Melaleuca Forest Research Articles

The phenomenon of Peatmass Change and Its Impact on Water Level in The Regenerated Melaleuca Forest Following a Fire Incident in U Minh Thuong National Park, Vietnam

Purpose: The study was conducted in U Minh Thuong National Park to address forest regeneration. Theoretical framework: After a major forest fire in Vietnam, various measures were taken to promote forest regeneration, including afforestation, silvicultural solutions, and hydrological techniques such as rainwater storage to maintain humidity and prevent future fires. Method: Using a drill hand to collect samples at 15 plots to understand forest growth on three thickness levels of a pea. Each site to collect samples is three; each sample was one kg and coded a member of the site as UTM1, UTM2, UTM3, then gets to the Southern Institute of Forestry Science laboratory for analysis. Results and conclusion: There was a relationship between peat chemical indicators and the evolution of the Melaleuca forest. Peat thickness and flooding regime significantly influenced the growth of the Melaleuca forest, while another identified a relationship between peat chemical indicators and forest growth. Peat water's chemical composition changed considerably during the rainy and dry seasons, with nutrient content and pH affecting forest growth. Peat thickness and flooding regime were essential in regulating forest growth. These studies highlight the importance of considering multiple factors, such as peat thickness and chemical properties, when developing effective forest restoration strategies. Implications of the research: By understanding the relationship between peat thickness, chemical properties, and forest growth, forest managers can develop targeted strategies to promote regeneration while minimizing negative impacts on biodiversity. Originality/value: This study explores the relationship between peat thickness, chemical properties, and forest growth in forest regeneration after major fires. It integrates forestry, ecology, and hydrology to provide a holistic understanding of vegetation dynamics and the importance of peatlands in forest regeneration.

Peatmass Change and Water Level Influencing Regenerated Melaleuca Forest after a Fire in U Minh Thuong National Park, Vietnam

Following the largest forest fire in Vietnam in 2002, various activities were undertaken to sustain the mangrove forest on peat soil remnants in the Mekong Delta region. These activities included promoting natural regeneration, afforestation, and rapid forest restoration measures, in addition to other protective measures such as rainwater retention to maintain moisture levels for fire prevention. However, two critical challenges emerged: allowing the forest to naturally regenerate would lead to annual forest fires but maintaining a constant water level through year-round water retention would harm biodiversity. The study was conducted in U Minh Thuong National Park to address forest regeneration. After a major forest fire in Vietnam, various measures were taken to promote forest regeneration, including afforestation, silvicultural solutions, and hydrological techniques such as rainwater storage to maintain humidity and prevent future fires. A hand drill was used to collect samples, and a total of 15 plots were set up to survey the growth of the forest at three peat thickness levels. At each of the three collection sites, samples of one kg were collected and labeled according to the site as UTM1, UTM2, and UTM3. The samples were then sent to the laboratory of the Southern Institute of Forestry Science for analysis. There was a relationship between the chemical indicators of peat and the evolution of the Melaleuca forest. Peat thickness and flooding regime significantly influenced the growth of the Melaleuca forest, while another identified relationship was between peat chemical indicators and forest growth. The chemical composition of peat water changed significantly due to the rainy and dry seasons, with nutrient content and pH affecting forest growth. Peat thickness and flooding regime were essential in regulating forest growth. These studies highlight the importance of considering multiple factors, such as peat thickness and chemical properties, when developing effective forest restoration strategies. By understanding the relationship between peat thickness, chemical properties, and forest growth, forest managers can develop targeted strategies to promote regeneration while minimizing negative impacts on biodiversity.

