A review of dipterocarps - Center for International Forestry Research

Root Symbiosis and Nutrition
where inoculum already exists (Alexander 1989).
However, Smits (personal communication) reported
that dipterocarps have been successfully established
on a large-scale in heavily burned secondary forest
at Longnah, East Kalimantan.
5. The mycorrhizal fungi should be compared for effects
on hosts in different soils under controlled
conditions and for adaptability to handling in nursery
inoculation processes and to nursery cultural
practices.
Brundrett et al. (1996) have comprehensively
discussed the differential effect of various soil
attributes on mycorrhizal fungal growth which have
implications for tree establishment.
6. Host specificity and compatibility of selected
ectomycorrhizal fungi should be determined in pot
experiments with selected host species and genera.
7. Efforts on the selection of mycorrhizal fungi for
inoculation of seedlings should be continued. This
should be based on a set of criteria which would
include satisfactory vegetative growth or abundant
sporulation for production of large quantities of
inoculum, adaptability to inoculation manipulation,
ability to form mycorrhizas with a broad range of host
species, and ability to enhance growth of the host
tree (Trappe 1977, Marx et al. 1992).
8. Inoculation experiments should be conducted with
identified or known and preferably indigenous
mycorrhizal strains.
This is to ensure that results are repeatable and
verifiable and for development into practical application
techniques for field use. This is important for the
sustained production of effective mycorrhizal inoculum.
Current Mycorrhizal Research Groups
and Needs
Presently dipterocarp mycorrhizal research is most
actively being pursued in Indonesia and Malaysia and to
a lesser extent in Thailand. Some research has also
recently begun in the Philippines.
Indonesia
Among the Southeast Asian nations, Indonesia has the
most numerous researchers and research institutes
engaged in dipterocarp mycorrhizal research. The main
institutes are BIOTROP and Bogor Agricultural
University in Bogor, Gadjah Mada University in
108
Yogyakarta, Universitas Mulawarman and the
TROPENBOS Project in East Kalimantan which includes
the Association of Forest Concession Holders. A variety
of topics are being investigated but most of the results
are published in local Indonesian journals in Bahasa
Indonesia (see Supriyanto et al. 1993a) and often are
very brief with details of experiments missing. This
situation is slowly changing with the emergence of
collaborative projects funded by foreign agencies such
as the European Economic Community (EEC), Overseas
Development Authority of the U.K. (ODA), the Dutch
TROPENBOS and the Japanese government, and as more
international symposia on mycorrhizas are organised.
However, there appears to be some lack of coordination
and communication between the various research groups,
with each group appearing to work in isolation. It has
also been pointed out that many of these groups conduct
research in nurseries or in small experimental
dipterocarp plantations outside the area of their natural
occurrence (Smits 1992). Consequently not all the
results may be of equal importance for an understanding
of the functioning of dipterocarp mycorrhizas under
natural conditions. Comprehensive reports of the status
of mycorrhizal research in Indonesia are given in Hadi
et al. (1991) and Supriyanto et al. (1993a).
Malaysia
In Malaysia dipterocarp mycorrhizal research is
presently only being conducted at the Forest Research
Institute Malaysia (FRIM). Considerable progress has
been made towards the understanding of the biology and
ecology of some dipterocarp mycorrhizas, and
techniques are being developed and improved for
controlled inoculation of dipterocarp planting material.
The research has largely benefited from collaboration
with researchers from Europe under a joint FRIM-
Commission of the European Communities collaborative
project. The survey and identification of mycorrhizal
fungi are actively being pursued under another
collaborative project with the Royal Botanic Garden,
Edinburgh, funded by the ODA. Results have been
published in several international journals.
Thailand
There are two institutes conducting dipterocarp
mycorrhizal research in Thailand, these being the Faculty
of Forestry at Kasetsart University and the Royal Thai
Forest Department. Most of the research has