K. Wiklund et al., EFFECT OF IRRIGATION, FERTILIZATION, AND ARTIFICIAL DROUGHT ON BASIDIOMA PRODUCTION IN A NORWAY SPRUCE STAND, Canadian journal of botany, 73(2), 1995, pp. 200-208
A total of 63 mycorrhizal and 49 saprotrophic species was found in a 3
0-year-old Picea abies stand in southwestern Sweden. Nitrogen addition
had an obvious negative effect; all mycorrhizal species ceased to pro
duce basidiomata in the 4th year of supply. Nitrogen-free fertilizatio
n resulted in reduced basidioma number and dry mass production by abou
t 50% compared with the control. An increase in basidioma number was o
bserved as result of irrigation, whereas the dry mass production was u
naffected compared with the control. No fructification occurred, howev
er, when nutrients were added together with the water. Artificial drou
ght resulted in reduced basidioma production. The Ist year of recovery
from drought resulted in an increase in basidioma number and biomass
by a factor of 5 and 9 respectively, compared with the control. Produc
tion of Cortinarius species, Lactarius theiogalus, and Russula emetica
increased as a result of irrigation, while a decrease was observed in
Boletus edulis that instead was favoured by earlier drought. The sapr
otrophic species were only to a minor extent affected by the treatment
s. It is concluded that increased N deposition would result in decreas
ed basidioma production and species number of mycorrhizal species and
that changed precipitation climate would result in another species com
position of mycorrhizal basidiomata in coniferous forests.