Valuation of provisioning ecosystem services from tram chim national park, Dong Thap province, Vietnam

Abstract

The final report of the project on the rational use of wetland natural resources in Tram Chim National Park (TCNP) with community participation during the 2012-2016 period has provided many interesting statistical data on the total number of households exploiting resources, average income, total products obtained, types of products, estimated total revenue, etc. However, since the end of the project until now, TCNP has not updated any additional data. This article uses a survey method of farmers combined with a market-based valuation method to determine the types of resources being exploited belonging to 4 groups of provisioning service: food, fuel, medicinal plants, and decorative materials. To assess the value, the article estimates the proportion of households and the average amount of resources exploited from 70 survey questionnaires. Results achieved: (i) Type of resources: there are 11 types of resources being exploited; (ii) Exploitation rate: food - 90% of surveyed households, medicinal plants 5.5%, fuel 3.5%, and decorative materials 1.0%; (iii) Annual exploitation volume: 284.3 tons of food, 2.0 tons of fuel, 1.4 tons of medicinal plants, and 1.2 ton of decorative materials; (iv) The estimated total value is 17.94 billion VND per year, with an average of 18,1 (±2,3) million VND/household/month. The results from the article demonstrate that TCNP is still providing a significant value of resource supply to society.

Introduction

Wetlands are an irreplaceable form of natural capital 1 , providing high-value ecosystem services that support a wide range of economic production and consumption activities. Wetland ecosystem services (WES) encompass the various goods and services derived from wetlands and semi-wetlands, including marshes, swamps, and tidal flats 2 , They contribute directly and indirectly to human welfare 3 . WES can be divided into four categories: (i) Provisioning services, providing direct-use resources, such as shrimp, fish, vegetables, medicine; (ii) Regulating services, helping reduce the impact of natural disasters, replenishing groundwater, and storing carbon through biomass (iii) Cultural services, providing resources for tourism, entertainment, aesthetics, and education activities; and (iv) Supporting services, which are the essential ecological functions that support ecosystem processes 4 . WES are inherently spatially heterogeneous in nature 5 . In some cases, the loss of these services is irreversible 6 , leading to irreparable environmental damage and associated negative impacts on human welfare.

The depletion and degradation of wetlands due to overuse are occurring rapidly on a global scale, reducing both the number and quality of WES. For example, 35% of global wetlands were lost from 1970 to 2015 7 , which has had a profound impact on human welfare. Therefore, wetlands need to be used strategically 8 to generate a more sustainable income stream. However, the value of WES and the changes in that value over time must be systematically and scientifically assessed.

Tram Chim National Park (TCNP) is one of the last remnants of the Dong Thap Muoi wetland ecosystem 9 . TCNP’s landscape largely depends on hydrology and soil type (Shepherd, 2008). The differences in composition and structure of plant communities among the wetlands contribute to the richness of ecological functions and biodiversity of TCNP, thereby providing a variety of valuable ecological goods and services 10 , 11 .

In their final report on the pilot co-management of natural resources in TCNP in 2009 12 , the management board presented statistics on the quantity of some of the products harvested within TCNP, such as fish, grazing grass, vegetables, snails, and firewood. In 2016, authors Tran Triet and Jeb Barzen noted that the most ‘desirable’ resource in TCNP for the buffer zone residents was fish. The local community also exploited other resources, such as turtles, snakes, birds, lotus, and water lilies for food. Additionally, some types of grass, such as ginger grass or nan grass, were harvested by local vegetable growers as covering material 13 . The final report of the project on the sustainable use of wetland resources in TCNP conducted during the period 2012–2016 14 and incorporating community participation, outlined the following: (i) employment of 300–350 households in the buffer zone, with an average income of 1.5–2.0 million VND/household/month; (ii) authorized utilization of resources included aquaculture, vegetables, grass, snails, melaleuca firewood, permitted exploitation period spanned four months annually, from September to December; (iii) the total revenue generated by the project was approximately 1.740 billion VND. Consequently, the 2016 data from this study were the most recent available statistics on resource usage in TCNP. According to clause 3, article 5 of Resolution No. 04/2024/NQ-HDTP of the Supreme People’s Court Council 15 , national parks are areas where fishing is prohibited under point b, clause 1 of article 242 of the Criminal Code. Therefore, it is necessary to conduct a study on the current state of resource exploitation inside TCNP to provide data to support management decisions.

