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Applicazione dei criteri IUCN a popolazioni periferiche di specie artico-alpine in Appennino settentrionale. Biogeografia dell'Appennino centrale e settentrionale
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Can the IUCN criteria be effectively applied to peripheral isolated plant populations?
No full textThe IUCN criteria 2001 are considered one of the best methods to evaluate species extinction risk at the global and regional levels. The aim of this work is to test the applicability of the IUCN criteria to peripheral isolated plant populations (PIPPs). PIPPs have been a topic of scientific debate in Conservation Biology for about 15 years and international conventions such as ESPC address the issue of their conservation. Conservation measures often rely on Red Lists based on IUCN criteria, but there is little evidence supporting their application to PIPPs. In this work, we tested the hypothesis that PIPPs' intrinsic restricted range and rarity lead to the overestimation of their extinction risk. We compared and analyzed four IUCN criteria (A, B, C, D), considering 17 species with PIPPs in different Italian administrative regions. Special attention must be given to the spatial scale at which PIPPs are assessed, the evaluation of the threats affecting the populations, and their decline. PIPPs should not be assessed within political boundaries and we propose a new area designation that better corresponds to the characteristics of PIPPs. Criterion B is strongly biased by restricted range and overestimates the extinction risk of PIPPs, particularly when the population decline is only suspected and not observed. In this case, criterion D more accurately assesses the status of PIPPs. Criterion A is also suitable for assessing PIPPs, because it is not affected by their phytogeographic rarity. The proposed statements could also be valid for the global assessment of narrow endemic species. © Springer Science+Business Media B.V. 2009
Response of alpine plant flower production to temperature and snow cover fluctuation at the species range boundary
No full textSurface temperatures have risen globally during the last 30 years, especially in alpine areas. It is recognized that these increases are influencing phenology, physiology and distribution of plants. However, few studies have addressed the effects of climate warming at the species range boundary, where plants are expected to be more stressed. We analysed 11-year data sets of inflorescence production of four alpine plants (Carex foetida, Leucanthemopsis alpina, Senecio incanus, Silene suecica) at the southern boundary of their distribution range in the N-Apennines (N-Italy), in relation to air temperature and snow cover persistence. Inflorescence production of all species fluctuated greatly and was significantly affected by the variation of the mean temperature of June/July. We found significant relationships also between species data series and the snow cover persistence. Moreover, species responded differently to such parameters. One species showed a significant decrease of the reproductive effort, whereas the other three showed a stable trend of inflorescence production. We have shown that some alpine species are favoured by increased temperature and reduced snow cover even at the boundary of their range, where they are thought to be particularly sensitive to warming. However, the aptitude to cope with climate change might be limited by competition against thermophilous species migrating from lower altitude and in some cases by the low altitude of mountain peaks that prevent species upward migration. The individualistic response of species to climate change found here, support the statement that the composition of plant communities might rapidly change in the future. © 2011 Springer Science+Business Media B.V
Valutazione dello stato di conservazione di popolazioni marginali in Appennino settentrionale: Cerastium cerastioides (L.) Britton e Salix herbacea L.. Comunicazione
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