全球桉树人工林发展面临的困境与对策

桉树人工林是世界人工林的重要组成部分,在木材供给和应对气候变化等方面扮演着越来越重要的角色。世界热带亚热带地区的国家都在大力发展桉树人工林,使全球桉树人工林的面积呈现不断增加的趋势,近15年来全球桉树人工林面积年平均增长110万hm~2。面对可利用林地资源的限制、立地条件的制约、气候变化的胁迫、社会对林产品需求的变化,以及社会舆论博弈的影响,世界桉树人工林必将在营林制度、经营策略和经营途径方面发生深刻变化和重大调整。营林制度上由短周期纯林连作的林分经营转变为短中长周期循环混交轮作的景观经营,经营策略上从注重桉树造林面积扩张转变为人工林单产和生态系统服务的全面提升,经营途径上更加重视多目标森林生态系统可持续经营将成为未来桉树人工林发展的主流趋势。然而,在由单一的木材经营转变为多目标森林生态系统可持续经营过程中,桉树人工林仍将保持以木材生产为主导功能的发展格局,这是桉树人工林的比较优势和特点决定的。但有效权衡和协同桉树木材生产主导功能与其他生态服务功能是今后经营的方向。

The Predicament and Countermeasures of Development of Global Eucalyptus Plantations

Eucalyptus plantations are an important component of global plantations and play an increasingly important role in the supply of timber and climate change.Countries in the tropical and subtropical regions of the world have all been vigorously developing Eucalyptus plantations, and the area of global Eucalyptus plantations has been increasing.Over the past 15 years, the global average area of Eucalyptus plantations has increased by 1.1 million hm² annually.In the face of limitation of available forest resources, restrictions on site conditions, stress of climate changes, changes of society demand for forest products and influence of social media games, the regime, strategy and approach of global Eucalyptus plantations culture and management will certainly be profoundly changed and significantly regulated.The mainstream tendency of development of Eucalyptus plantations in the future should be:(1) forest culture and management regime change from forest stand management with successive short rotation to landscape management with short-, medium-and long-term cyclic rotation; (2) management strategy changes from focusing on the expansion of Eucalyptus plantation areas to the comprehensive promotion of per unit yield and ecosystem services; (3) management approach attaches more importance to the sustainable management of multi-purpose forest ecosystems.However, in the transition from a single timber-centered objective to a sustainable management of multi-purpose forest ecosystems, Eucalyptus plantations will still maintain a development pattern with timber production as the dominant function, which is determined by the comparative advantages and characteristics of Eucalyptus plantations.Effective trade-offs and synergies between leading functions and other ecological service functions of Eucalyptus timber production are the direction of management in future.