Title Page
ABSTRACT
Contents
ABBREVIATIONS 12
INTRODUCTION 14
Ⅰ. Statement of the problems 22
Ⅱ. Objectives of the study 29
LITERATURE REVIEWS 29
Ⅰ. Forest resource in Laos 29
Ⅱ. Tropical Forest in Southeast Asia 32
Ⅲ. Species composition and diversity 35
Ⅳ. Stand structure of secondary forest 40
Ⅳ. Natural regeneration of tree species in tropical forest 41
Ⅴ. Biomass and Carbon content of tree species in tropical region 42
MATERIAL AND METHODS 45
Ⅰ. Description of study site 45
1. Collection and analysis of soil samples 47
Ⅱ. Tree species composition and potential of natural regeneration 48
1. Field survey in study sites 48
2. Analysis of species composition and biodiversity recovery 51
3. Statistical analysis 56
Ⅲ. The investigation of biomass and carbon contents of 6 deciduous tree species 57
1. Destruction of sample tree 57
2. Measurement biomass and carbon sequestration of sampled trees 58
3. Statistical analysis 60
RESULTS AND DISCUSSIONS 62
Ⅰ. Species composition and potential of biodiversity recovery 62
1. Species composition of 3 different age classes of secondary forest 62
2. Stand structure of 3 different age classes of secondary forest 88
3. Species richness and diversity of natural regeneration 99
Ⅱ. Biomass and carbon contents 6 deciduous tree species 109
1. Biomass of 6 deciduous tree species 109
2. Carbon content of 6 deciduous tree species 111
CONCLUSIONS 113
LITERATURE CITED 118
SUMMARY IN KOREAN 135
Table 1. Composition of growing stock and diversity of tree species in ASEAN countries in 2005 33
Table 2. Study area: forest fragment of 3 categories age classes 50
Table 3. Comparison of species richness and diversity among different age classes of forest fragment in Sangthong district, Lao PDR (trees with DBH≥5 cm) 62
Table 4. Comparison of stand parameters among different age classes of forest fragment in Sangthong district, Lao PDR. 70
Table 5. Ten Highest families IV of 10 years old secondary forest in Sangthong district, Lao PDR. 72
Table 6. Ten Highest families IV of 20 years old secondary forest in Sangthong district, Lao PDR 74
Table 7. Ten Highest families IV of 30 years old secondary forest in Sangthong district, Lao PDR 76
Table 8. Ten highest species IV of 10 years old secondary forest 79
Table 9. Ten highest species IV of 20 years old secondary forest 81
Table 10. Ten highest species IV of 30 years old secondary forest 83
Table 11. Sorensen's index and Lamprecht's modified index on floristic similarity among the study sites 87
Table 12. Distribution of stock density and basal area to diameter classes of 10 years secondary forest fragments 88
Table 13. Distribution of stock density and basal area to diameter classes of 20 years secondary forest fragments 89
Table 14. Distribution of stock density and basal area to diameter classes of 30 years secondary forest fragments 90
Table 15. Distribution of species, stock density, and basal area over the vertical layers of 10 years old secondary forest 92
Table 16. Distribution of species, stock density, and basal area over the vertical layers of 20 years old secondary forest 93
Table 17. Distribution of species, stock density, and basal area over the vertical layers of 30 years old secondary forest 95
Table 18. Ten highest sapling species IV of 10 years old secondary forest 103
Table 19. Ten highest sapling species IV of 20 years old secondary forest 105
Table 20. Ten highest sapling species IV of 30 years old secondary forest 107
Table 21. Biomass accumulation in each component of sampled trees of 6 tree species 109
Table 22. Carbon distribution to the components of the sampled trees (n=7 per species) 111
Figure 1. Conceptual of the study 28
Figure 2. Forest cover changes in Lao PDR 30
Figure 3. Map of Sangthong and Xor village 46
Figure 4. Sampling plots designed 48
Figure 5. Relationship between species diversity and number of species 66
Figure 6. Height (total height)-diameter curves of 10 years secondary forest 97
Figure 7. Height (total height)-diameter curves of 20 years secondary forests 98
Figure 8. Height (total height)-diameter curves of 30 years secondary forests 98
Figure 9. Sapling density of 3 age classes secondary forest 99
Figure 10. Seedling density of 3 age classes secondary forest 100