Organic matter decomposition and associated microbial communities in wetlands: insights from tropical and subtropical Melaleuca forests in Australia

Organic matter decomposition and associated microbial communities in wetlands: insights from tropical and subtropical Melaleuca forests in Australia

Economic valuation from direct use of melaleuca forest at U Minh Ha National Park, Vietnam

This paper investigates the direct use values of melaleuca forests at U Minh Ha National Park. The market price method (MPM) was utilised to estimate the economic value. A semi-structured questionnaire comprising multiple-choice and open-ended questions was administered to 360 families in 2022 to collect data on the various forest products available locally, the quantity of these products collected, as well as their corresponding prices and costs. The results revealed that the total net benefits that the local people derived from the entire melaleuca ecosystem were US$ 73,022,184 per year, or an average worth of US$ 1,723 per person per year. Most of the local annual income was derived from construction pole harvesting (US$ 57,092,223), followed by wood for fishing boats (US$ 5,792,757) and fish (US$ 6,226,995). The melaleuca ecosystem was significant, contributing an average of 75% to the total annual per capita income for the local people. However, the U Minh Ha melaleuca ecosystems are threatened and predicted to disappear in 118 years if the current extraction rate of wood products (2,204 kg/person/year) remains uncontrolled. This suggests an urgent need for an integrated management plan that incorporates melaleuca preservation, as well as the commercial and local use interests in this area.

Methane Emissions and Related Physicochemical Soil and Water Parameters in the Peat Swamp and Melaleuca Forests of U Minh Thuong National Park in Vietnam

Methane Emissions and Related Physicochemical Soil and Water Parameters in the Peat Swamp and Melaleuca Forests of U Minh Thuong National Park in Vietnam

Assessing the Impacts of Dike Systems on Water Quality in Natural Reserves of the Vietnamese Mekong Delta

Protected places such as nature reserves (NRs) are used to maintain ecological balance, biodiversity, and support surrounding ecosystems. However, the development and operation of infrastructure such as dikes and sluice gates in NRs, as seen in the Vietnamese Mekong Delta (VMD), often adversely affects the hydrological regime and water quality at both local and regional scales. This study analyzes the consequences of a constructed dike system on the hydrological regime and water quality in the NRs through an integrated approach including hydrochemical analysis (using descriptive statistics and weighted arithmetic water quality index (WAWQI) analysis), traditional interviews (face to face), using semi-structured questionnaires, field surveys, and secondary data. Results show that constructed infrastructure has helped maintain water supplies for both livelihoods and forest fire prevention. However, considerable impacts on the hydrological regime and water quality have occurred. From water quality assessments in three NRs, 29% of sampling sites in the My Phuoc melaleuca forest (MPMF) had WAWQI values over 100, while all sites in Lung Ngoc Hoang NR (LNHNR) and Mua Xuan Agriculture Center (MXAC) had WAWQI values over 100. This was to a large extent due to elevated concentration of chemical oxygen demand (COD), biological oxygen demand (BOD5), and phosphate (PO43−). Meanwhile, during the wet season, pollution was marginally reduced by dilution, with 42.86% of sites at Lung Ngoc Hoang NR, 28.57% of sites at MXAC, and 78.57% of sites at MPMF having WAWQI values of less than 100. These results show the issue of water pollution at spatio-temporal scales, and call for better holistic management options for improving the hydrological regime and water quality.

Restoration impacts on rates of denitrification and greenhouse gas fluxes from tropical coastal wetlands

Forested coastal wetlands are globally important systems sequestering carbon and intercepting nitrogen pollution from nutrient-rich river systems. Coastal wetlands that have suffered extensive disturbance are the target of comprehensive restoration efforts. Accurate assessment of restoration success requires detailed mechanistic understanding of wetland soil biogeochemical functioning across restoration chrono-sequences, which remains poorly understood for these sparsely investigated systems. This study investigated denitrification and greenhouse gas fluxes in mangrove and Melaleuca forest soils of Vietnam, using the 15N-Gas flux method. Denitrification-derived N2O was significantly higher from Melaleuca than mangrove forest soils, despite higher potential rates of total denitrification in the mangrove forest soils (8.1 ng N g-1 h-1) than the Melaleuca soils (6.8 ng N g-1 h-1). Potential N2O and CO2 emissions were significantly higher from the Melaleuca soils than from the mangrove soils. Disturbance and subsequent recovery had no significant effect on N biogeochemistry except with respect to the denitrification product ratio in the mangrove sites, which was highest from the youngest mangrove site. Potential CO2 and CH4 fluxes were significantly affected by restoration in the mangrove soils. The lowest potential CO2 emissions were observed in the mid-age plantation and potential CH4 fluxes decreased in the older forests. The mangrove system, therefore, may remove excess N and improve water quality with low greenhouse gas emissions, whereas in Melaleucas, increased N2O and CO2 emissions also occur. These emissions are likely balanced by higher carbon stocks observed in the Melaleuca soils. These mechanistic insights highlight the importance of ecosystem restoration for pollution attenuation and reduction of greenhouse gas emissions from coastal wetlands. Restoration efforts should continue to focus on increasing wetland area and function, which will benefit local communities with improved water quality and potential for income generation under future carbon trading.

