ASSESSMENT OF PLANT BIODIVERSITY AND HUMAN ACTIVITY IMPACTS ON MANGROVE ECOSYSTEM IN CON VANH AREA TIEN HAI DISTRICT THAI BINH PROVINCE

VNU UNIVERSITY OF SCIENCE, HANOI FACULTY OF ENVIRONMENTAL SCIENCES SCIENTIFIC RESEACH REPORT ASSESSMENT OF PLANT BIODIVERSITY AND HUMAN ACTIVITY IMPACTS ON MANGROVE ECOSYSTEM IN CON VAN

VNU UNIVERSITY OF SCIENCE, HANOI FACULTY OF ENVIRONMENTAL SCIENCES

SCIENTIFIC RESEACH REPORT

ASSESSMENT OF PLANT BIODIVERSITY AND HUMAN ACTIVITY IMPACTS ON MANGROVE ECOSYSTEM IN CON VANH AREA - TIEN

HAI DISTRICT - THAI BINH PROVINCE

Instructor Associ.Prof Tran Van Thuy

Students

Vu Thi My Hanh Dao Thi Dung Nguyen Huong Giang

K57 Advanced Undergraduate Program of Environmental Science

Hanoi – 2016

ACKNOWLEDGEMENT

With all of our gratefulness, we would like to send heartfelt thanks to Associate Professor Tran Van Thuy, Header of Ecology Department, Faculty of Environmental Sciences, VNU University of Science, who enthusiastically instructed and helped us from the very first beginning of our student scientific research

We also sincerely thank all professors from Faculty of Environmental Sciences, as well as VNU University of Science, who guided and imparted us not only specific knowledge but also morality

Finally, we would like to say thank to our families and friends, who always supported, encouraged and helped us during our research

Hanoi, June 16 th 2016

Students

Vu Thi My Hanh Dao Thi Dung Nguyen Huong Giang

CONTENTS

OVERVIEW ……… 1

CHAPTER I: INTRODUCTION ……… 2

1.1.Overview of flora diversity study ……….2

1.2 Mangrove Vegetation Research………. 7

1.3 Study objects and study sites ………11

CHAPTER II: MATERIALS AND METHODS ………13

2.1 Materials ……….13

2.2 Methods ……… 13

CHAPTER III: RESULTS AND DISCUSSION ……… 18

3.1 Floral Biodiversity ……….18

3.2 Human impact activities ………36

3.3 Solutions ……….38

CONCLUSION ………41

REFERENCE ……… 42

LIST OF TABLES

Table 1: Flora geographical elements in Vietnam 4

Table 2: Raunkiaer‟s life form (1934) 6

Table 3: List of mangrove plants in Con Vanh area 14

Table 4: Diversity of plant groups in the mangrove ecosystem of Con Vanh area 18

Table 5: Species composition of mangrove plants in Con Vanh area 18

Table 6: The life form of mangrove species in Con Vanh area 27

Table 7: Use values of mangrove species in Con Vanh area 29

Table 8: Stratified structure of mangrove vegetation in Con Vanh area 31

LIST OF FIGURES

Figure 1: Mangrove plants‟s composition in Southeast Asia 9 Figure 2:Mangrove plant „s compostion in Southeast 10 Figure 3:Ảnh vệ tinh Landsat 5 ngày 14-01-2003, Figure 4: Ảnh vệ tinh Landsat 8 ngày 22-09-2013 15 Figure 5: Map of substrate geograghy in mudlat Tienhai district, ThaiBinh province, Vietnam 16 Figure 6: The percentage of different life forms of species in Con Vanh area 28 Figure 7: The current plant community biodiversity map in Con Vanh area 31

OVERVIEW

The mangrove ecosystem in Con Vanh area, Tien Hai District, Thai Binh province is a typical ecosystem in tropical region This area also belongs to the accretion of the Red River system, flat topography, and seasonal salinity fluctuation The growth of both planted and naturalized mangroves play important roles in regional socio-economic development and ensure ecological functions for the local environment Although the current mangroves were planted several decades ago, they still keep wild and unstable because of mostly young forest However, huge pressures

of global climate change, increasing population and economic growth rate cause biodiversity deterioration and ecosystem damage Due to these facts, it is necessary to make a detailed research about specific characteristics of mangrove ecosystem in Con Vanh area in order to give scientific basis for policy decision making and rational use

of resources Our research gives a detailed assessment of plant biodiversity of mangrove ecosystem basing on the previous research results and field investigation Then, using MapInfo 12.5 software creates a map of the current plant biodiversity through interpreting and digitalize from satellite image The results showed that the flora in Con Vanh area has 97 species, 33 families and 2 phylums and Magnoliopsida

is the highest proportion (57.7% total species) It dominates with mainly wood plants

