The growth and quality of indigenous tree species planted under the forest canopy in thach thanh district thanh hoa province

MINISTRY OF AGRICULTURE AND RURAL DEVELOPMENT VIETNAM NATIONAL UNIVERSITY OF FORESTRY STUDENT THESIS THE GROWTH AND QUALITY OF INDIGENOUS TREE SPECIES PLANTED UNDER THE FOREST CANOPY IN THACH THANH DISTRICT, THANH HOA PROVINCE Major: Natural Resources Management Faculty: Forest Resources and Environmental Management Student: Nguyen Ngoc Khanh Student ID: 135 309 1001 Class: K59B - Natural Resources Management Course: 2014 - 2019 Advanced Education Program Developed in collaboration with Colorado State University, USA Supervisor: Assoc.Prof Dr Pham Minh Toai Ha Noi, October/2018 CONTENTS LIST OF TABLES LIST OF FIGURES LIST OF ABBREVIATIONS ACKNOWLEDGEMENT ABSTRACT INTRODUCTION CHAPTER 1: OVERVIEW OF RESEARCH 1.1 In the world 1.1.1 Research on mixed plantations 1.1.2 Research on indigenous trees planting under forest canopy 1.2 In Viet nam 1.2.1 Research on mixed plantations 1.2.2 Research on indigenous trees planting under forest canopy 1.3 Techniques for planting indigenous forests under the forest canopy of the project 1.3.1 History of forest plantation in the research area 1.3.2 Techniques for planting Acacia auriculiformis forests of the project 10 1.3.3 Technique for planting indigenous forest under forest canopy 10 1.3.3.1 Technical procedures for planting Erythrophleum fordii based on the project regulations (2011) 10 1.3.3.2 Technical procedures for planting Hopea odorata based on the project regulations (2011) 11 CHAPTER 2: OBJECTIVES, CONTENTS AND RESEARCH METHODS 12 2.1 Objectives of the research 12 2.2 Subjects and research methods 12 2.2.1 Research methodology on standard plot 12 2.2.2 Research on the physical characteristics of soil in the research area 12 2.2.3 Research on the structure of forest 13 2.2.4 Methods of data processing 14 CHAPTER 3: NATURAL CONDITIONS OF RESEARCH AREA 16 3.1 Geographical location 16 3.2 Topographic 16 3.3 Hydrological conditions 17 3.4 Soil 17 3.5 Water resources 18 3.6 Forest resources 18 CHAPTER 4: RESULTS AND DISCUSSION 19 4.1 Growth characteristics and quality of indigenous trees under forest canopy in the study area 19 4.1.1 Growth characteristics and quality of Erythrophleum fordii 19 4.1.1.1 Growth characteristics of Erythrophleum fordii 19 4.1.1.2 The quality of growth of Erythrophleum fordii 22 4.1.2 Growth characteristics and quality of Hopea odorata 23 4.1.2.1 Growth characteristics of Hopea odorata 23 4.1.2.2 The growth quality of Hopea odorata 27 4.2 Evaluate the factors affecting the growth of indigenous plants 28 4.2.1 Factors affecting the growth of Erythrophleum fordii 28 4.2.1.1 The structure and growth of tall plant of Acacia auriculiformis 28 4.2.1.2 Characteristics of soil under forest canopy 30 4.2.2 Factors that affect the growth of Hopea odorata 31 4.2.2.1 The structure and tall plant growth of Acacia auriculiformis 31 4.2.2.2 Characteristics of soil under forest