Orchids diversity on six forest types in Wasur National Park, Merauke, Papua, Indonesia

Abstract. Kusumastuti NK, Suratman, Pitoyo A. 2021. Orchids diversity on six forest types in Wasur National Park, Merauke, Papua, Indonesia. Asian J For 5: 101-110. Orchidaceae is one of the two largest families of flowering plants. Wasur National Park is the habitat of many orchid species and one of the in-situ conservation areas in Papua that is very suitable for orchids. This research aimed to determine the orchid species in Seksi Pengelolaan Taman Nasional Wilayah III (SPTN III) Wasur, Wasur National Park, Merauke District, Papua Province, Indonesia and to determine the distribution of orchid species in six different types of forest. This research was conducted using the exploratory method. A total of 25 orchid species belonging to 11 genera have been identified from SPTN III Wasur. Monsoon forest is the type of forest with the highest number of orchid species, with 15 orchid species. It is followed by savanna with ten species, Melaleuca forest with ten species, woodland forest with nine species, riparian forest with six species, and Melaleuca-Eucalyptus forest with 5 species. Dendrobium smillieae and Dendrobium rigidum are the most widely distributed epiphytic orchid species, and occur in almost all forest types. However, the terrestrial orchids, Geodorum densiflorum and Apostasia wallichii, are only found in the monsoon forest.

Modelling the susceptibility of wetland plant species under climate change in the Mekong Delta, Vietnam

Wetlands are important ecosystems that provide many critical services for ecology and human communities. In the Mekong Delta (MD), Vietnam, the combined effects of climate change and sea level rise (SLR) threaten coastal mangrove forest wetlands, while inland Melaleuca forest wetlands are affected by regional changes in climate. Hence, it is essential to understand the impacts of climate change and SLR on these wetlands, particularly on the dominant species, which are integral to the structure and function of each wetland type. However, future climate suitability for wetland species is not yet well documented and well researched for the region. Therefore, this study examines the potential impacts of climate change and SLR on the three dominant species of these wetland types, Avicennia alba (A. alba) and Rhizophora apiculata (R. apiculata) in coastal mangrove forest wetlands and Melaleuca cajuputi (M. cajuputi) in inland Melaleuca forest wetlands, utilizing an ensemble modelling approach. The species occurrence points, bioclimatic and eco-physiological variables were used to model habitat suitability for the three species under current and future climate scenarios, RCP4.5 and 8.5 for 2050 and 2070. The projected reduction in habitat suitability of A. alba, R. apiculata, and M. cajuputi by mean values of 27.9%, 28.7% and 30.0%, respectively by the year 2070 indicates the vulnerability of the wetland species to climate change impacts. Increases in temperature, and in seasonal variation in precipitation and temperature, and SLR were key driving factors responsible for the losses of suitable habitat. Our findings provide useful information and data sources for development of plans and strategies to protect and conserve the wetlands from future climate change impacts.

Methane and carbon dioxide emissions from different ecosystems at the end of dry period in South Vietnam

