2.1 Study area

This research was conducted in the Wain River Protected Forest (Hutan Lindung Sungai Wain) located in East Kalimantan, Indonesia, at coordinates 116º 47’ – 116º 55’ E and 01º 02’ – 01º 10’ S. The area comprises both primary and secondary forest, the latter having regenerated after a major fire in 1997–1998. The Wain and Bugis Rivers flow through this forest, with water from these rivers stored in reservoirs to meet the needs of the surrounding communities.

The forest is rich in biodiversity, including endemic flora and fauna. The surrounding population includes ethnic groups such as Paser, Bugis, Javanese, and Dayak communities, who have historically lived in and utilized the forest using traditional knowledge. Social and cultural dynamics in the area reflect interactions between indigenous traditions and migrant communities, influencing how natural resources are managed. As a buffer zone to Indonesia’s new capital city, the area offers a unique context to study how large-scale development pressures impact traditional ecological knowledge. A series of maps—starting with a world map, followed by maps of Indonesia, East Kalimantan, and finally the study site—illustrate the research location.

2.2 Data collection

This study employed a mixed-methods approach, integrating qualitative and quantitative techniques to assess the sustainability of forest management based on local wisdom. Data collection took place from May 26 to June 3, 2023. All respondents and informants participated voluntarily after receiving an explanation of the study’s objectives and provided informed consent. Their identities remain confidential, and all data were anonymized in compliance with standard research ethics. The Ethics Commission for Social and Humanities Research of the National Research and Innovation Agency has granted ethical clearance (Decision No: 320/KE.01/SK/05/2023) for this study.

Qualitative data were collected through in-depth interviews, focus group discussions (FGDs), and direct observation. Group interviews provided broader perspectives, while FGDs helped to gain deeper insights into natural resource management practices. Direct observations were conducted to examine community activities, ecosystem conditions, and the actual implementation of forest policies.

Quantitative data were collected from 90 respondents—nearly three times the recommended minimum for non-probability sampling in unknown population sizes. Participants included local residents who utilize forest resources and environmental services. Data were gathered through questionnaires, interviews, document reviews, and observations in Karang Joang Village. Observed variables included community activities such as harvesting firewood, rattan, bamboo, honeybee products, and other forest resources, as well as institutional roles in land use and forest protection. Respondents demonstrated ecological awareness and a strong commitment to sustainability for future generations.

Justification for selecting 90 respondents.

A non-probability purposive sampling approach was used in this study to select respondents based on specific criteria as mentioned above. The number of 90 respondents was determined based on the need to obtain representative data, taking into account the limitations of research resources.

The sample size was calculated using Slovin’s Formula, namely:

Assuming a population of 120 people (the community relevant to forest management) and a margin of error of 10%, the following is obtained:

Power analysis was not explicitly conducted because the primary objective was to obtain relevant qualitative and quantitative data related to forest management, not to generalise to a broader population.

Flowchart of MDS analysis steps.

The following are the steps of the MDS analysis that have been carried out, which will be presented in the form of a flowchart:

1. Data Collection: Sustainability attribute data was collected from questionnaires and interviews.
2. Attribute Assessment: Each attribute was scored by respondents using a Likert scale.
3. Data Normalisation: Attribute values are normalised using the formula:

1. Attribute Weighting: Weights are assigned based on the importance of attributes using the pairwise comparison technique.
2. Calculation of Sustainability Index: The index is calculated for each dimension (economic, socio-cultural, environmental, etc.).
3. Classification of Sustainability Status: The status is classified into weak, moderate, or strong categories based on the index value.

Numerical example of standardisation formula application.

An example of standardisation formula application will be included in the revised manuscript. For example:

If the economic attribute value for a particular respondent is 40, with a minimum value of 30 and a maximum value of 70, then the normalised value is calculated as follows:

Numerical examples such as this will clarify how the analysis works for reproducing research.

2.3 Data analysis

Sustainability assessment was conducted using MDS to evaluate the attributes of local wisdom-based management across six dimensions. The analysis process involved ordination using RAPFISH software [22] and the calculation of a sustainability index for both the general condition and each individual dimension. The assessment phase evaluated each attribute on an ordinal scale according to sustainability criteria in each dimension. This involved ordination analysis using the MDS method, index construction, and the determination of the sustainability status of local wisdom functions in management, covering both the general condition and each dimension [23]. The MDS pairwise comparison technique provided relative weights for the criteria, allowing for an in-depth evaluation of sustainability factors [24].