canopy 32 4.3 Proposing some silvicultural techniques to promote the growth of indigenous trees in the research area 33 4.3.1 Impact solution in Erythrophleum fordii forest 34 4.3.2 Impact solution in the Hopea odorata forest 34 CHAPTER 5: CONCLUSION, CONSTRAINTS AND RECOMMENDATIONS 35 5.1 Conclusion 35 5.2 Constraints 35 5.3 Recommendations 36 REFERENCES APPENDIX LIST OF TABLES Table 2.1: Forest land profile analyzing results 12 Table 2.2: Growth characteristics of Acacia auriculiformis 13 Table 2.3: Growth Characteristics of indigenous trees 14 Table 4.1: Growth Characteristics of Erythrophleum fordii (7 years) 19 Table 4.2: Comparison of the difference in diameter at breast height (D1.3) of Erythrophleum fordii between standard plots (U standard) 19 Table 4.3: Comparison of the difference in the total height (Ht) of Erythrophleum fordii between standard plots (U standard) 20 Table 4.4: Comparison of the difference in diameter of the canopy (Dc) of Erythrophleum fordii between standard plots (U standard) 21 Table 4.5: Percentage of good, medium and bad trees of Erythrophleum fordii forest 22 Table 4.6: Growth Characteristics of Hopea odorata (7 years) 23 Table 4.7: Comparison of the difference in diameter at breast height (D1.3) of Hopea odorata between standard plots (U standard) 23 Table 4.8: Comparison of the difference in the total height (Ht) of Hopea odorata between standard plots (U standard) 24 Table 4.9: Comparison of the difference in diameter of the canopy (Dc) of Erythrophleum fordii between standard plots (U standard) 25 Table 4.10: Percentage of good, medium and bad trees of Hopea odorata forests are summarized in the table: 28 Table 4.12: Distribution of growth quality of Acacia auriculiformis forest (Erythrophleum fordii under canopy) 29 Table 4.13: Erythrophleum fordii forest land profile analyzing results 30 Table 4.14: Growth characteristics of Acacia auriculiformis (Hopea odorata under canopy) (11 years) 31 Table 4.15: Distribution of growth quality of Acacia auriculiformis forest (Hopea odorata under canopy) 32 Table 4.16: Hopea odorata forest land profile analyzing results 33 LIST OF FIGURES Figure 4.1: Comparison of diameter at breast height (D1.3) of Erythrophleum fordii under canopy of Acacia auriculiformis 20 Figure 4.2: Comparison of the total height (Ht) of Erythrophleum fordii under canopy of Acacia auriculiformis 21 Figure 4.3: Comparison of diameter of the canopy (Dc) of Erythrophleum fordii under canopy of Acacia auriculiformis 22 Figure 4.4: Comparison of diameter at breast height (D1.3) of Hopea odorata under canopy of Acacia auriculiformis 24 Figure 4.5: Comparison of the total height (Ht) of Hopea odorata under canopy of Acacia auriculiformis 25 Figure 4.6: Comparison of diameter of the canopy (Dc) of Erythrophleum fordii under canopy of Acacia auriculiformis 27 Picture 4.2: Soil profile in Hopea odorata area 33 LIST OF ABBREVIATIONS SP Standard plot D1.3 Diameter at breast height (m) HT The total height (m) HUC The height