The carbon cycle includes important fluxes of methane (CH4) and carbon dioxide (CO2) between the ecosystem and the atmosphere. The fluxes may acquire either positive (release) or negative values (consumption). We calculated these fluxes based on short-campaign in situ chamber measurements from four ecosystems of South Vietnam: intact mountain rain forest, rice field, Melaleuca forest and mangroves (different sites with Avicennia or Rhizophora and a typhoon-disturbed gap). Soil measurements were supplemented by chamber measurements of gas fluxes from the tree stems. Measuring CH4 and CO2 together facilitates the assessment of the ratio between these two gases in connection with current conditions and specificity of individual ecosystems. The highest fluxes of CH4 were recorded in the Melaleuca forest, being within the range from 356.7 to 784.2 mg CH4–C m−2 day−1 accompanied by higher fluxes of CH4 release from Melaleuca tree stems (8.0–262.1 mg CH4–C m−2 day−1). Significant negative soil fluxes of CH4 were recorded in the mountain rain forest, within the range from − 0.3 to − 0.8 mg CH4–C m−2 day−1. Fluxes of CO2 indicate prevailing aerobic activity in the soils of the ecosystems investigated. Quite a large variability of CO2 fluxes was recorded in the soil of the Avicennia mangroves. The in situ measurements of different ecosystems are fundamental for follow-up measurements at different levels such as aerial and satellite gas fluxes observations.

Разработка карт состояния земельных угодий национального парка Трам Чим (Вьетнам) по результатам мониторинга

Tram Chim National Park in Southern Vietnam is a wetland area included in the system of specially protected natural areas (SPNA). For the purposes of land monitoring, we studied Landsat-5 and Sentinel-2B images obtained in 1991, 2006 and 2019. The methods of normalized difference vegetation index (NDVI) and water objects – normalized difference water index (NDWI) were used to estimate the vegetation in National Park. The allocated land is classifi ed by the maximum likelihood method in ENVI 5.3 into categories. For each image, a statistical analysis of the land after classifi cation was performed. Between 1991 and 2019, land changes occurred in about 57 % of the Tram Chim National Park total area. As a result, the wetland area has signifi cantly reduced there due to climate change. However, the area of Melaleuca forests in Tram Chim National Park has increased due to the effi ciency of reforestation in protected areas. Melaleuca forests are also being restored.

Vegetation Indices for Identifying Melaleuca Forest from Multispectral Satellite Sensors

Melaleuca forest or locally known as Gelam forest mostly occur in beach ridges interspersed with swales (BRIS) sandy areas, coastal, wetland, peatland, and lowland regions. It is a mono-specific species dominance ecosystem, where Melaleuca cajuputi trees are dominant. It is fringing along the coast of Terengganu and Kelantan and certain parts along the west coast of Peninsular Malaysia. The landscape is small but it has equal importance to other ecosystems in terms of local environmental functions and economic contributions. The benefits include timber for building constructions and furniture and other traditional uses, such as for fuel wood, charcoal, tea-tree, honeybee breeding areas and others. However, this forest is inevitable from threats by anthropogenic activities such as land clearing and conversion to other land uses that can affect the ecosystem. These activities occur because most of this ecosystem reside on stateland areas, where development is rapid. Only small patches of this forest was protected as Permanent Forest Reserve, which is secure from any threat. Currently the information about the tracts and extents of this forest is very scarce. Therefore, this study was carried out to acquire latest information on the distribution and extent of Melaleuca forest in Peninsular Malaysia through the utilization of remotely sensed data. Optical images from Landsat-8 OLI were used as primary input for this study. Spectral characteristic from visible and infrared regions were analyzed to produce a specific vegetation index for recognizing Melaleuca forest ecosystem on the images. The study demonstrated that the Melaleuca forest covers some 23,000 ha in Peninsular Malaysia that are intact but vulnerable to surrounding threats. The findings of study should attract attentions from the relevant State Governments to take appropriate management actions to protect this unique and priceless ecosystem in the future.

English

U Minh Thuong National Park is one of the two significant areas of peatland swamp forest remaining in Vietnam, and is recognized as one of the three highest priority sites for wetland conservation in Mekong Delta. A large area of Melaleuca Forest in the park was destroyed and degraded by a devastating fire in 2002. Besides this, an artificial flooding technique for controlling fire applied all over the park for several years changed the natural development of Melaleuca Forest. As the natural condition of the forest has changed, water management (artificial flooding) needs to be implemented to save this situation. Flooding regime has changed the structure and composition of the peatland, making it to be loose and reduced in structure. The peatland area in the park has water level of 30 cm underground and occupies 15% of the total park area. It emits very large amount of CO2 emissions. The main objective of this work is to study how to protect the forest biodiversity from fire by controlling its water level optimally after rainy season and to study the chemical and physical characteristics of the peatland soil of the forest that affect its water level Key words: Melaleuca Forest, peatland, flooding,

