INTRODUCTION
Introduction
Vietnam is highly vulnerable to climate change, ranking 6th on the Global Climate Risk Index 2020 by Germanwatch, which highlights a significant increase in vulnerability from previous years The country's weather patterns have become increasingly erratic, leading to severe phenomena such as droughts, floods, landslides, storms, and rising sea levels, further complicating the impacts of climate change.
Vietnam has 28 coastal provinces with a total length coastline of 3260 km (MOFA,
Vietnam boasts over 200,000 hectares of mangrove forests, making it one of the countries with the largest mangrove areas globally Notable mangrove regions include the Can Gio mangroves, the mangroves in Tam Giang lagoon, and the Ca Mau mangroves.
Quang Ninh, located in northern Vietnam, is home to significant mangrove forests, particularly in the Dong Rui and Hai Lang communes of Tien Yen district These mangroves showcase the unique characteristics of northern Vietnam's coastal ecosystems, featuring a diverse array of tree species and aquatic life Importantly, these mangrove forests offer essential ecosystem services that help society adapt to climate change.
Extreme weather events and natural disasters are increasingly difficult to predict, highlighting the vital role of mangroves in our ecosystem These forests are crucial for maintaining biodiversity and supporting the food web, while also mitigating the impacts of climate change on communities and contributing to economic development Notably, mangroves serve as one of the largest carbon sinks globally, effectively reducing carbon dioxide levels, a primary driver of global warming The mangrove forests in Dong Rui and Hai Lang communes of Tien Yen district exemplify a sensitive and biologically diverse ecosystem that underscores the importance of preserving these vital habitats.
2 accounts for a large proportion of the natural area of the two communes Therefore, the socio-economic activities of the two communes are strongly related to mangroves
Currently, mangrove forests in these two communes are under significant threat due to various challenges in their exploitation, use, and management Economic and social development activities, coupled with population growth, are exerting pressure on these vital ecosystems Additionally, the degradation of natural resources and environmental pollution from over-exploitation pose increasing risks to the mangroves in the region.
The rising effects of climate change on coastal regions highlight the critical need to evaluate the role of mangroves in climate change adaptation The mangrove forests in Dong Rui and Hai Lang represent a unique ecosystem characteristic of Vietnam's northern area Additionally, Quang Ninh Province is in the process of establishing the Dong Rui Wetland Reserve in Tien Yen District, underscoring the vital importance of conserving mangroves in Dong Rui.
The significant effects of climate change (CC) and the crucial function of mangroves in Hai Lang and Dong Rui Communes prompted me to explore the topic: "The Role of Mangroves in Addressing Climate Change in Dong Rui and Hai Lang Communes, Tien Yen District, Quang Ninh Province."
This study evaluates the significance of mangrove forests in delivering essential ecosystem services that aid human society in addressing climate change (CC) Additionally, it offers recommendations to enhance the resilience of mangroves in combating CC The research was conducted in two areas with comparable natural and social conditions to facilitate effective comparison and analysis.
Study area
This study was carried out in the Dong Rui and Hai Lang communes of Tien Yen district, Quang Ninh province, situated in northeastern Vietnam Dong Rui commune spans a total area of 5,045.08 hectares and is located 18 kilometers southwest of the district center Characterized by its coastal plains, Dong Rui offers a favorable environment for concentrated farming, aquaculture, population growth, and mangrove planting.
In recent years, the commune has constructed a robust system of dykes to mitigate the impact of natural disasters, complemented by surrounding mangroves and aquaculture areas A concrete road connects Ba Che bridge to National Highway 18A, serving as the primary route for goods exchange with neighboring districts.
Hai Lang is a coastal commune in Tien Yen district, featuring a unique mountainous coastal terrain and covering a total land area of 8,183 hectares The geography of Hai Lang is diverse, encompassing mountains, hills, midland plains, aquaculture zones within dikes, and intertidal regions with rivers and canals outside the dikes.
Figure 0-1: Administrative map of Dong Rui and Hai Lang communes
Dong Rui and Hai Lang, situated in the eastern Quang Ninh province, experience a humid tropical climate characterized by an annual average temperature of 22.4°C Winters in this region can be cold and dry, often featuring prolonged periods of frost and temperatures occasionally dropping below 4°C.
Rain usually focuses from June to September with thunderstorms Drizzly rain occurs from December to April, focusing on February Summer often has thunderstorms,
4 storms, and cyclones with a frequency of about 3-4 storms per year The annual rainfall average is 2427 mm, drizzly and often foggy in winter (Nga, 2011)
1.2.3 Social - Economic Status of Hai Lang and Dong Rui communes
Dong Rui commune is characterized by a diverse population, primarily consisting of various ethnic groups such as the Kinh, Tay, San Chi, San Diu, and Dao, with the Kinh making up 84% of the population (Thuyết minh bản đồ hiện trạng sử dụng đất năm 2019 xã Đồng Rui, 2019) In contrast, Hai Lang commune has a significant representation of ethnic minorities, comprising 68% of its population This commune includes 13 villages, three of which—Doi Che, Khe Ho, and Thanh Hai—are entirely inhabited by ethnic minorities Hai Lang is home to 1,510 households, totaling approximately 6,100 residents (Điều kiện tự nhiên xã Hải Lạng, 2019).
Dong Rui is a mountainous coastal commune characterized by complex topography, where residents face significant challenges and low incomes The local economy primarily revolves around agriculture, livestock farming, afforestation, and both near-shore and offshore fishing and aquaculture In recent years, Dong Rui has made concerted efforts to enhance living conditions and promote economic development through various initiatives led by the commune Party committee These initiatives focus on advancing agriculture, forestry, fisheries, and commercial services, while also fostering diverse trades and socio-cultural growth, alongside strengthening national defense and security.
Hai Lang commune, a coastal area, is well-suited for the growth of agriculture, forestry, and fishery The agricultural sector is steadily improving, while cultural and social initiatives are advancing positively A dedicated and well-trained team of local leaders is actively contributing to the development of a new rural landscape, fostering vibrant cultural movements in the community.