under canopy (m) DC Diameter of the canopy (m) ̅ 1.3 The average of diameter at breast height (m) ̅t The average of total height (m) ̅c The average of diameter of the canopy (m) CC Canopy cover JICA Japan International Cooperation Agency KfW German Reconstruction Banks ACKNOWLEDGEMENT This thesis was completed at the Vietnam National University of Forestry, following the undergraduate training programs in the period of 2014-2019 with the natural resources management major (Advanced Education Program) This major was developed in collaboration with Colorado State University, USA During the implementation and completion of the thesis, the author has received the support from School-Board of University, Faculty of Silviculture, Faculty of Forestry and Environmental Management that was precious and effective The author expresses the sincere and deepest gratitude to Assoc Prof Dr Pham Minh Toai as an instructor who has paid attention to the thesis, spent a lot of time for instruction and provided many relevant valuable materials These have helped the author to complete this thesis The author would like to thank the leaders and officers of the Management Board for Forestry Projects to facilitate the study and completion of the thesis Finally, the author would like to express sincere gratitude to friends, classmates, and supporters during the studying years as well as the completion of this thesis Sincerely thanks! Hanoi, October 30th, 2018 Student Nguyen Ngoc Khanh ABSTRACT The purpose of this research is studying on growth characteristics and quality of indigenous tree species planted under the canopy of Acacia auriculiformis plantations The thesis has clarified the stand’s structure and quality of indigenous tree species, characteristics of soil under the forest canopy and the effects of tall trees to indigenous trees, then has provided silvicultural solutions The research will help to improve the growth of indigenous trees in the next years INTRODUCTION In recent years, the trend to develop indigenous tree species has become stronger and can achieve many objectives in terms of economic, social and environmental aspects However, the indigenous plantation programs/projects have still faced many difficulties due to the lack of support from managers, investors and forest owners The afforestation project implemented in Thanh Hoa and Nghe An provinces (KfW4) is one of the forestry programs focusing on the development of indigenous tree species, mainly such as Erythrophleum fordii, Peltophorum pterocarpum, Hopea odorata, Mylopharyngodon piceus, Michelia mediocris Dandy, etc with the target of developing 19,000 of sustainable production forest for over 14,000 households in 53 communes of 10 mountainous districts of two project provinces The development of indigenous tree species is carried out with two forest types: 1) Planting pure indigenous trees; 2) Planting indigenous trees under the Acacia auriculiformis canopy The area of 3,000 of planted pure indigenous tree