Hrner H.,Institute Of Botanique |
Krystufek B.,University of Primorska |
Ribas A.,Museu de GranollersCincies Naturals C Francesc Maci |
Ribas A.,Montpellier SupAgro |
And 6 more authors.
Journal of Mammalogy | Year: 2010
This study describes in detail the phylogeographic pattern of the edible dormouse (Glis glis) a European rodent with pronounced hibernating behavior. We used sequences of 831 base pairs of the mitochondrial DNA cytochrome-b gene from 130 edible dormice collected at 43 localities throughout its distribution. Our results reveal presence of 3 main haplogroups: Sicilian, South Italian (restricted to the Calabrian region), and European (a widespread lineage corresponding to all remaining western, central, and eastern European populations). Examination of paleontological data confirms refugial regions for G. glis in the 3 Mediterranean peninsulas, although overall low genetic diversity is found. The low diversity of the European lineage is probably the result of a recent expansion (dated around 2,000 years ago) from a single refugium. Other factors, such as the ecological constraints on the species, may have caused genetic bottlenecks that reinforced the low genetic variability of G. glis. This work could have important implications for strategies to conserve the edible dormouse by defining important areas for their conservation. © 2010 American Society of Mammalogists.
Descamp P.,Andromede Oceanologie |
Holon F.,Andromede Oceanologie |
Ballesta L.,Andromede Oceanologie |
Guilbert A.,Andromede Oceanologie |
And 4 more authors.
Marine Pollution Bulletin | Year: 2011
Posidonia oceanica is an endemic seagrass from the Mediterranean Sea. It is an indicator of water quality and of the ecological state of coastal ecosystems. The aim of this paper is to test acoustic telemetry for monitoring the position of P. oceanica meadow limits with varied types. After evaluating the accuracy of the system, we present results from a spatiotemporal survey of P. oceanica meadows on nine sites located on the French coast. The method has been demonstrated to be highly efficient for high precision underwater mapping regardless of meadow type, with 1cm accuracy for a distance of 40m between the base and the pointer. A temporal survey led at Cerbere-Banyuls shows a weak global progression of 4m2 (progression of 26m2 - regression of 22m2) between 2006 and 2010. Finally, we discuss the cost and efficiency of this method, and wether it should be generalized for further studies. © 2010 Elsevier Ltd.
Pagnoux C.,Paris-Sorbonne University |
Pagnoux C.,Institute Of Botanique |
Bouby L.,Institute Of Botanique |
Ivorra S.,Institute Of Botanique |
And 6 more authors.
Vegetation History and Archaeobotany | Year: 2014
The origins and biogeographical history of Vitis vinifera L. (domesticated grapevine) remain largely unknown. Shape and size have long been used as criteria to distinguish between wild and domesticated grape pips. Here we have analyzed variations of seed morphology in order to provide accurate criteria for the discrimination of different groups of varieties. Diversity in present-day cultivars and wild grapevines of Greek and east Mediterranean origin in relation to other Asiatic and European varieties and wild grapevines provides the basis for our analysis, which aims to allow the characterization of the ancient diversity of cultivated grapes in relation to present-day cultivars. Geometric morphometric analyses (Elliptic Fourier Transform method) have been used to characterize the seed shape and size of modern and archaeological material using 40 variables per seed. 197 archaeological grape pips from the 7th century bc sanctuary of Hera in Samos, Greece were compared with an extended reference collection of 269 modern cultivars and 83 wild populations, 10,518 seeds in total. Our study confirms the relationships between seed shape and domestication. Modern diversity is partly structured by the geographical origin of cultivars, but influence of other factors may play a significant role in clustering. The wide diversity of varieties offered at the Heraion of Samos during the Archaic Period, including cultivars growing on the island, imported grapes and wild morphotypes, is related to the history and geographical location of the island as well as to the diversity in the geographical range of pilgrims making offerings to the sanctuary. © 2014 Springer-Verlag Berlin Heidelberg.
Fowler A.M.,University of Auckland |
Boswijk G.,University of Auckland |
Lorrey A.M.,NIWA - National Institute of Water and Atmospheric Research |
Gergis J.,University of Melbourne |
And 5 more authors.
