农林复合系统的水土保持效益

Soil and water conservation benefits of agroforestry systems

农林复合系统作为一种兼顾生态效益、社会效益和经济效益的人工生态系统,对于生态环境保护及农林业的可持续发展具有重要意义.文章针对全球不同类型的农林复合系统分别展开讨论,阐述其防止水土流失的机制和特点,并在前人研究的基础上估算了其水土保持效益.结果表明,农林复合系统能够平均减少54.0%(1.0%~95.8%)的径流和71.7%(17.8%~99.9%)的土壤损失,河岸植被缓冲带减少径流和泥沙效益最高,分别为60.0%(1.0%~94.4%)和76.8%(28.0%~97.0%);农林间作、林草(牧)复合和农田防护林则分别减少56.6%(14.2%~95.3%)、49.0%(9.0%~88.5%)、49.6%(1.7%~95.8%)的径流量和72.4%(30.7%~99.9%)、73.5%(30.0%~96.7%)、61.4%(17.8%~99.9%)的产沙量,表明农林复合系统具有显著的水土保持功能.未来有关农林复合系统的水土保持效应的研究应该聚焦于其效益评估综合化、机理研究深入化、实践指导科学化的方面.

Agroforestry systems are of great importance to environmental conservation and sustainable development of agroforestry as an ecological system with ecological, social and economic benefits. Through literature review, different types of agroforestry systems were discussed, the mechanism and characteristics of their prevention of soil and water losses were expounded, the benefits of soil and water conservation based on previous research was estimated. The analyses revealed that agroforestry systems could reduce an average 54.0%(1.0%–95.8%) of runoff and 71.7%(17.8%–99.9%) of soil loss. Riparian vegetation buffers had the highest benefit in reducing runoff and sediment, with 60.0%(1.0%~94.4%) and 76.8%(28.0%~97.0%) of runoff and sediment reduction respectively;while silvoarable agroforestry systems, silvopastoral systems and shelterbelts reduced runoff by 56.6%(14.2%~ 95.3%), 49.0%(9.0%~ 88.5%), 49.6%(1.7%~ 95.8%) respectively, and reduced sediment yield by 72.4%(30.7%~99.9%), 73.5%(30.0%~96.7%), 61.4%(17.8%~99.9%) respectively. The results indicated that the agroforestry systems have significant function in soil and water conservation. Future researches on soil and water conservation benefits of agroforestry systems should be focused on its comprehensive benefits evaluation, deep mechanism research and scientific practice guidance.