Dipterocarps and Mycorrhiza. An ecological adaptation and a factor in forest regeneration

Each dipterocarp has its own species of fungus, forming an ectomycorrhiza. From literature and experiments (in East Kalimantan and in vitro) ecological consequences are explored. These help explain the clumping of dipterocarp trees in the forest, the lack of hybrids, the poor dispersal, and speciation as dependent on the viability of the root-fungus combination on a particular soil type. Mycorrhizas are located in the top soil. They are extremely sensitive to increase of soil temperatures as occur after canopy opening, and to soil compaction by machinery and log skidding. This explains the setback of dipterocarp growth after crude logging. It is suggested that avoidance of soil compaction during logging, quick restoration of soil cover, and the use of fungus-inoculated seedlings for enrichment planting are important consequences for forest management. Key words: Dipterocarpaceae, ecology, enrichment planting, logging, management, mycorrhiza. Mycorrhiza — Dipterocarpaceae — The role of the symbiosis — The influence of logging on the fungi — Conclusions — References.