VIETNAM NATIONAL UNIVERSITY, HANOI VIETNAM JAPAN UNIVERSITY HOANG TUAN CHI THE ROLE OF MANGROVES IN RESPONSE TO CLIMATE CHANGE IN CU LAO DUNG DISTRICT, SOC TRANG PROVINCE, VIETNAM M
INTRODUCTION
Overview
Vietnam's diverse topography and varying climate patterns result in significant regional differences According to the National Climate Assessment Report 2021, the country faces numerous hydro-meteorological disasters each year, which impede socio-economic development In recent years, increasingly abnormal climate conditions and extreme natural disasters have severely impacted people's lives and properties, posing a substantial threat to the national economy (MONRE, 2021).
The Mekong Delta, Vietnam's largest agricultural hub, is significantly impacted by climate change A rise in sea levels exceeding 1 meter could submerge 38.9% of the region's land, directly affecting 10% of its population This scenario poses a critical threat to food security in Vietnam and globally.
Soc Trang province, situated at the mouth of the Hau River and bordering the East Sea with 72 km of coastline, faces significant risks from climate change According to the MONRE climate change scenario, over 55% of the province is vulnerable to flooding if sea levels rise by more than 100 cm, with Nga Nam district (86.90%) and Thach Tri (84.38%) being the most at risk The region has already experienced severe impacts, including rising temperatures, drought, saltwater intrusion, frequent tornadoes, and flooding from high tides, which have led to riverbank and coastline erosion These challenges pose serious threats to the daily lives and productivity of Soc Trang's residents.
Cu Lao Dung, located in Soc Trang Province, is surrounded by the Hau River and the East Sea, making it particularly susceptible to natural disasters and coastal erosion.
2 saline intrusion, alluvial sedimentation, storm surges, inundation, and soil degradation, these factors have markedly impacted both the society and economy of Cu Lao Dung
According to the 2021 climate change projections for Vietnam, approximately 23.57% of the Cu Lao Dung region is expected to be inundated due to a projected sea level rise of 100cm Historical data modeling indicates potential consequences, including significant agricultural land loss, increased saline intrusion, more frequent flooding events, soil degradation, and other related challenges.
The coastal protection forest in Soc Trang province encompasses 6,544.7 hectares across three districts: Cu Lao Dung, Tran De, and Vinh Chau town (Tho N, 2021).
The mangrove ecosystem in Cu Lao Dung district, Soc Trang province, is a crucial area that provides significant value and essential services to the local community It nurtures various aquatic species, supplies medicinal materials, fuels, and industrial raw materials, and creates attractive landscapes for tourism and educational activities Additionally, it acts as a protective barrier for coastal regions and functions as a vital green lung, absorbing carbon dioxide and regulating temperature and climate According to the Biodiversity Conservation Plan for Soc Trang province, this coastal mangrove ecosystem is home to numerous rare and valuable animal and plant species.
Mangroves have faced significant degradation due to overuse for housing, agriculture, and aquaculture, resulting in water pollution and land degradation Many mangrove areas have been abandoned, leading to increased salinity and loss of habitat (People’s Committee of Soc Trang province, 2019) According to Tamura from Ibaraki University, approximately 11 kilometers of the 72-kilometer coastline in Soc Trang Province are currently eroding This coastal erosion is attributed to several factors, including the reduction of mangroves due to population growth and land use changes, decreased upstream sediment supply, sand and soil extraction for construction, and climate-related impacts like sea level rise and heavy rainfall, as well as land subsidence caused by groundwater extraction (Tamura et al., 2018).
Recognizing the significance of coastal forests in responding to climate change,in 2021, the Prime Minister issued the Decision No 1662/QĐ-TTg to approve the project
"Protecting and developing forests in coastal areas to respond to climate change and promote green growth in the 2021-2030 period" (The Government of Vietnam, 2021)
As climate change increasingly affects coastal regions, evaluating the significance of mangroves in adaptation strategies becomes crucial This evaluation is particularly pertinent in Soc Trang province, where the "Establishment of Cu Lao Dung Mangrove Nature Reserve" project is underway Given the severe consequences of climate change and the vital functions that mangroves serve in the Cu Lao Dung district, this topic warrants focused attention.
"The role of mangroves in response to climate change in Cu Lao Dung district, S o c
This research evaluates the significance of mangrove forests in supporting biodiversity and food webs while also providing livelihoods for local communities adapting to climate change Additionally, the study presents recommendations to enhance the resilience of mangroves in the face of climate change.
Study area
Figure 1.1 Location of Soc Trang province in Vietnam and mangrove areas
Figure 1.2 Satellite map of An Thanh Nam and An Thanh 3 communes
Cu Lao Dung, the largest island in the Hau River, is located in the lower Hau River region near the East Sea, completely surrounded by water Covering over 26,481.9 hectares, the island's total landmass is entirely within the district, featuring a coastline of 17 kilometers, nearly a quarter of Soc Trang province's total coastline The terrain is predominantly flat with various islands and unstable areas, while elevation ranges from +0.5 to +1.3 meters, mostly between +0.7 and +0.9 meters Much of the land is below high tide level, making it vulnerable to flooding during high tide, which can adversely affect agricultural production and community infrastructure.
Figure 1.3 The position of the Cu Lao Dung district, Soc Trang province
An Thanh Nam and An Thanh 3 communes, situated at the southern end of provincial road 933B in Cu Lao Dung district, are bordered by the Hau River on one side and the sea on the other The local residents primarily rely on sugarcane cultivation, aquaculture, farming, and fishing as their main sources of livelihood.
