Current status of mangrove forest and solutions for conservation and development of mangrove forests in tien hai nature reserve thai binh province

1 MINISTRY OF AGRICULTURE AND RURAL DEVELOPMENT VIETNAM NATIONAL UNIVERSITY OF FORESTRY STUDENT THESIS CURRENT STATUS OF MANGROVE FOREST AND SOLUTIONS FOR CONSERVATION AND DEVELOPMENT

1

MINISTRY OF AGRICULTURE AND RURAL DEVELOPMENT

VIETNAM NATIONAL UNIVERSITY OF FORESTRY

STUDENT THESIS CURRENT STATUS OF MANGROVE FOREST AND SOLUTIONS FOR CONSERVATION AND DEVELOPMENT

OF MANGROVE FORESTSIN TIEN HAI NATURE RESERVE

TIEN HAI DISTRICT, THAI BINH PROVINCE

Major: Advanced Curriculum in Natural Resources Management

Code: D850101 Faculty: Forest Resources & Environmental Management

Class: K60 - Natural Resources Management Course: 2015 – 2019

Advanced Education Program

Developed in Collaboration with Colorado State University, USA

Supervisor: Dr Ha Quang Anh

Ha Noi, October 2019

1

ACKNOWLEDGEMENT

This thesis would not have been possible without the support and help from

my lecturers, friends, family and many people I would like to express my special appreciation of following people who supported me with my sincere gratitude:

First of all, I would like to express my sincere thanks to my advisor Dr Ha Quang Anh for his untiring and excellent guidance, valuable suggestions in my dilemmas His comments and advices have helped me to finish my thesis

I am also thankful to Professor Pham Van Dien for his enthusiam in guiding

me to construct thesis proposal, and Dr Duong Thi Bich Ngoc with her comments and criticism on my proposal helped me to present better final thesis

Further, I would like to thank the Wetland Management Board in Tien Hai District for support and giving me the chance to study in Tien Hai Nature Reserve Besides, I also thank the local authorities and residents in three communes (Nam Hung, Nam Phu, Nam Thinh) for providing valuable information and data of the area

I wish to thank the Center of Laboratory and Practice of Vietnam National University of Forestry for providing me with survey instrument (GPS Garmin) for filed survey I also thank officials of Thai Binh Department of Agriculture and Rural Development for their enthusiastic help in the process collected data in field survey

Last but not least, my everlasting gratitude goes to my parents who always encouraged and supporting me all the time

Hanoi, October 2019

Pham Thu Thao

4.1.1.3 Construction of mangroves 27

4.2 Impacts of current human activities and related policies/

regulations on the mangrove conservation and development 42

4.2.2 Related policies and regulations on the mangroves conservation

4.3 Solutions to preserve and develop mangrove forests 46

Chapter 5 CONCLUSIONS, LIMITATIONS AND FURTHER

ABBREVIATIONS

A1 Globally threatened species

CRES Natural Resources and Environmental Studies

FAO The Food and Agriculture Organization of the United Nations GIS Geographic Information System

GPS Geographic Position System

IBA The International Bar Association

IUCN International Union for Conservation of Nature

IUCN Category IV Habitat/Species Management Area

MARD Ministry of Agriculture and Rural Development

MCD Centre for Marinelife Conservation and Community Development MERD Mangrove Environment Research Division

NGO Non-Govermental Organization

UNESCO United Nations Educational, Scientific and Cultural Organization

LIST OF TABLES

Table 3.1 The average monthly tidal water level in the estuary 16 Table 3.2 Sampling design in Tien Hai district 22 Table 4.1 Vascular plant composition in Tien Hai mangrove forest 26 Table 4.2 Forest land status in 3 communes of Nam Thinh, Nam Hung,

