Characteristics of mangrove forests in nam phu commune tien hai district thai binh province

MINISTRY OF AGRICULTURE AND RURAL DEVELOPMENT VIETNAM NATIONAL UNIVERSITY OF FORESTRY *** STUDENT THESIS CHARACTERISTICS OF MANGROVE FORESTS IN NAM PHU COMMUNE, TIEN HAI DISTRICT, THAI BINH PROVINCE Major: Natural Resources Management Code: D850101 FAculty: Forest Resources and Environmental Management Student: Vu Thanh Thao Student ID: 1453091299 Class: K59B Natural Resources Management Course: 2014 - 2018 Advanced Education Program Developed in collaboration with Colorado State University, USA Supervisor: Dr Ha Quang Anh Hanoi, 2018 ABSTRACT Mangrove forests in Nam Phu commune belong to zone II which play an important role for protecting coastal area From this results, mangrove soil in Nam Phu commune is soft clay and the highest flood tide is 1.7 m in survey transect which is located near the estuary of Tra Ly river Besides, there isn’t a difference of growth of mangrove species in each plot of three transects in terms of mean height and mean DBH However, regarding the H-D correlation of mangrove species in each transect, they have a srong relationship There are three dominent species in study site having form Clumped distribution including Kandelia candel (Kc), Aegiceras corniculatum (Ac), and Sonneratia caseolaris (Sc) They also represent with difference layers in each trip of three transects In addition, there is a significant difference about the percentage of canopy cover in each trip basing on canopy area of mangrove species in each cross profile of three transects.Moreover, there is also a sediment accummulation in each transect Although, mangrove forests in Nam Phu commune have lots of strengths and opportunities, they still exist some weaknesses, especially some threats that impa r ct on sustainable mangrove forest management By this reason, we need to have some solutions to protect and manage sustainable mangrove forests in Nam Phu commune Key words: mangrove; structure; threats, sustainable management i TABLE OF CONTENT ABSTRACT i TABLE OF CONTENT ii ABBREVIATION iv LIST OF TABLES v LIST OF FIGURES vi CHAPTER I INTRODUCTION 1.1 Mangrove forests in the world 1.2 Mangrove forests in Vietnam CHAPTER II GOAL, CONTENTS, STUDY SITE AND METHODOLOGY 2.1 GOALS 2.2 CONTENTS 2.3 GEOGRAPHICAL LOCATION, TOPOGRAPHY 2.3.1 Climate 2.3.2 Biodiversity 2.4 Methodology 2.4.1 Data collection method 2.4.2 Data analysis methods 14 2.4.3 Data analysis methods 19 CHAPTER III RESULTS AND DISCUSSION 22 3.1 Characteristics of mangrove forests in the Nam Phu commune, Tien Hai district, Thai Binh province 22 3.1.1 Site characteristics 22 3.1.2 Growth characteristics 22 3.1.3 Species composition 34 3.1.4 Canopy cover 38 3.1.5 Distribution characteristics 42 ii 3.2 Sediment Accummulation 43 3.3 Some main threats that influence to mangrove forests in Nam Phu commune 45 3.4 Propose appropriate solutions for sustainable mangrove management in Nam Phu commune, Tien Hai district, Thai Binh province 49 CHAPTER IV GENERAL CONCLUSION, LIMITATIONS AND FURTHER STUDY 50 4.1 General conclusion 50 4.2 Limitations and further study 50 REFERENCES APPENDIX iii ABBREVIATION DBH Diameter at Breast Height Hvn The Height of Tree Hdc The Height Under Branches Dcanopy Diameter of Canopy SWOT Strength, Weakness, Opportunity, Threat GPS Global Positioning System iv LIST OF TABLES Table 3.1: Site characteristics in each transect 16 Table 3.2: Measurement of trees 17 Table 3.3: Measurement of canopy cover 18 Table 3.4: SWOT analysis 21 Table 4.1: Site characteristics in Nam Phu commune 22 Table 4.2: Statistic of height in three survey transects 23 Table 4.3: Statistic of DBH in three survey transects 28 Table 4.4 Tree density of mangrove communities in Nam Phu commune 33 Table 4.5 Composition of mangrove species follows to plots in each transect 34 Table 4.6: Appearance frequence of mangrove species in transects 35 Table 4.7: Mangrove plant communities in transects 35 Table 4.8 Measurement of canopy cover 40 Table 4.9 Distribution characteristics of mangrove species in Nam Phu commune 42 Table 4.10 Three-weekly sedment trap thickness data obtained with sequential sediment traps in each plot 43 v LIST OF FIGURES Figure 3.1: Geographic location in Nam Phu commune, Tien Hai district, Thai Binh province Figure 3.2: Mangrove forests distribution in Nam Phu commune, Tien Hai district, Thai Binh province in 2018 Figure 4.1: Height distribution in plots of transect 23 Figure 4.2: Vertical profile in transect 25 Figure 4.3: Height distribution in plots of transect 25 Figure 4.4: Vertical profile in transect 26 Figure 4.5: Height distribution in plots of transect 27 Figure 4.6: Vertical profile in transect 28 Figure 4.7: DBH distribution in plots of transect 29 Figure 4.8: DBH distribution in plots of transect 30 Figure 4.9: DBH distribution in plots of transect 31 Figure 4.10: Cross profile in transect 39 Figure 4.11: Cross profile in transect 39 Figure 4.12: Cross profile in transect 40 Fig 4.13 Three-weekly sediment trap volume data obtained with sequential sediment traps 44 Figure 4.14: Percentage of human Activities related to mangrove forest 47 vi CHAPTER I INTRODUCTION Mangroves are a group of trees and shrubs that live in the coastal intertidal zone (NOAA) The word “mangrove” has been used to refer either to the constituent plants of tropical intertidal forest communities to the community itself (Kasawani, 2007) Mangroves appear in tems of woody plants that distribute on the interfAce between land and sea in tropical and sub-tropical latitudes Mangroves trees therefore grow in soil that is more or less permanently water-logged and in water those salinity fluctuates and may be as high as that of open sea 1.1 Mangrove forests in the world Mangrove forests distribute mainly on the equator and sides tropical hemisphere The limit of mangrove trees in South is New Zealand (38o03’South latitude) and the South of Australia (38o43’South latitude) Basing on analyzing the data from NASA's Landsat satellite imagery system, the scientists estimate that mangrove remains survival Accounting for 12.3% of the Earth's surfAce area (approximately 137,760 km²) and distributed in 123 countries around the world ( Tamnhin.net, 2010) Of which about 42% of mangroves in the world found in Asia, in Africa with 21%, 15% in the North and Central America, 12% in Oceania and South America with 11% The distribution of mangrove forests in the world are divided two main regions : IndiaPAcific areas (Southern Japan, Southeast Asia, India, the Red Sea coast, East Africa, Australia, New Zealand, the South PAcific Island, and Xamoa archipelago) and West Africa-Americas areas (covering the coast of Africa in the Atlantic Ocean, the Galapagos Islands, and the Americas) 1.2 Mangrove forests in Vietnam Mangroves located primarily in southern Viet Nam (Mekong Delta and