species (mainly Aquilaria crassna, Chukrasia tabularis, etc.) has become forest and has been initially evaluated to be well-grown While the area of about 300 of indigenous tree species has been planted under the forest canopy such as Erythrophleum fordii, Peltophorum pterocarpum, Hopea odorata as a pilot in Thach Thanh, Cam Thuy and Vinh Loc districts (Thanh Hoa province) and in Quynh Luu and Yen Thanh districts (Nghe An province) Within the scope of KfW4 plantation area, factors such as site conditions, seedlings, and climatic conditions are almost identical but canopy cover is the most important factor affecting the growth of indigenous tree species planted under the forest canopy Generally, most indigenous species are well-grown in shade-tolerant conditions at an early age, but their light needs will change over time Therefore, the assessment of affect of canopy cover during each specific development stage of indigenous trees is practical as a basis for proposing appropriate measures to promote the growth of indigenous tree species under forest canopy With the above reason, the project on "The growth and quality of indigenous tree species planted under the forest canopy in Thach Thanh district, Thanh Hoa province" is necessary, contributing to construction of theoretical and practical basis to develop the indigenous plantations in the coming project phases CHAPTER 1: LITERATURE REVIEWS 1.1 In the world 1.1.1 Research on mixed plantations Researches in many countries around the world show that pure plantations have shown many disadvantages Therefore, scientists in the world have been interested in studying the development of mixed forest models for sustainable forest business, especially in the current phase of climate change In Malaysia (1999) [19], the multi-layered forestation project has introduced a model of mixed plantation on three species: natural forest, 10-15 year Acacia plantation and - year Acacia plantation The project uses 23 valuable indigenous species by planting strips in natural forest, each strip includes three rows of indigenous trees Total of 14 indigenous species planted under the Acacia mangium canopy is divided into two experimental blocks: Block A: Open the10m strip, plant rows of indigenous trees Open the 20m strip, plant rows of indigenous trees Open the 40m strip, plant 15 rows of indigenous trees Block B: Cut a row of acacia, plant a row of indigenous trees Cut rows, plant rows of indigenous trees Cut rows, plant rows of indigenous trees The results show that three species among 14 species of Block A have the fastest treeheight growth and the best diameter growth, including Shorea roxburrghii, Shorea ovalis and Shorea leprosula The tree-height growth of indigenous tree species planted in the 10m and 40m strips is better than those planted in the 20m strip The best tree-height growth is shown in the formula of mixed planting of one Acacia row and one indigenous row From this studying result, some recommendations to adjust the