Table 4.3 Area of forest types and forestry land according to use

Table 4.4 Area of forest types and forestry land according to use

Table 4.5 Area of forest types and forestry land according to use

Table 4.6 Forest cover of mangrove forest in Nam Phu, Nam Thinh and

Table 4.7 Planted area of forest classified by tree species and age level

Table 4.8 Planted area of forest classified by tree species and age level

Table 4.9 Planted area of forest classified by tree species and age level

Table 4.10 Types of functional zoning land conservation areas 42 Table 4.11 Population and labor statistics in Nam Hung, Nam Thinh 43

and Nam Phu communes

Table 4.12 Area of mangrove forest in Tien Hai Nature Reserve

LIST OF FIGURES

Figure 3.1 Location of study area: a) Location of Thai Binh province

on Vietnam map; b) Location of Tien Hai district; c) Location of Tien

Figure 4.1 Mangrove management scheme in Tien Hai district 39

ABSTRACT

Mangrove forest plays an important role in protecting shorelines from damaging storms, hurricanes, wind, waves and upgrading people's standard of living Protecting and restoring mangrove forest will improve the lives of people in the region and help deal with problems of climate changes in the coastal regions In Tien Hai district, Thai Binh province, the total area of mangrove forest is 331.3 hectares in 2015

For conservation purposes, the Vietnamese government has made many decisions and policies to protect and develop Tien Hai mangrove forest This research concentrates on three objectives: descriptive current status of mangrove forest in Tien Hai district; study the impact of current human activities and related policies or regulations on the mangrove conservation and development; recommend solutions for either protecting and developing mangroves or increasing the standard living conditions of local people

Keywords: mangrove forest, Tien Hai Nature Resserve, Tien Hai, Thai

Binh

CHAPTER 1

INTRODUCTION

Mangroves are a type of forest which formed from trees and shrubs adapted

to saltwater environments, developed in estuarine areas in tropical and subtropical seas The mangrove forest is a very important ecosystem, providing both the demand for fuel, food for coastal communities, as well as a solid green wall against storms, tsunamis, landslides and cleanings coastal environment, limits saline intrusion, protects underground water, regulates climate, maintains biodiversity when natural disasters occur and preserve coastal wetland ecosystems, etc In Thai Binh, there are 3,708.98 hectares of mangrove forest Mangrove forests

in general and in Thai Binh province, in particular, are increasingly asserting their important roles in the sustainable development strategy of the nation, especially in the context of climate change and current sea-level rise

Mangroves are commonly found along sheltered coastlines in the tropics and sub-tropics where they fulfil important socio-economic and environmental functions These include the provision of a large variety of wood and non-wood forest products; coastal protection against the effects of wind, waves and water currents; conservation of biological diversity – including a number of endangered mammals, reptiles, amphibians and birds; protection of coral reefs, sea grass beds and shipping lanes against siltation; and provision of habitat, spawning grounds and nutrients for a variety of fish and shellfish, including many commercial species High population pressure in coastal areas has, however, led to the

conversion of many mangrove areas to other uses, including infrastructure, aquaculture, rice and salt production Numerous case studies describe mangrove losses over time, but information on the status and trends of mangrove area extent

at the global level is scarce The first attempt at estimating the total mangrove area

in the world was undertaken as part of the FAO/UNEP Tropical Forest Resources Assessment in 1980, where the world total was estimated as 15.6 million hectares

In 2007, total mangrove forest of the world is 17 075 600 ha (FAO, 2007) For many of these studies, countries with small areas of mangroves were excluded due

to lack of information and because their combined area of mangroves would not significantly affect the world total

Many concepts about mangrove forests have been developed According to Phan Nguyen Hong (1999), the mangrove trees that live in the transition zone between the sea and land environment, the impact of environmental factors affect their distribution, mangroves are trees and evergreen shrubs, belonging to many families do not have a close relationship with each other but have similar requirements on habitat Mangroves are typical vegetation types for tropical and subtropical coastal areas In addition, mangroves are communities of plants formed

in coastal areas and estuaries where tidal influences in tropical and tropical Asia There are many different names in the world for mangroves such as "coastal forests", "tidal forests" and "mangrove forests" (FAO, 1994) In Vietnam, most scientists agree the common name is "Mangrove Forest" (Ngo Dinh Que, Vo Dai Hai, 2012) According to Thai Van Trung (2000), the subtype limit of mangroves

into saline soils, submerged in seawater daily or in each period, contains mainly NaCl and other salts with a lower rate