Ca Mau Province) Vietnam is located in tropical climate with advantages for mangrove forest development.In 1943, there are 408,500 of mangrove forest areas in Vietnam, but this area decreases to 270.000 in 2015 due to many different reasons such as war, mining, and unsustainable management of mangrove forests At present, our country has an area of 155,920 of mangroves and the area is still on the decline (Mai Sy Tuan and MFF Vietnam NCB, 2016) In Viet Nam and other countries on the world, there are many articles and researches about mangrove forest, especially reAcarches of Phan Nguyen Hong about mangrove forest His researches helps him become one of the leading doctor in research of mangrove forest in Viet Nam The number of mangrove species in Southern of Viet Nam is 100 species, there are 69 mangrove species in Central of Viet Nam and 52 mangrove species in Northern of Viet Nam The distribution of mangrove species is different in these location because there are a significant difference of climate condition, geographic features and hydrology (Phan Nguyen Hong, 1999) Based on geographical fActors, fieldwork and part of results Remote Sensing, P.N.Hong (1991, 1993) were divided into Vietnam mangrove areas and 12 sub-zones: Zone I: Northeast in the Coastal, from Mui Ngoc to Do Son Zone II: North Delta in the Coastal, from Do Son to LAch Truong Zone III: Central Vietnam in the Coastal, from LAch Truong to Vung Tau Zone IV: Southern in the Coastal, from Vung Tau to Mui Nai - Ha Tien  Zone I: Mangroves grown by the outer shielding island, the species mainly Rhizophora stylosa, Kandelia obovata, Bruguiera gymnorrhiza (L), Aegiceras corniculatum (L) Blanco, Avicennia marina Due to the air temperature in the winter cold, so the tree is small in size, only a height of about 1.5 to m  Zone II: Despite the extensive alluvial, alluvial-rich, but here empty beach, no shielding storm islands, only a few mangrove estuaries in the main tree species such as Sonneratia L , Kandelia obovata, Aegiceras corniculatum (L) Blanco, AcanthAceAc Sonneratia L relatively large size  Zone III: Mudflats narrow, less silt coast by steep, windy storm, forests of narrow strip just inside the estuary The trees are mostly plants: RhizophorAcAca, Bruguiera gymnorrhiza (L.), Aegiceras corniculatum (L.) Blanco, Avicennia marina, often small trees, the branches more Zone IV: There are extensive mudflats, numerous sediment by the Dong Nai river system and the Mekong River system provides less wind storm so well developed mangroves, especially Ca Mau peninsula The forest has many species of trees, with a high diversity and large size According to this division, mangrove forests in Nam Phu commune, Tien Hai District, Thai Binh Province belong to zone II So, mangrove forests in here bring many common characteristics of this region but they still exist some peculiarities of the terrain leading to the difference of mangrove forest structure which will be outtransectd in the next part Nam Phu is a commune located in the southern part of Tien Hai district, Thai Binh province It is one of three communes of Tien Hai Nature Reserve (Nam Hung, Nam Phu and Nam Thinh) In Nam Phu commune, there is a large sand dune called Con Vanh with an area of 1,696 and a beach stretching for about km Canh Vanh has about 700 of mangroves, 56ha of casuarina forest And in the mangrove ecosystem is quite rich with many species of plants, over 200 species of