1.2.4 Some manifestations of CC in Dong Rui and Hai Lang communes
The weather station in Tien Yen town is essential for measuring and transmitting hydro-meteorological data This facility plays a crucial role in monitoring weather conditions in the Tien Yen district, ensuring accurate and timely information is available for effective decision-making.
The analysis of weather changes from 1990 to 2020 in the study area focuses on data from the Tien Yen weather station, located approximately 24.9 km from Dong Rui commune and 14.3 km from Hai Lang commune.
Figure 1.2 below shows the highest, lowest, and average temperature of the Tien Yen weather station during the period 1990-2020:
Figure 0-2: The lowest, highest, and average temperatures of Tien Yen weather station in the period 1990-2020 (Unit: o C)
Source: Tien Yen Weather station (Tien Yen Weather station, 2020)
Figure 1.2 highlights a significant temperature variation, with a difference of 30-33 °C between the highest and lowest temperatures During December and January, the lowest temperatures range from 3-7 °C, while from May to August, the highest temperatures reach between 35-37 °C.
Followed by figure 1.3 showing the temperature difference compared to the period 1990-2020 average:
Figure 0-3: Temperature anomaly (average, max, and min) in Tien Yen weather station in period 1990-2020 (Unit: o C)
Source: Tien Yen Weather station (Tien Yen Weather station, 2020)
Figure 1.3 illustrates the continuous changes in temperature anomalies (average, maximum, and minimum) over the years Notably, both the highest and average temperatures show a rising trend, while the lowest temperatures gradually decline This results in an increase in both extreme heat and extreme cold occurrences Despite the decrease in minimum temperatures, the more significant rise in maximum temperatures leads to an overall increase in the annual average temperature for the region over time.
In 2011, Northern Vietnam experienced a significant drop in temperatures compared to the previous year, primarily due to the La Niña phenomenon This climatic event led to a notably colder winter, resulting in multiple cold spells across the region.
The temperature trends in two communes mirror those observed throughout Vietnam and the Northern region, showing a notable increase in temperatures, particularly in recent decades Most areas experience rising temperature extremes, although some southern weather stations report a decrease in extreme heat This shift contributes to more frequent droughts during the dry season While the number of extremely cold days is declining, unusual cold spells have been noted (Tran et al., 2016).
Figure 1.4 shows total rainfall and most significant precipitation statistic in the period 1990-2020 in Tien Yen in the below:
Figure 0-4: The highest precipitation and average precipitation of Tien Yen weather station in the period 1990-2020 (Unit: mm)
Source: Tien Yen Weather station (Tien Yen Weather station, 2020)
Over the years, total and maximum rainfall have shown a continuous decline, particularly during the rainy season from June to September, when heavy rains typically occur This decrease in overall rainfall is likely to contribute to increased water scarcity in affected regions.
Day max Total Linear (Day max) Linear (Total)
Number of rainy days Linear (Number of rainy days)
Figure 0-5: Total precipitation day of Tien Yen weather station in period 1990-
Source: Tien Yen Weather station (Tien Yen Weather station, 2020)
Figure 1.5 indicates a slight increase in the number of rainy days, while Figure 1.6 shows a decrease in total annual rainfall This shift suggests that precipitation is becoming more evenly distributed throughout the year, which may help mitigate the risks of inundation and flooding in the region.
Figure 0-6: Precipitation anomaly (max and average) in period 1995-2019 (Unit: mm)
Source: Tien Yen Weather station (Tien Yen Weather station, 2020)
Literature Review
1.3.1 The concept of mangrove ecosystem
Mangrove forests thrive in tropical and subtropical regions, extending into temperate areas but are limited by freezing temperatures (Hogarth, 2015) These unique trees flourish in low-oxygen soils where slow-moving waters facilitate sediment accumulation Characterized by specialized root systems, particularly breathing roots, mangroves adapt to tidal flooding conditions (NOAA, 2021) The term 'mangrove' encompasses both the plant communities and their habitat, contributing to a distinct ecosystem known as the "mangrove ecosystem," which includes various animals and organisms (Clough, 2013).
1.3.2 Impact of CC on mangrove
Recent research highlights the significant effects of climate change on mangrove ecosystems, as well as the vital role these forests play in both adaptation and mitigation efforts Understanding these dynamics is essential for stakeholders to effectively plan for the conservation and sustainable development of mangroves moving forward.
The study "Impact of Expected Climate Change on Mangroves" by Colin Field identifies key factors influencing mangrove distribution and development, with sea level rise being the most significant, though its effects vary by region Rising air temperatures are expected to have minimal impact on mangroves, but they may lead to a shift in their range towards the North and South The influence of atmospheric CO2 on mangroves remains uncertain, while climate change poses increased risks of saline intrusion, coastal erosion, flooding, and storm surges (Field, 1995).
A study by Eric L Gilman and colleagues highlights the significant threats posed by climate change (CC) to mangrove ecosystems, with sea level rise identified as the most critical risk Mangroves in the Pacific Islands face a high likelihood of decline due to these environmental changes To mitigate the effects of climate change on mangroves, it is essential to implement strategic planning measures, including coastal planning, managing activities that influence long-term sediment elevation in mangrove basins, and restoring degraded mangrove areas (Gilman et al., 2008).
1.3.3 The role of the mangrove ecosystem in response to CC
Mangrove forests are unique coastal ecosystems that play a crucial role in providing essential ecosystem services to help human societies adapt to climate change Numerous studies worldwide have explored the significant contributions of mangrove forests to environmental health and resilience.
In the "Mangrove Manual Secondary Vietnamese," authors Daniel G Spelchan and Isabelle A Nicoll outline six essential roles of mangrove forests: they provide livelihoods for local communities, offer protection against natural disasters, and play a crucial role in reducing erosion while safeguarding soil integrity.
(4) Reduce pollutant; (5) Minimize the impact of CC, and (6) Provide food and habitat for many animals (Mangrove Manual Secondary Vietnamese, n.d.)