The mangrove ecosystem plays a big role in protecting and developing estuarine and coastal resources and environment for socio-economic and community expressed through functions and services such as: providing O2 and CO2 absorption to improve regional climatic conditions like other forest types; Carbon accumulation; providing food, breeding, nursing and nursery for coastal aquatic species, home to migratory birds, contribute to minimizing the harms of wind, storms, sea-level rise and tsunamis; increasing the amount of sediment deposition, expanding land boundaries; filtering water and absorbing toxic substances, polluting coastal river mouths; preserving genetic resources; providing information for research, education and training, preserving cultural and religious identity

Mangrove forests could be affected by many factors such as: natural disasters (sea level rises, storm, flood); climate change; human activities (illegal cutting, clam fin, indiscriminate deforestation, changing in land-use); diseases, pests and invasive species

Currently, due to the need of economic development, ecological models of aquaculture and exploitation of aquatic resources from thousands of hectares of shrimp and fins system, indiscriminate exploitation of people has made the area Mangroves are seriously degraded Although the government and local management board have given certain attention to the conservation and development mangrove forest, there is still no optimal solution yet Therefore, I did

my thesis about "CURRENT STATUS OF MANGROVE FOREST AND

MANGROVE FORESTS IN TIEN HAI NATURE RESERVE, THAI BINH

PROVINCE" in order to provide information about mangrove forest in Tien Hai

Nature Reserve, effects of related policies, regulations, laws, etc then suggest solutions to conserve and increase mot only area but also quality of mangrove forests in Tien Hai Nature Reserve

The specific objectives of this research are:

- To determine the current status of mangrove forests in Tien Hai Nature Reserve, Thai Binh province

- To evaluate the impacts of policies/regulations and human activities on forest management

- To propose some appropriate solutions for the conservation and development of the mangrove forest

CHAPTER 3

STUDY SITE AND METHODS

3.1 Study site

Figure 3.1 Location of study areas: a) Location of Thai Binh province on Viet

Nam map; b) Location of Tien Hai district; c) Location of Tien Hai Nature Reserve

Tien Hai Nature Reserve is located in Tien Hai district, Thai Binh province with co-ordinates from 20013'34.66'' to 20023'59.28'' north latitude and

c) a)

b)

106034'38.95'' to 106039'05.22'' east longitude, covering 9 748.316ha The establishment of Tien hai Nature Reserve was decreed on 5th September 1994 Decision No.4895/KGVX of the Government Office Tien Hai Nature Reserve is bordered by the west is adjacent to Nam Thinh fishing port, the embankment of Nam Thinh sea dike 5, the Nam Thinh fishery lagoon, the Nam Hung aquatic lagoon, the eastern edge of Con Vanh sandbank in Nam Phu; the north borders Lan deep creek; in the south is Nam Hung creek from the confluence of Hung Thinh

river to the opening gate No 3; the east is the isobath of 6m of water at low tide

3.1.1 Boundary position

Mangrove forest in Tien Hai Nature Reserve is special-use forest located in

3 coastal communes Nam Hung, Nam Phu and Nam Thinh

The western boundary is adjacent to sea dike 5 in Nam Hung, Nam Phu, Nam Thinh The north is adjacent to Lan deep creek, the South is the Red River, the East is bordered by the East Sea from the Ba Lat gate to the Lan gate

3.1.2 Natural conditions

Topography and soil characteristics

Terrain with high waveforms in the middle, low toward the beach and the sea, southwest-northeast slope, lower towards the sea and Lan Sau creek

This is the saline soil deposited by alluvial soil of the Red River and the impact of the tide, the soil mechanic component is gradually decreasing in the southwest-northeast direction

