Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
This paper describes an operational protocol for integrating conservation and restoration with land-use planning in islands. Conservation challenges are intensified in insular systems due to higher ecosystem vulnerability, limited spatial options, low data availability, rapid land-use change and, globally, short-term vision planning. Our operational planning protocol integrates ecological and socio-economic factors to identify the best spatial options for conserving and restoring biodiversity, inside and outside extant reserves, while minimising future land-use conflicts. Conservation and restoration targets are formulated for species, habitats and ecological processes that support biodiversity. An optimal network of priority sites is selected to achieve those targets across the landscape. The prioritisation process integrates a Conservation Costs Index to optimise conservation and restoration investments. We discuss the outcomes of the planning protocol in terms of site prioritisation, stakeholders' participation and general implications for spatial planning in insular systems. As with many islands, the study area of Réunion Island has experienced rapid urban and agricultural expansion, which threatens its unique biodiversity. Forty three per cent of the island is currently protected in a National Park but only half of this reserve network contributes to the achievement of targets. An additional 21% of land should be conserved mainly to ensure the persistence of ecological connections between the marine, terrestrial and freshwater realms. Finally we emphasize that our method doesn't substitute the land-use planning debate but is aimed to better prepare the conservation sector for negotiating future land-use allocation with other socio-economic sectors in islands
Landscape and Urban Planning

halsde-00676425
https://hal.archives-ouvertes.fr/halsde-00676425
DOI : 10.1016/j.landurbplan.2011.02.004

Éditeur(s) : HAL CCSD
Résumé : absent
Plantes et peuplements virtuels
Lyon, France, France

hal-01032391
https://hal.archives-ouvertes.fr/hal-01032391

Éditeur(s) : HAL CCSD Public Library of Science
Résumé : International audience
Domestication can influence many functional traits in plants, from overall life-history and growth form to wood density and cell wall ultrastructure. Such changes can increase fitness of the domesticate in agricultural environments but may negatively affect survival in the wild. We studied effects of domestication on stem biomechanics in manioc by comparing domesticated and ancestral wild taxa from two different regions of greater Amazonia. We compared mechanical properties, tissue organisation and wood characteristics including microfibril angles in both wild and domesticated plants, each growing in two different habitats (forest or savannah) and varying in growth form (shrub or liana). Wild taxa grew as shrubs in open savannah but as lianas in overgrown and forested habitats. Growth form plasticity was retained in domesticated manioc. However, stems of the domesticate showed brittle failure. Wild plants differed in mechanical architecture between shrub and liana phenotypes, a difference that diminished between shrubs and lianas of the domesticate. Stems of wild plants were generally stiffer, failed at higher bending stresses and were less prone to brittle fracture compared with shrub and liana phenotypes of the domesticate. Biomechanical differences between stems of wild and domesticated plants were mainly due to changes in wood density and cellulose microfibril angle rather than changes in secondary growth or tissue geometry. Domestication did not significantly modify "large-scale" trait development or growth form plasticity, since both wild and domesticated manioc can develop as shrubs or lianas. However, "finer-scale" developmental traits crucial to mechanical stability and thus ecological success of the plant were significantly modified. This profoundly influenced the likelihood of brittle failure, particularly in long climbing stems, thereby also influencing the survival of the domesticate in natural situations vulnerable to mechanical perturbation. We discuss the different selective pressures that could explain evolutionary modifications of stem biomechanical properties under domestication in manioc.
PLoS ONE

halsde-00917926
https://hal.archives-ouvertes.fr/halsde-00917926
https://hal.archives-ouvertes.fr/halsde-00917926/document
DOI : 10.1371/journal.pone.0074727