growth of experimental models at eight times of 2-8-12-18-28-34-41-47 years after planting are given This is one of research projects on the of mixed-species forest establishment that is relatively complete in terms of technical measures, from the selection of tree species to study of planting method, timing of planting and model adjustment following the growing process for a long time Therefore, these pilot models will have many promising successes in future and can be replicated in practice The outstanding feature of mixed plantations is the multi-layered canopy Therefore, many global scientists have been interested in the establishment of multi-layered plantations During the study of canopy structure of mixed stands, Bernard Dupuy (1995) [20] has shown that the canopy structure of mixed plantations depends on the growth and solidarity of tree species in stands This shows that the mixed plantation models having reasonable structure and taking full advantage of nutrient space in maximum are only established once we base on 24 9.55 3.4 2.7 3.05 9.5 3.0 TB 25 13.32 3.6 3.1 3.35 11.0 2.5 T 26 9.97 3.2 3.7 3.45 8.5 4.5 X 27 14.45 4.3 3.9 4.1 10.5 4.5 TB 28 16.13 5.1 4.5 4.8 15.0 3.0 T 29 20.36 5.5 6.1 5.8 16.0 5.0 T 30 9.33 2.6 2.1 2.35 9.5 2.0 X 31 15.54 4.2 3.6 3.9 11.0 3.5 T 32 17.42 5.0 4.2 4.6 13.5 5.5 T 33 12.11 3.5 3.7 3.6 9.0 5.5 TB 34 16.36 4.0 4.3 4.15 11.0 5.5 T 35 10.02 3.5 2.8 3.15 9.5 3.5 TB 36 11.22 3.0 3.4 3.2 10.5 2.5 TB 37 12.03 3.3 3.1 3.2 9.0 3.5 TB 38 15.56 4.0 3.5 3.75 14.0 3.0 T 39 13.33 3.5 3.4 3.45 11.0 4.0 T 40 14.45 3.8 4.1 3.95 11.5 3.5 T 41 12.72 3.9 3.4 3.65 11.0 4.0 T 42 10.65 3.1 3.5 3.3 10.5 3.5 TB 43 17.36 4.5 4.2 4.35 16.0 5.0 T 44 8.66 3.4 2.9 3.15 10.0 3.5 X 45 11.82 3.8 3.5 3.65 11.0 4.5 TB 46 19.68 4.1 4.5 4.3 13.0 4.5 T 47 10.55 3.5 3.9 3.7 10.5 3.5 TB 48 9.46 3.3 3.7 3.5 10.0 4.0 TB 49 13.41 3.0 3.7 3.35 11.5 3.5 T Growing characteristics of indigenous trees in SP6 8.05 D00 (cm) 10.09 3.5 Ht (m) 4.5 6.27 7.02 2.3 4.0 TB 4.87 7.12 2.5 4.5 TB 3.85 5.18 1.5 2.5 X 7.13 8.43 3.3 6.0 T 6.31 8.21 2.5 4.5 TB 5.95 8.75 2.8 6.5 T 6.34 7.64 2.1 4.0 T 6.23 7.23 2.5 4.5 TB 10 5.76 7.54 2.6 5.0 TB 11 4.32 8.72 3.5 6.5 TB 12 4.91 6.78 3.3 5.5 T 13 4.32 5.31 2.8 5.5 TB 14 5.37 6.11 2.9 6.5 TB 15 6.81 8.14 2.7 3.5 T 16 6.42 8.81 3.4 5.5 T 17 8.45 10.32 3.5 7.0 T 18 6.44 7.75 3.0 8.5 T D1.3 (cm) Dc(m) Quality T Notes Growth characteristics of Acacia auriculiformis in SP7 Dc (m) D1.3 (cm) HT (m) HUC (m) Quality 12.73 WE NS 4.3 4.7 A 4.5 8.5 5.5 T 7.92 3.6 3.5 3.55 8.0 5.5 X 13.35 4.8 5.1 4.95 12.0 6.0 T 14.37 4.3 3.8 5.05 12.5 6.5 T 11.65 3.8 3.5 3.65 10.5 5.5 TB 11.82 3.6 3.3 3.45 10.0 6.0 TB 8.32 2.7 2.4 2.55 9.5 5.5 X 10.73 3.8 3.5 3.65 9.5 4.5 TB 11.53 3.6 4.1 3.85 11.0 4.5 T 10 9.72 2.8 2.4 2.6 8.0 3.5 X 11 11.86 4.4 5.1 4.75 13.0 4.5 T 12 21.68 3.8 4.5 4.15 10.5 5.5 T 13 6.23 2.2 3.5 2.85 6.5 3.0 X 14 15.45 3.9 4.4 4.15 9.0 4.5 T 15 13.45 3.9 4.5 4.2 12.0 5.0 T 16 12.44 3.8 4.2 4.0 11.5 4.5 T 17 11.57 3.4 3.7 3.55 10.5 4.5 TB 18 7.36 