Nutrition and mycorrhizal requirements of tropical trees for plantation and agroforestry systems

Papua New Guinea, Solomon Islands, Vanuatu

Dr Paul Reddell
Phone: +61 7 4089 7777
Fax:
Email: paul.reddell@ecobiotics.com.au

• Department of Forestry, Vanuatu
• Kolombangara Forest Products Ltd, Solomon Islands
• Department of Agriculture, Forestry and Fisheries, Niue
• Forest Research Institute, Papua New Guinea
• Queensland Forest Service, Australia

$1,289,500

01/01/1992 - 31/12/1995

31/12/1995 - 30/06/1996

Dr John Fryer

In many areas of developing countries, tropical rainforests - an important economic and environmental resource - are diminishing rapidly due to uncontrolled logging and encroachment of agriculture. As a result, there are increasing pressures to conserve remnant natural forests and to develop low-input, sustainable systems for production of valuable forest products from previously cleared and/or degraded land. However, the establishment and silvicultural requirements of most high-value tropical tree species are poorly known, and the technology to support the production of cabinetwood and other forest products from plantings - either in village agroforestry systems or in plantations - has not been developed.

This project has been set up to:

. identify nutritional factors that affect establishment and early growth of high-value rainforest trees on major groups of forest soils in the tropical western Pacific;

. determine nutritional and mycorrhizal requirements of 10 high-value rainforest tree species with potential for cabinetwood production, agroforestry and reforestation;

. establish a regional genetic resource collection of mycorrhizal fungi; and

. develop suitable potting media and methods of inoculation of nursery stock with mycorrhizal fungi that enhance establishment and maximise growth while minimising fertiliser inputs.

Because the research will be conducted across a range of soil types and production systems in northern Queensland, Papua New Guinea, Vanuatu, Solomon Islands and Niue, the results will also be broadly applicable to other parts of the western Pacific and Southeast Asia. The participation of the four developing nations is crucial to the success of the project, as personnel and infrastructure resources for this type of research are limited in the individual Pacific island nations.

The 10 rainforest tree species for study will be selected (depending on the availability of seed or other propagating material) from a list of 18 promising species drawn up following discussions between the collaborating organisatons. Of the 18 species, 17 are cabinetwoods - three of these also produce fruits or nuts - and the other produces wood for oil extraction. The mycorrhizal status of most of the 18 species is currently unknown.

CSIRO scientists in northern Queensland (Townsville and Atherton) with many years of forestry research experience between them, will coordinate the research. They will collaborate with counterparts in the Queensland Forest Service and in similar organisations in the four partner countries. Overseas visits by Australian scientists are planned to coincide with crucial stages of the research (e.g. layout of field trials, planting of nursery stock, application of fertilisers); and a workshop on design, layout and analysis of nursery and field trials in the second year will bring together participants from all the partner countries.

Australia and each of the partner countries will undertake similar research. The collaborators will identify, in glasshouse and/or field trials, soil nutritional constraints to tree seedling establishment and growth, and assess the nitrogen and phosphorus requirements of the 10 high-value species.

They will collect and catalogue mycorrhizal fungi of native tropical forests, and conduct nursery inoculation and field trials to investigate the effects of applied nutrients and the interaction of various treatments with the mycorrhizal infection of seedlings. They will also develop nursery potting mixes and fertiliser prescriptions for growing selected species and investigate simple and reliable procedures for inoculation of nursery stock with mycorrhizal fungi.

Expected benefits of the project will be an increase in the productivity of agroforestry and plantation systems, increased rural and export incomes from wood and non-wood products, increased timber production in Australia and partner countries, reduced pressure for the exploitation of natural forest resources, and the training of collaborators in forest nutrition and microbiological research techniques, trial design, experimental analysis, report writing and presentation.

Outcomes for this project are currently being prepared