title: Weak Evidence of Regeneration Habitat but Strong Evidence of Regeneration Niche for a Leguminous Shrub.
abstract: The identification of an ecological niche specific to the regeneration phase has mobilised significant attention. However, the importance of the regeneration niche concept remains unclear. Our main objective was to study the existence of such a regeneration niche for a leguminous shrub, Ulex europaeus. This study was carried out in southwest France in the context of water and nutrient stresses (mainly phosphorus limitation) due to the presence of nutrient-poor sandy soils. We analysed the regeneration of the species from the germination of seeds and emergence of new seedlings until the seedlings reached young shrub size. Our design included a P fertilisation treatment. We also investigated microsite characteristics (micro-topography and vegetation development) as they can interact with meteorological conditions and determine water availability for seeds and seedlings. We found that P availability controlled seedling growth and the time necessary to reach young shrub size. Water availability appeared to impact the species germination and seedlings survival. We also found that P and water availability depended on the interactions between microsite characteristics and climatic variations. Finally we found evidence that P and water availability are important ecological factors shaping the regeneration niche of the species, but we found weak evidence that any microsite would be appropriate for the regeneration of the species in the long term. Future studies regarding regeneration niches need to distinguish more clearly the ecological factors important for regeneration (the regeneration niche per se) and the physical world where the seedlings appear and develop (the regeneration habitat).
authors.affiliation: INRA, UMR 1391 ISPA, Villenave d'Ornon F-33140, France; Bordeaux Science Agro, UMR 1391 ISPA, Gradignan F-33883, France; Bordeaux INP, G&E, EA 4592, F-33600, Pessac, France; Univ. Bordeaux Montaigne, G&E, EA 4592, F-33600, Pessac, France.
authors.forename: Florian
authors.initials: F
authors.lastname: Delerue
authors.affiliation: INRA, UMR 1391 ISPA, Villenave d'Ornon F-33140, France; Bordeaux Science Agro, UMR 1391 ISPA, Gradignan F-33883, France.
authors.forename: Maya
authors.initials: M
authors.lastname: Gonzalez
authors.affiliation: Université de Bordeaux, UMR 5805 EPOC, F-33405 Talence, France.
authors.forename: Richard
authors.initials: R
authors.lastname: Michalet
authors.affiliation: INRA, UMR 1391 ISPA, Villenave d'Ornon F-33140, France.
authors.forename: Sylvain
authors.initials: S
authors.lastname: Pellerin
authors.affiliation: INRA, UMR 1391 ISPA, Villenave d'Ornon F-33140, France.
authors.forename: Laurent
authors.initials: L
authors.lastname: Augusto
mesh_terms: D004463:Ecology; D017753:Ecosystem; D007887:Fabaceae / Q000254:growth & development*; D005602:France; D018525:Germination / Q000502:physiology; D010758:Phosphorus; D036226:Seedlings / Q000254:growth & development; D012639:Seeds / Q000254:growth & development; D012987:Soil; D013045:Species Specificity; D013312:Stress, Physiological / Q000502:physiology; D014867:Water
chemical_list: D012987:Soil; D014867:Water; D010758:Phosphorus