Plant Diversity And Structure Of Mangroves In Hai Ha District Quang Ninh Province

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ACKNOWLEDGEMENT

First and foremost, I would like to express my sincere gratitude to my advisor Assoc.

Prof. Dr. Vu Quang Nam for the continuous support of my student thesis study and research,

for his motivation, enthusiasm, and immense knowledge. His guidance helped me in all the

time of research and writing of this thesis.

Beside my advisor, I would like to thank professor from Colorado State University,

Dr. Lee Macdonald, for his guidance, patience, and providing my class with an excellent

atmosphere for our research. My sincere thanks also goes to Mr. Nguyen Van Hieu- vice￾leader of mangrove forest protection, who provided me many useful knowledge about

mangrove forest and all of officers in Hai Ha district, for their giving information about the

local area and culture that helped me a lot in this study.

Lastly, I would like to thank to my family: my father who always support to me and

my friends who helped me in my research.

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ABSTRACT

Mangrove at Hai Ha district constitutes a mangrove flora that contributes to the

biodiversity in the coastal region. This research concentrates on three objectives: descriptive

the biodiversity species and role of mangroves forest in Hai Ha district; determine species

composition, structure and distribution of the mangrove flora in Hai Ha district; proposed

some solutions to protect and develop sustainable mangrove forest.

To conduct these objectives above, the research established 6 survey lines is

perpendicular with the sea dike and set up 18 standard plots for six communes in Hai Ha

District, each plot has area with 400 m2

(20x 20m) along the transect line.

From the results collected, I constructed the list of vascular plants including 41 species

belonging to 26 genera, 10 main mangrove species and 31 species living in mangrove forest.

They distribute in 5 main regions: regular intertidal zone; irregular intertidal zone; sands

sludge formation and improvements; improvement sand area less tidal and coastal shrimp

farms, road and sea dike. There are three communities in study site: Avicennia marina -

Rhirophora stylosa - Aegiceras corniculatum (Am - Rs - Ac), Aegiceras corniculatum -

Bruguiera gymnorrhiza - Rhirophora stylosa (Ac - Bg - Rs) and Aegiceras corniculatum -

Avicennia marina - Rhirophora stylosa (Ac - Am - Rs). Over time, mangrove succession have

trend to the sea and we need some solutions to protect and develop sustainable mangrove

forest in Hai Ha district.

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TABLE OF CONTENTS

CHAPTER I. INTRODUCTION............................................................................................ 1

CHAPTER II. LITERATURE REVIEW ................................................................................ 4

2.1. Mangrove forest in the world........................................................................................... 4

2.2. Mangrove forests in Vietnam: ......................................................................................... 6

CHAPTER III. STUDY GOAL, OBJECTIVES, SCOPE OF THE STUDY AND

METHODOLOGY ................................................................................................................ 9

3.1.1. Goals: Assessment of biodiversity and structure of coastal mangrove forests, which

proposed several solutions to contribute to better management of coastal mangroves. ............ 9

3.1.2. Specific Objectives: ...................................................................................................... 9

3.2. SCOPE OF THE STUDY................................................................................................ 9

3.2.1. Geographical location, topography ............................................................................... 9

3.2.2. Climate: ..................................................................................................................... 10

3.2.3. Hydrology: ................................................................................................................. 11

3.2.4. Salinity: ...................................................................................................................... 12

3.2.5. Soil conditions: .......................................................................................................... 12

3.3. CONTENTS AND METHODOLOGY ......................................................................... 14

3.3.1. Research Content ....................................................................................................... 14

3.3.2. Methodology .............................................................................................................. 14

3.3.2.1. Data collection method: ........................................................................................... 14

CHAPTER IV. RESULTS AND DISCUSSION .................................................................. 19

4.1. DIVERSITY OF MANGROVE FORESTS IN COASTAL AREA HAI HA DISTRICT,

QUANG NINH PROVINCE................................................................................................ 19

4.1.1. List of mangroves in the study area ........................................................................ 19

4.1.2. Value of mangrove forest ........................................................................................... 27

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4.2. DISTRIBUTION AND STRUCTURE OF MANGROVE FORST IN COASTAL

AREA HAI HA DISTRICT, QUANG NINH PROVINCE ................................................... 33

4.2.1. Characteristic and distribution of mangrove forest in Hai Ha district .......................... 33

4.2.2. Combination of species .............................................................................................. 35

4.2.3. Species density ........................................................................................................... 40

4.2.4. Stratified structure ...................................................................................................... 41