Sonneratia caseolaris, Aegiceras corniculatum, Kandelia obovata to form

mangrove In addition, there are primary six dominated communities including some

typical species: Ipomoea pes-caprae, Myriophyllum dicoccum), Cyperus malaccensis,

Sonneratia, Kandelia obovata, Aegiceras corniculatum and Casuarina equisetifolia

However, the negative impacts of human activities such as aquaculture, fishing and tourism lead to decrease in mangrove and reduce plant biodiversity Therefore, researchers suggest several orientations for the management and rational use of the ecosystem

CHAPTER I: INTRODUCTION

1.1 Overview of flora diversity study

According to A.I Tolmachev (1974) a particular flora is “flora of given area on the Earth‟s surface, geographically homogeneous, just divergence in ecological conditions” [4]

Another definition in Vietnam Encyclopaedia Dictionary: “Flora (so-called flora zone) is whole genus, species in geographical area, a period of geological history such as Europe – Asia flora, Hon Gai flora at Trias Age Flora and vegetation are clearly distinguished, flora referred to species composition, while vegetation considered to all composition of plants

1.1.1 Overview of flora diversity study in the world

In history of flora study from 19th century (1885), De Candolle has analyzed relationship between the numbers of species and the area based on the collected information of flora at Strasburg suburb (960 species in 100 km2), Dagico flora (1362 species in 1000 km2), Svealand flora (1114 species in 4000 km2) [4]

The period from 1928 to 1932 is considered as the beginning of particular flora studies In that time, A.I Tolmachev had tasked researching flora of Taimua which located at 74020‟-250

North 102030‟ East [4]

In recent years, a lot of organizations, conservation association and international conferences were founded holding many activities of biodiversity conservation

United Nations Conference on Environment and Development (UNCED), Rio

de Janeiro, June 3rd to 14th 1992 is one of the most prominent examples There were

150 countries that signed on Convention on Biological Diversity (CBD) [11] In order

to contribute to conservation activities, WWF (1990) published a book namely “The

importance of biological diversity”; IUCN, UNEP, WWF released World

conservation strategy (1990), Caring for the Earth (1991); and Global biodiversity assessment was published by WCMC (1995) [7, 11]

In addition, thousands of scientific publications and articles were published Simultaneously meetings and conferences were organized to discussing and reporting the archive in biodiversity studies and conservation on over the world Those results created a large amount of information about the diversity of species and raise awareness of people about creature diversity and preservation

1.1.2 Overview of the flora diversity study in Vietnam

There are many scientific researches of Vietnam flora system Some could be dated back to nineteenth century, with the contribution of Loureiro (1970), Pierre (1879 – 1907); or French colonial period with the valuable series “Flore general de L‟indo – chine” of M.H Lecomte The series was a great work that created the cornerstone for the following studies After that time, international and Vietnamese botanists has conducted lots of precious works such as “Cây cỏ thường thấy ở Việt Nam” of Lê Khả Kế (1969 – 1976), “1900 cây có ích ở Việt Nam” of Trần Đình Lý (1993) and “Từ điển cây thuốc Việt Nam” of Võ Văn Chi (1996) A series is considered as an irreplaceable publication because of its methodical examination and illustration so called “An Illustrated Flora of Vietnam” of Phạm Hoàng Hộ [27]

