The enlargement of 21 canopy gaps associated with the root pathogen Heterobasidion annosum (Fr.:Fr.)
Bref. (; Fomes annosus (Fr.) Karst.) in the mixed-conifer forest of Yosemite Valley was monitored between 1971 and
1998. Mean expanded gap area was 232 m2 (range 38–802 m2) in 1971 and 1455 m2 (range 150–4216...