1.6 2.1 1.85 5.5 3.0 X 19 9.87 2.3 2.1 2.2 4.5 3.5 X 20 12.26 4.1 4.5 4.3 9.5 4.0 T 21 14.63 4.6 5.1 4.85 12.0 4.5 T 22 11.37 3.6 4.3 3.95 8.5 4.0 TB 23 9.23 2.1 2.6 2.35 5.5 3.0 X 24 10.68 3.5 4.1 3.8 10.0 4.0 TB 25 17.48 4.8 5.2 5.0 14.0 5.5 T 26 14.45 4.1 4.7 4.4 12.5 5.0 T 27 11.23 3.5 3.3 3.4 10.5 3.5 TB 28 18.57 4.8 4.2 4.5 12.5 4.0 T 29 9.73 2.6 2.4 2.5 5.5 3.5 X 30 13.24 3.8 4.2 4.0 10.5 3.5 T 31 16.43 4.2 4.5 4.35 11.0 4.5 T 32 14.65 3.2 3.8 3.5 9.0 4.0 TB 33 13.76 3.4 2.9 3.15 9.5 3.5 TB 34 9.69 2.3 1.9 2.1 4.0 3.0 X 35 12.28 3.1 3.6 3.35 9.5 3.5 TB 36 12.56 3.5 4.0 3.25 8.5 4.0 TB 37 19.63 4.8 4.3 4.55 13.5 4.0 T 38 15.85 5.3 4.5 4.9 12.0 3.5 T 39 13.34 3.1 3.7 3.4 8.5 3.0 X 40 20.35 5.1 4.7 4.9 13.0 4.5 T 41 16.36 3.8 4.3 4.05 11.5 4.0 T 42 14.55 3.5 3.9 3.7 10.5 3.5 TB 43 12.42 3.8 3.3 3.55 9.5 3.5 TB 44 20.67 4.7 4.2 4.45 10.5 4.0 T 45 16.37 3.9 3.4 3.65 11.5 3.5 T 46 8.86 2.2 1.9 2.05 7.0 3.5 X 47 13.32 3.4 3.1 3.25 10.5 3.0 T 48 12.47 3.8 3.3 3.55 12.5 4.0 T 49 10.39 3.1 3.5 3.3 9.0 3.5 TB 50 8.86 2.2 1.9 2.05 7.0 3.5 X 51 14.62 3.7 4.1 3.9 11.5 4.0 T Growing characteristics of indigenous trees in SP7 9.06 D00 (cm) 11.3 3.2 Ht (m) 4.5 13.9 15.4 2.5 5.5 TB 15.6 19.2 3.3 6.5 T 14.7 17.3 4.6 6.5 T 16.3 19.7 4.2 5.5 T 6.8 8.6 2.7 3.0 X 8.8 12.6 3.6 3.5 X 13.4 16.6 3.2 6.5 T 12.2 15.3 4.8 7.0 T 10 13.3 17.7 4.1 8.5 T 11 12.6 14.4 4.2 6.0 T 12 11.6 14.7 2.4 5.5 TB 13 15.6 18.2 3.7 9.0 T 14 13.1 15.2 2.3 6.5 T 15 14.8 16.7 3.8 5.5 T 16 15.3 17.2 2.5 4.5 TB 17 15.4 17.6 2.3 6.0 T 18 15.59 18.93 3.5 7.5 T 19 7.4 11.7 2.3 4.0 X 20 18.34 20.87 3.7 8.5 T 21 5.79 7.23 2.5 7.0 TB D1.3 (cm) Dc(m) Quality TB Notes Growth characteristics of Acacia auriculiformis in SP8 Dc (m) D1.3 (cm) HT (m) HUC (m) Quality 9.31 WE 4.1 NS 3.7 A 3.9 11.5 4.5 TB 12.49 5.2 5.8 5.5 12.5 5.5 TB 15.54 4.2 3.6 3.9 11.0 3.5 T 16.42 5.2 4.4 4.8 12.0 5.5 T 12.11 3.5 3.7 3.6 9.0 5.5 TB 16.36 4.0 4.3 4.15 11.0 5.5 T 15.54 4.2 3.6 3.9 11.0 3.5 T 8.81 2.2 1.9 2.05 13.5 6.0 T 6.87 2.1 1.6 1.85 11.0 5.5 TB 10 18.21 3.4 3.8 3.6 14.0 6.5 T 11 18.93 4.8 5.3 5.05 14.5 4.5 T 12 8.16 3.5 4.1 3.8 13.5 7.0 T 13 9.72 2.8 2.4 2.6 8.0 3.5 X 14 11.86 4.4 5.1 4.75 13.0 4.5 T 15 21.68 3.8 4.5 4.15 10.5 5.5 T 16 14.7 4.2 3.6 3.9 14.5 7.0 T 17 13.57 3.9 4.6 4.25 9.5 3.5 TB 18 9.73 3.8 3.4 3.6 8.0 3.0 TB 19 12.72 3.9 3.4 3.65 11.0 3.0 T 20 8.44 2.1 1.7 1.9 5.5 4.5 X 21 12.22 3.3 3.9 3.6 11.5 3.0 T 22 12.56 3.5 4.0 3.25 8.5 4.0 TB 23 17.67 4.5 4.1 4.3 13.5 4.0 T 24 10.21 2.9 3.3 3.1 11.5 3.0 TB 25 16.33 4.6 4.2 4.4 13.5 5.0 T 26 13.23 3.5 3.3 3.4 9.5 3.0 TB 27 8.53 3.2 2.9 3.05 9.5 5.5 X 28 11.76 3.7 4.1 3.9 10.0 3.5 TB 29 13.54 3.5 3.9 3.7 9.0 3.5 TB 30 15.37 4.2 3.7 3.95 12.0 5.5 T 31 12.78 3.2 2.9 3.05 10.0 2.5 TB 32 18.43 4.2 4.5 4.35 14.0 3.0 T 33 11.33 2.5 3.3 2.9 10.5 7.0 TB 34 11.63 2.8 2.5 2.65 10.5 3.5 TB 35 13.34 3.8 4.2 4.0 11.0 3.0 T 36 17.58 4.3 4.5 4.4 10.5 3.0 T 37 14.64 3.2 3.7 3.45 10.0 3.0 TB 38 8.33 2.2 3.1 2.65 7.0 4.0 X 39 17.37 3.3 4.2 3.75 11.0 3.5 T 40 16.37 3.9 3.4 3.65 11.5 3.5 