Many species composition studies of flora systems in specific regions are carried out Pócs Tamás (1965) has listed 5190 species (including some species located between 120 and 170 North and 155 introduced species); Phan Kế Lộc (1969) added and raised the number of species in North to 5609, 1660 genus and 140 families (belonged to Engler system); “Cây cỏ Việt Nam” of Phạm Hoàng Hộ showed a statistic of 5326 species which includes 60 thallophyta, 20 mosses and 5246 vascular

plants; study of Phan Kế Lộc et al about Central Highlands flora system; studies of Nguyễn Nghĩa Thìn et al about flora system at nature reserves, national parks, some

of them has released as books such as “Tính đa dạng thực vật ở Cúc Phương”, “Đa dạng sinh học hệ Nấm và thực vật VQG Bạch Mã”, “Đa dạng thực vật VQG Pù Mát”,

“Đa dạng thực vật KBTTN Na Hang, tỉnh Tuyên Quang”, etc [7, 11, 19]

Recently, “Thực vật chí Việt Nam” series has introduced a variaties of flora families with some well-known publication such as Annonaceae of Nguyễn Tiến Bân

(2000), Myrsinaceae of Trần Thi Kim Liên (2002), etc The latest document about Vietnam flora system is “Danh lục các loài thực vật Việt Nam” was compiled by Vietnamese botanists They provide the most general and sufficient information about Vietnam flora system in three volumes: the first volume (2001) introduced Mushroom, Thallophyta, Moss and gymnosperms; the second volume (2003 and 2005) overviewed about angiosperms in which entire Monocotyledon was described in third volume Those are very important data which is considered as basis in evaluation of biodiversity in Vietnam [1, 2, 10]

1.1.2.1 Studies about geographical feature of flora

“Góp phần nghiên cứu hệ thực vật Đông Dương” (1926) and “Giới thiệu về hệ thực vật Đông Dương” (1944) of Gagnepain are the first studies about geographical features of Vietnam flora After that, Pócs Tamás (1965) constructed spectrum of geographical features of Northern Vietnam flora in which its characteristics as well as composition had changed compared to Gagnepain‟s research [25]

In 1987, based on the species statistic of Northern Vietnam flora system, Thái Văn Trừng believed that three % genus and 27.5 % species of Vietnam are endemic However, according to Pócs Tamás and the knowledge of “Một số đặc điểm cơ bản của hệ thực vật Việt Nam” [5], Lê Trần Chấn (1999) summarized and reached a conclusion that Vietnam flora system is created by following factors:

Table 1 : Flora geographical elements in Vietnam

1 North Vietnam In the administrative boundary of North

4 Vietnam In the administrative boundary of Socialist

Republic of Vietnam

5 Indochina In Vietnam, Laos, Cambodia and tropical

regions of Myanmar, Thailand

6 South China In Vietnam, the tropical regions of Southwest

and South of China

7 Hainan, Taiwan and

Philippines In Vietnam, Hainan, Taiwan and Philippines

8 Himalaya In the tropical area of Himalaya; or even in

Laos, Cambodia, Thailand and Myanmar

9 Indian In Indochina and India

10 Malaysia In Vietnam, Malaysian peninsula and islands of

Malaysia

11 Malaysia – Indonesia In Vietnam, Malaysian and Indonesia

12 Malaysia – Indonesia and

Australia In Vietnam, Malaysian, Indonesia and Australia

13 Tropical Asia In India, Indochina, Malaysia, Indonesia,

Philippines and islands on Pacific

14 Paleo-tropic In the tropical regions of Asia, Africa and

Australia

15 Neo-tropical and Pantropic In the tropical regions of America, Asia, Africa

16 East Asia In North Korea, Japan, South of China, Taiwan

and North of Vietnam

18 Northern temperate In temperate regions of Asia, Europe and

Vietnam

19 Widely distributed On over the world

20 Exotic and introduced

1.1.2.2 Study about life-form of flora

Study of life-form spectrum is one of the main activities of flora research Although there are many types of life-form categories but Raunkiaer‟s system is most gradually used because of its science and easy to use [11]

Raunkiær (1934) has classified plants according to the place where the growth point is located during the less favorable seasons, provided the plant maintains the capability to survive these difficult conditions (see table here below)

Table 2: Raunkiaer’s life form (1934)

No Terms Raunkiaer life-form definitions Sign

1

1 Phanerophytes

Projecting into the air on stems – normally woody perennials - with resting buds more than 25 cm above soil level,