Soc Trang province has a tropical monsoon climate, influenced by the sea, divided into two distinct seasons (rainy season and dry season) with high temperature and relatively large rainfall
Table 1.1 Climate characteristics of Soc Trang province in the period 2015 - 2021
(Statistics Office of Soc Trang, 2021) Temperature:
The average annual temperature is 27 – 28 0 C, the average seasonal temperature range is
5 – 6 0 C; The average temperature of the lowest month (January) of the year can drop to
24 - 25 0 C, the average temperature of the highest month (May 2020) can be up to 30,3 0 C Sunshine duration:
The average annual total radiation remains consistently high, ranging from 140 to 150 kcal/cm2.The average annual sunshine hours amount to 2.417,3 hours (recorded from
2015 to 2021), with the peak typically occurring in March and reaching 301,0 hours (in
2016), while the lowest recorded month is December (2016) with 107,0 hours of sunshine
The annual average humidity level is 82%, with a peak of 88% during the rainy season in 2021, and the lowest recorded level of 71% during the dry season in 2020
Over the past seven years, the average annual rainfall has been 1,676.5 mm, with precipitation primarily occurring from May to October This period exhibits significant monthly rainfall variation, while the dry season from November to April experiences minimal rainfall and high evaporation rates Consequently, this leads to severe water shortages for both agricultural production and daily life, particularly affecting coastal and remote areas distant from water sources, thereby contributing to the instability of agricultural output in the province.
Soc Trang is located in the area affected by monsoon, there are two main wind directions in the year, East - North and West - South
From November to April, the East-North wind direction brings alternating East and Northeast winds This East wind plays a significant role in transporting salty water from the East Sea into rivers and canals during the dry season, leading to increased salinity levels Additionally, it directly affects the coastal areas, resulting in severe erosion.
From May to October, the West-Southwest wind significantly influences the timing of the first seasonal rains, with its early or late arrival playing a crucial role in determining when these rains begin.
Soc Trang province is located in an area less affected by storms According to hydro- meteorological records, in the past 100 years, only 02 storms hit Soc Trang (1952, 1997) causing great damage
Cu Lao Dung boasts a dynamic network of over 360 rivers and canals, along with 17 kilometers of coastline primarily located in Con Tron and An Thanh Nam communes The district's rivers and streams exhibit irregular semi-tidal patterns, with water levels fluctuating significantly during tidal peaks Notably, the highest tidal peak occurs in October and November, reaching 160 centimeters, while the lowest occurs in May and August at 123 centimeters Additionally, the highest tide is recorded at -24 centimeters in November, and the lowest at -103 centimeters in June, resulting in an average tidal range of 194 to 220 centimeters.
1.2.4 Some manifestations of CC in Cu Lao Dung
Climatic conditions significantly impact the local population's primary means of subsistence and unique ecosystems Key factors include unpredictable rainfall patterns, characterized by excessive precipitation during rainy seasons and unexpected rainfall during dry periods Additionally, prolonged heat waves, flooding due to rising sea levels, and landslides further exacerbate these challenges, affecting both livelihoods and environmental stability.
8 the interaction of waves, counter-winds, and inundation; and 5) Tropical depressions and typhoons
Listed below are climate-related events and risks that have impacted characteristic ecosystems and primary livelihoods in Cu Lao Dung District (Vo et al, 2018):
Table 1.2 Impacts of Climate Change on Habitat and Ecosystems
Counter-seasonal rain in dry season
In dry season, local great rains come suddenly, sometimes at nights
Irregular rain: long-lasting and intense rain and at the end of the rainy season
- At the onset of the rainy season, there appear sudden intense thundershowers
- End-of-rainy-season rains can be unpredictable, highly intense, and long-lasting Long-lasting heat wave - Unpredictable weather conditions in dry seasons
- Higher frequency of days with temperature above 35 0 C than 10 years ago
Inundation alongside sea level rise The escalating significance of saline intrusion is caused by the rise in sea level together with notable inundations within a year (October and November)
Erosion due to the combination of waves, winds and inundation
Erosion could be brought on by flooding and counter-wind, especially in January and February (as happened in An Thanh Dong and Dai An 1 communes)
Tropical depressions, typhoons and cyclones
Typhoons and tropical depressions are predicted to increase in frequency compared to
10 years ago and defy established regulations.
Literature review
1.3.1 The concept of mangrove ecosystem
Mangroves are unique intertidal ecosystems found along calm tropical and subtropical shorelines, often referred to as 'coastal woodlands,' 'tidal forests,' or 'mangrove forests,' according to Professor Peter from Southern Cross University In optimal conditions, these ecosystems can develop into extensive, productive forests, while in less favorable environments, they may appear as stunted, scattered shrubs that do not fit neatly into the categories of "woodlands" or "forests," but rather occupy a space in between (Saenger, 2003).
Research by Brandon at the University of Wisconsin-Stevens Point highlights mangroves as remarkable survivors, thriving in harsh, saline, and muddy conditions that challenge most plants Their success is attributed to unique adaptations, such as a complex root system that stabilizes them in shifting sediments and a filtration mechanism that effectively removes excess salt Additionally, mangrove ecosystems support a rich diversity of wildlife, including species exclusive to these forests Brandon emphasizes the growing understanding of the vital role mangrove swamps play in maintaining planetary health and human well-being (Wolf, 2012).
1.3.2 Assessment of biodiversity in mangroves a Diversity of advanced flora
The 2014 project "Study on Scientific Basis and Propose Solutions to Adapt to Climate Change for Sustainable Development in Cu Lao Dung District, Soc Trang Province," conducted by IWRE, revealed that Cu Lao Dung Island is home to 141 plant species across 97 families This diverse flora includes 15 official mangrove tree species, along with 94 higher plant species that have integrated into the local mangrove ecosystem.
