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 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 16th 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.

1


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].
2


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 thƣờng 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 Phƣơng”, “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), Cyperaceae of Nguyễn Khắc Khôi (2002), Lamiaceae of Vũ Xuân Phƣơng
3

(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 Dƣơng” (1926) and “Giới thiệu về hệ
thực vật Đông Dƣơng” (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.
No.

Elements

1

North Vietnam

2

Middle of Vietnam

3

South Vietnam

Taxon distribution
In the administrative boundary of North
Vietnam
In the administrative boundary of Middle
Vietnam
In the administrative boundary of South
Vietnam

4


4

Vietnam

5

Indochina

6

South China

7

Hainan,

In the administrative boundary of Socialist
Republic of Vietnam
In Vietnam, Laos, Cambodia and tropical
regions of Myanmar, Thailand
In Vietnam, the tropical regions of Southwest
and South of China
Taiwan

Philippines

8

Himalaya

9

Indian

10

Malaysia

11

Malaysia – Indonesia

12

and

Malaysia – Indonesia and
Australia

13

Tropical Asia

14

Paleo-tropic

15

Neo-tropical and Pantropic

16

East Asia

17

Asia

18

Northern temperate

In Vietnam, Hainan, Taiwan and Philippines
In the tropical area of Himalaya; or even in
Laos, Cambodia, Thailand and Myanmar
In Indochina and India
In Vietnam, Malaysian peninsula and islands of
Malaysia
In Vietnam, Malaysian and Indonesia
In Vietnam, Malaysian, Indonesia and Australia
In India, Indochina, Malaysia, Indonesia,
Philippines and islands on Pacific
In the tropical regions of Asia, Africa and
Australia
In the tropical regions of America, Asia, Africa
In North Korea, Japan, South of China, Taiwan
and North of Vietnam
In territory of Asia
In temperate regions of Asia, Europe and
Vietnam

5


19
20

Widely distributed
Exotic

and

On over the world
introduced Originating from migration and introducing to

elements

Vietnam by many

This geographic factor spectrum was applied in order to study about life-form
spectrum of Con Vanh mangrove.
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.

1

Terms
1
Phanerophytes

Raunkiaer life-form definitions

Sign

Projecting into the air on stems – normally
woody perennials - with resting buds more Ph
than 25 cm above soil level,
Buds on persistent shoots near the ground –

2

2
Chamaephytes

woody plants with perennating buds borne
close to the ground,no more than 25 cm

Ch

above the soil surface

3

4

3
Hemicryptophytes

Buds at or near the soil surface, e.g. daisy,

4
Cryptophytes

Below ground - with resting buds lying

Therophytes
5

Annual

dandelion

either beneath the surface of the ground
plants
6

which

survive

He

Cr

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):
SB = 46Ph + 9 Che + 26 He + 6 Cry + 13 Th
Some studies about flora in different region of Vietnam are published. “Góp
phần nghiên cứu một số đặc điểm cơ bản của hệ thực vật Lâm Sơn (tỉnh Hòa Bình)”
(1987 – 1990) of Lê Trần Chấn et. al. is a prominent example:
SB = 51,3Ph + 13.7 Ch + 17.9 Hm + 7.2 Cry + 9.9 Th
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”:

7


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.

8


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.

9


Số loài TVNM Chính thức

60
50
40
30
20
10

PN
G
M
al
ay
sia
In
do
ne
sia

Th
ai
la

Si
n
ng
ap
or
Ca
e
m
bo
di
a
M
ya
n
Ph mar
ilip
pi
ne
s

Ti

m

or
-L
es
te
Br
un

ei
Vi
et
na
m

0

Quốc gia

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
10

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).

11


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 37 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.

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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 Dƣơng, (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:

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Table 3: List of mangrove plants in Con Vanh area

No.

Scientific

Vietnamese

name

name

Life form

Geographical

Values of

features

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,

14


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

15


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.

16


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.

17


CHAPTER III: RESULTS AND DISCUSSION

3.1 . Floral Biodiversity

3.1.1. Species composition
Base on scientific documents and investigation, the flora in Con Vanh area
consists of 93 mangrove species in total 33 families, that belongs to 2
phylums. Polypodiophyta has only 5 species in 2 families (5.4% total
species). Magnoliophyta accounting for 94.6%, is dominant with 53 species of
Magnoliopsida and 35 species of Liliopsida.
Table 4:Diversity of plant groups in the mangrove ecosystem of Con Vanh area
Phylum

Class

Family
Number

%

Number

%

2

6.1

5

5.4

Magnoliopsida

26

78.8

53

57.0

Liliopsida

5

15.1

35

37.6

33

100

93

100

Polypodiophyta
Magnoliophyta

Species

Total

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

Scientific Name

POLYPODIOPHYTA

Vietnamese

Life

Name

form

Ngành
DƢƠNG XỈ
18

Conservation
Use value

value (IUCN
2014)


Scientific Name

Dennstaedtiaceae
Pteridium aquilinum (L.)
Kuhn

Vietnamese

Life

Name

form

Ráng cánh to

Acrostichum aureum L.

Ráng biển

Pteris vittata L.
MAGNOLIOPHYTA

MAGNOLIOPSIDA
Acanthaceae
Acanthus ebracteatus

value (IUCN
2014)

tiết

Họ Chân xỉ

Pteris semipinnata L.

Use value

Họ Ráng đăng

Pteridaceae

Pteris ensiformis Burm .f.

Conservation

Cr

Ta

Cr

Ráng chân xỉ
hình gƣơm
Ráng chân xỉ
lƣợc
Chân xỉ có xọc

Cr

Cr

Cr

Ngành NGỌC
LAN
Lớp HAI LÁ
MẦM
Họ Ô rô
Ô rô

Na

LC

Acanthus ilicifolius L.

Ô rô nƣớc

Na

LC

Hygrophila erecta Hochr.

Đình lịch đứng

Na

Đình lịch

Na

T

Thuốc trặc

Na

T

Quả nổ

Na

T

Vahl

Hygrophila salicifolia
(Vahl.)
Justicia gendarussa
Burm.f.
Ruellia tuberosa L.
Aizoaceae

Họ Rau đắng
đất

19

Scientific Name

Sersuvium portulacastrum
L.

Vietnamese

Life

Name

form

Sam biển

Conservation
Use value

2014)

Hm

Annonaceae

Họ Na

Annona glabra L.

Na biển

Asteraceae

Họ Cúc

Ageratum conyzoides L.

Cứt lợn

Na

T

Bidens pilosa L.

Đơn buốt

Th

T

Wedelia biflora (L.) DC.

Cúc hai hoa

Li

T

Ké đầu ngựa

Th

T

Xanthium inaequilaterum
DC.
Avicenniaceae
Avicennia marina (Forsk)
Veirh

Mi

Họ Mắm
Mắm biển

Me

Boraginaceae

Họ Vòi voi

Heliotropium indicum L.

Vòi voi

Caesalpiniaceae

Họ Vang

LC

Th

T

Mi

Ca,T

Me

G,Tn,T

Dầu giun

Th

D,T

Rau muối

Th

Ta,T

Senna sulphurea
(Colladon) Irwin &

Muồng biển

Barneby
Casuarinaceae
Casuarina equisetifolia J.
R. et J.G.
Chenopodiaceae
Chenopodium
ambrosioides L.
Chenopodium ficifolium
Smith.

value (IUCN

Họ Phi lao
Phi lao
Họ Rau muối

20