Spatial pattern of the density of Armillaria epiphytic rhizomorphs on tree collar in an oak stand

Patron spatial de densité de rhizomorphes épiphytes sur les collets des arbres dans un peuplement de chênes

Benoit Marçais (1) , O. Caël (1)

1 IAM - Interactions Arbres-Microorganismes

The density of Armillaria gallica epiphytic rhizomorphs on tree collar was mapped in a young stand of pedunculate oaks (Quercus robur). A quick method to estimate the rhizomorphs density was developed, investigating 19 trees, and was used in the subsequent study. The method consists of measuring the frequency of rhizomorphs presence on a grid applied to an exposed small area of the tree collar. The pattern in tree collar rhizomorph density was closely related to the pattern of stump colonisation by Armillaria and stumps were therefore important as inoculum sources. Rhizomorph density on tree collar showed a strong aggregated spatial pattern which could not be explained by variability in the soil characteristics, in particular waterlogging, or by a spatial pattern in tree vigour. Also, rhizomorph density on tree collar did not depend on their dominance status.

Mots clés: AMILLARIA GALLICA; OAK; RHIZOMORPH; CHENE PEDONCULE

Mots clés: QUERCUS ROBUR; DENSITE POPULATION

Domaines: Phytopathologie et phytopharmacie; Mycologie

Benoit Marçais, O. Caël. Spatial pattern of the density of Armillaria epiphytic rhizomorphs on tree collar in an oak stand. Forest Pathology, 2006, 36 (1), pp.32-40. ⟨10.1111/j.1439-0329.2006.00431.x⟩. ⟨hal-02068539⟩