4.3. PROPOSING SOME SOLUTIONS TO USE SENSIBLY, PROTECT AND

DEVELOP HAI HA MANGROVE FOREST...................................................................... 45

4.3.1. Status of mangrove forest in Hai Ha district................................................................ 45

4.3.2. Proposing some solutions to use, protect and develop Hai Ha Mangrove forest .......... 45

CHAPTER V. GENERAL CONCLUSION AND RECOMMENDATION .......................... 50

5.1. Conclusion .................................................................................................................... 50

5.2. Recommendation .......................................................................................................... 50

REFERENCES .................................................................................................................... 50

APPENDIX ......................................................................................................................... 52

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LIST OF TABLES

Table 3.1: The area of tidal ground has salt-marsh vegetation in Hai Ha district. .................. 13

Table 4.1. List of mangroves in 6 coastal communes in Hai Ha district, Quang Ninh province. ..... 19

Table 4.2. Numbers of species in phyla and classes found in Hai Ha mangrove forest. ................. 23

Table 4.3. Life forms of mangrove plants in Hai Ha district, Quang ninh provice. ................ 26

Table 4.4. Values of mangrove species in Hai Ha district. .................................................... 30

Table 4.5. Groups of valuable plants in Hai Ha mangrove forest. ......................................... 32

Table 4.6. Composition of mangrove strata follows to plots ................................................. 35

Table 4.7. Mangrove communities in 6 strata ....................................................................... 36

Table 4.8. Tree density of mangrove communities in Hai Ha District ................................... 40

Table 4.9. Awareness of coastal people about roles of mangrove forest................................ 46

Table 4.10.Awareness of secondary students about roles of mangrove forest........................ 46

Table 4.11. Coastal people’s knowledge about roles of mangrove forest .............................. 47

Table 4.12. Hai Ha student’s knowledge about roles of mangrove forest .............................. 47

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LIST OF FIGURES

Figure 2.1: Global mangrove forests distribution 2000 (Giri et al., 2011). Map redrawn by

UNEP/DEWA. Red lines/areas indicated to mangrove forest. ................................................ 4

Figure 3.1: Research sites ..................................................................................................... 13

Figure 3.1: Standard plots are set up on survey line .............................................................. 15

Figure 3.2: Plot establishment .............................................................................................. 16

Figure 4.1: Vertical profile in line 1+2 ................................................................................. 42

Figure 4.2: Cross profile in line 1+2 ..................................................................................... 42

Figure 4.3: Vertical profile in line 3 ..................................................................................... 43

Figure 4.4: Cross profile in line 3 ......................................................................................... 43

Figure 4.5: Vertical profile in line 4+5+6 ............................................................................. 44

Figure 4.6: Cross profile in line 4+5+6 ................................................................................. 44

Chart 4.1. Percentage of species found in Hai Ha mangrove forest. ...................................... 24

Chart 4.2. Awareness of coastal people and secondary students about roles of mangrove forest..... 46

Chart 4.3. Knowledge about roles of mangrove forest of coastal people and secondary student

in Hai Ha district.................................................................................................................. 47

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CHAPTER I. INTRODUCTION

Located between sea and mainland, mangrove forests are the specially ecosystem of

tropical and subtropical sea but they are sensitive with the human impact. Flora and fauna in

this forest have special biological characteristics to adapt with muddy, frequently saltwater

environments.

The existence of mangrove forests have the important meaning for environment and

socioeconomic, mangrove forests not only provide valuable forest products such as: timbers,

coals, woods, tannins, foods, medicines, etc. but also be the detritus source to raise the local

aquatic species or the species that live in estuaries and adjacent coastal. Mangrove forest is

the wintering habitats of migratory birds and nesting place of waterfowls (Phan Nguyen

Hong, 1991) [12]. Mangrove forests play important role in protecting environment,

controlling climate, preventing storm, expanding the area of the continent, preventing inland

encroachment of saltwater. They also supply foods for raising livestock’s and breeding bees.

Mangrove forests help the poor coastal people to improve their life. They also are the

attractive ecotourism location for domestic and foreign tourists, researching and studying

places of students and scientists about mangrove ecosystems. However, Vietnam mangrove

vegetation has being seriously degraded because of consequents of wars. After wars, due to

poor conditions of economy, population explosion, low awareness of resident, people exploit

indiscriminately mangrove forest for materials, destroy forest to grab land for agriculture,

shrimp farms, salt fields. These activities make the mangrove forest areas reduce, soil degrade

seriously, thousands of hectares of forest land be abandoned and not restored, biodiversity

resources and fishery resources of coastal areas be impaired and environment be polluted.

Recognizing the importance of mangrove forests, especially from the consequences of

natural disaster in the coastal areas that lost mangrove forest, the mangrove ecosystem

planting and restoring movement has being flourished in coastal areas across the country such