The MDS technique maps similar objects or points together, portraying them as adjacent points. Conversely, dissimilar objects or points are represented as distant points. The scores for each attribute form an X matrix (n × p), where n represents the number of regions with reference points and p is the number of attributes used. These scores are then standardized for each attribute, ensuring uniform weighting for each attribute and eliminating differences between measurement scales [24,25].

The following are the stages of MDS along with their general explanations:

1. a. Determining dimensions and attributes based on the issues at hand.
2. b. Weighting the data obtained from opinions and real conditions in the research area through pairwise comparison.
3. c. Establishing primary references as either “good” or “bad” by scoring across all variables/attributes.
4. d. Creating two additional main points: the “midpoint” representing both the bad and good points. These serve as vertical directional references (“up” and “down”).
5. e. Establishing additional reference points known as “anchors” to assist in the ordination results.
6. f. Creating ordination for all attributes within each dimension. The results of the ordination are visualized through horizontal and vertical axes. Through a rotation process, the positions of points can be visualized on the horizontal axis, assigning a sustainability index value of 0 percent (bad) to 100 percent (good).
7. g. Standardizing score values for each attribute using the following formula:

Where:

𝑋_𝑖𝑘𝑠𝑑 = Standardized score value for each region (including its reference points) for i = 1, 2, ... n, for each attribute for k = 1, 2, ... p;

𝑋_𝑖𝑘 = Initial score value for each region (including its reference points) for i = 1, 2, ... n, for each attribute for k = 1, 2, ... p;

𝑋_𝑘 = Midpoint score value for each attribute for k = 1, 2, ... p;

𝑆_𝑘 = Standard deviation of score values for each attribute for k = 1, 2, ... p.

Field observations, analyses, and secondary data informed the scoring of each attribute, reflecting the sustainability of management dimensions. Scores ranged from “poor,” indicating the least favorable condition for sustainability, to “good,” representing the most favorable. Intermediate values were assigned based on the number of rankings for each attribute. The sustainability status of management functions in local wisdom was categorized into four levels based on index values [26,27]:

• 0 ≤ index ≤ 25: Not sustainable
• 25 < index ≤ 50: Less sustainable
• 50 < index ≤ 75: Weakly sustainable
• 75 < index ≤ 100: Sustainable

The sustainability index for local wisdom functions was further analyzed using sensitivity analysis to identify attributes most critical to sustainability. This was determined by evaluating changes in the Root Mean Square (RMS) ordination along the x-axis (sustainability scale). Larger RMS changes resulting from attribute removal indicated higher sensitivity, highlighting the attribute’s significance in shaping the sustainability of forest management functions through local wisdom.

Secondary data was obtained from the Wain River Protected Forest Management Agency (BPHLSW) and the Karang Joang Sub-district Office to explore policies and regulations related to forest management. A literature review also contributed to enriching this analysis.

3.1 The role of TEK in the Wain River protected forest conservation

Indonesia’s Minister of Environment and Forestry Regulation on local wisdom in natural resource and environmental management underscores the need to reexamine ecological wisdom. Local wisdom is a vital cultural system, deeply embedded in a community’s way of life, and evolves to address the challenges of sustaining life and growth. Rooted in the values and circumstances of a society, it serves as a guiding framework for navigating life’s complexities and promoting sustainable development. This is evident among some members of the Karang Joang community, who, despite relocating, continue to honor their ancestral traditions. On specific occasions, they visit their ancestral village to pay respects at forefathers’ graves, seeking blessings for success in life and agriculture.

The traditional wisdom of the Wain River community highlights their enduring connection to the forest. Tombstone inscriptions from 1928 AD and 1351 Hijri (1930 AD) indicate their settlement predated the Kutai Kertanegara Sultanate’s designation of the area as protected. Initially coexisting harmoniously with the Sultanate’s policies, the community was relocated in 1975 during the construction of the Wain reservoir. This relocation acknowledged their inseparable bond with the forest and their cultural practices, aligning with sustainability principles recognized at the time.

