PAGÈS, J.P.; MICHALET, R.

doi:10.1007/s11258-005-0976-x

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PAGÈS, J.P.
Ecosystèmes montagnards [UR EMGR]

MICHALET, R.
Biodiversité, Gènes et Ecosystèmes [BioGeCo]

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Article de revue

Ce document a été publié dans

Plant Ecology. 2006, vol. 187, n° 2, p. 179-187

Springer Verlag

Résumé en anglais

Positive associations between adult trees and understorey species have been explained either by direct or indirect facilitation. We tested both models by comparing the performance of two understorey species with contrasted stress-tolerance abilities Galium odoratum and Deschampsia flexuosa. Individuals of both species were transplanted in the four combinations of two treatments (gap and removal of an herbaceous competitor, Molinia caerulea). Our experiment demonstrated that direct facilitation of adult trees may explain the restricted occurrence of the shade-demanding Galium within closed forest communities. In contrast, the shade-tolerant Deschampsia was subjected to additional competition within the forest, likely because adult trees had a higher negative effect on light availability and a similar negative effect on nitrogen availability within the forest than did Molinia in the gaps.< Réduire

Mots clés

NITROGEN

Mots clés en anglais

COMPETITION INTENSITY

FOREST COMMUNITIES

INDIRECT EFFECTS

LIGHT

Mots clés en italien

MOLINIA CAERULEA