Table of Contents
ISRN Ecology
Volume 2011, Article ID 751472, 12 pages
http://dx.doi.org/10.5402/2011/751472
Research Article

Recovery of Vegetation Structure and Species Diversity after Shifting Cultivation in Northwestern Vietnam, with Special Reference to Commercially Valuable Tree Species

1Lab of Forest Utilization, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan
2Silviculture Research Division, Forest Science Institute of Vietnam, Tu Liem, Ha Noi, Vietnam

Received 1 July 2011; Accepted 19 July 2011

Academic Editors: S. F. Ferrari and D. Yemane Ghebrehiwet

Copyright © 2011 Do Van Tran et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

A fallow stand (FS) in northwestern Vietnam that was created by shifting cultivation 32 years earlier had 43% of the species number, 72% of the stem density, and 53% of the basal area when compared with nearby old-growth forest (OGF); however, the values for commercial species were lower at 35%, 67%, and 26%, respectively. In terms of species diversity, the Shannon index of OGF (3.4) was significantly higher than that of FS (2.6), while the differences were not significant in terms of Evenness and species-size class distribution. Both FS and OGF had similar patterns of stem diameter frequency distribution but the diameters were more diverse in OGF compared to FS according to the Shannon index. Fallow stand was characterized by only 2 canopy layers (lower than 10 m and 10–20 m) and was simpler in vertical structure than that of OGF which included an additional upper canopy layer higher than 20 m. Our results indicate that increasing stem density of commercial species is necessary and can be realized by artificial seeding, planting seedlings, and/or natural regeneration from remaining mother trees in the fields.