The Sultanate’s efforts to protect the forest underscored the importance of hydrological cycles vital for the region’s rivers, which remain crucial to the local water supply, including Balikpapan’s Wain Reservoir. Community practices, such as sustainable harvesting of rattan, bamboo, nipa palm leaves, fruits, and honey, reflect a balance between utilization and conservation. These activities, guided by traditional norms and taboos (pamali), emphasize sustainability over exploitation. Local customs prohibit actions like excessive resource use, tree cutting, unauthorized forest entry, hunting, and harmful practices. Such beliefs and regulations have become ingrained in their social structure, fostering positive impacts on forest conservation. As noted by Prasetyo [28], in several cases of forest management by communities, it has been observed that the wisdom of the people in managing forests has resulted in positive impacts on forest conservation. Due to their high dependence on the forest, their patterns of utilization tend to prioritize sustainability.

TEK reflects communities’ historical practices in adapting to their environments through socio-cultural, technological, and agricultural activities. Spiritual beliefs often guide sustainability efforts, including the preservation of ecosystems and adherence to prohibitions (pamali). The Wain River community demonstrates environmentally conscious practices, such as resource-efficient technologies and sustainable agriculture, rooted in local knowledge. This knowledge safeguards ecological processes, biodiversity, and ecosystems, ensuring sustainable economic benefits. Recognized since the 1990s in ethnobiology, TEK underpins development in fields like medicine, agriculture, forestry, and conservation. It represents the knowledge, practices, and beliefs integral to communities’ sustainable livelihoods, as seen in the Wain River protected forest.

In recent times, extensive urbanization and changes in land ownership have led to land use conversions. At KM 11 and KM 13 in Karang Joang, factory buildings have emerged, exerting pressure on the buffer zones. This development’s impact affects the sustainability of local wisdom ingrained in the lives of farming communities. However, there are still local communities that honor the guidance of their ancestors, primarily among the Dayak Paser people. In the Wain River protected forest area, various forms of ecological engineering activities have been conducted, providing evidence that locally designed systems could be useful in managing ecological processes across different observable scales. The evidences are as follows:

1. (a). The initial evidence comes from the belief system, where one practice involves venerating sacred graves and implementing measures primarily aimed at preserving the forest. A tradition that endures among the local people involves visiting ancestral graves to seek safety for both the community residents and the forested area. The value derived from this wisdom lies in their ancestors’ lives and growth within the forest, understanding the ethics of adaptation and forest conservation. They understand how to sustainably utilize the environmental services provided by the forest. In addition, they are rooted in a deep-seated intimacy and concern for their homeland, integrated both materially and spiritually within their landscape. TEK represents rational and dependable knowledge developed over generations through an intimate relationship between indigenous people and their land [29]. The assumption that TEK constitutes fundamental knowledge often aligns with the notion that the community’s worldview elements intricately weave into their TEK system. Berkes defines TEK as “a body of knowledge, practices, and beliefs accumulated and evolved through adaptive processes, transmitted culturally across generations, concerning the relationships between living beings (including humans) and the environment” [12,30]. This definition situates TEK as a corpus of “knowledge, practices, and beliefs” inspired by specific worldviews and bioregions, interwoven into the community’s cultural tapestry.
2. (b) The second evidence lies in ecological engineering through policies, as issued by the Kutai Kertanegara Sultanate to safeguard the forest and ensure hydrological sustainability. Dam construction technology utilizes water resources while simultaneously preserving the forest as part of the hydrological cycle. This endeavor is believed to have considered the geological conditions of the region, particularly the presence of alluvial plains resulting from the breakdown of claystone, which usually forms waterproof surfaces, delaying water absorption into the soil. The existence of claystone complicates the infiltration of surface water into the ground. Theoretically, due to its impermeable nature, claystone makes it difficult for groundwater to be obtained and stored. The presence of impermeable layers on the soil surface in the Wain River protected forest is manifested in the form of natural ponds or reservoirs like the Wain River dam [31]. The policy initiated by the Sultan of Kutai Kertanegara Sultanate became a reference for the construction of the first Wain River reservoir, built by the colonial oil company, namely Bataafsche Petroleum Maatschappij (colloquially known as BPM) in 1947, covering an area of 0.7 hectares. Subsequently, in 1969, SHELL took over the reservoir’s operation. From 1972 to date, PERTAMINA has managed it, with a reservoir area of 3.1 hectares. Currently, PERTAMINA utilizes around 15,000 cubic meters of reservoir water per day, meeting about 26% of Balikpapan’s clean water needs. This sustainable water supply helps prevent floods and meets domestic, agricultural, and fishing water requirements for Balikpapan and surrounding areas, particularly for those in the buffer zone of the protected forest area. The Kutai Kertanegara Sultanate holds significance as a pioneer in safeguarding the Wain River Forest as a protected area. Ecological engineering efforts were focused on safeguarding the forest to preserve hydrology and ensure the river’s safety, which traverses the forest area (see Fig 1 in S1 Appendix).
3. (c). The third evidence involves sustaining the Wain River protected forest by utilizing forest services with a strategy that considers sustainability. For instance, thatch craftsmen use forest services in the forms of rattan, nipa palm leaves, and bamboo. They selectively harvest mature rattan from the forest, leaving sprouting shoots to encourage further growth. Similarly, they use mature nipa leaves to ensure continued growth. These craftsmen employ forest services derived from renewable forest elements (see Fig 2 in S1 Appendix and Table 1).
4. (d). The fourth evidence lies in the implementation of community forests in the buffer zones of the Wain River protected forest. The ecological aim is to economically benefit the community by utilizing sustainable agricultural land management. Several practices by farmers support policies aimed at conserving the protected forest area, such as terracing steep slopes to prevent landslides and cultivating protective plants. However, decline occurs in the community forests due to land conversion, thereby posing a threat to the safety of the protected forest. This situation also leads to the loss of certain local farming community wisdom in the buffer zones of the Wain River protected forest.