Mangrove forests play a crucial role in both natural and social systems Their extensive trunks, branches, and roots protect shorelines from erosion and wave impacts while aiding in land expansion through encroachment Additionally, mangroves filter out pollutants, sediment, and nutrients, contributing to the health of oceans and rivers They are vital in carbon storage, helping combat climate change Furthermore, mangroves provide essential habitats and food sources for diverse wildlife, including fish, shellfish, birds, and mammals, supporting a rich ecosystem.
Mangroves play a crucial role in supporting the livelihoods of local communities by providing resources such as fish, firewood, and materials for tourism They also offer essential ecosystem services, including coastal protection against natural disasters and extreme weather events like typhoons and floods The structure of mangrove trees, with their trunks, branches, and roots, serves as a natural barrier that mitigates the impact of rising tides, flooding, and strong winds, safeguarding homes and agricultural fields from potential damage.
1.3.3.1 The role in the natural system
Maintaining biodiversity and food web
The study "The habitat function of mangroves for terrestrial and marine fauna: A review" by I Nagelkerken et al highlights the critical role of mangroves in supporting biodiversity and food webs These ecosystems provide diverse habitats, with insects, reptiles, birds, and mammals residing above water, while bivalves, sponges, tunicates, and algae thrive underwater Additionally, the soft substratum in mangroves supports various infaunal and epifaunal species, while the spaces between tree roots serve as habitats for shrimp, fish, and crabs Fallen leaves and organic waste are vital components of the mangrove food web, alongside plankton, epiphytes, and microorganisms, which form an essential foundation for the ecosystem (Nagelkerken et al., 2008).
The study "Managing mangroves with benthic biodiversity in mind: Moving beyond roving banditry" highlights the significance of mangrove benthic fauna, which can influence tree formation and growth Despite their importance, mangrove management frequently overlooks these species (Ellison, 2008) Peter J Hogarth's book "The Biology of Mangroves and Seagrasses" emphasizes the rich biodiversity found in mangroves, serving as habitats for various organisms, including aquatic and terrestrial insects, fish, reptiles, and mammals Additionally, Hogarth examines the effects of climate change and human activities on the biodiversity of mangroves and seagrasses (Hogarth, 2015).
Mangrove forests are among the largest carbon sinks globally, with each hectare in the Indo-Pacific region storing an average of 1.023 Mg of carbon However, mangrove deforestation contributes significantly to carbon emissions, generating between 0.02 to 0.12 Pg of emissions annually, which accounts for approximately 10% of global deforestation emissions, despite these forests covering only 0.7% of the rainforest area (Donato et al., 2011).
A study conducted in China revealed that mangroves store approximately 6.91 ± 0.57 Tg C, with 81.74% of this carbon located in the top 1-meter soil layer, 18.12% in mangrove biomass, and a mere 0.08% at ground level, including mangrove mats and seedlings The average carbon density of mangroves in China is 355.25 ± 82.19 Mg C ha −1, aligning with the global average carbon densities found in mangrove ecosystems.
16 at similar latitudes but higher than C densities average in terrestrial forests China Thus, it is possible to increase C storage in mangroves by selecting species with high
C densities for afforestation and reforestation, and even more by increasing mangrove area (Liu et al., 2014)
Mangroves play a vital role in conservation and restoration efforts while significantly reducing greenhouse gas emissions Despite covering just 0.5% of the world's coastal areas, they are capable of storing 10-11% of carbon in sediments and exporting an equal percentage of terrestrial particulate carbon to the ocean Notably, mangroves possess a carbon storage capacity comparable to that of tropical humid evergreen forests and coral reefs.
The expansion of mangroves into salt marshes significantly enhances the carbon storage capacity of wetlands, potentially doubling it due to higher biomass levels Furthermore, mangrove forest coverage has risen to 69%, leading to an increase in wetland carbon storage within wildlife refuges at a remarkable rate of 2.7 MgC ha -1 yr -1, which more than doubles the natural carbon sequestration rates of coastal wetlands (Doughty et al., 2016).
Can Gio Mangrove Forest Park is the largest restored mangrove forest in Vietnam's Mekong Delta A study conducted there assessed various factors such as tree biomass, roots, woody debris, organic sediment carbon, and overall depth to evaluate the forest's carbon storage capacity The findings revealed that the average aboveground carbon storage was 102 ± 24.7 MgC ha−1 for the fringe forest, 298.1 ± 14.1 MgC ha−1 for the transitional forest, and 243.6 ± 40.4 MgC ha−1 for the inland forest These results indicate that the high carbon stocks both above and below ground contribute significantly to the ecosystem's overall carbon storage (Dung et al., 2016).
Objectives of the research
The study hypothesizes that mangrove forests are crucial for delivering ecosystem services that support human communities in adapting to climate change in the Dong Rui and Hai Lang communes.
To analyze the role of mangrove forest, the study has two research questions include:
(1) What do mangrove forests play essential roles in protecting and preserving coastal resources and coastal communities in the context of CC?
(2) How to increase the CC responding capacity of mangrove forests?
From research questions, the specific objectives of the study are:
(1) Analyze the role of mangrove forests in maintaining the coastal resource
(2) Analyze the role of mangrove forests in supporting coastal communities under
(3) Propose solutions for suitable use of mangrove forests for CC response
DATA COLLECTION AND METHODOLOGIES
Logical framework
This article presents a framework for analyzing the multifaceted roles of mangroves in responding to climate change (CC), categorized into natural and social functions The natural roles encompass three key aspects: maintaining biodiversity and food webs, providing coastal protection, and facilitating carbon storage Conversely, the social roles are divided into two areas: supporting livelihoods and mitigating the impacts of climate change A variety of research methods were employed to effectively study these diverse roles of mangroves, ensuring a comprehensive understanding of their significance.
Figure 0-1: Logical framework of the research
Mangroves play interconnected roles, offering essential ecosystem functions and services that benefit local communities However, human activities significantly affect the biodiversity within these vital ecosystems The rich biodiversity of mangroves is crucial for sustaining their health and the services they provide.