Nature Climate Change | Year: 2012
It is not known how global warming will affect the El NiÃ ±o/Southern Oscillation (ENSO). The instrumental record is too short to discern centennial-scale trends and modelling results are inconclusive. Proxy reconstructions indicate that ENSO activity was relatively high during the late twentieth century, but whether this was unusual in the millennial context remains uncertain. Here we present insights into these issues derived from rings of the kauri tree (Agathis australis), a rare long-lived conifer endemic to the forests of northern New Zealand. Our results indicate that the twentieth century was the most 'ENSO-active' century of the past 500 years, but may not be unique in the context of the past 700 years, and that ENSO activity comparable to or elevated above that experienced during the late twentieth century is plausible under warmer-than-present conditions. We also find evidence that there may have been significant changes in the ENSO teleconnection to the New Zealand region during the fourteenth and fifteenth centuries, and of multi-decadal fluctuations in ENSO-related activity building up to the present day. Although these two features may delay the expression of increased ENSO activity in the New Zealand region, our results indicate that New Zealand climate is likely to be more dominated by ENSO-related inter-annual variability as the world continues to warm. © 2012 Macmillan Publishers Limited. All rights reserved.
Despons L.,Institute Of Botanique |
Uzunov Z.,Institute Of Botanique |
Uzunov Z.,Sofia University |
Louis V.L.,Institute Of Botanique
Comptes Rendus - Biologies | Year: 2011
This short article presents an overview of tandem gene arrays (TGAs) in hemiascomycete yeasts. In silico and in vivo analyses are combined to address structural, functional and evolutionary aspects of these particular chromosomal structures. Genomic instability of TGAs is discussed. We conclude that TGAs are generally dynamic regions of the genome in that they are the seats of chromosomal rearrangement events. In addition, they are often breeding grounds of new genes for a rapid adaptation of cells to demands of the environment. © 2011 Académie des sciences. Published by Elsevier Masson SAS. All rights reserved.
Saltre F.,Institute Of Botanique |
Saltre F.,Oregon State University |
Bentaleb I.,Montpellier University |
Favier C.,Montpellier University |
Jolly D.,Montpellier University
Climatic Change | Year: 2013
Paleo-data suggest that East African mountain treelines underwent an altitudinal shift during the Last Glacial Maximum (LGM). Understanding the ecological and physiological processes underlying treeline response to such past climate change will help to improve forecasts of treeline change under future global warming. In spite of significant improvements in paleoclimatic reconstruction, the climatic conditions explaining this migration are still debated and important factors such as atmospheric CO2 concentration, the impact of lapse rate decreasing temperature along altitudinal gradients and rainfall modifications due to elevation have often been neglected or simplified. Here, we assess the effects of these different factors and estimate the influence of the most dominant factors controlling changes in past treeline position using a multi-proxy approach based on simulations from BIOME4, a coupled biogeography and biogeochemistry model, modified to account for the effect of elevation on vegetation, compared with pollen, and isotopic data. The results indicate a shift in mountain vegetation at the LGM was controlled by low pCO2 and low temperatures promoting species morphologically and physiologically better adapted to LGM conditions than many trees composing the forest belt limit. Our estimate that the LGM climate was cooler than today's by -4.5 °C (range: -4.3 to -4.6 °C) at the upper limit of the treeline, whereas at 831 m it was cooler by -1.4 °C (range: -2.6 to -0.6 °C), suggests that a possible lapse rate modification strongly constrained the upper limit of treeline, which may limit its potential extension under future global warming. © 2013 Springer Science+Business Media Dordrecht.
