends associated with elevation and slope aspect (exposure) in the European declining species Rhododendron myrtifolium (Ericaceae) to assess its adaptive responses to spatially changing environment. Measurements of 23 leaf anatomical traits from 40 individuals sampled at 24 locations along a broad elevational range from 1,248 to 2,034 m a.s.l. in the Eastern Carpathians (Ukraine) were analysed using multivariate statistics. Significant intercorrelations between traits indicate a tendency towards leaf xeromorphy with increasing elevation. Trait shifts along a south-to-north aspect gradient parallel those observed with increasing elevation and correspond to presumed differences between the aspects in water availability. Different leaf traits display distinct clinal and non-clinal patterns of variation across elevational strata, with an overall decline in the range of variation at high elevations. Significant effects of growth form, vegetation cover and populational characteristics on leaf traits are also found. The results indicate that despite plastic response of R. myrtifolium to ecological gradients, the species appears well-adapted to a limited range of habitats (north-exposed sites at medium and high elevations) and is likely impacted by abiotic stresses and increased competition for resources at south-facing and low-elevation locations.

The objective of this study was to evaluate the phytochemical profile of Byrsonima using metabolomics and high-resolution mass spectrometry to better understand the chemical diversity in this clade, comparing these results to the classification and more recent phylogenetic systematics of the genus. We analysed fragments of stem bark from 42 specimens of fifteen Byrsonima species using HPLC-DAD-MS. The species used were Byrsonima affinis, B. arthropoda, B. basiloba, B. chrysophylla, B. coccolobifolia, B. crassifolia, B. cydoniifolia, B. intermedia, B. pachyphylla, B. rigida, B. salzmanniana, B. sericea, B. spicata, B. umbellata and B. verbascifolia, derived from two traditional subgenera of Byrsonima: subg. Byrsonima and subg. Macrozeugma. The data were processed, aligned and evaluated statistically using multivariate analysis. Thirty-seven compounds were characterized, confirming the homogeneous chemical profile of Byrsonima and that the subgeneric classification should be reviewed. The chemical homogeneity in Byrsonima could be related to the presence of galloyl esters, which inhibit oxidation reactions for the biosynthesis of secondary metabolites. Galloyl ester compounds have been considered chemical markers of recently diversified groups and galloyl derivatives could be an important strategy for plant survival. The results also suggest that this genus belongs to a recent lineage within the Malpighiaceae.