22 and improving people's livelihoods On the other hand, the exploitation of the people also affects the number of species in the mangrove forest
Mangroves play a crucial role in carbon storage, which helps mitigate climate change by reducing weather variability and the frequency of extreme weather events This natural protection not only alleviates pressure on coastal areas but also safeguards communities living nearby from adverse environmental impacts.
Data collection
This research will use two data sources: Secondary data and Primary data
The article outlines the collection of secondary data essential for understanding the environmental and socio-economic landscape of Tien Yen district, Quang Ninh province This includes weather data from the Tien Yen weather station, land use maps from 2019, reports on the natural conditions and development potential for salt and brackish aquaculture, and insights into natural disaster prevention efforts during the 2020 rainy season Additionally, it references recent studies conducted in Dong Rui and Hai Lang communes, as well as the biodiversity of mangrove species in the region, highlighting the carbon accumulation capacity of mangrove forests based on previous research.
(7) Types of forest function in Dong Rui and Hai Lang communes from Forestry Data Sharing System
Primary data was collected through observation, household surveys, and in-depth interviews Observations involved photographing the mangrove ecosystem, biodiversity, and local livelihoods The household survey included responses from 113 households, representing the study site's population Additionally, four local leaders and staff were interviewed to gain deeper insights.
Respondents have different questionnaires to collect relevant information for analysis
(1) For Household survey: The interview area was divided into two communes: Dong
Phase 1: Interviewed 19 families in Hai Lang and 34 families in Dong Rui at the end of July 2020 (2 villages: Doi May and Ha Thu)
Phase 2: Interviewed 60 families in Dong Rui from 20-25 January, 2021 (4 villages: Thuong, Ha, Trung and Bon)
The natural forest area in Hai Lang has significantly diminished due to the expansion of aquaculture, resulting in a limited number of people relying on mangroves However, mangroves are crucial for the residents of Dong Rui commune, prompting a survey to investigate their importance, particularly in relation to climate change adaptation.
During the interview, I categorized the villages based on their diverse livelihoods and collected six key pieces of information: (I) General details about households, including family members, occupations, and income; (II) Climate change (CC) data, focusing on disaster types and pre-disaster warnings; (III) Insights on mangroves and their CC impacts, detailing the types present and their conditions over time; (IV) The benefits of mangroves, such as supporting livelihoods, mitigating typhoon effects, and protecting coastal areas; (V) The costs associated with mangrove conservation, including its impacts on local communities and livelihoods; and (VI) Perspectives on the significance of mangrove conservation for socio-economic development and climate change mitigation (Refer to the detailed questionnaire in the appendix.)
An in-depth interview with four local leaders and staff reveals critical insights into the socio-economic conditions of the area, the effects of natural disasters and climate change on local livelihoods, and the current state of mangrove forests The findings highlight the significant role mangrove ecosystems play in supporting the community's resilience against environmental challenges.
CC response and developing livelihood
Table 0.1: Datatypes use in research
Mangroves area; aquatic species and mangrove species
(habitat, chain food, etc.), characteristics of mangroves
(height, density, age), the role of mangroves for the
Interview Hai Lang and Dong Rui Government; and others research
Data types Data sources coastal area (forest function)
CC/natural disaster/extreme weather event in Dong Rui and Hai Lang Communes (Precipitation, temperature, sea-level rise)
A recent survey conducted through interviews with local government officials, weather stations, and other research entities highlights the significant impact of climate change and extreme weather events on mangroves and surrounding ecosystems These changes have led to increased erosion, a decline in aquatic animal populations, and a reduction in the overall area of mangrove forests.
Survey local people; interview government and internet
Carbon storage (carbon accumulates at forest trees and in the soil)
Impact of CC/natural disaster/extreme weather event on coastal communities (typhoon, saline intrusion, etc.) and the role of mangrove forests in reducing the impact of CC
(waves, saline intrusion, wind, etc)
Survey local people; interview government and Statistical yearbook
Type of livelihoods related to mangroves and natural resources exploit (fishing, aquaculture, etc.) to increase income
Survey local people; interview government and Statistical yearbook
The benefit of mangroves with local people (increase air quality, protect biodiversity, etc)
Survey local people; interview government
Methodologies
This research employs various methods tailored to each phase and objective, ensuring accurate problem analysis that aligns with real-world conditions A detailed overview of the research methods utilized in this study is presented in Table 2.2.
Table 0.2: Methods used in the research
Synthesis method Collect secondary data and information M1
Observation Collect primary data and information about mangrove forests
Field Survey Collect primary data and information about mangrove forests
Summarize the data and find trends (climate data, the impact of CC, etc.)
Analyze the data from responses to survey
Analyze the data, information, and sharing from observation and survey
For collecting secondary data, I used the synthesis method
Secondary data from Dong Rui and Hai Lang Commune People's Committees, along with information from the weather forecast station, is utilized to assess the socio-economic and natural development status of both regions.
I synthesized other CC and natural disaster data from the results of some existing researches
This study analyzes the vital role of mangroves in maintaining biodiversity and food webs, drawing on data from previous research on the flora and fauna inhabiting these ecosystems Additionally, it examines the carbon storage capacity of mangroves in Dong Rui and Hai Lang, utilizing existing data for comparison Furthermore, information regarding the coastal protection functions of mangroves was sourced from the Forestry Data Sharing System, highlighting their significance in safeguarding coastal environments.
This study used the qualitative method to collect primary data through in-depth interviews, observation, and quantitative methods
This study utilized in-depth interviews with local leaders from Dong Rui and Hai Lang communes to gather insights on the impacts of climate change disasters and the role of mangrove forests in their communities By employing open-ended questions, the interviews facilitated a deeper exploration of the respondents' knowledge and perspectives The qualitative approach proved vital for collecting valuable data from specialists in the field, enabling a comprehensive understanding of the subject matter.
During my recent trip to the mangrove forest, I explored the area by boat and later rode a motorbike along the dyke to assess the condition of the mangroves This hands-on observation proved invaluable for gathering reliable data The results of my findings were documented through photos and videos, showcasing the current state of the mangrove ecosystem.