The data from the Department of Natural Resources and Environment of Soc Trang in
2019 have recorded 112 species of higher plants, belonging to 44 families, and shown in the Error! Reference source not found
Table 1.3 Life form of flora in Cu Lao Dung mangrove area of Soc Trang
Life form Number of species Ration (%)
(Department of Natural Resources and Environment of Soc Trang, 2019) b Characteristics of the fish species distribution
A study conducted by Tran and colleagues on the fish species composition in Cu Lao Dung revealed significant seasonal variations Samples were collected during the rainy season (August 2019, October 2019, and June 2020) and the dry season (December 2019, February 2020, and April 2020) The findings showed that out of 67 species, 56 (83.58%) were identified in the rainy season, while 53 (79.1%) were found in the dry season Notably, the order Perciformes was the most prevalent in both seasons, with 35 species (66.04%) in the dry season and 34 species (60.71%) in the rainy season This variation in fish species composition is likely linked to the spawning migration of certain species during the rainy season (Dinh et al., 2021).
Figure 1.4 Number of fish species in different orders (Dinh, et al., 2021)
1.3.3 Impact of CC on mangroves
Processes contributing to mangrove vulnerability to sea level rise
A 2016 study by Ward, Friess, and colleagues highlighted that rising sea levels pose a significant threat to mangrove ecosystems, as these plants are sensitive to salt levels exceeding their physiological tolerance and variations in flooding duration and frequency Extended flooding can lead to plant mortality at the seaward margins of mangroves and alter species composition, ultimately diminishing ecosystem productivity and services The document indicates that coastal flooding is expected to increase due to a global rise in sea levels, which has averaged 3.2 mm per year in recent decades and is projected to rise by approximately 0.28 to 0.98 meters in the future.
Local sea level rise (SLR) rates are highly variable due to regional factors, with measurements ranging from 1.9 mm per year in the Caribbean to 7.5 mm per year in parts of Indonesia Notably, some areas, such as the lower Mississippi River Delta, experience even higher rates, reaching up to 9 mm per year (Raymond et al.).
In the most recent study published in 2022 regarding the potential effects of sea level
Rising sea levels due to global climate change pose a significant threat to coastal zones, particularly wetland and mangrove ecosystems in the Mekong Delta, Vietnam, as highlighted by Dang and colleagues The study indicates that while all ecosystems in the region will be affected, mangroves are likely to be the most vulnerable These mangroves are crucial for providing essential ecosystem services in the area, emphasizing the urgent need to address the impacts of sea level rise on these vital ecosystems (Dang et al., 2022).
Factors contributing to mangrove resilience to sea level rise
Krauss and researchers from the University of Nebraska – Lincoln emphasize that mangroves actively alter their environment rather than merely reacting to changes These vital ecosystems enhance habitat stability and play a crucial role in coastal adaptation by promoting sediment deposition and peat formation in response to rising sea levels (Ken et al., 2013).
The IUCN report on managing mangroves for climate change resilience highlights the unique adaptations of mangroves, including aerial roots, support roots, and buttresses, which enable them to thrive in challenging muddy, shifting, and saline environments These trees can respond to sea level changes by migrating landward or seaward, or by growing vertically Additionally, mangroves contribute to peat formation by trapping sediment, decomposing organic matter, and developing extensive root systems, which helps them cope with rising sea levels A notable example is found in western Jamaica, where mangrove ecosystems have successfully survived due to sedimentation rates that exceeded the rate of sea-level rise during the mid-Holocene period.
Mangroves can expand their habitat in response to rising sea levels if sediment accumulation occurs at a sufficient rate However, local factors such as infrastructure, including roads, agricultural fields, and urban development, as well as terrain features like steep slopes, can hinder their ability to migrate If mangroves cannot migrate inland or expand quickly enough to keep up with rising sea levels, they risk gradual decline and potential extinction over time.
The 2022 report "Hurricane Damages to Mangrove Forests" by Silveira and his team highlights the essential function of mangrove forests as protective barriers against hurricanes on tropical and subtropical coastlines The study reveals that hurricanes can severely affect mangroves through strong winds, storm surges, sediment deposition, flooding, and coastal erosion.
Hurricanes significantly impact forests by uprooting vegetation, breaking branches, and removing canopy foliage, which disrupts sediment dynamics, nutrient cycles, and biodiversity These changes compromise the forest's structure and functionality, while also altering topography, hydrology, and sediment properties Collectively, these factors are essential for evaluating the effects of hurricanes on forest ecosystems (Jorge, 2022).
According to the IPCC 2021 report, global land precipitation has likely increased since the mid-20th century, with moderate confidence in this trend, while confidence in earlier trends is low Since the 1980s, there has been a notable acceleration in land precipitation, characterized by significant inter-annual variability and regional differences Conversely, estimates of precipitation trends over the global ocean remain uncertain due to challenges in satellite data retrieval, merging methodologies, and a lack of in situ observations.
Ward and colleagues proposed that changes in rainfall patterns will likely affect the distribution, size, and growth rates of mangrove forests, particularly those at the limits of their tolerance Notably, significant shifts in precipitation can alter seasonal average salinity levels in various mangrove ecosystems, with differences noted among fringe, estuarine, and inland mangroves A decrease in precipitation, combined with increased evaporation, contributes to these changes.