T 41 18.35 3.9 4.6 4.25 12.0 5.0 T 42 16.67 3.2 3.5 3.35 11.5 2.5 T 43 8.87 3.1 2.4 2.75 8.5 3.5 X 44 12.94 3.6 4.2 3.9 10.0 4.5 TB 45 21.45 5.1 4.6 4.85 13.0 3.0 T 46 14.25 4.6 5.2 4.9 11.0 4.0 T 47 14.97 3.7 2.9 3.3 13.0 3.5 T 48 9.57 4.0 3.5 3.75 9.5 5.0 TB Growing characteristics of indigenous trees in SP8 12.15 D00 (cm) 14.57 4.25 Ht (m) 9.0 11.85 13.4 4.43 10.5 T 10.05 13.2 3.48 9.5 T 14.55 17.78 4.15 14.0 T 15.35 18.32 4.75 15.0 T 8.82 11.21 2.85 7.5 TB 10.31 12.33 3.80 7.5 T 15.45 18.2 4.00 12.5 T 15.35 17.3 4.78 12.0 T 10 14.25 18.7 4.50 11.5 T 11 15.25 18.4 4.00 13.0 T 12 15.35 18.37 4.78 12.5 TB 13 11.45 16.2 3.90 9.5 TB 14 16.00 19.2 4.00 13.0 T 15 10.05 13.7 3.50 8.0 X 16 16.15 20.2 4.45 13.5 TB 17 16.20 19.6 4.55 14.5 T 18 17.20 18.93 4.25 15.5 T D1.3 (cm) Dc(m) Quality TB Notes Growth characteristics of Acacia auriculiformis in SP9 Dc (m) D1.3 (cm) HT (m) HUC (m) Quality 13.51 WE 4.1 NS 3.7 A 3.9 11.5 4.5 T 12.49 5.2 5.8 5.5 12.5 5.5 T 15.54 4.2 3.6 3.9 11.0 3.5 T 17.42 5.0 4.2 4.6 13.5 5.5 T 10.50 4.50 3.60 4.05 9.0 5.5 TB 14.65 3.40 3.70 3.55 11.0 5.5 T 15.80 5.00 5.10 5.05 11.0 3.5 T 14.95 4.00 4.35 4.18 13.5 6.0 T 12.25 4.50 4.35 4.43 11.0 5.5 TB 10 16.50 4.30 4.20 4.25 14.0 6.5 T 11 11.05 5.00 5.50 5.25 14.5 4.5 T 12 15.35 4.90 4.00 4.45 13.5 7.0 T 13 16.20 4.50 4.95 4.73 8.0 3.5 X 14 10.55 4.60 4.50 4.55 13.0 4.5 T 15 14.65 4.50 3.60 4.05 10.5 5.5 T 16 14.7 4.2 3.6 3.9 14.5 7.0 T 17 13.57 3.9 4.6 4.25 9.5 3.5 TB 18 9.73 3.8 3.4 3.6 10.0 3.0 TB 19 12.72 3.9 3.4 3.65 11.0 3.0 T 20 8.44 2.1 1.7 1.9 5.5 4.5 X 21 12.22 3.3 3.9 3.6 11.5 3.0 T 22 12.56 3.5 4.0 3.25 8.5 4.0 TB 23 17.67 4.5 4.1 4.3 13.5 4.0 T 24 10.21 2.9 3.3 3.1 11.5 3.0 TB 25 16.33 4.6 4.2 4.4 13.5 5.0 T 26 13.23 3.5 3.3 3.4 9.5 3.0 TB 27 8.53 3.2 2.9 3.05 9.5 5.5 X 28 11.76 3.7 4.1 3.9 10.0 3.5 TB 29 13.54 3.5 3.9 3.7 9.0 3.5 TB 30 15.37 4.2 3.7 3.95 12.0 5.5 T 31 12.78 3.2 2.9 3.05 10.0 2.5 TB 32 18.43 4.2 4.5 4.35 14.0 3.0 T 33 11.33 2.5 3.3 2.9 10.5 7.0 TB 34 11.62 2.8 2.5 2.65 10.0 3.5 TB 35 13.34 3.8 4.2 4.0 11.0 3.0 T 36 17.58 4.3 4.5 4.4 10.5 3.0 T 37 14.64 3.2 3.7 3.45 10.0 3.0 TB 38 8.33 2.2 3.1 2.65 7.0 4.0 X 39 17.37 3.3 4.2 3.75 11.0 3.5 T 40 16.37 3.9 3.4 3.65 11.5 3.5 T 41 18.55 3.9 4.6 4.25 12.0 5.0 T 42 16.67 3.2 3.5 3.35 11.5 2.5 T 43 8.87 3.1 2.4 2.75 8.5 3.5 X 44 13.49 3.6 4.2 3.9 11.0 4.0 T 45 14.7 4.2 3.6 3.9 14.5 7.0 T 46 13.57 3.9 4.6 4.25 9.5 3.5 TB 47 9.73 3.8 3.4 3.6 8.0 3.0 TB 48 17.53 3.7 4.3 4.0 14.0 4.5 T 49 13.15 4.19 3.93 4.06 12.5 5.5 T 50 6.6 1.8 1.6 1.73 5.5 3.5 X Growing characteristics of indigenous trees in SP9 12.15 D00 (cm) 14.57 4.25 Ht (m) 9.0 11.85 13.4 4.43 10.5 T 10.05 13.2 3.48 9.5 T 14.55 17.78 4.15 14.0 T 15.35 18.32 4.75 15.0 T 8.80 11.21 2.85 7.5 TB 10.30 12.33 3.80 7.5 T 15.45 18.2 4.24 12.5 T 12.35 15.3 4.78 12.0 T 10 14.25 17.7 4.50 11.5 T 11 10.95 12.4 4.00 13.0 T 12 12.10 15.37 4.78 12.5 T 13 10.40 13.2 3.90 9.5 T 14 11.50 14.2 4.00 13.0 T 15 10.05 13.7 3.50 8.0 X 16 16.15 20.2 4.45 13.5 TB 17 16.20 19.6 4.55 14.5 T 18 