While traveling on the boat, I observed mangroves species and animals in the mangrove forest I also observed local people exploit resources in the mangroves
Figure 0-2: Observation in the boat
I embarked on a boat trip along the Ba Che River, exploring remote mangrove areas that exhibit minimal human impact The mangroves in this region are well-preserved and thriving However, environmental pollution remains a significant concern, with various forms of plastic waste, including bottles and bags, washing ashore.
Figure 0-3: Observation of mangrove forest
The research aimed to explore the role of mangrove forests in delivering essential ecosystem services to support human society in addressing climate change To achieve this, a household survey was developed, consisting of a structured questionnaire featuring close-ended questions, following the identification of the research objectives.
The interviews were conducted primarily with local residents of Dong Rui and Hai Lang communes, ensuring a diverse range of perspectives by including participants of varying ages, genders, livelihoods, and living areas.
The sample size for the study was established with time constraints in mind, aiming for approximately 100 households and ultimately surveying 113 families During the interviews, the questions and scale were clearly explained to the respondents, facilitating their understanding and engagement with the topic.
Data processing was conducted using Microsoft Excel 2010, where primary data was summarized and synthesized into an Excel sheet, serving as the foundation for generating figures Additionally, QGIS was utilized to create an administrative map of the Dong Rui and Hai Lang communes.
In details, the data results were processed as follows:
Manifestations of CC in Dong Rui and Hai Lang communes: secondary data were collected and analyzed through descriptive analysis methods to show the main signs of
CC and natural disasters (such as temperature, precipitation, flood, drought, salinity intrusion, inundation, etc.) in the study area
Structure and characteristics of mangroves: secondary data were collected to describe the characteristics of species, distribution, the height of the tree species in the mangrove forest
Maintaining biodiversity and food webs of mangroves: The data used for analysis is secondary data Descriptive analysis methods are used to describe and analyze the relationships of mangrove species
The study utilized secondary data collected and analyzed through descriptive methods to assess carbon storage capacity in mangroves, focusing on both mangrove trees and soil The findings were compared across two distinct study areas to evaluate their carbon storage potential.
Coast protection efforts involve the collection and analysis of secondary data through descriptive methods to highlight the functions of protection forests, particularly in shielding against tides Additionally, primary data gathered from surveys assess local awareness regarding the vital role of mangroves in coastal protection, utilizing content analysis techniques.
A survey was conducted to evaluate the effects of climate change (CC) on local communities, utilizing primary data to assess its impact on residents' lives The findings also highlight strategies for mitigating the effects of CC and natural disasters, emphasizing the importance of community resilience in adapting to these challenges.
The narrative analysis method was employed to examine survey and in-depth interview data, focusing on various aspects of people's livelihoods, including occupations, resources extracted from mangroves, and fishing methods utilized within the forest.
RESULTS AND DISCUSSION
Structure and characteristics of mangroves in Dong Rui and Hai Lang communes
Mangroves are found along the coastline of Tien Yen Bay and its surrounding islands, with Dong Rui and Hai Lang communes exhibiting similar mangrove species However, Dong Rui boasts a larger mangrove area compared to Hai Lang In addition to mangrove planting, the hilly and mountainous terrain of Hai Lang commune supports the cultivation of other industrial crops, particularly acacia.
Figure 0-1: Geo-vegetation map of wetland area in Dong Rui, Tien Yen
Source: Project to establish Dong Rui wetland conservation area - Tien Yen, Quang Ninh province (Nguyen Cao Huan, 2018)
In Dong Rui and Hai Lang, the main mangroves include Bruguiera gymnornitreza, Rhizophora stylosa, Kandela obovata, Avicemia marina and Aegiceras corniculatum
The region is predominantly home to salt-tolerant plants, with fewer brackish water species Mangrove ecosystems are crucial for preserving biodiversity and supporting local livelihoods, serving as vital habitats for valuable species like mud crabs, octopuses, earthworms, and clams Additionally, they are essential for providing shrimp, crab, and fish, which are important resources for coastal communities.
Figure 0-2: Mangrove ecosystems of Dong Rui and Hai Lang Communes
The mangrove system in the two communes exhibits a well-developed structure with varied distribution across regions The Corniculatum Aegiceras community thrives in low-tide areas, experiencing significant tidal inundation, with tree heights ranging from 2 to 3 meters In contrast, pure communities of Kandela obovata, Rhizophora stylosa, and Bruguiera gymnornitreza are found in the tidal zone, where the substrate is primarily mud and clay, influenced by infrequent tides These communities can reach heights of 3 to 3.5 meters, with some trees growing up to 8 meters, creating a lush green belt that protects the tidal zone Additionally, shrub communities are predominantly located in high-tide areas, facing less impact from daily flooding, alongside anthropogenic plantations of Kandela obovata and Bruguiera gymnornitreza (Nguyễn & Mai, 2018).
Table 0.1: Height and distribution of mangroves communities in Dong Rui commune
No Name of community Height
No Name of community Height
1 B gymnorrhiza + R stylosa 2.8 Middle to the high intertidal zones
12 B gymnorrhiza 2.6 Middle intertidal zone to the high intertidal zone
9 Ae Corniculatum + K obovata 2.5 In scattered lower intertidal zones along the rivers and canals
2.1 In scattered lower intertidal zones along the rivers and canals
2.0 From lower to middle intertidal zones
6 A marina 1.9 In the lower intertidal zones along the rivers
1.8 Along the dike into the island, in scattered lower intertidal zones along the rivers
1.4 In high intertidal, or rarely submerged
1.2-1.4 From lower to middle intertidal zones, scattered along the rivers and canals
11 A marina in abandoned shrimp ponds
1.3 From lower to middle intertidal zones
14 Plant mangrove forest K obovata and R stylosa
In mangroves, the growing conditions of each tree species are different Therefore, depending on the location and various plants, this community or the other is dominant (detail in table 3.1).
