35 research outputs found
Atlante corologico delle Pteridofite nell'Italia nordorientaleDistribution Atlas of the Pteridophytes of North-Eastern Italy
Si tratta di un lavoro di cartografia floristica sovraregionale (il primo in Italia), basato sul metodo adottato dal Progetto Cartografico dell\u2019Europa Centrale (CFCE), esteso su un territorio di 55.507 kmq (per complessivi 1700 quadranti), comprendente le regioni Friuli Venezia Giulia, Veneto, Trentino Alto Adige e Lombardia orientale (province di Mantova, Cremona Brescia, Bergamo, Lecco e Sondrio). Sono stati considerati 108 taxa e numerose forme ibride le cui distribuzioni vengono commentate e discusse alla luce dei principali fattori ecologici e inquadrate in modelli distributivi di nuova proposizione. Durante il quadriennio 2001-2004 sono stati complessivamente implementati circa 63600 record fra dati di campagna, d\u2019erbario e di letteratura. Ci\uf2 ha portato alla realizzazione di 92 carte che rappresentano la situazione aggiornata della distribuzione delle Pteridofite dell\u2019Italia nordorientale, dalle quali si evince anche la contrazione dell\u2019areale subita da alcune specie rispetto alla situazione descritta nelle flore storiche
Contributions to the sociology and chorology of contrasting plant communities in the southern part of the ?Wienerwald? (Austria)
Relationships among levels of biodiversity and the relevance of intraspecific diversity in conservation - a project synopsis
International audienceThe importance of the conservation of all three fundamental levels of biodiversity (ecosystems, species and genes) has been widely acknowledged, but only in recent years it has become technically feasible to consider intraspecific diversity, i.e. the genetic component to biodiversity. In order to facilitate the assessment of biodiversity, considerable efforts have been made towards identifying surrogates because the efficient evaluation of regional biodiversity would help in designating important areas for nature conservation at larger spatial scales. However, we know little about the fundamental relationships among the three levels of biodiversity, which impedes the formulation of a general, widely applicable concept of biodiversity conservation through surrogates. Here, we present the set-up of an international, interdisciplinary project, INTRABioDiv (http://www.intrabiodiv.eu), which studied vascular plant biodiversity at a large scale, i.e. across the European Alps and the Carpathians. Our assessment comprises species richness (high-mountain flora), genetic variation (amplified fragment length polymorphisms, AFLPs) and environmental diversity (modelled potential habitat diversity). Our primary aims were to test for correlations between intra- and interspecific diversity and to identify possible environmental surrogates to describe biodiversity in the two study regions. To the best of our knowledge, INTRABioDiv represents the first multispecies study on intraspecific, molecular-genetic variation in relation with species and habitat diversity. Here, we outline the theoretical background, our sampling scheme, the technical approaches and the feasibility of a concentrated and standardized sampling effort. We further show exemplary results. Our three data sets will be made freely available and will provide a playground for further hypothesis testing in conservation, ecology or evolution open to the scientific community. (C) 2008 Rubel Foundation, ETH Zurich. Published by Elsevier GmbH. All rights reserved
Relationships among levels of biodiversity and the relevance of intraspecific diversity in conservation - a project synopsis
International audienceThe importance of the conservation of all three fundamental levels of biodiversity (ecosystems, species and genes) has been widely acknowledged, but only in recent years it has become technically feasible to consider intraspecific diversity, i.e. the genetic component to biodiversity. In order to facilitate the assessment of biodiversity, considerable efforts have been made towards identifying surrogates because the efficient evaluation of regional biodiversity would help in designating important areas for nature conservation at larger spatial scales. However, we know little about the fundamental relationships among the three levels of biodiversity, which impedes the formulation of a general, widely applicable concept of biodiversity conservation through surrogates. Here, we present the set-up of an international, interdisciplinary project, INTRABioDiv (http://www.intrabiodiv.eu), which studied vascular plant biodiversity at a large scale, i.e. across the European Alps and the Carpathians. Our assessment comprises species richness (high-mountain flora), genetic variation (amplified fragment length polymorphisms, AFLPs) and environmental diversity (modelled potential habitat diversity). Our primary aims were to test for correlations between intra- and interspecific diversity and to identify possible environmental surrogates to describe biodiversity in the two study regions. To the best of our knowledge, INTRABioDiv represents the first multispecies study on intraspecific, molecular-genetic variation in relation with species and habitat diversity. Here, we outline the theoretical background, our sampling scheme, the technical approaches and the feasibility of a concentrated and standardized sampling effort. We further show exemplary results. Our three data sets will be made freely available and will provide a playground for further hypothesis testing in conservation, ecology or evolution open to the scientific community. (C) 2008 Rubel Foundation, ETH Zurich. Published by Elsevier GmbH. All rights reserved
Break zones in the distributions of alleles and species in alpine plants
Aim We test for the congruence between allele-based range boundaries (break zones) in silicicolous alpine plants and species-based break zones in the silicicolous flora of the European Alps. We also ask whether such break zones coincide with areas of large elevational variation.
Location The European Alps.
Methods On a regular grid laid across the entire Alps, we determined areas of allele- and species-based break zones using respective clustering algorithms, identifying discontinuities in cluster distributions (breaks), and quantifying integrated break densities (break zones). Discontinuities were identified based on the intra-specific genetic variation of 12 species and on the floristic distribution data from 239 species, respectively. Coincidence between the two types of break zones was tested using Spearman’s correlation. Break zone densities were also regressed on topographical complexity to test for the effect of elevational variation.
Results We found that two main break zones in the distribution of alleles and species were significantly correlated. Furthermore, we show that these break zones are in topographically complex regions, characterized by massive elevational ranges owing to high mountains and deep glacial valleys. We detected a third break zone in the distribution of species in the eastern Alps, which is not correlated with topographic complexity, and which is also not evident from allelic distribution patterns. Species with the potential for long-distance dispersal tended to show larger distribution ranges than short-distance dispersers.
Main conclusions We suggest that the history of Pleistocene glaciations is the main driver of the congruence between allele-based and species-based distribution patterns, because occurrences of both species and alleles were subject to the same processes (such as extinction, migration and drift) that shaped the distributions of species and genetic lineages. Large elevational ranges have had a profound effect as a dispersal barrier for alleles during post-glacial immigration. Because plant species, unlike alleles, cannot spread via pollen but only via seed, and thus disperse less effectively, we conclude that species break zones are maintained over longer time spans and reflect more ancient patterns than allele break zones