Frejaville T.,National Research Institute of Science and Technology for Environment and Agriculture |
Frejaville T.,EPHE Paris |
Curt T.,National Research Institute of Science and Technology for Environment and Agriculture |
Carcaillet C.,EPHE Paris |
Carcaillet C.,Institute Of Botanique
Frontiers in Plant Science | Year: 2013
Relationships between the flammability properties of a given plant and its chances of survival after a fire still remain unknown. We hypothesize that the bark flammability of a tree reduces the potential for tree survival following surface fires, and that if tree resistance to fire is provided by a thick insulating bark, the latter must be few flammable. We test, on subalpine tree species, the relationship between the flammability of bark and its insulating ability, identifies the biological traits that determine bark flammability, and assesses their relative susceptibility to surface fires from their bark properties. The experimental set of burning properties was analyzed by Principal Component Analysis to assess the bark flammability. Bark insulating ability was expressed by the critical time to cambium kill computed from bark thickness. Log-linear regressions indicated that bark flammability varies with the bark thickness and the density of wood under bark and that the most flammable barks have poor insulating ability. Susceptibility to surface fires increases from gymnosperm to angiosperm subalpine trees. The co-dominant subalpine species Larix decidua (Mill.) and Pinus cembra (L.) exhibit large differences in both flammability and insulating ability of the bark that should partly explain their contrasted responses to fires in the past. © 2013 Frejaville, Curt and Carcaillet.
Roiron P.,Institute Of Botanique |
Chabal L.,Institute Of Botanique |
Figueiral I.,Institute Of Botanique |
Terral J.F.,Institute Of Botanique |
Ali A.A.,Institute Of Botanique
Review of Palaeobotany and Palynology | Year: 2013
The palaeobiogeography of Pinus nigra subsp. salzmannii is investigated in an attempt to understand the environmental mechanisms responsible for its present-day fragmented distribution. A synthesis of data based on cone imprints from travertine deposits and wood charcoal from archaeological sites suggests that, in the past (Holocene), P. nigra subsp. salzmannii had a larger distribution in the north-western Mediterranean Basin. This species has disappeared from eastern France probably as a result of the competition with other ligneous species, such as Quercus ilex and Pinus halepensis, which were favoured by anthropogenic disturbances during the Late Holocene. Current environmental changes, including increasing drought and fire events, will further contribute to the regression of P. nigra subsp. salzmannii populations. The safeguard of this pine in the Mediterranean landscapes relies on sustained national and European conservation programs. © 2013 Elsevier B.V.
Chauchard S.,Montpellier University |
Chauchard S.,Institute Of Botanique |
Beilhe F.,Montpellier University |
Beilhe F.,Institute Of Botanique |
And 3 more authors.
Forest Ecology and Management | Year: 2010
Global environmental changes observed during recent decades are likely to have had an impact on the distribution of species. Currently, silver fir (Abies alba) is becoming established in the subalpine forests of the west central Alps at elevations higher than 2000 m a.s.l.; prior to the 1970s its upper altitudinal limit was 2000 m. Several hypotheses could explain this recent expansion of the upper tree-limit. Silver fir regeneration could be linked (1) to land-use changes or (2) to current climatic warming. Using dendrochronology, the age structure of 31 forest plots containing at least one silver fir was examined in order to elucidate the population dynamics of subalpine communities. This allowed us to decipher the timing of fir regeneration in relation to the mean age of the stands examined and of the other tree-canopy species present. The majority of the firs germinated sporadically since 1950, before the regional temperature increase. The pattern of fir recruitment did not appear to relate to altitude, but followed a pattern characteristic of secondary succession. The age structures identified showed an exponential increase in tree-density during the 20th century; the stands were first dominated by Larix decidua during the 18th and 19th centuries, and then by Pinus cembra during the 20th century. In most stands, fir regeneration occurred after Larix and before P. cembra dominated, following a similar pattern to Picea abies regeneration. The number of local inhabitants and temperature both exhibited a negative relationship with fir tree recruitment, thus supporting the land-use change hypothesis. There has been a significant upward shift of the altitudinal range of fir, amounting to an increase of about 300 m since 1950. This followed the abandonment of low-productivity land. This trend is likely to continue during the 21st century, because of new agricultural and forestry practices which involve limited intervention in low-productivity areas and may be because of the effects of global warming. © 2010 Elsevier B.V. All rights reserved.
PubMed | Institute Of Botanique
Type: Journal Article | Journal: Comptes rendus biologies | Year: 2011
This short article presents an overview of tandem gene arrays (TGAs) in hemiascomycete yeasts. In silico and in vivo analyses are combined to address structural, functional and evolutionary aspects of these particular chromosomal structures. Genomic instability of TGAs is discussed. We conclude that TGAs are generally dynamic regions of the genome in that they are the seats of chromosomal rearrangement events. In addition, they are often breeding grounds of new genes for a rapid adaptation of cells to demands of the environment.