valuable seafood and many rare bird species The terrain is relatively flat, with an average elevation of 0.5-0.75 m above sea level (Nguyen Thi Hong Hanh, 2015) This is one of the localities with favorable geographic conditions and favorable terrains for mangroves and agricultural plants to grow and develop (thaibinh.gov.vn) The tidal regime is the diurnal tide The lowest tide level can be down to 0.1 m; The highest is 3.9 m The average temperature is 23.5oC Average rainfall is between 1,700 and Table 04: Growth index of mangrove in plot belongs to transect No Species Hvn (m) D (cm) Kandelia candel 13.1 Kandelia candel Dt Dt E-W S-N 28 9.2 12 10.6 10.4 17.6 4.5 6.1 5.3 Kandelia candel 10.7 18 4.9 5.8 5.35 Sonneratia caseolaris 13.6 27.5 8.2 7.9 8.05 Kandelia candel 11 20 4.7 5.5 5.1 Sonneratia caseolaris 12.8 27 7.3 7.7 7.5 Kandelia candel 9.1 15.8 2.4 2.6 2.5 Sonneratia caseolaris 14.1 32.5 8.3 9.1 8.7 Kandelia candel 12.3 27 8.8 8.1 8.45 10 Kandelia candel 11.2 23.2 5.2 5.1 11 Sonneratia caseolaris 14 30.3 8.5 8.25 12 Kandelia candel 13.5 16.2 3.1 3.8 3.45 13 Sonneratia caseolaris 14.5 34.2 8.2 8.6 14 Kandelia candel 10.2 19.2 3.7 3.5 3.6 15 Kandelia candel 9.8 17.1 2.9 3.3 3.1 16 Kandelia candel 11.9 24.2 6.4 7.1 6.75 17 Sonneratia caseolaris 13 33.7 7.6 7.8 18 Kandelia candel 12 29.1 7.7 7.5 7.6 19 Kandelia candel 12.7 32.2 8.6 8.1 8.35 20 Kandelia candel 10 17.9 3.7 3.35 21 Sonneratia caseolaris 14.6 34.6 9.3 10 9.65 Table 05: Growth index of mangrove in plot belongs to transect No Species Hvn (m) D (cm) Kandelia candel 11.6 Kandelia candel Dt Dt E-W S-N 23.3 4.2 3.6 3.9 11.2 27.4 4.9 4.95 Sonneratia caseolaris 13 29.8 7.1 7.55 Kandelia candel 10.3 23 3.9 3.5 3.65 Kandelia candel 9.7 15.4 2.8 3.1 2.95 Sonneratia caseolaris 13.4 34.2 8.7 8.8 8.75 Kandelia candel 11.9 25 7.2 6.4 6.8 Kandelia candel 12.1 28.4 8.6 8.9 8.75 Kandelia candel 10.9 16.9 4.1 4.55 10 Kandelia candel 10.6 16.4 3.6 5.3 4.45 11 Kandelia candel 11.4 20.1 7.4 7.7 7.55 12 Kandelia candel 9.5 17 2.5 2.75 13 Kandelia candel 10 17 3.9 4.6 4.25 14 Kandelia candel 10.8 19.3 6.4 4.8 5.6 15 Sonneratia caseolaris 14.8 36.1 9.1 9.7 9.4 16 Kandelia candel 10.7 19.2 4.8 4.1 4.45 17 Kandelia candel 11.8 27.7 8.3 8.15 18 Kandelia candel 11.9 29.1 8.5 8.2 8.35 19 Kandelia candel 12 28.3 7.6 7.3 20 Kandelia candel 10.3 19.2 5.2 4.1 4.65 21 Kandelia candel 11.9 25.6 6.4 7.5 6.95 22 Sonneratia caseolaris 13.6 33.7 7.1 7.55 23 Kandelia candel 11.3 22.4 6.1 6.6 6.35 Table 06: Growth index of mangrove in plot belongs to transect No Species Hvn (m) D (cm) Kandelia candel 12.5 Kandelia candel Dt Dt E-W S-N 31.5 8.6 8.1 8.35 11.6 20.3 7.1 7.2 7.15 Kandelia candel 11.9 24 6.8 7.6 7.2 Sonneratia caseolaris 14.8 39.2 9.2 9.5 9.35 Kandelia candel 10.5 20.7 4.6 4.2 4.4 Aegiceras corniculatum 10.9 22.6 4.8 4.9 Kandelia candel 12.3 30.1 8.3 8.15 Kandelia candel 11.4 27.7 7.5 6.7 7.1 Sonneratia caseolaris 13.7 31.6 8.2 8.3 8.25 10 Sonneratia caseolaris 14.3 36.9 8.9 8.95 11 Kandelia candel 11.8 24 6.9 7.1 12 Sonneratia caseolaris 11.9 23.7 7.8 6.5 7.15 13 Kandelia candel 12 30 8.2 8.8 8.5 14 Aegiceras corniculatum 11.5 27.9 8.1 7.7 7.9 15 Kandelia candel 11.1 26.8 7.6 7.3 7.45 16 Aegiceras corniculatum 10.8 22.5 6.7 6.85 17 Sonneratia caseolaris 12.9 29.9 7.4 7.9 7.65 18 Kandelia candel 11.1 20.3 4.8 6.1 5.45 19 Kandelia candel 11.4 21.8 6.9 5.45 20 Kandelia candel 12.1 28.6 7.6 8.3 7.95 21 Kandelia candel 11.6 24.7 7.2 6.1 22 Sonneratia caseolaris 2.6