Vegetation management in tropical forest plantations

Abstract

Forest plantations cover approximately 1% of the tropical land mass capable of supporting forest cover, i.e., 25.3 × 106 ha. Deforestation issues and the high potential growth rates of tropical plantations are driving an increase in reforestation activities in the tropics. The underlying principles and objectives of competition control here are similar to those in other areas of the world. Timely early competition control, until the tree crop gains dominance on the site, has proven critical to the success of these efforts because of the rapid and persistent development of weed competition on most tropical sites. Plantation survival has been increased by as much as 90% with early competition control and volume growth by more than 50% at 2 years short of rotation age. Manual weed control methods are used most extensively in the tropics. Cover crops and grazing have been used only to a limited extent. However, as economic development continues in many tropical countries, mechanical methods and herbicides are being used more widely. Herbicide usage is somewhat problematic in these areas owing to the lack of effective regulatory programs, limited herbicide research, few people knowledgeable and trained in herbicide use, and misinformation regarding herbicides.