1,721,074 research outputs found
Conservation and restoration of indigenous plants to improve community livelihoods: the Useful Plants Project
No full textSeed production and in situ germination of Lamyropsis microcephala (Asteraceae), a threatened Mediterranean mountain species
No full textSeed reproduction is considered a critical bottleneck of the plant life cycle, constraining population growth, especially in the Mediterranean area. In this study, we investigated seed reproduction of Lamyropsis microcephala (Asteraceae), a threatened species occurring only in the Gennargentu massif (CE Sardinia, Italy). Seed output was quantified in two of the four localities where the species occurs, which differed in population size.
Germination of seeds from all the four localities was assessed, both in the field and under controlled conditions, and the annual trend of soil temperature recorded by data-loggers.
Plants had ca. 60 cypselas (i.e. the fruits of Asteraceae) per capitulum in the larger Rio Aratu and ca. 30 in the smaller Pisargiu locality, with only ca. 1.7 and 0.3 germinating cypselas per capitulum, respectively. Under controlled conditions, seeds of the two large localities (Bau ‘e Laccos and Rio Aratu) germinated above 80%, while those of the two small ones (Bruncu Spina and Pisargiu) did not reach 55%. All seeds sown in the field germinated in April–June, when diurnal fluctuations of temperatures were almost 10 times higher than in winter, limiting the length of the growing season before the onset of summer drought, and highlighting an increasing threat from global warming
Advances in modelling thermal-induced seed dormancy loss and germination in rare Mediterranean mountain species under a changing climate
No full textRegional responsibility for plant conservation: The 2010 GSPC Target 8 in Sardinia
No full textThe collections stored at the Sardinian Germplasm Bank (BG-SAR) were analysed to verify if setting conservation priorities
on the exclusive endemic flora of Sardinia (Italy) would make it possible to reach the 2010 GSPC Target 8. By 2010, 39.9%
of the exclusive-endemics of Sardinia, 43.1% of the BGCI European threatened species and 65.0% of the taxa listed in
Annex II of DIR 92/43/EEC present on the island had been stored in BG-SAR. Of the stored plants, 40% of those listed in
the DIR 92/43/EEC, and only 25.69% of the BGCI threatened plants are represented by an adequate number of
populations. For a few of the stored threatened plants (ca. 36%), and for 60% of the DIR 92/43/EEC ones, at least one
seedlot with more than 5000 seeds is available. These data indicate that focusing on exclusive endemics gave a substantial,
although not decisive, contribution towards the achievement of the 2010 GSPC Target 8 in Sardinia, and that more efforts
are needed to guarantee the effective long-term conservation of these threatened taxa with the aim of reaching the 2020
GSPC target
Effects of temperature, light and pre-chilling on germination of Rhamnus persicifolia, an endemic tree species of Sardinia(Italy)
No full textRhamnus persicifolia is an endemic small tree or shrub belonging to the R. cathartica group. It grows along
mountainous waterways of the Central-Eastern Sardinia (Italy). The purpose of this study was to report the effects
of temperature, light and pre-chilling on germination of R. persicifolia seeds. The applied treatments included
a range of constant temperatures (5-30°C) and two alternating temperature regimes (15/5 and 25/10°C), with
two photoperiods (8 h light / day and darkness). In addition, the most effective germination temperature (25°C)
was repeated including a pre-chilling period (5°C for 3 months). R. persicifolia reached maximum germination
percentages (> 70%) at warm temperatures (≥ 20°C), with no differences between constant and alternating
regimes and no response to light. While the pre-chilling period did not increase germination percentage it had
a positive effect on germination rate, reducing T50 by more than 50%. These studies provide new information
on the seed biology of this endemic species and enable ex situ seed germination, which may prove useful for
habitat restoration activities
A checklist of the exclusive vascular flora of Sardinia with priority rankings for conservation
Full text linkSardinia is the second-largest island in the Mediterranean Sea and its isolation
and high geological diversity have created a wide range of habitats
with high levels of endemism, especially on its mountain massifs,
where there are conditions of ecological insularity. In this study the exclusive
