TREE GIRDLING TREATMENTS FOR TIMBER STAND IMPROVEMENT IN BOLIVIAN TROPICAL FORESTS

• Published in: Journal of tropical forest science Vol. 15; no. 4; pp. 583 - 592
• Main Authors: Pariona, W., Fredericksen, T. S., Licona, J. C.
• Format: Journal Article
• Language: English
• Published: Forest Research Institute Malaysia (FRIM) 01-10-2003
• Subjects: Dry forests; Girdles; Herbicides; Mortality; Sustainable forest management; Tree crowns; Tree felling; Trees; Tropical forestry; Tropical forests
• ISSN: 0128-1283

The efficacy and costs of three tree girdling treatments to remove non-commercial trees were evaluated in both dry and humid Bolivian tropical forests that were recently harvested. The treatments included chainsaw girdling only and chainsaw girdling immediately followed by application of two different herbicide solutions (glyphosate and 2,4-D) to the girdled surfaces. Two years following the application, girdling + 2,4-D killed more than 75% of the crown on 75% of treated trees, while girdling + glyphosate and girdling only treatments killed 61 and 14% respectively. No significant differences in treatment efficacy were observed between forest types, although there were differences between tree species in response to treatments. Glyphosate killed trees more slowly than 2,4-D. Treatment costs were $0.16 / tree for girdling + 2,4-D, $0.32 / tree for girdling + glyphosate and $0.09 / tree for girdling only. Keberkesanan dan kos bagi tiga rawatan penggelangan pokok untuk menyingkir pokok yang tiada nilai komersial dinilai di hutan tropika Bolivia yang kering dan yang lembap yang baru dibalak. Rawatannya ialah penggelangan menggunakan gergaji rantai dan penggelangan menggunakan gergaji rantai diikuti serta-merta oleh rawatan dengan dua larutan herbisid berlainan (glifosat dan 2,4-D) pada permukaan yang digelangkan. Dua tahun selepas rawatan, penggelangan + 2,4-D menyebabkan lebih daripada 75% kematian silara pada 75% daripada pokok yang dira wat manakala penggelangan + glifosat dan penggelangan sahaja masing-masing mempengaruhi 61% dan 14% pokok. Tiada perbezaan bererti dalam keberkesanan rawatan diperhatikan untukjenis hutan. Namun, perbezaan bererti diperhatikan di antara spesies pokok. Glifosat membunuh pokok dengan lebih perlahan daripada 2,4-D. Kos rawatan ialah $ 0.16 setiap pokok untuk penggelangan + 2,4-D, $0.32 setiap pokok untuk penggelangan + glifosat dan $0.09 setiap pokok untuk penggelangan sahaja.