Evaluation of current situation of melaleuca forest in the U Minh Ha national park, Vietnam under the situation of climate change and proposed solutions for conservation and sustainable development

U Minh Ha National Park (UMHNP) is one of the important biosphere reserves in Viet Nam, this park still has a pristine ecosystem like natural melaleuca forest on peatland in the core zone of UMHNP. Melaleuca forest is not only economic revenue for native people but also the habitat for all the species in UMHNP. However, facing to current climate change and fire prevention of UMHNP has made the growth of melaleuca forest get some negative effects. Melaleuca cajuput can grow in a wetland if the depth of water is not high and waterlogged duration is not last long. If the water depth is over 50 cm and waterlogged duration is more than 5-6 months the roots of this land will be damaged. Currently under the condition of climate change, in the dry season, the high temperature and prolonged heat make the herbaceous and liana vegetation die and form burning materials. Unevenly distributed rainfall combined with prolonged heat increases the risk of forest fire, especially in the last months of the dry season. To prevent forest fires, the U Minh Ha national management board always maintains high water levels in canals, maintaining high water levels for a long time reducing the risk of forest fire but also makes peat land dilated leads to the fallen of Melaleuca trees. At the same time, at the beginning of the rainy season, heavy local rainfall led to the phenomenon of alum in this area. This research has shown the current state of U Minh Ha National Park under climate change status and proposed some measures to help Melaleuca forest grows sustainably.

Thành phần loài cá trong vùng đệm khu bảo tồn U Minh Thượng và U Minh Hạ

U Minh National Parks, which comprises of U Minh Thuong (UMT, Kien Giang province) and U Minh Ha (UMH, Ca Mau province) with the typical Melaleuca forest ecosystem submerged in aluminum soil is a habitat for many freshwater fish species. This study was aimed to identify fish composition distributed in areas around UMT and UMH National Parks. After the sampling period (09/2017 to 08/2019), 54 fish species were found belonging to 40 genera, 23 families and 10 orders in UMT, and 31 fish species belong to 22 genera, 13 families and 6 orders in UMH. Ooders Cypriniformes and Perciformes show high numbers of species in both two areas. Nevertheless, fish in UMT area is more abundant and diverse. Particularly, there were 4 orders, 10 families and 20 genera only appearing in UMT such as Cyclocheilichthys apogon, Clupeichthys aesarnensis, Macrognathus circumcinctus, Parambassis wolffii,… Conversely, two fish species including Amblypharyngodon chulabhornae and Parambassis siamensis were found only in UMH. Differences in fish composition can be explained by levels of water exchange inside and outside of National Park and degrees of alum intrusion in water in these two study areas.

Recent use of habitat service value for tourism and impacts on coral reefs in the target destinations in Southern Vietnam

Coral reef-based tourism has developed quickly in Southern Vietnam, taking into account the target locations namely Cu Lao Cham islands, Nha Trang bay, Ninh Thuan and Phu Quoc islands during last decade. Among them, Nha Trang bay had longer history of marine tourism, starting with inshore development and expanding to islands in and around the bay. Tourist activities in Cu Lao Cham islands and Ninh Thuan were developed in linkages with MPA development and management. Meanwhile, Phu Quoc had become a new destination and drawn huge investments for extensive development of tourism in the islands. Economic value that was brought from use of coral reefs for tourism has increased significantly. For example, the payment of entry fee to Cu Lao Cham MPA has quickly increased year by year, reaching approximately 700,000 USD in 2018 and that in Ninh Thuan around 50,000 in 2017 and up to 200,000 USD in 2018. Reclamation for infrastructure building on inshore land and islands was considered as a serious impact, resulting in loss of terrestrial and underwater habitats (e.g. loss of Melaleuca forest in Phu Quoc islands or seagrass beds and coral reefs in Nha Trang bay) and increased sediment loading to coral reefs. Overexploitation of living resources for high food and souvenir demands occurred at all areas, leading to modification of communities, poorness and uncertainty for resource recruitment. Among these tree areas, Phu Quoc waters are the most vulnerable to coral bleaching due to increased surface temperature with records of mass bleaching in 2010 and 2016. Although MPAs existed in all study areas, role of conservationists in developing coral reef tourism was significantly considerable only in Cu Lao Cham case but poor in others. Local managers and businesses should pay more attention to sustainability in order to ensure not only coral reef conservation but also long-term benefits of local communities and tourist sector itself.