Therophytes Annual plants which survive the Th

5 unfavorable season in the form of seeds and

complete their life-cycle during favorable seasons

By determining the life forms of a sample of 1000 species from the world's floras, Raunkiaer showed a fundamental formula to compare the flora systems in different regions on the Earth It is called Spectrum Biology (SB):

In 1994, scientific studies of flora diversity of Cuc Phuong National Park,

Nguyễn Nghĩa Thìn et al (1996) eliminated the life form for this region:

SB = 57.78Ph + 10.46 Ch + 12.38 Hm + 8.37 Cr + 11.01 Th

Based on this method, some other studies of Ben En National Park (Thanh Hoa province), vascular flora in Quang Ninh province, Na Hang Nature Reserve (Tuyen Quang province), etc are also implemented

1.2 Mangrove Vegetation Research

1.2.1 Definitions and characteristic of mangrove trees

* Mangrove definition

The term “mangrove” refers to an assemblage of tropical trees and shrubs that grows

in the intertidal zone Mangroves include approximately 16 families and 40 to 50 species (depending on classification) According to Tomlinson (1986), the following criteria are required for a species to be designated a “true or strict mangrove”:

1 Complete fidelity to the mangrove environment

2 Plays a major role in the structure of the community and has the ability to form pure stands

3 Morphological specialization for adaptation to the habitat

4 Physiological specialization for adaptation to their habitat

5 Taxonomic isolation from terrestrial relatives

* Mangrove trees characteristics

Mangrove is group of high plants living in brackish and salty conditions The mangrove tree is a halophyte, a plant that thrives in salty conditions It has the ability

to grow where no other tree can, thereby making significant contributions that benefit the environment Their coverage of coastal shorelines and wetlands provides many diverse plant species Mangroves preserve water quality and reduce pollution by filtering suspended material and assimilating dissolved nutrients

Until now, there is still not an exact number of mangrove species It is estimated that the world‟s official mangrove plants number is around 50-70 species according to different classifying systems [21], [25]

In Southeast Asia area, the mangrove vegetation has extensive development and abundant species composition They often distribute from east to west including Đông Timo, Papua New Guinea, Brunei, Philippine, Indonesia, Malaysia, Singapore, Việt Nam, Thái Lan, Campuchia và Myanmar More detail , the total number of inundated plants is 268 in which 129 trees and shrubs , 50 terrestrial herbaceous species ( 27 grasses types), 28 species of epiphytes, 24 species of ferns, 7 coconut species, and a species of wild pineapple and sesame (cycads) In 268 mangrove plants mentioned, 52 species of them are official species compared to 60 species in the world

Figure 1: Mangrove plants’s composition in Southeast Asia

(source (Wim Giesen, 2006)

According to Wim Giensen và cs (2006) data statistic, Indonesia had the largest composition of mangrove plants with 48 of 52 species officially, the second rank was Malaysia (42 species) , and Vietnam had the tenth position in the total of 11 countries

in the region

Figure 2:Mangrove plant ‘s compostion in Southeast

Source: (Wim Giesen, 2006)

According to flora mangroves survey in the Pacific coastal areas of Phan Nguyen Hong et al (2004), the authors listed 184 species belonging to 131 genera, 60 plant vascular families In particular, 14 mangrove species mainly belong to Rhizophoracea, Avicenniacea , 37 associate mangroves and the remaining is invaded pecies

According to the survey results of Vu Trung Tang et al (2005) in couple years, the mangrove plants in coastal Giao Thuy district and vicinity including Tien Hai had 192 species, 145 genera and 60 accounting for 39.1%, 42.1% and 52.6% equivalent with the number of species, genus, families throughout the region in which 13 true mangrioves and following trees: Acanthaceae, Avisenniaceae, Combretaceae, Euphorbiaceae, Myrsinaceae, Pteridaceae, Rhizophoraceae, Sonneratiaceae, especially

8 fern species (4.1%) of 6 genera, 5 families: Legs slag (Pteridaceae), banana leaf fern (Oleadraceae), balloons (Schizeaceae), Rang published details (Dennstaedtiaceae) One class has 49 species cotyledons (accounting for 25.5% of the species), 29 genera,

8 families Although they are less diverse in species composition, thet are rich in the number of individuals, often creating high coverage and maintaining soil moisture Absolute dominated species in the area are two cotyledons class, with 135 species (70.3% accounting for the number of species), 110 genera and 47 families, mostly

