A review of dipterocarps - Center for International Forestry Research

Root Symbiosis and Nutrition
Table 1. (continued) Dipterocarp species reported to be ectomycorrhizal based on root examination.
Genera Species Location Vegetation Reference/Source
S. siamensis Miq. Thailand Dry deciduous forest Aniwat (1987)
S. smithiana Sym. Kalimantan Lowland rainforest Bimaatmadja in Hadi et al. (1991)
S. stenoptera Burck Java Dipterocarp arboretum Setiabudi in Hadi et al. (1991)
" Kalimantan Lowland rainforest Smits (1992)
S. sumatrana (Sloot. ex Thor.) Sym. Pen. Malaysia Rainforest Mohd. Noor (1981)
S. talura Roxb. " " "
S. teysmanniana Dyer ex Brandis " " "
Vatica
Vatica sp. 1 Kalimantan Lowland rainforest Smits (1992)
V. chartacea Ashton " " "
V. papuana Dyer ex Hemsl. Pen. Malaysia Lowland rainforest Singh (1966)
V. rassak (Korth.) Bl. Kalimantan Lowland rainforest Smits (1992)
V. sumatrana Sloot. Java Dipterocarp arboretum Hadi & Santoso (1988)
V. umbonata (Hook. f.) Burck Kalimantan Lowland rainforest Smits (1992)
Vateria
V. indica L. S. India Wet evergreen forest Alexander & Hogberg (1986)
Vateriopsis
V. seychellarum Heim Aberdeen greenhouse Potted plant Unpublished data
be consistent with the theory that dipterocarps are
ectomycorrhizal. Smits (1983) suggested that the
clumped distribution of dipterocarps was due to an
ecological adaptation between suitable fungi and selected
dipterocarp species on the different sites. He (Smits
1994) has also suggested that dipterocarp mycorrhizas
contribute to speciation amongst the Dipterocarpaceae
through enhanced isolation. Janzen (1974) speculated
that dipterocarps which shed their litter containing large
amounts of phenols and other secondary compounds
required ectomycorrhizas to avoid self-toxicity. Other
researchers speculate that the high mortality of outplants
and lack of success in vegetative propagation of
dipterocarps may be due to a lack of or death of
ectomycorrhizas (Ashton 1982, Becker 1983, Smits
1983, Noor and Smits 1987). Lee et al. (1966) however,
have shown that outplanted seedlings of Hopea nervosa
and Shorea leprosula survived better and had higher
levels of ectomycorrhizal infection in logged forest than
in undisturbed forest.
Although dipterocarps were known to form
ectomycorrhizas since the 1920s (Van Roosendael and
Thorenaar, and Voogd, cited in Smits 1992), it was only
103
in the last ten years that research into applied aspects of
the dipterocarp root symbiosis, in particular its role in
plant establishment and nutrition, has intensified, with
the growing need for rehabilitation and reforestation.
Mycorrhizas are also viewed as ‘biofertilisers’, an
alternative to chemical fertilisers for infertile tropical
soils where reforestation is being carried out (de la Cruz
1991). This chapter discusses the current state of
knowledge of dipterocarp nutrition and root symbiosis,
and identifies priorities and needs for future research.
Mycorrhizal Fungi and Dipterocarps
Mycorrhizal Associates of the Dipterocarps
Ectomycorrhizas are usually formed by members of the
Basidiomycetes and Ascomycetes but in some cases may
also be formed by Zygomycetes (species of Endogone)
(Trappe 1962, Harley and Smith 1983). In the
Dipterocarpaceae most observations implicate
Basidiomycete genera. In Malaysia over fifty different
agarics and boleti, four earthballs and a new species of
Pisolithus have been found associated with dipterocarps
(Watling and Lee 1995). The dominant fungi were