17.20 18.93 4.25 15.5 T 19 14.30 16.7 4.55 13.0 X D1.3 (cm) Dc(m) Quality TB Notes Growth characteristics of Acacia auriculiformis in SP10 DC (m) D1.3 (cm) HT (m) HUC (m) Quality 12.73 WE NS 4.3 4.7 A 4.5 8.5 5.5 T 7.92 3.6 3.5 3.55 8.0 5.5 X 13.35 4.8 5.1 4.95 12.0 6.0 T 14.37 4.3 3.8 5.05 12.5 6.5 T 11.65 3.8 3.5 3.65 10.5 5.5 TB 11.20 3.6 3.3 3.45 10.0 6.0 TB 8.75 2.7 2.4 2.55 9.5 5.5 X 10.20 3.8 3.5 3.65 9.5 4.5 TB 14.15 3.6 4.1 3.85 11.0 4.5 T 10 16.50 4.3 4.1 4.2 15.0 3.0 T 11 11.70 3.7 2.9 3.3 13.0 3.5 T 12 7.35 3.5 3.8 3.65 8.5 2.0 X 13 12.50 4.4 4.2 4.3 10.0 3.5 TB 14 14.25 4.2 3.8 4.0 11.0 5.0 T 15 17.20 4.8 5.3 5.05 14.5 4.5 T 16 13.33 3.9 3.5 3.7 10.0 5.0 TB 17 11.57 3.4 3.7 3.55 10.5 4.5 TB 18 7.36 1.6 2.1 1.85 5.5 3.0 X 19 9.87 2.3 2.1 2.2 4.5 3.5 X 20 6.40 2.2 1.72 1.96 8.5 4.5 X 21 7.87 2.1 1.6 1.85 11.0 5.5 TB 22 18.21 3.4 3.8 3.6 14.0 6.5 T 23 15.11 4.3 4.1 4.2 13.0 6.5 TB 24 18.24 3.5 4.1 3.8 11.5 7.0 T 25 17.48 4.8 5.2 5.0 14.0 5.5 T 26 14.45 4.1 4.7 4.4 12.5 5.0 T 27 11.23 3.5 3.3 3.4 10.5 3.5 TB 28 18.57 4.8 4.2 4.5 12.5 4.0 T 29 9.73 2.6 2.4 2.5 5.5 3.5 X 30 6.1 1.8 1.6 1.73 5.5 3.5 X 31 11.6 4.1 3.57 3.83 14.5 3.5 T 32 10.73 4.6 3.76 4.18 13.5 4.5 T 33 11.36 4.2 3.54 3.87 12.0 5.5 T 34 12.67 2.1 1.86 1.98 11.5 6.5 TB 35 8.18 2.3 2.32 2.31 11.0 6.0 TB 36 12.19 5.1 4.7 4.9 12.5 4.5 T 37 19.63 4.8 4.3 4.55 13.5 4.0 T 38 15.85 5.3 4.5 4.9 12.0 3.5 T 39 13.34 3.1 3.7 3.4 8.5 3.0 X 40 17.35 5.1 4.7 4.9 13.0 4.5 T 41 16.36 3.8 4.3 4.05 11.5 4.0 T 42 14.55 3.5 3.9 3.7 10.5 3.5 TB 43 12.46 3.8 3.3 3.55 9.5 3.5 TB 44 16.67 4.7 4.2 4.45 10.5 4.0 T 45 15.37 3.9 3.4 3.65 11.5 3.5 T 46 8.86 2.2 1.9 2.05 7.0 3.5 X 47 12.32 3.4 3.1 3.25 10.5 3.0 T 48 13.47 3.8 3.3 3.55 12.5 4.0 T 49 10.39 3.1 3.5 3.3 9.0 3.5 TB 50 15.43 3.3 4.2 3.75 11.0 3.5 T 51 17.38 4.3 5.4 4.85 15.0 6.0 T Growing characteristics of indigenous trees in SP10 9.06 D00 (cm) 11.3 3.2 Ht (m) 7.5 13.9 15.4 2.5 15.5 T 15.6 19.2 3.90 10.0 T 14.7 17.3 5.05 12.5 T 16.3 19.7 3.90 12.5 T 6.8 8.6 4.50 6.0 TB 9.2 11.6 4.65 4.5 X 13.4 16.6 4.55 8.5 T 12.2 15.3 4.25 10.0 T 10 13.3 17.7 4.1 8.5 T 11 12.6 14.4 4.2 9.0 T 12 11.6 14.7 5.5 TB 13 11.40 14.2 4.25 9.0 T 14 12.25 15.2 5.55 7.5 T 15 15.85 18.7 3.90 9.5 T 16 10.65 13.2 4.00 8.5 T 17 11.20 14.6 2.3 12.0 T 18 15.59 18.93 3.5 9.5 T 19 8.9 11.7 2.3 4.0 X 20 17.34 20.87 3.7 9.5 T 21 8.85 10.23 3.5 11.5 T D1.3 (cm) Dc(m) 3.65 Quality TB Notes ... promote the growth of indigenous tree species under forest canopy With the above reason, the project on "The growth and quality of indigenous tree species planted under the forest canopy in Thach Thanh. .. university, planted 165 indigenous species under the canopy of Pinaceae and Acacia, of which 27 indigenous species planted under the Pinus massoniana canopy, 21 indigenous species planted under the Acacia... essential for developing the indigenous tree species under the canopy in the next stage in particular and contributing to planting indigenous tree species under the canopy in Vietnam in general 1.3