Zbigniew Mirek

Genetic diversity in widespread species is not congruent with species richness in alpine plant communities

The Convention on Biological Diversity (CBD) aims at the conservation of all three levels of biodiversity, that is, ecosystems, species and genes. Genetic diversity represents evolutionary potential and is important for ecosystem functioning. Unfortunately, genetic diversity in natural populations is hardly considered in conservation strategies because it is difficult to measure and has been hypothesised to co-vary with species richness. This means that species richness is taken as a surrogate of genetic diversity in conservation planning, though their relationship has not been properly evaluated. We tested whether the genetic and species levels of biodiversity co-vary, using a large-scale and multi-species approach. We chose the high-mountain flora of the Alps and the Carpathians as study systems and demonstrate that species richness and genetic diversity are not correlated. Species richness thus cannot act as a surrogate for genetic diversity. Our results have important consequences for implementing the CBD when designing conservation strategies.

Taxonomy of the Solidago virgaurea Group (Asteraceae) in Poland, with Special Reference to Variability along an Altitudinal Gradient

The morphological differentiation and taxonomic treatment of lowland and high-mountain morphotypes within the Solidago virgaurea group are controversial. To clarify the taxonomic status of these taxa, we conducted a morphometric analysis of 1,746 individuals from 80 localities along an altitudinal gradient from the lowlands of northern Poland to the Carpathians and Sudetes of southern Poland. Multivariate morphometric analyses, cluster analyses and principal component analyses, were used to examine the morphological differentiation within the S. virgaurea group in Poland. Canonical discriminant analysis was applied to determine the morphological characters that best discriminate among the taxa. The stability of the high-mountain Solidago minuta morphotype was tested in an experimental field established in lowland Poland; individuals transplanted from various mountain sites were cultivated at this site, and the morphotypes remained stable in terms of their floral and vegetative characters. Multivariate analyses revealed two morphologically distinct taxa in the S. virgaurea group, which correspond to lowland S. virgaurea s. str. and high-mountain S. minuta as recognised in some European floras. The most important morphological characters for distinguishing the taxa are the number of tubular florets per capitulum, inner involucral bract width and involucre height. Vegetative and inflorescence characters appear to have less taxonomic value because they changed continuously with altitude. A key for identifying S. virgaurea and S. minuta in Poland is presented.

Distribution and ecology of high-mountain Solidago minuta (Asteraceae) in Poland

Abstract Solidago minuta L., a high-mountain species of the Solidago virgaurea group, occurs on some European mountain chains but it has been suggested that morphological differentiation of S. minuta is controversial due to the existence a wide range of morphologically intermediate plants between lowland S. virgaurea s.s. and high-mountain S. minuta. However, the recent study of this group revealed that both S. minuta and S. virgaurea are morphologically distinct taxa and that their most important taxonomical characters are those relating to the capitulum and florets. The aim of the present study is to verify the distribution of S. minuta in the Polish Carpathians and Sudetes and to identify the ecological characteristics of the species in relation to soil and vegetation. Solidago minuta was found most commonly in the Tatra Mts, but was also frequently encountered on Babia Góra Mt. and on the Karkonosze Mts. In the Tatra Mts, this species occurs most frequently in the subalpine belt, ascending in places to the alpine belt and descending in open areas to the upper montane belt. The preferred soils were acid, the pH mainly being between 3.5 and 5.0, and with relatively low nutrient content. Direct gradient analysis (CCA) revealed that the most important environmental variables explaining the general variability in species composition were altitude, as well as soil calcium content and soil acidity. S. minuta was found to occur mainly in communities of the Calamagrostietalia villosae order, growing amongst tall grass on lime-deficient substrata and grazed semi-natural vegetation, which here, in the subalpine belt, is widespread.

Biodiversity of Poland: An Exemplary New Series@@@Flowering Plants and Pteridophytes of Poland: A Checklist = Krytyczna lista roślin naczyniowych Polski@@@Census Catalogue of Polish Mosses@@@Ecological Indicator Values of Vascular Plants of Poland = Ekologiczne liczby wskaźnikowe roślin naczyniowych Polski@@@Flowering Plants and Pteridophytes of Poland: A Checklist = Krytyczna lista roslin naczyniowych Polski@@@Ecological Indicator Values of Vascular Plants of Poland = Ekologiczne liczby wskaznikowe roslin naczyniowych Polski

Polyploidy is frequent among the grasses. This study indicates that it has a high frequency in the subfamily Chloridoideae, where more than 90% of the studied specimens are polyploids. These levels range from diploid (2n = 20 for x = 10 and 2n = 18 for x = 9) to 16-ploid (2n = 160) for x = 10 in Ctenium concinnum Nees and 20-ploid (2n = 180) for x = 9 in Hilaria mutica Benth. This polyploid trend is seen in southern Africa, as well as worldwide. Analysis indicates that many polyploids are alloploids, suggesting extensive hybridization within this group. This is supported by the presence of apomixis in many members of the subfamily. Both polyploidy and apomixis are thought to be important evolutionary mechanisms in Chloridoideae as well as closely related Panicoideae, and have a high frequency in southern Africa. Due to the stable ecological, geographical and climatological history of Africa, the continent is ideally suited for the stabilization of hybrid complexes by means of apomixis and polyploidization.