The popular semi-submerged areas are light meat, sand mixed with sand, and low lying areas of the surface, which are light meat and meat The low intertidal zone has a sand ratio of 39.19% - 43.69%, the maximum is 75.24%; The high tidal zone has a sand ratio of 83.64% - 86.5%, the maximum is 98.32%

Sandy area is mainly mixed sand, small grains in the discrete, sand ratio is 90% - 100%

The coastal area consists of a layer of organic mud, covered with sand and silt

Meteorological characteristics

The mangrove forest of the Tien Hai Nature Reserve is located in the tropical monsoon climate In addition to the general characteristics of the province, the region is dominated by the coastal climate The values of rainfall, wind speed, storm intensity are greater and the temperature is milder than the sea Extreme weather phenomena, snails, and thunder are stronger

Hydrological characteristics

The area is dominated by the diurnal regime and floods of the Red River, always interacting with each other to create coastal estuarine intertidal areas of wetland conservation areas Hot season: high flood, low tide; cold season: low flood, high tide.Floods spread along the canal system: Hong Lap river, Moi river, Cha Rao creek, Nam Hung creek, Dai 5 creek and other tidal creeks that bring tidewater to enter the beach and drain back to the river and the sea That water flow has created the intertidal habitats, nurturing the thriving organisms and attracting migrating birds to stop and feed The salinity of the water is seasonal: 20-25% in flood season and 25-32% in dry season

Tidal water changes by day, about 25 hours and 14-day tidal cycle, low tide (from day 1-5), high tide (from day 7-11, 12)

Table 3.1 The average monthly tidal water level in the estuary

(unit: cm)

(Source: Thai Binh hydro-meteorological center, 2016)

The wave regime associated with the prevailing wind direction is the Northeast-Southeast, with an average wave height off the coast of 0.5 - 1.3m, on the shoreline of 0.4 - 0.9m, with large waves off the coast up to 1.5 - 6.0m, on the shore of 0.3 - 0.4m In summer, the average wave is 0.8 - 1.3m, the coast is 0.7 -

Station River Quantity Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Max 175 165 137 138 175 186 221 307 247 291 193 187Min -128 -124 -127 -135 -121 -199 -113 -83 -84 -91 -102 -122Max 210 200 117 178 221 220 257 247 254 248 229 214Min -93 -82 -82 -82 -84 -84 -75 -48 -43 -53 -65 -44

Dinh Cu Tra Ly

Ba Lat Red

River

1.2m, the big wave is when the storm is 4m, the shore is 2.6 - 6.0m The Red River flow carries 0.6 -1.0 kg/m3 of alluvial seasonal changes, accretion in the estuary, with sea encroachment from 30 - 40 m/year, helping the intertidal areas to be constantly expanded and replenished abundant nutrition for biological population

3.1.3 Natural features

Tien Hai Nature Reserve is wetland zone so it has full typical characteristics

of wetland zone According to Ramsar Convention of Wetland, wetlands are defined that "Wetlands are areas of marsh, fen, peatland or water, whether natural

or artificial, permanent or temporary, with water that is static or flowing, fresh, brackish or salt, including areas of marine water the depth of which at low tide does not exceed six meters" Together with the Xuan Thuy National Park in Nam Dinh province, the first Ramsar, recognized site in Southeast Asia, Tien Hai Nature Reserve in Thai Binh province plays a significant role in preserving national and international biodiversity The site is one of the core zones of Red River Delta Biosphere Reserve and was recognized by UNESCO as a world biosphere reserve

in 2004 According to IUCN protected area categories system, Tien Hai Nature Reserve is classified as habitat/species management area (category IV), to protect particular species or habitats and management reflects this priority Moreover, according to IBA criteria, the nature reserve is classified as A1 (globally threatened species)