The role of mangrove forests in the natural system
3.2.1 Benefit from maintaining biodiversity and food webs
3.2.1.1 Assessment of biodiversity in mangroves
Mangroves are vital components of the diverse ecosystems found in wetlands, particularly in Dong Rui and Hai Lang, where natural forests thrive and support biodiversity conservation These mangroves serve as crucial breeding grounds for various marine species, including fish, shrimp, crab, and clams, thus enhancing the abundance of marine life and supporting local livelihoods However, widespread fishing practices and environmental pollution pose significant threats to these species and jeopardize the region's biodiversity.
Figure 0-3: Cormorants includes 28 birds in the mangrove forest of Dong Rui commune
In Dong Rui and Hai Lang communes, the mangroves forest ecosystem have 9 groups of creatures distributed with 700 different species
152 species Main species composition Thalassiosira, Coscinodiscus, Rhizosolenia, Chaetoceros, Nitzschia, Ceratium, etc Seaweed fauna recorded 9 species, including 2
34 species of the Rivulariaceae family, 5 species of the Cladophoracea family, and 2 species of the Ulvaceae family (Nguyen Cao Huan, 2018)
159 species, many unique species such as Scaevola hainanense, Loranthus tienyenensis, Jasminum alongens, etc Three species in Red List of Threatened Species
Vietnam (2007): Drynaria bonii, Fallopia multiflora, and Scirpus kimsonensis Define
14 plant communities (Nguyen Cao Huan, 2018)
50 species: 34 species belong to Arthropoda, Annelida has 5 species, Mollusca has 4 species, Chaetognatha has 2 species, and Protochordata has 5 species (Nguyen Cao
Define 67 species There are 19 species of economic value, such as Austriella corrugata, Cyclina sinensis, Thais gradata, Telebralia sulcata, Cerithidea djadjariensis, Scylla spp Especially, Phascolosoma arcuatum species has in this ecosystem (Nguyen Cao Huan, 2018)
The study identifies a total of 60 species, with Lepidoptera being the most dominant group, comprising 24 species Following Lepidoptera, Coleoptera includes 11 species, while Hemiptera and Hymenoptera each account for 7 species Homoptera and Orthoptera contribute 5 species each, and Diptera is represented by a single species (Nguyen Cao Huan).
41 species Pices distribute in this ecosystem, in which Bostrichthys sinensis is a very endangered species (C.R.) only distributed in this ecosystem (Nguyen Cao Huan,
4 species: Gekko gecko (V.U.), Enhydris chinensis, Rhabdophis subminiatus, and Xenochrophis flavipunctatus (Nguyen Cao Huan, 2018)
130 species There are 2 species in the Red List of Threatened Species IUCN (2016):
Platalea endangered (EN) and Mycteria leucocephala near threatened (N.T.) (Nguyen
There are 3 species in the Red List of Threatened Species Vietnam: Platalea endangered (EN) and Mycteria leucocephala and Ceyx lugubris Vulnerable (V.U.) (Nguyen Cao Huan, 2018)
The mangrove ecosystem is home to 37 identified mammal species, including two listed on the IUCN Red List of Threatened Species (2016): Aonyx cinerea, classified as vulnerable (V.U.), and Lutra lutra, which is near threatened (N.T.) Additionally, three species are recognized on Vietnam's Red List of Threatened Species: Rhinolophus thomasi, Aonyx cinerea, and Lutra lutra, along with Ratufa bicolor, also listed as vulnerable (V.U.) (Nguyen Cao Huan).
The mangrove ecosystem in the Dong Rui - Tien Yen wetland area is characterized by its unique environmental features and diverse biomes This ecosystem boasts rich biodiversity and abundant resources, highlighting its significant potential for sustainable exploitation, agriculture, and ecotourism development.
Figure 0-4: Different species of animals in the mangroves (a) crab, (b) sea snail, (c) sea oysters, and (d) mussels
The Embryophyta group stands out as the most diverse, boasting 159 species, followed closely by Algae with 152 species and Aves with 130 species In contrast, other animal groups have significantly fewer species, with Amphibia and Reptilia representing the least diverse, each comprising only 4 species.
Primary food sources for aquaculture include 152 species of algae and 50 species of zooplankton, which provide essential nutrition for rearing molluscs, crustaceans, and fish The diverse ecosystems that host these organisms also offer potential habitats for sustainable aquaculture practices, promoting both food production and environmental conservation.
Mangrove forests serve as vital ecosystems, offering habitat and nourishment for a diverse array of organisms, including producers like mangroves and bacteria, decomposers such as heterotrophic bacteria, and various consumers including fish, shrimp, and crabs These species occupy distinct habitats within the mangrove environment, utilizing tree trunks, roots, and subterranean areas for shelter and sustenance.
Trees serve as a vital habitat for insects and reptiles, while also attracting various bird species that seek shelter within their branches The mangrove ecosystem is home to numerous bird species, including some that are listed as endangered on Vietnam's Red List of Threatened Species This highlights the area's importance as a suitable habitat that provides essential food and resources for their survival and growth.
Mangrove roots serve as crucial habitats for shellfish like sea oysters and mussels, while their complex root systems create safe living spaces and feeding areas for fish, helping to shield them from predators Aquatic invertebrates found in these environments play a vital role in the diets of various birds, fish, and other invertebrates Additionally, the forest floor supports a diverse range of species, including snails, clams, crabs, and other invertebrates, contributing to the rich biodiversity of mangrove ecosystems.
Each year, the abundant fallen leaves contribute to a highly productive food web, as their decomposition, along with that of dead animals, creates organic matter that serves as a vital food source for forest invertebrates This organic matter then supports larger species, including birds, reptiles, shrimp, and crabs Additionally, tidal movements transport essential nutrients deep into the forest, nourishing the diverse species that inhabit mangrove ecosystems.
Diverse wildlife thrives in habitats with minimal human interference, low predation risks, and plentiful food sources like fish, crabs, and crustaceans Notably, mangroves serve as vital sanctuaries, offering protection for animals from harsh weather conditions and predators (Rajpar & Zakaria, 2014).