endemic flora of Sardinia has been updated to 168 taxa, 139 of
which are species, 23 subspecies, 4 varieties and 2 hybrids, belonging to
37 families and 72 genera. Despite this rich biodiversity and the threats
to these species, few biological conservation studies have been carried
out up to now. A conservation project for the most threatened exclusive
endemic species of Sardinia was therefore funded in 2007 by the “Regione
Autonoma della Sardegna”. To categorize these species of conservation
interest, a priority list was created by applying 11 parameters
based on rarity, threats and protection status. This work allowed the
identification of the most threatened species of the Sardinian endemic
flora
Seed dormancy and germination ecology of Lamyropsis microcephala: a mountain endemic species of Sardinia (Italy)
No full textLamyropsis microcephala only occurs in a very restricted area in the Gennargentu massif (CE-Sardinia, Italy)
at 1450-1700 m a.s.l. This rare species has been inserted in the International Union for Conservation of Nature
(IUCN) Red Lists under Critically Endangered. In this study, the effect of a pre-chilling period (90 days at 5°C)
on germination was investigated as well as the ability of this species to form a soil seed bank. L. microcephala
seeds exhibited type 2 non-deep physiological dormancy. Pre-chilling increased the final germination percentages,
the germination speed and the temperature range at which high levels of germination were observed. The high
optimal germination temperatures (ca. 70% germination at 30°C) demonstrate that this species is well adapted
to a temperate climate and the lack of a persistent soil seed bank represents a rarity trait that likely exacerbates
the threats to the survival of this species
Comparative germination ecology of the endemic Centranthus amazonum (Valerianaceae) and its widespread congener Centranthus ruber
No full textCentranthus amazonum Fridl. & A. Raynal (Valerianaceae) is a critically endangered
narrow endemic to Central–Eastern Sardinia (Italy), where it occurs in rocky habitats. In
the present study, the germination ecology of this species was investigated and compared
with the relatively widespread species Centranthus ruber (L.) DC. subsp. ruber. In particular,
the effects of a range of constant temperatures (5–25°C) and two alternating
temperature regimes (25/10 and 30/15°C) on seed germination were analyzed. For the two
species, cardinal temperatures were determined as the reciprocal of time to 50% germination
(t50). In addition, seed persistence in the soil was assessed by experimental seed
burials. Seeds of both species were non-dormant; however, C. amazonum produced more
empty seeds and germination was slower and reached lower final percentages than C.
ruber. Moreover, seed and seedling mass of C. ruber were higher than for C. amazonum
and the lack of a persistent soil seed bank detected for C. amazonum increases vulnerability
to extinction for this species. The present study provides new data on the germination
ecology of the previously unstudied C. amazonum that may explain the rarity of
this species when compared with the commonness of C. ruber
Studi di biologia della conservazione di specie vegetali endemiche della Sardegna nell'ambito del progetto "GENMEDOC"
Full text linkConservation biology studies on the endemic species from Sardinia within the "GENMEDOC" Project - The achieved results
of the Interreg IIIB "Genmedoc" project (2004-2006) are here reported. Data focused on the conservation biology studies
of Sardinian endemic species are showed in this work. During the project 26 populations of 16 species were investigated
and the ex situ conservation for these species was guaranteed by storage of 65 seed lots in the seedbank. Furthermore 8
species were analysed by in situ characterization of 17 populations: for each population ecological studies were carried out.
Real and possible threats that affect these populations were detected. For 6 species effective germination protocols were
identified and also valied by other two project partners. These protocols allow evaluating seed quality for the stored lots
and their longevity during next years; moreover the knowledge of the best germination conditions will be able to schedule
a possible cultivation or an in situ re-introduction for these species. These results were obtained by sistematic conservation
biology studies of threatened endemic species of Sardinia by a tested and internationally acknowledged methodology
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