Climate

The Tien Hai Nature Reserve has a monsoon humid tropical climate The average temperature is 15oC in winter and 38oC in summer The rain season starts from May to October and between October and January of the following year is the

dry season The average annual rainfall from 1600 to 1800mm and approximately 80% of total rainfall appeared in rain season

Hydrology and tide

The Tien Hai Nature Reserve was supplied water and alluvium from Red river There are two major rivers in the nature reserve: Lan and Red rivers Besides, two main rivers, there are much steam from Red River drain through the mangrove forest to provide water and alluvium for growing of mangrove forest Every year, Red river supplies a large amount of alluvium and sediment for the nature reserve, average 6-7 kg/cm3 in the rain season The average amount of alluvium and sediment from Red river brought by the sea is about 114 million tons The tide of Tien Hai Nature Reserve is diurnal The tide is relatively weak, about 150-180 cm/day, with 3.3-3.9m to max tidal water level, 0.4m to min tidal water level Due to tide and hydrology created condition for growing of mangrove forest, aquaculture production, typically raising platform land and expand the area for the nature reserve The main types of soil in the Tien Hai Nature Reserve include sandy soil, salty soil, saltmud soil and alluvial soil

Biodiversity

The nature reserve is rich in mangroves and casuarinas forests, shrimp

ponds, tidal flat, dunes and banks It is home to 215 species of birds and Platalea minor (cò mỏ thìa) is a species in Red Book In addition, along with 116 species of

higher plants - a major source of food for birds, 43 medicinal plants, 113 insect species, 107 fish species and 37 amphibians and reptile species Moreover, the mangroves are the important ecosystem of the nature reserve, with the diversity of

mangroves with majority species such as Acanthus ilicifolius (ô rô), Aegiceras corniculatum (sú), Kandelia candel (trang), Sonneratia caseolaris (bần chua), etc

3.1.4 Socio-economic features

- The population of three communes in the buffer zone of Tien Hai Nature Reserve is 18142 people, including 5684 people in Nam Hung, 5213 people in Nam Phu and 7245 people in Nam Thinh Almost people are farmers and large differences in the income of local people

An Ninh, Phuong Cong, Van Truong, Bac Hai, Dong Lam, Dong Co, Dong Phong, Dong Tra, Dong Quy, Dong Xuyen, Dong Long, Dong Hoang, Dong Minh, Dong Hai, Dong Trung, Nam Ha, Nam Hai, Nam Hong, Nam Chinh, Nam Trung, Nam Thang, Nam Thanh, Nam Thinh, Nam Hung, Nam Phu, Nam Cuong

- In 2018, the total production value of Tien Hai district reached 15516.05 billion VND In the production structure of the district, Agriculture, forestry and fisheries account for 35.43%; Industry and construction account for 49.99%, of

which industry accounts for 40%; Services account for 14.58%.The total social investment capital of the district was 3619.36 billion VND The total export turnover reached 26.6 million VND The population of the district is 209 769 people with an average income per capita was about 41.2 million VND/month

- The economic structure of Tien Hai district is expected to be in 2020 (at current prices) as follows: Agriculture, forestry and fishery sector accounts for 30.45%; Industry and construction accounted for 55.43%; Service sector accounted for 14.13%

- The average income per capita in Tien Hai district is estimated at 2020 to reach 50.4 million VND/person/year

3.2 Data collection

3.2.1 Interview

Interview data was collected from interviews which are considered as a good way to get information directly from people live there and manager of the nature reserve Due to their knowledge about the study site, collecting information from them is true and useful for research From interviewees, we can directly know the current status of mangrove forests, local people activities and how policies, decrees, regulations effect on mangrove forests To have good result at interviewing, the guideline survey questionnaire were designed (Appendix 1, 2)

Because the limitation of budget, time and human resources, I conducted a survey with 2 officers of the management board of Tien Hai Nature Reserve and

30 local people in the buffer zone The interviews local people were carried out

with 30 farmers was chosen randomly of buffer zone of the nature reserve; and number of farmers was chosen randomly during the processing of field work