Increased soil salinity can negatively impact the survival, productivity, and growth rates of mangrove seedlings, potentially leading to the loss of mangroves and their transformation into hyper-saline mudflats over several decades Conversely, heightened precipitation may facilitate the landward migration of mangroves into salt marsh zones, thereby expanding their regions The response to increased rainfall may vary by species; for instance, Sonneratia alba may show accelerated growth, while Bruguiera gymnorrhiza might remain unaffected Additionally, increased precipitation can lower pore water salinity and sulfate concentration, enhancing overall mangrove productivity This rise in rainfall is also expected to boost river discharge, which can increase allochthonous sediment input, elevate mangrove surface levels, and improve resilience against sea level rise in estuarine mangroves.
Research questions and hypothesis
✓ What are roles of mangroves in response to climate change in Cu Lao Dung district?
✓ What are solutions for effective and sustainable use of mangrove forest in the context of CC?
✓ Cu Lao Dung mangroves play an important role in maintaining biodiversity and food web in this area;
✓ Cu Lao Dung mangroves play an important role in storing carbon;
✓ Cu Lao Dung mangroves play an important role in maintaining local livelihood;
✓ Cu Lao Dung mangroves play an important role in reducing the impacts of climate change;
✓ Improving livelihoods for people in the model of aquaculture under the forest canopy;
✓ Increasing local revenue based on exploitation of ecotourism services in mangroves;
✓ Promoting, developing and improving tourism and accommodation services in mangrove areas;
✓ Accessing to the market for carbon credits.
Research objectives and tasks
To ensure the effective and sustainable use of mangrove forests in Cu Lao Dung district, Soc Trang province, it is essential to assess the current state of mangrove forest utilization and the quality of these ecosystems Addressing climate change impacts requires strategies that maintain the ecological functions of mangroves over time Implementing conservation practices, promoting community engagement, and enhancing restoration efforts will be crucial for preserving these vital coastal resources.
Specific objective: To Assess the role of mangroves in response to climate change in Cu Lao Dung district, Soc Trang province;
Objects and Scope of the research
Object: Roles of mangrove in response to climate change in Cu Lao Dung district and sollutions for effective and sustainable use of mangrove forest in the context of CC
The total area of mangrove forests in the region is 1.787,64 hectares The specific areas in each commune are as follows:
- An Thanh Dong commune: 6,50 hectares;
- An Thanh Nam commune: 1.669 hectares; and
The data reveals that 98.6% of the forest area is concentrated in the two communes of An Thanh 3 and An Thanh Nam, which is why these communes were chosen for the research study.
Efficiency and sustainability of mangrove use and exploitation
✓ Study area: coastal area of Cu Lao Dung district, Soc Trang Province, including: An Thanh Nam and An Thanh 3 communes
✓ Content: Focus on current status of mangrove forest use and current status of mangrove forest quality and ecological function maintenance, except for coastal protection.
RESEARCH METHODOLOGY
Logical framework
I created a framework focused on the objectives, tasks, and research techniques to analyze the role of mangroves in response to climate change This framework encompasses both natural and social roles, divided into two main sections I categorized mangrove functions into two distinct areas: (1) supporting biodiversity and food webs, and (2) carbon storage Additionally, I differentiated the social functions of mangroves into two separate categories.
This article explores the critical role of mangroves in sustaining local livelihoods and mitigating the impacts of climate change Through diverse research methodologies, I have examined the multifaceted functions of mangroves, highlighting their importance in environmental preservation and community support.
Mangroves are vital ecosystems that offer numerous interconnected services benefiting local communities Their biodiversity not only supports but also improves the quality of life for people However, human activities significantly affect the variety and number of species within mangrove forests, highlighting the need for sustainable management to protect these crucial habitats.
Mangroves play a crucial role in carbon storage, helping to mitigate climate change and reduce the effects of extreme weather and weather variability By doing so, they significantly lessen the impact on coastal areas and alleviate environmental pressures.
Table 2.1 Indicators for the roles of mangroves in response to climate change in Cu
No Dimension Indicator Code Data Reference
1 Maintaining biodiversity and food webs
Mass of CO2 per hectare
Households whose livelihoods depend on mangroves and Households whose livelihoods do not depend on mangroves
4 Reducing the impact of CC
- Natural disasters and climate change impacts
- The damage of climate change and natural disasters
- Awareness of local people on the importance of mangrove.
Figure 2.1 Logical framework of the thesis
Approaches
The exploration of sustainable mangrove utilization in the face of climate change encompasses diverse areas such as ecosystems, livelihoods, and both natural and economic systems Consequently, it necessitates the development of varied strategies to address these multifaceted challenges.
Mangroves are integral to the natural ecosystem, functioning within a complex interplay of environmental and societal elements To fully understand mangroves, it is essential to adopt a holistic perspective that highlights their interconnections A systematic approach allows researchers to conduct comprehensive assessments of mangrove ecosystems, leading to the development of effective and sustainable management solutions in the context of climate change.
The mangrove ecology in Cu Lao Dung district is highly vulnerable, facing significant threats from climate change, natural processes, and human activities It is essential to preserve the fundamental values and functions of this ecosystem to ensure sustainable use of mangroves.
Solutions for effective and suitable uses of mangrove forest for CC response
Maintaining biodiversity and food webs
Storing carbon Reducing the impact of CC Maintaining local livelihood
Therefore, when evaluating ecosystem assessment and suggesting effective and sustainable usage solutions for mangroves, it is crucial to employ ecosystem methodology
Mangrove forests share similarities with traditional forest resources but possess unique qualities influenced by regional factors In Cu Lao Dung district, Soc Trang province, these forests are shaped by local community management, environmental conditions, socio-economic aspects, and human activities To effectively address these complexities, a top-down strategy is essential, beginning with a comprehensive investigation into the general characteristics and roles of mangroves, followed by a focused exploration of the specific issues in the Cu Lao Dung area.
