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Work by Antonio Izzo
Based on 36 2 cm X 20 cm soil cores from a total of
9 plots contained within a 2.5 hectare region. 91
species of EM fungi
Facultative epiparasitism?
Douglas-fir seedling and manzanita
Ectomycorrhizal
community structure based
on root tip colonization
Data from mature Pt. Reyes, Bishop
pine communities summarized by
families.
Tomentella - a little fungus, but a big player
Early stage
Fungi ( r )
Fruit under
very young
trees
Fruit at
periphery of
older trees
Late stage
Fungi ( K )
Fruit under
older trees
Fruit near
stem of older
trees
Establish on Establish on
seedlings in
seedlings in
disturbed soil undisturbed
soil
Spores are
effective
inoculum
Spores are not
effective
inoculum
Attributes of Early versus Late-stage Ectomycorrhizal Fungi
as defined by Deacon and Fleming (1992)
Early stage (ruderal)
Late stage (K-selected)
fruit bodies develop in early years
fruit bodies develop in later years as trees
beneath young trees
mature
fruit bodies and mycorrhizas seen near
periphery of expanding root system
fruit bodies and mycorrhizas seen mainly
in older root zones
infect readily from spores or mycelial
inocula added to unsterile soil
do not infect from spores or mycelia
added to unsterile soil
persist when aseptically inoculated
seedlings are transplanted to soil
persist poorly after transplanting
have low sugar demand for extension
growth and infection in culture
have high sugar demand for extension
growth and infection in culture
spores germinable in culture or in
presence of plant roots
spores not readily germinable in culture
some are known to infect as monokaryons have not been shown to infect as
monokaryons
Example genera: Lacarria, Hebeloma,
Russula, Amanita, Boletus,
Inocybe
Rhizopogon species are dominants in seedling bioassay
Ectomycorrhizal
community structure based
on root tip colonization
Data from mature Pt. Reyes, Bishop
pine communities summarized by
families.
*
*
us
ot
he
r
ot
he
r
ot
he
r
ot
he
r
ot
he
R.
r
oc ot
h
ci
de er
nt
R.
al
ol
is
iv
o
ac
eo the
tin r
ct
us
eb
ro
s
40
35
30
25
20
15
10
5
0
sa
l
R.
30
25
10
5
0
r
de
nt
al
is
ci
ot
he
r
0
ot
he
r
eb
ro
su
s
ot
he
r
ot
he
10
oc
sa
l
60
R.
ct
us
ot
he
r
eo
tin
ac
R.
iv
ol
Rhizopogon *
R.
o
s
R. ale the
oc bro r
ci
de sus
nt
al
is
ot
he
ot r
he
ot r
he
ot r
he
ot r
he
ot r
he
ot r
he
ot r
he
ot r
he
r
R.
Rhizopogon and
Ascomycetes dominated
the roots of pine seedlings
after the Pt. Reyes fire.
*
50
40
30
20
*
*
*
20
15
*
*
Agerer’s Ectomycorrhizal exploration types
Ectomycorrhizal fungi are diverse at multiple spatial scales
Bever et al. 2001 Bioscience 51:926: “No
single sampling methodology was able to
reveal all of the species at the site. In fact,
it seems that each variant on the sampling
methodology, whether it be green-house
condition of the trap cultures, species of
plant host used in the traps, treatment of
soil prior to trapping, or season of
sampling field soil, would reveal additional
fungal species.”
Species diversity
of AM fungi
effect diversity
of plant
community and
ecosystem
function
From Van der
Heijden et al.
1998
Bever’s negative feedback model
Reynolds et al. - nutrient niche model for P
From Francis and Read
1995
Parasitism of surrounding
plants by Tuber melanosporum
an ectomycorrhizal fungus on
oak