The management board of Tien Hai Nature Reserve

Interview staffs of management board to get information about the current forest area, status of mangroves, as well as policy and regimes management, which are implemented in Tien Hai Nature Reserve After that, we could have an overview about the protected area, current status of mangrove forests and policies, regulations, degrees and laws related to the conservation and development of the mangroves in the nature reserve People belong to object of interview: staff of board management in Resources and Environment department in Tien Hai district, local authorities of three communes: Nam Hung, Nam Phu, Nam Thinh

Local communities in three communes of buffer zone

Local communities play an important role in management of Tien Hai Nature Reserve They affect directly on mangrove forests in the nature reserve They have better knowledge than anyone about the area Therefore, getting information from local people is the best way to have accurate information about the mangroves The interview local people also can have an overview about effectiveness of management plans of the nature reserve In this report, the interview local communities to determine livelihood activities and effects of policies, regulations on protection and development mangrove forest area before Local people who toward to object of interview include old or middle-age people and people with experiences Therefore, they could provide much information

about the mangrove forest, their opinions about effects of policies, laws, degrees

on conservation and development of mangrove forests in Tien Hai Nature Reserve

Tien Hai Nature Reserve is located in Nam Thinh, Nam Hung and Nam Phu communes According to data provided by the People's Committee of Tien Hai district, Nam Hung commune has 1526 households, Nam Phu commune has 1200 households and Nam Thinh commune has 1775 households Because of the limitation on time, budget and my capability, I based on the ratio of households among 3 communes to choose the number of surveyed households All the surveyed households live in the buffer zone, near the Tien Hai Nature Reserve

Table 3.2 Sampling design in Tien Hai district

Commune Total households Surveyed households

3.2.2 Secondary data collection

References material is another method to get more information about the study site, besides interview data The study used some information from the peer-reviewed articles, report, news, newspaper, official documents about the Tien Hai Nature Reserve These findings can provide more information for the management schemes of the Tien Hai Nature Reserve in current, the current status of mangrove forest about fauna, flora, tree composition and timber volume

The materials that used in the research are shown in the appendix 3

CHAPTER 4

RESULTS AND DISCUSSIONS

4.1 Current status of mangrove forests

4.1.1 Current status of mangrove forest in Tien Hai district

Mangrove forest area in Tien Hai district is located in 3 communes of Nam Hung, Nam Phu and Nam Thinh, on the southeastern edge of coastal district of Tien Hai district, 40 kilometers from Thai Binh city and 19 kilometers from Tien Hai town

The fauna is abundant, many species have high economic and scientific value, especially rare and endangered species listed in national and international Red Book In the area, there are 113 insect species, 98 species have been identified, 19 species have been identified including beetles, pollen wings, membrane wings, veins, insects, honey bees 107 species of fish belonging to 44 families, 12 orders Mammals have 9 species of 4 families with poor numbers, sometimes with dolphins 13 species of amphibians, 24 species of reptiles with 4 species in Vietnam's Red Book.The bird fauna is crowded with 215 species, including 65 native species and 150 migratory species There are 200 species of aquatic species which have economic value for high quantity.Tien Hai mangrove area is one of 63 important bird sanctuaries and also one of the 6 bird sanctuaries

of wetland nature of Vietnam

The pressures from the livelihoods of local residents, the development of trade in services and tourism, together with the complex changes of climate change have created enormous pressures and challenges for conservating and developing

mangrove forests of the district At present, the area is being encroached, overexploited, and has been losing its endemic values: migratory birds, ecological landscapes and biodiversity