Climate change significantly affects human activities, ecosystems, and environmental systems, particularly in coastal regions, despite substantial socioeconomic growth To ensure the survival of mangroves and mitigate these impacts, a sustainable development strategy is essential.
Data collection
In this research, two data sources are used: Secondary data and Primary data
Secondary data for the project is gathered from various credible sources, including the Meteorological Station of Soc Trang, which provides weather data such as temperature and precipitation, alongside a sea-level rise scenario for Vietnam projected for 2021 Additional insights are drawn from the current status of different species in the project area as reported by the Department of Natural Resources and Environment (DONRE) of Soc Trang in 2019, and the Action Plan to Address Climate Change in Soc Trang Province for 2021-2030 published by the People's Committee of Soc Trang Furthermore, the Soc Trang Statistical Yearbook 2021 from the Statistics Office of Soc Trang and recent studies on the Cu Lao Dung mangrove forest contribute valuable information for the project.
Primary data was collected through various methods, including observation, household surveys, and in-depth interviews Observations involved capturing images of biodiversity, mangrove conditions, and the daily lives of local inhabitants A household survey was conducted with 54 local households to gather information on mangrove tree development, community livelihoods, and factors affecting mangroves Additionally, in-depth interviews were held with six local officials and experts to obtain insights on mangrove biodiversity, protection, and conservation efforts.
A random selection of households was conducted in two communes with a total population of 16,728 people, averaging 4 individuals per household, which amounts to 4,182 households Using SurveyMonkey software to calculate the necessary sample size, it was determined that with a confidence level of 90% and a margin of error of 12%, a sample size of 47 households is required for the survey.
In reality, 54 households were interviewed, and this number meets the demand
Different answers for two groups, local households and authorities and experts, were collected to analyze relevant information
Two field trips to this area were implemented to observe and collect data: The first one was from 10-14 May, 2022 and the second one was from 04-09 December, 2022
(1) For Household survey: The interview was implemented in two communes: An Thanh Nam and An Thanh 3
54 households in 4 villages including Vo Thanh Van, Vam Ho, An Quoi, An Binh were interviewed and devided into 2 groups as follows:
(1): Households whose livelihoods depend on mangroves
(2): Households whose livelihoods do not depend on mangroves
Regarding questionnaire for households, information contains six primary types as
(I) General information (family members, job, livelihood, income, etc.);
(II) Information about CC (the kind of disaster/extreme weather impact, beforehand warning information, etc.);
(III) Information about mangroves in general and how CC affects mangroves (type of mangroves in the commune, the situation of mangroves: before and now);
(IV) Benefits of mangroves (preserving livelihood, minimizing typhoon impact, and defending the coastline, etc.);
(V) The cost of mangrove conservation (effects on communes and livelihoods as a result of conservation of mangroves, etc.);
(VI) Mangrove conservation perspectives (The importance of mangrove conservation for local socio-economic development and CC mitigation) (Detailed questionnaire at appendix)
An in-depth interview with six local leaders and experts revealed crucial insights into the socio-economic conditions of the commune, the impacts of climate change on local livelihoods, and the current state of the Cu Lao Dung mangrove forest in two communes This mangrove ecosystem plays a vital role in climate change adaptation and sustaining local livelihoods.
Table 2.2 Data types used in research
Mangrove features: Plant and animal species and mangrove species; Characteristics of mangrove (height, density, age)
- Interview the leaders of the Department of Forest Protection of
Cu Lao Dung; Co-management team and other materials
- People’s Committee of Soc Trang province (2019)
CC, natural disaster and extreme weather events in An Thanh 3 and An Thanh Nam communes
(Precipitation, temperature, sea-level rise)
Interview local authorities, weather station, and other materials
Effects of CC, natural disasters, and extreme weather on the ecology and mangroves (erosion,
Interview local residents; local authorities; Co-management reduce the amount of aquatic animal, reduce mangrove forest area, etc.) team; and other materials
Carbon storage (carbon accumulates at forest trees and in the soil)
According to Nguyen et al (2014), typhoons, saline intrusion, and other extreme weather events significantly impact coastal communities Mangrove forests play a crucial role in mitigating these effects, including reducing wave energy, minimizing saline intrusion, and protecting against strong winds.
Survey local inhabitants; interview local authorities, Co- management team and other materials
Types of livelihoods that exploit natural resources and ecosystems (fishing, aquaculture, etc.) to raise money
Survey local inhabitants; interview Co-management team and livelihood expert; and other materials
Mangroves' advantages for local residents
(increase air quality, protect biodiversity, etc.)
Survey local people; Co- management team interview government
Research methods
In this research, both quantitative and qualitative methods were applied to collect and analyse the data related to mangroves and local community livelihood, etc
Desk review Gather information on Cu Lao Dung mangroves and the impacts of climate change from relevant documents
Gather information about mangrove forests and primary data
Gather primary information and facts on mangrove forests
Summarize the data and find trends
(climate data, the impact of CC, etc.) Qualitative data analysis methods
Analyze the information from survey responses
Analyze the data, information, and sharing from observation and survey
The synthesis method was used to gather secondary data
Secondary data was gathered from the An Thanh Nam and An Thanh 3 Commune People's Committees, as well as the Department of Forest Protection and the Department of Agriculture within the Cu Lao Dung District People's Community This data provides insights into the socio-economic conditions and development trends of the region.