Materials and Methods

Study site

The TCNP buffer zone is located within the administrative boundaries of five communes and one town (Phu Tho, Phu Hiep, Phu Thanh B, Phu Duc, and Tan Cong Sinh). The population of the buffer zone in 2022 was 3,429 households with 46,762 people, accounting for approximately 46.7% of the total district population. Tram Chim town and Phu Tho commune have the highest population of the communities considered in the buffer zone. The buffer zone contains 247 households classified as living below the poverty line and 119 considered near-poor (i.e., just above the poverty threshold), together accounting for 10.7% of all households, which is substantially higher than the district average of 2.26% 16 . The primary economic activities of the communes in the buffer zone are agriculture, including sectors such as rice cultivation, horticulture, livestock, and aquaculture. Additionally, the citizens in the buffer zone engage in traditional crafts (for example, plastic chair weaving, water hyacinth weaving, drying, incense making) and work as hired labor for agricultural production (for example, rice planting, weeding, spraying, fertilizing).

Figure 1 . Administrative map of the buffer zone of Tram Chim National Park 16

Data collection

The objective of this study is to provide a statistical description of two primary indicators: (i) the estimated/verified participation rate of households engaged in utilizing resources in TCNP, and (ii) the estimated/verified average monetary value derived by households that utilize resources from TCNP. The primary data used to assess the value of the services provided by TCNP were collected through structured household questionnaires.

Data collection

The objective of this study is to provide a statistical description of two primary indicators: (i) the estimated/verified participation rate of households engaged in utilizing resources in TCNP, and (ii) the estimated/verified average monetary value derived by households that utilize resources from TCNP. The primary data used to assess the value of the services provided by TCNP were collected through structured household questionnaires.

Data collection

The objective of this study is to provide a statistical description of two primary indicators: (i) the estimated/verified participation rate of households engaged in utilizing resources in TCNP, and (ii) the estimated/verified average monetary value derived by households that utilize resources from TCNP. The primary data used to assess the value of the services provided by TCNP were collected through structured household questionnaires.

Valuation method

The monetary value of different resources is estimated using the Market Price Method, as applied in previous studies 17 . In general, the annual income of a household exploiting j resources from the i-th ecosystem service (where food = 1, fuel = 2, medicinal plants = 3, and decorative materials = 4) is calculated using formula (3). For example, if Mr. A’s household extracts fish and vegetables from TCNP, both of which are part of the food provisioning service, then i = 1 and j = 2.

Where: Rij: income from j resources belonging to the i-th ES (m VND/hh/y).

l: number of household members exploiting in the protected area.

k: number of times to the protected area for exploiting each month (times)

t: number of months of utilization in a year (months)

The results obtained from the pricing process are five sets of annual income data corresponding to the provision of food, fuel, medicine, decorative materials, and the total annual household income derived from these services. These results were then statistically described using SPSS software to determine the average value and average level of resource use per household per year.

Data analysis

A descriptive statistical analysis was undertaken to determine the average income of households exploiting each ecosystem service and for the population. The variables used for this analysis are presented in Table 1 . The calculated average incomes were then tested using a one-sample t-test to determine whether the survey results on the sample were representative of the population. Finally, the proportion of households exploiting ecosystem services and the monetary value of the services provided by TCNP were assessed, and these results were interpreted.

Table 1 Variables used in this study

Results and Discussion

Results

Results

Results

Discussion

We conducted a comparison of the results of this study with the data published by TCNP in 2010 and 2016, as well as Triet & Barzen 2016 12 , 13 , 14 . This comparison included characteristics of resource extraction activities in TCNP, household income from resource extraction, and the results of the valuation of services provided by TCNP. Several differences were noted for several aspects, including types of extracted resources, household income from extraction activities, and the estimated value of ecosystem provisioning services:

The types of resources extracted: this study recorded an additional six types of resources being extracted in TCNP: (i) melaleuca honey, (ii) ricefield rats, (iii) some medicinal plants such as creek premna, asiatic pennywort, periwinkle, stinking passion, (iv) water hyacinth (stem and flower), (v) young lotus leaves, and (vi) broodstock. Among these resources, the largest extraction output is water hyacinth (about 2.7 tons/year), followed by ricefield rats (about 2,1 tons/year) and medicinal plants (about 2.6 tons/year). The remaining resources have a smaller extraction yield.