3.2.1.2 The impact of climate change on biodiversity
Two main causes are leading to the decline of biodiversity in the mangrove forest: human activities and CC
Human activities significantly impact mangrove forests, particularly through land-use changes, pollution, and economic development In Dong Rui and Hai Lang, mangroves situated at the estuary are increasingly polluted by waste from nearby residential areas and upstream sources Additionally, some forested areas have been converted for aquaculture, leading to further contamination from wastewater generated by these operations and industrial zones Moreover, the development of economic projects has hindered the growth of mangroves in certain regions, resulting in their underdevelopment.
Mangroves are highly vulnerable to climate change (CC) and rising sea levels, which threaten their unique ecosystems and the species that rely on them These species often have narrow climatic tolerances and specific habitat needs, making them particularly susceptible to environmental changes The degradation of mangrove forests not only jeopardizes biodiversity but also poses significant risks to local human populations who depend on these ecosystems for their livelihoods and cultural heritage As human activities continue to put pressure on these vital habitats, the impacts of climate change will only worsen, further endangering the socio-economic development of indigenous peoples and local communities (Habiba et al., 2003).
CC has been causing significant impacts on nature and society, causing direct effects on human life and affecting biodiversity conservation: Some species will disappear;
Ecosystems, essential habitats for migratory and endangered species will be lost or narrowed; Ecosystems are transformed and fragmented; Invasion of alien species, etc
Mangrove forests are significant carbon sinks, with carbon accumulation occurring in three key areas: above ground in the forest trees, below ground in the root systems, and within the soil The biomass of mangrove trees in Dong Rui and Hai Lang communes demonstrates substantial carbon storage, as detailed in Tables 3.2 and 3.3.
Table 0.2: Total carbon accumulated in the biomass of mangrove trees at Dong
Carbon accumulated above the ground
Carbon accumulated below the ground
Carbon sink of mangrove forest tree (ton/ha) (%) (ton/ha) (%) (ton/ha) (%)
The role of mangrove forests in the social system
3.3.1 Benefit from reducing the impact of CC on the local community
CC/natural disaster impacts on the local community
Figure 3.12 shows natural disasters affecting people's lives in Dong Rui and Hai Lang communes:
Figure 0-12: Natural disasters affecting households in Dong Rui and Hai Lang communes (Unit: house)
A recent survey conducted in Dong Rui and Hai Lang communes revealed that 34 households in Dong Rui and 19 in Hai Lang are significantly impacted by various natural disasters Typhoons pose the greatest threat, affecting 85.29% of households in Dong Rui and 64.71% in Hai Lang Both communes, situated near the sea, experience direct consequences from these storms However, the presence of mangrove forests serves as a natural barrier, mitigating the intensity of waves and winds during typhoons Historically, Dong Rui and Hai Lang have suffered minimal damage during the rainy season, with only structurally weak houses experiencing substantial impacts.
Floods, erosion, and saline intrusion occur less frequently due to the dike system established in both communes, which effectively mitigates the impact of waves, tides, and saltwater intrusion Furthermore, the increased planting of mangroves in various regions enhances their density and distribution, providing additional protection Mangroves play a crucial role in reducing wave and tide impact while also safeguarding the integrity of the dike system.
Aquaculture contributes to increased salinity in the environment, as the brackish and salty water from shrimp and fish production ponds is released into nearby areas This discharge leads to saltwater infiltration into the soil, rendering the land unfit for growing vegetables, rice, or fruit trees, and even contaminating the freshwater wells of local communities.
Typhoon Flood Erosion Saline intrusion
The damage of CC to population communities
In 60 survey participants in Dong Rui commune, 58 people (corresponding 97%) rated that mangroves are extremely important (point 5) in reducing the impact of the typhoon The rest, one person, gave a score of 4, and one gave a score of 3 Thus, all survey respondents highly appreciated the role of mangroves in reducing the impact of the typhoon
(5_Extremely important; 4_Strongly important; 3_Moderately important; 2_Slightly important and 1_Not important)
Figure 0-13: The role of mangroves in reducing the impact of the typhoon in
Climate change negatively affects communities, particularly in Dong Rui and Hai Lang, where many residents live in temporary housing vulnerable to typhoons Severe storms can lead to significant damage, including blown-off roofs and fallen trees Fortunately, the presence of a mangrove forest provides some protection, mitigating the impact of these storms Additionally, the lack of designated boat shelters forces residents to move their boats deep into the mangrove forest during storms to safeguard their property from damage.
Typhoons significantly impact aquaculture by causing elevated water levels, which can breach banks and displace fish from lagoons Mangroves play a crucial role in mitigating water level rises, while proactive measures can further reduce potential damage Additionally, fluctuations in weather and salinity can make shrimp and other aquatic species vulnerable to disease, leading to mortality rates ranging from 30% to 70% depending on the severity of the conditions.
Information about CC and natural disaster
Figure 0-14: The percentage of respondents answering that they know about "CC" in Dong Rui Commune
Figure 0-15: Information channels providing knowledge about CC in Dong Rui Commune
Research results indicate that 75% of people, equivalent to 45 individuals, are aware of CC, primarily due to diverse information sources The most significant sources include television, radio, and newspapers, followed by local information channels, which account for 33 individuals Additionally, information from friends, relatives, neighbors, and the internet also contributes to public awareness.
A significant 100% of individuals are aware of CC, with up to 45 people receiving information through television, radio, and newspapers Many respondents indicated that they have a daily habit of watching the news, leading to frequent exposure to CC on TV.
The local information channel system ranks as the second most popular source of information, significantly enhanced by recent rural policies that have improved the commune's infrastructure, particularly the loudspeaker system This channel plays a crucial role in disseminating information about community events to residents However, the effectiveness of the multi-zone speaker system remains limited, as households located far from the speakers often struggle to receive announcements clearly, leading to challenges in accessing important information.