This study synthesized data on climate change and natural disasters from various existing research, while also examining the ecological and social significance of mangroves Utilizing a qualitative approach, primary data was collected through in-depth interviews and observations, complemented by quantitative methods for a comprehensive analysis.
This research utilized in-depth interviews with six local authorities, a livelihood expert, and a contractor representative involved in a recent 40-hectare mangrove planting project in An Thanh Nam commune, part of the MD-ICRSL initiative The interview process included clear explanations of the questions and context, facilitating the respondents' understanding and engagement with the issues at hand.
Open-ended questions were employed in face-to-face interviews to gather insights on the CC tragedy, the effects of natural disasters on the community, and the significance of mangrove forests This qualitative approach is vital for research as it facilitates information collection from experts in the field Additionally, in-depth interviews provided a deeper understanding of the interviewees' perspectives.
Surveys were conducted in the communes of An Thanh Nam and An Thanh 3 using a closed-ended questionnaire to explore the role of mangroves in helping local communities adapt to climate change This study highlighted the importance of mangroves in sustaining biodiversity, supporting the food web, and generating income for residents Due to time constraints, interviews were completed with 54 out of the 80 selected households.
A great effort was made to speak with a variety of subjects during the interview in order to achieve the goals of this study and get a range of responses
Figure 2.2 Interview resident and authorities
Figure 2.3 Meeting with authorities of Cu Lao Dung district
A trip by boat was taken to come inside the mangrove forest Besides, a motorbike was also used to go along the sea dyke and visit some livelihood models under the
The observation of the forest canopy and mangrove forest provided valuable insights, enhancing the reliability of data collection Accompanying photos effectively illustrated the findings from this observation, reinforcing the importance of visual documentation in environmental studies.
Various mangrove species and creatures in the mangrove forest were observed while traveling and taking advantage of the resources of mangroves in local communities was also recognized.
Figure 2.4 Observation in the boat in the first trip
Figure 2.5 Observation of mangrove forest in the second trip.
Figure 2.6 Visiting some livelihood models under the forest canopy
Microsoft Excel 2010 is utilized for data processing, with an Excel document serving as the basis for summarizing and synthesizing the primary data to generate the figures.
The data results were processed specifically as follows:
The study examines the manifestations of climate change (CC) and natural disasters in the An Thanh Nam and An Thanh 3 communes by analyzing key indicators such as temperature, precipitation, flooding, drought, salinity intrusion, and inundation Secondary data were collected and evaluated using descriptive analysis techniques to highlight these critical environmental changes in the region.
Structure and characteristics of mangroves: Secondary information was gathered to define the species' traits, distribution, and tree species' heights in the mangroves
Maintaining biodiversity and food webs of mangroves: Secondary datas used for analysis The links between mangrove species are described and examined using descriptive analysis techniques
Carbon storage: We gathered secondary data and used descriptive analysis techniques
40 to examine it In the two study regions, the data on the carbon storage capacity in mangroves (mangrove trees and soil) were studied and compared
The impact of climate change (CC) on community life was assessed through primary survey data, revealing insights into how effectively measures can be implemented to mitigate the effects of CC and natural disasters on individuals' lives.
The survey and in-depth interviews conducted revealed critical insights into maintaining livelihoods, focusing on various occupations, the types of resources harvested from mangroves, and fishing techniques utilized within the forest This data was meticulously analyzed using narrative analysis to uncover the intricate relationships between local communities and their natural resources.
RESULTS AND DISCUSSION
The impact of climate change on biodiversity
Distinctive ecosystems of Cu Lao Dung mangroves are subject to changes due to climate, which includes:
1) Erratic rains: counter-seasonal rain in dry seasons and heavy precipitation in rainy seasons;
3) Inundation associated with sea level rise;
4) Landslide due to the combination of waves, counterwinds and inundation;
The following diagram illustrates how climate-related hazards and events have affected
Cu Lao Dung's distinctive ecosystems in both positive and negative ways
Table 3.1 Climate-related hazards and events in Cu Lao Dung
Mani-festation Negative impact Positive influence
Counter- seasonal rain in dry season
In dry season, local great rains come suddenly, sometimes at nights
- Sudden rains can conduce to the appearance of alum at cultivation floor and poison farmed trees
- Some types of insect (mosquitoes, flies, etc.) may prosper after such rains
- Some sorts of water-lacked and salty farmed trees can avoid withering
- Dipping heat waves in dry seasons Irregular rain: long- lasting and
- At the onset of the rainy season, there appear
- Great rains might inundate, affecting farms
- Great rains at the onset of seasons bring about
42 intense rain and at the end of the rainy season sudden intense thundershowers
- At the end of the rainy season, there occur irregular highly intensive long- lasting rains
- Biologic progress could be affected positive effects for farms, which are about to be prepared
- Long-lasted great rains condition positively extensive shrimp farming, enhance metabolism inside aquatic farms and stimulate shrimp to grow stronger
- Great rains mean more supply for fresh water
- Unpredictable weather conditions in dry seasons
- Higher frequency of days with temperature above 35 0 C than 10 years ago
- Heat waves cause dramatic diseases
- Bivalves and mollusks growing on alluvium may die simultaneously owing to heat waves or heat- waves-related diseases
- Maladies such as bird flu have a tendency to boom, affecting negatively birds in general
Flora may blossom thanks to increasing photosynthesis
Inundation alongside sea level rise
The rise of sea level alongside remarkable inundations within a year (October and November) cause the accelerating seriousness of saline intrusion
- The area of mangroves might descend because of deep sinking
- Salinity-tolerant species can be extinguished
- Sedimentation advances may lead to constitution of new alluvium
- Sand-exploitation areas are enriched by the amount of sand from eroded ones or from deposited alluvium Erosion due to the combination of waves, winds and inundation
Inundation along with counterwind (especially in January and February) may cause erosion
- Erosion can cause the loss of soil and areas of forest and therefore, the loss of natural nourishment for species;
- Erosion may destroy the wave- protection-hedge
- Exploitation of sand along rivers could heighten the risk of land-sliding
Tropical depressions, typhoons and cyclones
Tropical depression and typhoon are likely to climb compared to 10 years ago and defy formed regulations
- Damage mangroves and living environs of many species
The natural role of mangrove forests
3.2.1 The role in storing carbon
The distinction between natural roles and social roles in storing carbon is relative because natural roles partly include social roles, and vice versa in this issue
Mangroves are vital tropical woodlands that serve both environmental and commercial purposes, exhibiting high productivity rates comparable to coral reefs and tropical forests Despite covering only 0.5% of the global coastline, they significantly contribute to coastal carbon storage, accounting for 10-15% of terrestrial carbon exports to the ocean Their importance in carbon sequestration has led to growing recognition of their conservation and restoration potential in mitigating greenhouse gas emissions However, deforestation poses a serious threat, resulting in carbon losses that can reach up to 970 TgC per year, which exceeds the carbon storage capacity of these ecosystems A notable amount of this carbon loss is attributed to the movement of dissolved inorganic carbon from deep soils to streams, potentially representing 40% of annual primary production.