Download:

• PPT
  PowerPoint slide
• PNG
  larger image
• TIFF
  original image

Table 1. roles of ecological wisdom in managing the Wain River Protected Forest.

https://doi.org/10.1371/journal.pone.0333008.t001

3.2. The sustainability status of TEK in managing the Wain River protected forest

Observing the decline that has occurred in local wisdom regarding the management of the Wain River protected forest, several influential factors have been identified as contributing to the loss of TEK components. These include local knowledge about forest management, traditional farming systems, and social institutions guiding resource management. Direct threats could arise due to excessive exploitation that disregards local values in utilizing natural resources, deviating from sustainable norms [18]. The contributing factors to the direct decline of TEK usually encompass cultural, economic, political, and institutional aspects, as evidenced in several case studies [32–35]. These factors are field-tested using the MDS method.

The MDS analysis results indicate that overall, the status of local wisdom in managing the Wain River protected forest falls within the weakly sustainable category with a score of 68.034 percent. This condition is influenced by several dimensions. The economic and infrastructure dimensions fall into the weak category, whereas the environmental, social-cultural, and legal-institutional dimensions fall into the strong sustainability category (see Fig 3 in S1 Appendix). The environmental dimension scores at 71.83 percent sustainability, the economic dimension at 62.83 percent sustainability, the social-cultural dimension at 68.52 percent sustainability, the infrastructure-technology dimension at 67.38 percent sustainability, and the legal-institutional dimension at 69.61 percent sustainability.

In managing the environmental services of the Wain River protected forest, particularly in the economic and infrastructure-technology dimensions, there is a need for enhancement. Several challenges exist in the realms of the economy as well as infrastructure and technology, such as the relatively low average income of the community compared to the regional minimum wage, the stability of agricultural product prices when utilizing the services of the Wain River protected forest, and the commitment of the regional government to establish the necessary infrastructure for utilizing services of the protected forest. Moreover, the suitability of technology and government aid in that area requires prioritized attention. While respondents provide satisfactory explanations regarding forest and water resource management, the benefits from these natural resources are not reaped by the residents who safeguard them. This disparity requires careful consideration and rectification to ensure that those preserving natural resources receive more substantial benefits, especially in the community’s economic sector.

3.3. Identification of influential attributes on sustainability dimensions

Leverage analysis results indicate that 10 attributes hold relatively significant influence over the sustainability value within each dimension. Two attributes are chosen for each dimension as pivotal factors with a sensitive impact on sustainability, which will be prioritized for improvement. The attributes significantly affecting the sustainability of local wisdom in managing the Wain River protected forest are as follows.

