De Román, Miriam; De Miguel, Anna Maria:

Post-fire, seasonal and annual dynamics of the ectomycorrhizal community in a Quercus ilex L. forest over a three year period.

In: Mycorrhiza, Jg. 15 (2005), S. 471-482
ISSN: 0940-6360
Zeitschriftenaufsatz / Fach: Biologie
Two study plots, burned and control, were
established in autumn 1998 in a Quercus ilex forest located
in northern Spain, part of which had been affected by a low
intensity fire in 1994. Soil samples for ectomycorrhizae
(ECM) were taken over a 3-year period in each study plot
in spring, summer, autumn and winter. ECM morphotypes
were identified and the relative abundance of each morphotype
in each soil sample calculated, along with species
richness, Shannon diversity index and percentage of mycorrhization
in each soil sample. The relative abundance of
certain ECM morphotypes differed between burned and
control plots, and the percentage of mycorrhizal tips was
significantly lower in the burned than in the control plot.
Nevertheless, there were no significant differences in the
diversity, species richness or species composition of the
ECM community in the burned and control plots. The dominant
ECM morphotypes in both stands were Cenococcum
geophilum and several thelephoroid fungi. Sphaerosporella
brunnea and Pisolithus tinctorius thrived especially in the
burned plot, whereas three ectomycorrhizal morphotypes
assigned to the genus Hebeloma were especially abundant
in the control plot. There was no significant variation in the
relative abundance of the ECM morphotypes between seasons,
but ECM community species richness was highest in
autumn and lowest in summer. The percentage of mycorrhizal
tips reached a maximum in winter, with its minimum
in autumn. Collection of samples over the 3-year period
also enabled us to detect a significant increase in percentage
of ECM colonisation in the burned stand over time.