Nguyen and her team conducted a study on carbon stock in the mangrove forests of Hai Lang Commune, Tien Yen District, Quang Ninh Province, Vietnam Their findings revealed that each hectare of mangroves sequesters a total of 607.48 tons of CO2 (Nguyen et al., 2018).
This study highlights the similarities in biodiversity between the mangroves of Cu Lao Dung and those in Hai Lang commune, Tien Yen district, Quang Ninh province Based on this data, we can estimate the results for the Cu Lao Dung mangrove ecosystem as follows:
Table 3.2 Total of CO2 sequestrationin Cu Lao Dung mangroves (Unit: Ton/ha)
CO2 sequestration in mangrove forest (ton/ ha)
Total of CO2 sequestration in mangrove forest (ton)
Mangrove forests are crucial for mitigating climate change as they effectively store carbon in three key areas: above-ground vegetation, below-ground roots, and soil These unique ecosystems can sequester three to four times more carbon than terrestrial forests, highlighting their significant role in carbon storage and climate regulation (Charles, 2020).
Mangroves play a crucial role in carbon storage, significantly aiding in climate change mitigation Although they occupy just 0.5% of the global coastline, these vital ecosystems contribute 10-15% of the carbon stored in coastal sediments and export 10-11% of terrestrial carbon to the ocean, highlighting their importance in coastal carbon dynamics.
Based on comparative studies, the Cu Lao Dung mangrove forest is estimated to have a carbon storage capacity similar to that of the mangroves in Hai Lang commune, Tien Yen district, Quang Ninh province The average CO2 sequestration rate in Cu Lao Dung is approximately 607.48 tons per hectare With a total area of 1,787.64 hectares, the overall CO2 sequestration in this region amounts to 1,085,955.55 tons.
Mangroves play a vital role in carbon storage and CO2 sequestration, significantly contributing to the reduction of greenhouse gas emissions and the fight against climate change To maintain their carbon storage capacity and maximize environmental benefits, it is essential to conserve and restore mangrove ecosystems Protecting existing mangrove forests and promoting the reforestation of degraded areas are crucial efforts to enhance carbon storage and preserve the invaluable services provided by these ecosystems.
The social roles of mangrove forests
3.3.1 The role in maintaining local livelihood a Status of resources in Cu Lao Dung mangroves
In recent years, forest resources have seen a significant increase, largely due to the efforts of local authorities and forest co-management boards, which have nearly halted deforestation Additionally, initiatives to plant more trees have greatly expanded forested areas.
Human activities and climate change have led to a significant decline in the production of natural aquatic species Interviews with local residents reveal that, in the past, fishery resources were plentiful and easily accessible Today, however, these resources are severely depleted, resulting in increased challenges for local communities.
In recent years, the livelihoods of residents in An Thanh Nam and An Thanh 3 communes have shifted from relying solely on natural aquatic resources to adopting sustainable practices due to declining aquatic species caused by human activities and climate change To enhance the coastal protection forest in Cu Lao Dung and balance local interests, the Provincial People's Committee has approved the expansion of forest areas on coastal alluvial land, integrating aquaculture beneath the forest canopy This innovative approach, particularly the cultivation of woolen snails and turtles, has not only provided stable incomes for many households but has also played a crucial role in preserving mangrove ecosystems in the Cu Lao Dung district.
People in 2 communes An Thanh Nam and An Thanh 3 live on different types of livelihoods, mainly focusing on farming, raising cattle and poultry, aquaculture and fishing
As mentioned above, this study separated households into two livelihood groups as follows:
(1) Households whose livelihoods depend on mangroves (Group 1 with 33 households)
(2) Households whose livelihoods do not depend on mangroves (Group 2 with 21 households)
Interview results are shown below:
Figure 3.1 Average monthly income of households
The study surveyed 33 households, revealing a significant income disparity; the lowest average monthly income was 7 million VND, while the highest reached 25 million VND after accounting for investment costs in their livelihood model Overall, households dependent on mangrove forests reported an average monthly income of 11 million VND.
The second group comprises 21 households, with average monthly incomes ranging from 5 million VND to 10 million VND, taking into account investment costs associated with their livelihood model As a result, the average monthly income for households dependent on mangrove forests is 7.1 million VND.