The time and frequency of extraction: previous documents determined about 4 months (from September to December) 14 . However, the results of this study show that the number of households extracting for up to 4 months accounts for 53% and the number of households extracting year-round accounts for 20% of the interviewed households. The average number of months of extraction is 6,6 with an average extraction frequency of 15 times/month.

The types of resources extracted: this study identified six additional types of resources being extracted in TCNP: (i) melaleuca honey, (ii) ricefield rats, (iii) some medicinal plants such as creek premna, asiatic pennywort, periwinkle, and stinking passion, (iv) water hyacinth (stem and flower), (v) young lotus leaves, and (vi) broodstock. Among these resources, the largest extraction output is water hyacinth (approximately 2.7 tons/year), followed by ricefield rats (approximately 2,1 tons/year) and medicinal plants (approximately 2.6 tons/year). The remaining resources have a smaller extraction yield.

The time and frequency of extraction: previous documents considered approximately 4 months (from September to December) of data 14 . However, the results of this study show that the number of households extracting for up to 4 months accounts for 53% and the number of households extracting over the entire year accounts for 20% of the interviewed households. The average number of months of extraction is 6.6, with an average extraction frequency of 15 times/month.

Extraction output: TCNP records in 2009 12 reported 15.526 tons of fish, 6.2 tons of vegetables, and 18.6 tons of snails. The reported figures in 2016 were 43.3 tons of aquatic products, 5.0 tons of vegetables, and 1.7 tons of snails 14 . In contrast, the estimated data from this study show numbers that are 10 times higher than the above statistics. Specifically, 359 tons of fish are harvested, 35 tons of vegetables are produced, and 125 tons of snails are harvested.

The average income of extracting households: the data in 2016 estimated approximately 1.4–2.0 million VND/person/month 14 , whereas the estimated value from the study is 18 million VND/month. This is approximately nine times higher than the data in 2016. As a result, the estimated value of TCNP’s provisioning services is substantially greater than previously reported.

The results of this study were converted into international dollars per hectare per year (int$/ha/year) to facilitate comparison with findings from other similar studies set in various regions (see Table 4 ). The provisioning service value estimated for TCNP is higher than those reported for wetland areas in Mozambique (by 71%) and Taiwan (by 73%). However, our estimate is significantly lower than values found in studies conducted in Laos (1.419% higher), Botswana (474% higher), and Uganda (231% higher). These disparities may be attributed to differences in the intensity and scale of resource exploitation, ecological characteristics, levels of market integration, and variations in national policies governing wetland use and conservation. Furthermore, methodological differences in resource valuation and data availability may also contribute to the observed variation in estimates.

Table 4 Comparison with other studies

Conclusions

The goal of this study was to identify the types of resources currently being exploited in TCNP, estimate the annual extraction output, and subsequently estimate the total value that these resources bring to the people in the TCNP buffer zone. The estimated amount represents the value of the provisioning ecosystem services of TCNP. This was achieved by using structured questionnaires to conduct interviews with 70 households currently engaged in resource extraction in TCNP. The most significant findings include: (i) the identification of 11 types of resources currently being exploited, including the addition of 6 new types to the previous TCNP resource list: honey, ricefield rats, medicinal plants, water hyacinth, young lotus leaves, and broodstock; (ii) the identification of the average annual extraction yield, with food accounting for the largest volume at approximately 284 tons/year, representing 98.4% of the total annual output of TCNP; (iii) the average calculated income of households when exploiting resources in TCNP was an estimated 18 million VND/month, nine times higher than the data provided by previous studies; and finally, (iv) the total estimated value of the ecosystem provisioning services of TCNP based on these data was 17,945 million VND/year.

Credit authorship contribution statement

Author 1: Methodology, Funding acquisition. Author 2: Formal analysis. Author 3: Investigation. Author 4: Investigation.

Declaration of competing interest

The authors declare that we have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.