SPECIES COMPOSITION AND HABITAT OF BUTTERFLY IN MUA XUAN AGRICULTURAL CENTER, HAU GIANG PROVINCE

The survey was carried out in Mua Xuan agricultural center, Hau Giang province from 9/2014 to 12/2014. The study recorded 41 butterfly species, which belong to 32 genera of 05 families. Nymphalidae was the most dominant family, followed by Pieridae, Hesperiidae and Lycaenidae whereas Papilionidae had the lowest frequency of occurrence. The findings also indicated that Melaleuca forest and roadside sight were two diverse habitats where the butterfly species were found most.

Enhancing bird diversity through improved water management in a Viet Nam wetland national park

U Minh Thuong National Park, one of the two largest remaining peat swamp, melaleuca forests in Viet Nam is a very Important Bird and Conservation Area because of its diverse wetland habitats. A devastating forest fire in 2002 resulted in a new regime of fire control based on an imposed permanent flooding regime over large areas of the Park that led to severe wetland and forest degradation. This in turn negatively impacted on bird species diversity and populations. In 2009, the Government of Viet Nam and the park authority adopted an improved water management practice. A survey four years later recorded two new species in the list of 159 bird species for the park. Of these, 25 threatened species were using the wetland park and adjacent Buffer Zone for living and feeding habitat. Based on the largest count occurring during three continuous days, the water bird population in the bird colony in 2013 increased by 33 per cent compared to the 2009 level. The positive response of avifauna to the changes in U Minh Thuong with respect to the hydrology of seasonally flooded melaleuca wetland forest indicates the need to understand how the ‘normal’ wetland processes operate in support of biodiversity conservation before modifying them for fire management.

Xác định các dịch vụ hệ sinh thái của hệ sinh thái rừng tràm ở vùng đệm Vườn Quốc gia U Minh Hạ - Cà Mau

This study is aimed to evaluate ecosystem services in the buffer zone of the National Park of U Minh Ha, Ca Mau province. One hundred and twenty households representing four cultivating models including intensive cultivation of Acacia hybrid and Melaleuca cajuputy, two rice crops, and integrated rice-shrimp were interviewed for the direct and indirect benefits supporting local people’s livelihoods in order to control and harvest the forest’s production as well as to maintain this natural resources concurrently. The overall results showed that provisioning services, regulating services and supporting services were the most important evaluation form those models (scored 5) accounting for 46.8%, 28.13%, and 25%, respectively whereas cultural services get no ideas for evaluation (0%). In this scope, it is necessary to identify Melaleuca ecosystem services under perception of different local stakeholders, in order for the local government to have a closer look on the common benefits among multi-stakeholders depending on Melaleuca forest, and thus to apply more appropriate strategies to conserve this ecosystem services such as ecotourism activities, scientific research enhancement.

Ảnh hưởng của biến động dòng chảy và độ mặn theo mùa đến (sinh trưởng và phát triển) cây tràm và cây dừa nước – Nghiên cứu tại rừng tràm Mỹ Phước, tỉnh Sóc Trăng

The Melaleuca forest plays an important role in preserving ecosystem services in My Phuoc, Soc Trang. Full-dyke and sluice gate system hasbeen built to prevent salinity and manage water. However, the change in water regime inside the dyke system may impact native plants. The aim of this research is to assess the effect of changes in water level and discharge to plant development inside the dyke system. The survey of cross section and average velocity was carried out during the dry season (5/2018) and rainy season (8/2018). The multivariates analysis and direct interview were also used to evaluate the water regime changing and plant development during both wet and dry seasons. The results show that the water level changes slightly and similarly in both seasons. Besides, the tendency of native plants area reduction is being paid attention and looked for solutions.