4.1.1.2 Mangrove forests in Tien Hai Nature Reserve

According to 2015 forest inventory data, Thai Binh province has 3709.1 hectares of mangrove forest and 341.6 hectares of non-mangrove forest; in the wetland reserve of Tien Hai district and in the buffer zone, there are 883.60 hectares of mangrove forest and 140.1 hectares of unqualified forest, total forest area is 1023.7 hectares Since 2015, Thai Binh province has planted hectares of forests in Nam Thinh, Nam Hung and Nam Phu in the reserve According to a survey in 2018, non-dike forests in the reserve are mangrove forests with an area of 573.99 hectares, and non-mangrove forests with an area of 399.931 hectares The mangrove forest area decreases by 35% because the forest in the lagoon in Nam Phu, the forest at the north of Con Vanh and Con Thu collapsed due to storms and tidal waves

Mangroves in the forest include 42 families, 99 genera and 116 species, of which 11 species of mangroves are common and 37 species are involved in mangroves Plant communities related to natural forest communities, plantation forest communities, plant communities in aquatic marshes and pioneer communities in newly accreted areas, major plants in mangroves include:

- Aegiceras corniculatum (sú): small timber trees grow on the edge of the

forest, dense populations along canals or small forests in swampy, salty swamps

- Bruguiera gymnorrhiza (vẹt dù): belonging to Rhizophora genus (chi

Đước), knee roots, growing in estuaries along canals and on the intertidal flats

- Kandelia candel (trang): belonging to Rhizophora genus (chi Đước), bony

roots, small trees grow slowly on sandy soil, mixed with Sonneratia and other species to create forests in Nam Thinh and Nam Hung communes, in lagoons and along rivers and canals there is high salinity in the north of the nature reserve

- Conneratia caseolaris (bần chua): belonging to the Sonneratiaceae family

(họ Bần), 2 cotyledons, woody stems, breathing roots, common in newly formed intertidal estuaries, growing alternately, crossing canopy

- Sonneratra apetala (bần không cánh): woody plants, belonging to the Sonneratiaceae family, dicotyledonous, breathing roots, planted in the forest near

the tidal flats of Nam Thinh and Nam Hung communes

- Rhizophora stylosa (đâng): belonging to Rhizophora genus (chi Đước),

medium-sized timber, pompano roots are distributed in estuaries and riverside

- Excoecaria afallocha (giá): belonging to Euphorbiaceae family (họ Thầu

Dầu), dicotyledonous, angiosperms, woody plants grow in low-flooded highlands and lagoons, interspersed with other plants

- Derris trifoliata (cóc kèn leo): belonging to the Fabaceae family (họ Đậu),

vines, is a fast-growing pioneer that grows in estuaries, canals, ditches, and forest edges

- Lumnitzera racemosa (cóc vàng): belonging to the Combretaceae family

(họ Bàng), medium-sized woody trunks, developing along river banks, canals

- Acrostichum aureum (ráng đại): belonging to the Pteridaceae family (họ

Quyết), growing naturally on the banks of canals, salt marshes, in secondary forests or in the foothills of the evergreen forest, in bushes and grasslands

- Acanthus ebracteatus (ô rô hoa trắng): belonging to the Acanthaceae (họ Ô

Rô), shrub type, growing on estuarine and marine sides, growing under the forest canopy and small flap at forest edge

- Acanthus ilicifolius (ô rô hoa tím): belonging to the Acanthaceae (họ Ô

Rô), shrub form, growing on estuarine and marine sides, growing under forest canopy

- Vitex trifolia (đẹn ba lá): belonging to the Lamiaceae (họ Hoa Môi),

simpleleaf chastetree, a large coastal shrub or small tree

- Sesuvium portulacastrum (sam biển): belonging to the Aizoaceae family

(họ Rau Đắng Đất), growing mainly in mangrove swamps, sandy beaches, common in Con Vanh casuarina forest

- Avicennia marina (mấm ổi): belonging to the Acanthaceae family (họ Ô

Rô), occurring in the intertidal zones of estuarine areas

- Trees in Cyperaceae family (họ Cói), Poaceae family (họ Lúa) grow

among patches of forest, forest edge, riverside and in lagoon Diverse parasitic molds on trees are one of the causes of forest degradation

- There are 3 types of algae in the mangrove canopy: cyanobacteria (tảo lam), plankton (tảo phù du), clinging algae (tảo bám)