Interviews reveal that mangrove forests play a vital role in supporting the livelihoods of dependent households, which enjoy significantly higher average monthly incomes In contrast, households not reliant on mangroves experience an average income that is approximately 65% lower.
Interviews reveal that many households not directly dependent on mangrove forests are eager to explore livelihood models under the forest canopy However, these households currently face barriers that prevent their participation Several diverse livelihood models are available in the region, highlighting the potential for greater engagement.
Aquaculture and fishing under the forest canopy:
Mr Tran Van Khoe, a member of the Forest Planting and Protection Group in An Thanh 3 Commune, joined the initiative in 2020, benefiting from support to raise clams and snails under the forest canopy He has successfully cultivated over 3.7 tons of snails and scallops, which he harvests after four months, alongside poultry farming, yielding a monthly profit of tens of millions of Vietnam dong Currently, Mr Khoe maintains a 2-hectare area under the forest canopy, with more than 700 kg of snails and 3 tons of scallops, supported by the ICRSL Project.
Since the beginning of 2022, he has successfully harvested 600 kg of snails, selling them at 80,000 VND per kg, resulting in earnings exceeding 30 million VND Additionally, his scallop yield is estimated at 6 tons, with a selling price of 30,000 VND per kg, generating a profit of over 18 million VND He notes that raising scallops and snails under the forest canopy incurs no costs for food and care, as these creatures thrive on the abundant natural food supply available in their environment, leading to impressive growth.
Many households engaged in forest protection not only practice aquaculture beneath the forest canopy but also set up nets to catch permitted seafood, generating an additional income of 200,000 to 300,000 VND per day This extra income is sufficient for families to meet their daily expenses.
Mr Tran Van Muoi - Head of the aquaculture group under the forest canopy, An Thanh
Since 2019, An Thanh 3 commune has implemented a model for raising aquatic species under forest canopies, starting with a pilot farming area of 2,000 m² This initiative has successfully expanded to encompass 10 hectares of aquaculture, within a total forest area of over 97 hectares in the commune.
With the backing of various programs and agencies, the area dedicated to aquaculture under forest canopies has significantly increased This initiative not only enables local communities to engage in forest conservation but also provides them with an additional income source, particularly benefiting households lacking productive land and promoting sustainable livelihoods.
Sea ducks are a newly developed species well-suited to the challenges posed by climate change, such as salinity intrusion and drought An Thanh Nam, a coastal commune, provides an ideal environment for sea duck farming Breeding these ducks is similar to traditional methods, requiring minimal investment while allowing for the utilization of abundant, nutrient-rich natural food sources.
The Department of Animal Husbandry and Veterinary Medicine in Soc Trang province, in partnership with the Veterinary Station of Cu Lao Dung district, conducts regular training sessions on biosecurity and climate change adaptation techniques for raising sea ducks These sessions target numerous farming households in An Thanh Nam commune, enhancing their farming practices and sustainability.
With a selling price of approximately 80,000 VND per kilogram, households can earn tens of millions of VND monthly from their duck herds, including additional income from selling duck eggs.
Recommendations
Interviews with officials and local residents have led to several recommendations aimed at promoting the sustainable and effective use of natural resources while enhancing the Cu Lao Dung mangrove forest's role in addressing climate change.
About improving livelihoods for people in the model of aquaculture under the forest canopy.
The local government has permitted certain households to engage in aquaculture under the forest canopy, supported by initial seed funding from both domestic and foreign projects These households have reported positive outcomes, with income generated from selling their aquaculture products significantly contributing to their livelihoods To enhance the well-being of communities surrounding mangroves, it is essential to sustain this livelihood model and explore additional projects and funding opportunities to enable broader participation.
About increasing local revenue based on exploitation of ecotourism services in mangroves.
Currently, the only ecotourism service available is a bamboo bridge system managed by a local household in An Quoi hamlet, An Thanh 3 commune, which allows visitors to explore the forest free of charge This lack of fees means local authorities are unable to secure funds for future maintenance and upgrades To address this, it is essential to introduce a fee for visitors, which would help generate revenue for the local budget Additionally, implementing a program where each visitor can purchase and plant a small tree could provide further financial support for mangrove protection efforts.
Identifying capital sources and applying a comparable fee-based model in An Thanh Nam commune is crucial, given that its mangrove forest area is significantly larger than that of An Thanh 3 commune.
Promote, develop and improve tourism and accommodation services in mangrove areas.
Soc Trang province's tourism development plan for 2022-2025, with a vision towards 2030, emphasizes marine eco-tourism in Cu Lao Dung The province is equipped with a high-speed wharf facilitating the Tran De-Con Dao route, operational since 2017, with 3-5 daily trips However, most tourists tend to visit Con Dao island and then proceed to other destinations, with few choosing to explore Cu Lao Dung This is largely due to the lack of diverse accommodation options and forest tours in the area Therefore, enhancing and promoting tourism and accommodation services in the mangrove regions is essential for attracting more visitors.
Access to the market for carbon credits
Local authorities in Cu Lao Dung have yet to capitalize on the potential of mangrove forests for carbon credit trading, despite the current market price of approximately $5 per ton of CO2 (Stephen et al., 2021) The mangroves in Cu Lao Dung have a carbon storage capacity of around 2,806 tons per year, which could generate an estimated annual revenue of $14,030 By engaging in carbon credit trading, the government could leverage this revenue to invest in forest protection and conservation, ultimately supporting sustainable environmental practices.
64 economic and social benefits derived from the mangroves, as well as support the livelihoods of local communities.