Éditeur(s) : Musée des Cultures Guyanaises (Cayenne)
Extrait de : Rencontres transfrontalières Oyapock, les 1er et 2 décembre 2012. Université des Antilles et de la Guyane
Description : Qu'arrive-t-il lorsque une population s'empare du musée, se l'approprie et en fait un espace de rencontre, de débat, de partage ? L'idée d'un musée plus proche des populations s'est développée en France et dans le monde à partir des années 1970, sous l'appellation éco-musée,musée-communautaire. Parmi ses objectifs : replacer l'homme au centre du musée, renforcer son appartenance au territoire et permettre aux habitants de devenir acteur de la préservation de leur patrimoine dans un contexte de mutation rapide des modes de vie. C'est à ce musée-participatif que l'atelier sera consacré à travers plusieurs exemples guyanais et brésiliens. Comment construire un musée participatif ? Quelle médiation utiliser ? Comment susciter l'adhésion de la population locale ? Et, une fois mise en place, comment utiliser le musée ?
Siècle(s) traité(s) : 21
Droits : CC-BY-NC-ND - Attribution - Pas d'utilisation commerciale - Pas de modification
Permalien : http://www.manioc.org/fichiers/V13110
V13110

Éditeur(s) : HAL CCSD Nature Publishing Group
Résumé : While Amazonian forests are extraordinarily diverse, the abundance of trees is skewed strongly towards relatively few 'hyperdominant' species. In addition to their diversity, Amazonian trees are a key component of the global carbon cycle, assimilating and storing more carbon than any other ecosystem on Earth. Here we ask, using a unique data set of 530 forest plots, if the functions of storing and producing woody carbon are concentrated in a small number of tree species, whether the most abundant species also dominate carbon cycling, and whether dominant species are characterized by specific functional traits. We find that dominance of forest function is even more concentrated in a few species than is dominance of tree abundance, with only ≈1% of Amazon tree species responsible for 50% of carbon storage and productivity. Although those species that contribute most to biomass and productivity are often abundant, species maximum size is also influential, while the identity and ranking of dominant species varies by function and by region.
ISSN: 2041-1723

hal-01204225
https://hal.archives-ouvertes.fr/hal-01204225
DOI : 10.1038/ncomms7857
PRODINRA : 305614
PUBMED : 25919449

Éditeur(s) : HAL CCSD Wiley
Résumé : International audience
Aim To examine variation in the phylogenetic diversity (PD) of tree communities across geographical and environmental gradients in Amazonia.Location Two hundred and eighty-three c.1ha forest inventory plots from across Amazonia.Methods We evaluated PD as the total phylogenetic branch length across species in each plot (PDss), the mean pairwise phylogenetic distance between species (MPD), the mean nearest taxon distance (MNTD) and their equivalents standardized for species richness (ses.PDss, ses.MPD, ses.MNTD). We compared PD of tree communities growing (1) on substrates of varying geological age; and (2) in environments with varying ecophysiological barriers to growth and survival.Results PDss is strongly positively correlated with species richness (SR), whereas MNTD has a negative correlation. Communities on geologically young- and intermediate-aged substrates (western and central Amazonia respectively) have the highest SR, and therefore the highest PDss and the lowest MNTD. We find that the youngest and oldest substrates (the latter on the Brazilian and Guiana Shields) have the highest ses.PDss and ses.MNTD. MPD and ses.MPD are strongly correlated with how evenly taxa are distributed among the three principal angiosperm clades and are both highest in western Amazonia. Meanwhile, seasonally dry tropical forest (SDTF) and forests on white sands have low PD, as evaluated by any metric.Main conclusions High ses.PDss and ses.MNTD reflect greater lineage diversity in communities. We suggest that high ses.PDss and ses.MNTD in western Amazonia results from its favourable, easy-to-colonize environment, whereas high values in the Brazilian and Guianan Shields may be due to accumulation of lineages over a longer period of time. White-sand forests and SDTF are dominated by close relatives from fewer lineages, perhaps reflecting ecophysiological barriers that are difficult to surmount evolutionarily. Because MPD and ses.MPD do not reflect lineage diversity per se, we suggest that PDss, ses.PDss and ses.MNTD may be the most useful diversity metrics for setting large-scale conservation priorities.
ISSN: 1366-9516

hal-01557462
https://hal.univ-lorraine.fr/hal-01557462
DOI : 10.1111/ddi.12357

Éditeur(s) : HAL CCSD American Association for the Advancement of Science
Résumé :  
Amazon forests are a key but poorly understood component of the global carbon cycle. If, as anticipated, they dry this century, they might accelerate climate change through carbon losses and changed surface energy balances. We used records from multiple long-term monitoring plots across Amazonia to assess forest responses to the intense 2005 drought, a possible analog of future events. Affected forest lost biomass, reversing a large long-term carbon sink, with the greatest impacts observed where the dry season was unusually intense. Relative to pre-2005 conditions, forest subjected to a 100-millimeter increase in water deficit lost 5.3 megagrams of aboveground biomass of carbon per hectare. The drought had a total biomass carbon impact of 1.2 to 1.6 petagrams (1.2 × 1015 to 1.6 × 1015 grams). Amazon forests therefore appear vulnerable to increasing moisture stress, with the potential for large carbon losses to exert feedback on climate change.
ISSN: 0036-8075

hal-01032111
https://hal.archives-ouvertes.fr/hal-01032111
DOI : 10.1126/science.1164033