0 10 20 30 40 50 60

Cam

bodia

Myanm ar

Philippi

nes P G

Mal

aysia

Indo

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woody plants, which are main participants in shaping the mangroves Thus, angiosperms still keep dominance in flora comprising over 95.8% species, 96.6% genera and 92% of families

In term of conservative value, although the mangrove area is not large, the mangrove vegetation in Tienhai has a great value in use and ecosystem services which are very useful for local social and economic development The study of the characteristics of the mangrove vegetation and mangrove ecosystems of coastal mudflats play important roles in providing the basis for the development of rational use of resources

1.3 Study objects and study sites

The study objects of this research are the mangrove vegetation in Con Vanh area, Tien Hai district, Thai Binh province

 Natural conditions of region:

Thai Binh is the basin of the two major river systems which are Thai Binh river system and the Red River system Every year, 114 million tons of sediment is deposited creating extensive tidal flats in Ba Lat estuarine These are favorable conditions for mangrove vegetation development

+ Muddy intertidal sediments are fine sandy loam with fast deposition rate Additionally, the concentration of N, P is equivalent with the Red River alluvial and unchanged Sediment is made up of fresh air environment, no mangroves (Thanh et al, 1985)

+ Tidal regime is heterogeneous, particularly diurnal day has 5-7 days per month in range of 3-4 m The average elevation of the water level in the Ba Lat estuarine is 3.2

m, the average level of 0.4 m tide masterpiece; tide goes down is much faster velocity than its raise

+ Salinity depends on the flow rate of rivers and tides In the flood season, the low average salinity is 10%, reduced to 5-10% in heavy storm In Van Ly lowest salinity is 1.4% (11/08/1961) Lowest average salinity is 1.9% monthly , 2.44% yearly (Hieu, 1990)

Besides the above favorable characteristics, factors that have the greatest impact causing uncontiuous mangroves along the coastal are still monsoon and typhoon In winter (June 10-1) predominant wind direction is east, northeast, and wind speed is 3-

7 m / s Average in the winter months, 3-4 cold flows with high speed, while summer wind direction is southeast with the speed from 3.7 to 7 m/s under storm, huge wind speed is 18 m/s when the gust to 30 m / s

Like other provinces in northern coastal Vietnam, coastal protection forests in ThaiBinh coastal area especially mangrove vegetations are also strongly influenced by demographic pressures, economic activities, particularly the uncontrolled development of shrimp farming, hence in the period 1986-2003 this region lost hundreds of hectares of forests by converting into shrimp ponds that cause major impact on coastal ecosystems

CHAPTER II: MATERIALS AND METHODS

2.1 Materials

Materials used in the research are cameras, books,…

2.2 Methods

2.2.1 Field trip investigation

Charts sorting survey objects on the fieldtrip are examined according to the survey pointed that available online in 2013 The positioning points on the map are calibrated via GPS The thematic units of the thematic map in GIS are categorized and analysed along with images and fieldtrip testing in 2013 to establish the key analysis for the different thematic topics

2.2.2 Scientific name definition and name edition method

This is considered as the most important method in this research and was conducted based on the particular documents such as:

 Cây cỏ Việt Nam (Phạm Hoàng Hộ, 1991 - 1993, 1999 - 2000) [35]

 Cây gỗ rừng Việt Nam (YA, 1971 - 1988)

 Thực vật chí Đông Dương, (1907 - 1952)

 Tài nguyên cây gỗ Việt Nam (Trần Hợp, 2002)

 Danh lục các loài thực vật Việt Nam [10]

2.2.3 Method of assessing the flora biodiversity

2.2.3.1 Species composition diversity

Specialized documents about Con Vanh mangrove flora research were used in order to establish the table as below:

Table 3: List of mangrove plants in Con Vanh area

No Scientific

name

Vietnamese name Life form

Geographical features

Values of use

The list should express the necessary information for the research purposes Thus, the species were arranged by their families and families were arranged by their phylums In each group, all names were arranged based on the order of alphabet