In addition, people also know information through the internet and acquaintances Although the internet is much more popular than before, computers and phones with
51 internet connections are still limited in rural areas Therefore, the number of people who know about CC through the internet is still limited
(5_Extremely important; 4_Strongly important; 3_Moderately important; 2_Slightly important and 1_Not important)
Figure 0-16: The role of mangroves in CC response in Dong Rui
In Dong Rui commune, a significant majority of residents recognize the critical role of mangroves in combating climate change, with 98% rating their importance as either extremely or strongly significant Specifically, 37% of individuals rated mangroves as extremely important, while 61% deemed them strongly important This high level of appreciation is attributed to the close proximity of the community to the mangrove forest, resulting in a greater dependence on its resources.
3.3.2 Benefit from maintaining people's livelihood
3.3.2.1 Livelihood dependent on biodiversity resources of communities in Dong Rui and Hai Lang communes
The livelihood of people in Dong Rui and Hai Lang communes
Residents of Dong Rui and Hai Lang communes engage in a variety of occupations to enhance their income and support their daily lives This diverse livelihood reflects the community's adaptability and resourcefulness, as illustrated in Table 3.10, which details the range of jobs pursued by individuals in these two communes.
Table 0.10: Number of people participating in occupations in Dong Rui and Hai
Lang commune (Unit: People) Livelihood Main livelihood Side livelihood
Dong Rui Hai Lang Dong Rui Hai Lang
Livelihood Main livelihood Side livelihood
Dong Rui Hai Lang Dong Rui Hai Lang
From 94 questionnaires in 4 villages of Dong Rui commune and 17 questionnaires in two villages in Hai Lang commune, people mainly work in cultivation, cattle, and poultry breeding But some people work both in agriculture and fishing to increase family income The two communes have favorable conditions for aquaculture However, local authorities limited broaden the aquaculture area, so the number of households engaged in aquaculture is not much
In Dong Rui commune, 49 households, representing 52.13%, rely on agriculture as their primary source of livelihood Meanwhile, Hai Lang commune has 13 households, accounting for 76%, engaged in agricultural activities Overall, the agricultural sector plays a significant role in the livelihoods of these communities.
In Hai Lang commune, 62 households represent 65.96% of the population, while 16 households account for 94.12% Situated in rural areas, these households primarily engage in agricultural production, cultivating crops such as rice, sweet potatoes, potatoes, corn, and cassava Despite nearly all households participating in farming, their main source of income often stems from non-agricultural work due to the low profitability of agricultural endeavors Rice is predominantly used for family consumption.
The communities in the two communes primarily engage in agricultural production within the protective confines of dykes, which minimizes their vulnerability to saline intrusion and flooding The combination of dykes and mangroves effectively safeguards the agricultural zones, ensuring a stable environment for crop cultivation.
In Dong Rui, there are 15 households (corresponding to 15.96%) And in Hai Lang, there are 7 households (corresponding to 41.18%) with cattle and poultry farming as a
53 side livelihood Some households are breeding chickens and ducks only for their family's use
Recommendation
In a survey of 111 participants regarding the restoration and protection of mangroves, 70 respondents did not provide suggestions, while 41 offered specific solutions After analyzing these responses, seven key solutions emerged as the most significant for addressing the challenges faced by mangrove ecosystems.
(1) Officials and authorities should more deeply monitoring, managing, and protecting forests and need specific, flexible, realistic policies and linkages between departments
Local government policies serve as a foundation for guiding community decisions and actions Effective and practical policies enhance conservation efforts, while officials must engage closely with residents, prioritize their well-being, and consistently educate them on the importance of mangrove conservation.
Harmonious management that balances forest protection with the enhancement of people's livelihoods is essential for sustainable development By ensuring a stable output of agricultural products, communities can reduce their dependence on forest resources, ultimately fostering economic growth This approach not only supports local economies but also raises awareness about the importance of forest conservation.
The project aims to conserve and expand mangrove ecosystems while developing a sustainable eco-tourism area that generates income for local communities in Dong Rui and Hai Lang This initiative not only enhances air quality but also ensures long-term benefits and opportunities for future generations.
(4) Organize training and propaganda for people in the area and surrounding areas not to cut or destroy mangrove trees;
Fishing with explosives or electricity is strictly prohibited to protect and restore the environment It is essential to regulate the harvesting of aquatic species in forests and to fish marine species within sustainable limits and during appropriate seasons to ensure their growth and preservation.
To strengthen waste management, it is essential to enhance pollution control and waste reduction efforts Our focus is on integrating prevention strategies with effective pollution treatment to improve the environment of the reserve This includes increasing the management efficiency of waste generated in conservation areas, particularly from aquaculture and domestic sources.
To promote sustainable development and conservation of mangrove forests in Dong Rui and Hai Lang communes, it is essential to establish community-based ecotourism This initiative aligns with the ongoing development of the Van Don - Mong Cai expressway, ensuring that urban expansion does not compromise the natural ecosystem By focusing on eco-tourism, we can protect the unique natural conditions of the mangroves while fostering local economic growth.
65 with mangroves Moreover, Dong Rui and Hai Lang are two areas with beautiful scenery and potential for ecotourism development
The local government can enhance eco-tourism at Long Vang Beach by integrating sightseeing and educational experiences focused on mangroves This initiative not only generates additional income for local communities but also fosters awareness about the importance of mangrove conservation through nature-based tourism Furthermore, a portion of the tourism revenue could be allocated to establish a fund dedicated to local mangrove conservation efforts, which would support reforestation projects and educate both residents and visitors on the significance of protecting these vital ecosystems.
Figure 0-23: Long Vang beach in Dong Rui mangrove forest, Tien Yen district
Vietnam boasts successful ecotourism models, such as the seven-acre nipa palm forest in Cam Thanh commune, Quang Nam province This community-based tourism initiative allows locals to actively engage in both conservation efforts and tourism activities, ensuring the protection of the nipa palm forest while benefiting from visitor interactions.
Effective planning of tourist areas is essential to prevent detrimental impacts on mangrove ecosystems, such as deforestation, habitat reduction for wildlife, and environmental pollution To mitigate these risks, the government must ensure proper waste management practices are in place to protect mangroves from harmful effects.