Ecological considerations for using dipterocarps for restoration of lowland rainforest in Southeast Asia

The lowland dipterocarp forests of Southeast Asia support a substantial proportion of the world's biodiversity. They are of considerable environmental and economic value at the local, regional and global scale, providing many goods and services to a growing population. The forests of this region are among the fastest disappearing in the world and restoration is urgently required. This paper provides a review of the ecological constraints to restoration of lowland dipterocarp forest in Southeast Asia. It focuses on the production of planting stock, the significance of site-species matching and post-planting site maintenance. It identifies gaps in our knowledge and highlights priority areas of research. Adopting a long-term view is essential for restoring as well as conserving the dipterocarp forests of Southeast Asia. An immediate strategy for the conservation and management of dwindling genetic resources of these important timber species is essential. This will provide the foundations for sourcing seed and production of planting material for longer term restoration. The importance of species-site matching, mycorrhizal fungi and post-planting maintenance for restoration are apparent. Financing is a major limiting factor to dipterocarp forest restoration. Trading in carbon, private finance and environmental markets afford considerable opportunities for restoring these forests providing their total value is recognised. Despite the wealth of ecological knowledge we already have for scientifically-informed forest restoration, without the backing of governments and corporate stakeholders, forest restoration will not gain the urgently required momentum.