 Proportion of phylums in flora system

 Proportion of dicotyledonous versus monocotyledonous

 Proportion of ten most species richness in flora system

2.2.3.2 Life forms

Life form according to Raunkiaer‟s system (1934) is influenced by the place of the plant's growth-point (bud) during seasons with adverse conditions (cold seasons and dry seasons) The life forms are closely related to the climate and they are different among regions in the world Raunkiaer life forms were applied to category the plants of Con Vanh area

2.2.3.3 Geographical elements spectrum

According to Póc Tamás and the article “Some basic characteristics of Vietnam flora”, distribution region of species were defined in table in Appendix

2.2.3.4 Values of plant resource

The criteria to assess the value of using plant resources are set based on the following articles: Danh lục các loài thực vật Việt Nam, Cây cỏ có ích ở Việt Nam,

Cây cỏViệt Nam, Cây gỗ rừng Việt Nam, Những cây thuốc và vị thuốcViệt Nam, Từ điển cây thuốcViệt Nam, 1900 cây có ích, etc

2.2 4.Remote sensing data and GIS application

All 16 images LANDSAT from 2003 to 2013 were used to analysis and interpretation based on the documents and materials inherited the fieldtrip in 2013

Figure 3 :Ảnh vệ tinh Landsat 5 ngày 14-01-2003 Figure 4 :Ảnh vệ tinh Landsat 8 ngày 22-09-2013

SPOT 5 images are considered the last series data analyzed by high resolution In the analysis, database structure that we used is GIS MapInfo version 12.0 to analyze, overlay information layers as well as format layers of information linking to other professional software such as ArcGIS This is the rule in using compatible software application in order to build a database and analyze aggregate data by combining the principles of geographical space Compiling data in MapInfo 12.0 software, then completing data and linking them with the ArcGIS software Information about environment and biodiversity in the ecosystem is expressed as a thematic map that is

an essential tool for the management system The map can be regarded as a means of communication between researchers, leaders and those who do the planning

The method chosen to build a GIS database is direct connection between graphic information with plenty of information in the database This method is often used to

hold catching quick information on each region to create favorable conditions for both managers and users

Figure 5: Map of substrate geograghy in mudlat Tienhai district, ThaiBinh province,

Vietnam

Topographic data model is compiled based on:

- Topographic maps for the substrate layer for thematic environmental resources purpose

- Documentation of technical regulations of digitized maps at 1: 10000

Data sources include topographic map scale of 1: 10.000 was established by means of digital imaging technology in 2009 at the Institute of Geodesy and Cartography, Nationalcoordination VN 2000, projection zone 30, longtitide TW 105000 ' with the format “ * DGN ” divided into seven files including: the mathematics, aquatic systems, terrain, traffic, residential, and vegetation boundaries The data layer has been updated to add some information from the map scale of 1: 15000 by the Institute

of Geodesy and Cartography established in 2004

GIS data base was built with 4 standards: a standard reference system, data standards organizations (geodatabase), the standard topology and attribute data standards

Selected software used to create the layers of information, format and manage exploitation in MapInfo GIS is 12.0 version The main contents of the process are: + Organize information in the file, analyze and import data from satellite images

+ Create thematic information layers of vegetation under the appropriate classification + Analysis of the properties in the legend

+ Vegetation information layer is the main information of map 7 units of vegetation are expressed as a region and colored and used number to distinguish with eachother When digitalize information of vegetation layer, distribution of plant communities resulted from digitalizing sensing image interpretation Each plant communities are represented by a color according to the color scheme of the UNESCO guidelines (1973) Color is poured automaticall following codes in the process of digitizing In GIS, information layers are arranged under all the information vectors, and the information on the original data layer (image) which allows to display all expected information layers wants and do not let raster information cover

CHAPTER III: RESULTS AND DISCUSSION

Magnoliopsida and 35 species of Liliopsida

Table 4:Diversity of plant groups in the mangrove ecosystem of Con Vanh area

Table 5: Species composition of mangrove plants in Con Vanh area

Scientific Name Vietnamese

Name

Life form Use value

Conservation value (IUCN 2014)

DƯƠNG XỈ

Scientific Name Vietnamese

Name

Life form Use value

Conservation value (IUCN 2014)

Acrostichum aureum L Ráng biển Cr

Pteris ensiformis Burm f Ráng chân xỉ

Hygrophila erecta Hochr Đình lịch đứng Na