Aquatic communities in tidal creeks, in mangroves, have about 500 species

such as Halophila ovalis (cỏ xoan), Najas marina (dương xỉ Trung Quốc), Hydrilla verticillata (rong đuôi chó), Gracilaria verrucosa (rong câu chỉ vàng), and other

types of phytoplankton

Mangrove plants play a protective role, clean the atmosphere and provide wood, firewood, nectar, fruits, raw materials for tannin extract, medicine, shade and landscape In addition, mangrove plant communities play a role as a substrate for both terrestrial and aquatic animals, including migratory birds and most important in the intertidal areas

Table 4.1 Vascular plant composition in Tien Hai mangrove forest

The vegetation composition is relatively poor, with only 2 plant branches present in the region: Psilotophyta and Angiospermae In these two phyla, angiosperms are the majority In angiosperms, the dicotyledons plant class has twice the species composition of monocotyls

Nam Hung commune

Nam Phu commune

Total (ha)

7th drain to upstream)

7th drain to upstream)

Outside lagoon (from

7th drain to upstream)

(Source: Tien Hai wetland roject management board, 2019)

Table 4.3 Area of forest types and forestry land according to use purposes of Nam Hung commune

III Land without forests for forestry

(Source: Tien Hai wetland project management board, 2019)

Table 4.4 Area of forest types and forestry land according to use purposes of Nam Phu commune

-New planting on bareland 294.4 294.4 294.4 - 294.4 - - - -

III Land without forests for forestry

1 Land with planted forests has not

Forest classification Total

(Source: Tien Hai wetland project management board, 2019)

Table 4.5 Area of forest types and forestry land according to use purposes of Nam Thinh commune

-Freshwater flooded forest - - - - - - - - - - -

III Land without forests for forestry

(Source: Tien Hai wetland project management board, 2019)

Table 4.6 Forest cover of mangrove forest in Nam Phu, Nam Thinh and Nam Hung commune

(unit: hecta)

Commune

Total forest area

Area in the construction of 3 forest types

Natural area Canopy cover

(%) Total

Classified by origin Classified by purpose

Natural forest Plantation

Special use Protection Production

(Source: Tien Hai wetland project management board, 2019)

Based on the development stage of the forest stand people are divided into age levels:

Age level 1: young forest, level 2: pole forest, level 3: middle-aged forest, level 4: near mature forest, level 5: mature forest, level 6: forest too mature Production forests in the Tien hai Nature Reserve are young, the oldest forest is at age level 5

Age can be short or long, depending on the tree species, site conditions For fast-growing tree species, age can be 2-5 years; for

slow-growing plants, the age may be 10 years Trees in mangroves are fast-growing tree species such as Sonneratia caseolaris (bần chua), Kandelia candel (trang), Casuarina equisetifolia (phi lao)

Table 4.7 Planted area of forest classified by tree species and age level in Nam Hung commune

(unit: wood: m3)

forest yet Total Level 1 Level 2 Level 3 Level 4 Level 5

Sonneratia caseolaris (bần chua) + Kandelia candel (trang) 284.3 284.3 3.6 11.7 71.0 146.6 51.4 -

Sonneratia caseolaris (bần chua) 32.3 5.5 - 2.2 - - 3.3 26.8

Kandelia candel (trang) 27.2 27.2 - 27.2 - - - -

Casuarina equisetifolia (phi lao) 12.3 10.2 - 10.2 - - - 2.1

(Source: Tien Hai wetland project management board, 2019)

In Nam Hung commune, the total volume of planted area of forest, including Sonneratia caseolaris mixed Kandelia candel, Sonneratia caseolaris, Kandelia candel and Casuarina equisetifolia, is about 356.1 m3 Most species are under level 2, only

Sonneratia caseolaris is under level 1, level 3 and level 4 Sonneratia caseolaris mixed Kandelia candel, Sonneratia caseolaris had

the proportion under level 5