Introduction and cultivation experiments for Australian broadleaved tree species

• Chinese Academy of Forestry, China
• Chinese Academy of Forestry, China

China is making strenuous efforts to develop a coordinated forestry policy. In particular, forestry development in southern China is largely directed towards industrial plantations producing various forest products (pulp, paper, poles, plywood etc.) and for fuelwood and environmental protection. Australian trees have been popular there for the past 100 years and species such as Eucalyptus globulus, E. exserta, E. camaldulensis and E. citriodora are the basis of a new industrial forestry program. They currently occupy about 300 000 ha, but yields are often sub-optimal and the range of species is restricted. ACIAR Project 8457 made an excellent start towards achieving the broad aim of improving the productivity of Australian trees in southern China, and also the research capacity of forestry in the region. Through the planting of 17 field trials, promising species and provenances have been identified.

The present project seeks to consolidate these gains and expand them. To this end, it will maintain the current species and provenance trials of Eucalyptus, Acacia and Casuarina genera in China and monitor species' growth performance. The team will also establish additional species trials, to test species over a wider range of envoronments. For the first time in China Melaleuca species will also be included in the trials.

Chinese scientists will establish provenance trials of a small number of species previously identified as promising - Eucalyptus urophylla, Acacia crassicarpa, A. aulacocarpa, A. auriculiformis, A. cincinnata and Casuarina junghuhniana - and will determine the best natural seed sources for further collection and breeding.

Other initiatives include a tree-improvement project for Eucalyptus globulus in Yunnan Province and a tree-breeding program for Casuarina equisetifolia for coastal southern China.

CSIRO scientists will investigate drought stress in Eucalyptus globulus and E. nitens through physiological studies that emphasise gas exchange, changes in leaf area index and in soil water content and leaf water relations of the two species. Studies on drought tolerance in E. camaldulensis will begin with selection and assessment of trees at experimental sites in Queensland and the Northern Territory. A scientist from the Australian National University will study the trees' morphology, anatomy and gas-exchange characteristics under both high and low vapour pressure deficit conditions and will determine the course of growth from the dry season to the wet season.
Training activities through workshops and reciprocal visits aim at improving the scientific capabilities of Chinese scientists in trial design, statistical analyses, computing and tree breeding.

Extension activities will include the establishment of demonstration plantations of promising species and provenances (such as E. camaldulensis and E. urophylla), designed to provide large quantities of semi-improved seed for routine plantations. An important extension activity will be the preparation and publication of a book in Chinese language entitled 'Australian Trees in China'.

Australia will also benefit from the information gained on the growth of Australian native trees under a range of environments. Moreover, the physiological studies on drought stress for temperate species relate directly to ongoing Australian development of hardwood plantations of E. globulus and E. nitens, in which erratic rainfall patterns can impose severe limitations. Thus the project should assist plantation management in both countries and, because Australian trees are being increasingly planted world-wide, should have spillover benefits in many other countries, especially neighbouring Indochina.