1. 1). Employment absorption rate in utilizing environmental services of the Wain River protected forest and the community’s role in preserving local cultural values to safeguard the protected forest,
2. 2). Rate of conflicts associated with the utilization and conservation of the Wain River protected forest,
3. 3). Stability of agricultural product prices when utilizing environmental services of the Wain River protected forest,
4. 4). Average community income relative to the regional minimum wage,
5. 5). Rate of agricultural land conversion to non-agricultural use,
6. 6). Government support in spatial planning protection within the area,
7. 7). Clarity of the local community’s status within the organizational institution of the Wain River protected forest area,
8. 8). Government commitment and firmness in regulating community forest permits through protected forest land rules to prevent easy conversion,
9. 9). Government commitment to providing facilities and infrastructure, and
10. 10). Appropriate technological usage to enhance the value of the Wain River protected forest.

The analysis of the social-cultural sustainability index shows a score of 68.52 percent (see Fig 3 in S1 Appendix). Even though people residing around the Wain River protected forest no longer follow the Dayak Paser belief system, they still uphold local traditions. Respecting ancestral graves and sanctifying the areas around these graves are seen as efforts toward conservation. Similarly, the belief in “pamali” (taboos), which involves customary prohibitions regarding the use of nature and the environment, holds significance in safeguarding natural resources for their protection and sustainability. Preserving traditional wisdom faces challenges and threats due to disparities in urban communities’ social and cultural conditions.

As shown in Fig 4 in S1 Appendix, there are three key attributes associated with socio-cultural sustainability: the labor absorption rate in utilizing the environmental services, the communities’ role in preserving local cultural values, and the level of conflicts related to the utilization and conservation of the Wain River protected forest which is identified as the most sensitive attribute, with a sensitivity score of 0.63 compared to other socio-cultural attributes. The resulting impacts of leveraging the aforementioned factors are exhibited in Table 2. The community’s role in preserving local cultural values to protect the Wain River protected forest is currently weak, as the environmental services provided by the forest do not adequately meet the community’s livelihood needs. Additionally, the low employment rate is due to suboptimal forest management practices. To address these issues, it is suggested to transform the area into a sustainable tourist destination, focusing on specialized tourism that emphasizes environmental conservation and local cultural wisdom. This approach aims to reduce conflicts related to the utilization of the protected forest.

Download:

• PPT
  PowerPoint slide
• PNG
  larger image
• TIFF
  original image

Table 2. leverage factors influencing the decline of local ecological wisdom (traditional ecological knowledge).

https://doi.org/10.1371/journal.pone.0333008.t002

Despite the high sustainability score in the socio-cultural dimension, the analysis results of the sustainability index for the economic dimension indicate a lower score of 62.83 percent. Compared to the multidimensional outcomes, the economic dimension demonstrates a weak sustainability status. Economic stability significantly influences the preservation of local culture in managing the protected forest area. From the sensitivity analysis in Fig 4 in S1 Appendix, two major attributes pose significant influence on the economic dimension, namely the average income of the community relative to the regional minimum wage and the stability of agricultural product prices in utilizing the environmental services of the Wain River protected forest. The government has initiated efforts to improve community welfare through the allocation of community forest permits in the buffer zone of the Wain River protected forest. Ideally, communities granted permits should effectively manage their cultivated land to sustain their livelihoods while ensuring conservation and sustainability within the local area. However, field observations indicate a tendency among them to think pragmatically, aiming for benefits by repurposing land for non-agricultural uses.

This issue undoubtedly poses a threat to the continuity of the traditional values upheld by agricultural communities in environmental preservation. According to Ruifei Tang and Michael C. Gavin, the abandonment of traditional livelihoods due to the shift from traditional subsistence to non-traditional activities, such as industrial and trade pursuits, is a contributing factor [18,36]. Several underlying factors need attention as leverage points, including the necessity to increase prices for agricultural products and traditional industries. For instance, craftsmen making roofs from nipa palm leaves sell each piece for only 2,000 IDR, which is unsustainable. This discrepancy significantly impacts the average earnings of farmers, not aligning with the relative average income compared to the regional minimum wage. The comprehensive value of attributes within the economic dimension is depicted in Fig 4 in S1 Appendix.

The environmental dimension of the Wain River protected forest exhibited the highest sustainability index among all multidimensional outcomes, with a score of 71.82 percent. In this dimension, two sensitive attributes significantly impact sustainability: the conversion of agricultural land to non-agricultural use and government support in spatial planning and protection within the area. However, it is vital to note that these two sensitive attributes need attention due to the increasing land use conversion and inadequate government support in securing the area’s spatial planning. Field observations at KM 11 and KM 13 indicate industrial development encroaching into the buffer zone of the Wain River protected forest, with land being cleared for housing plots within this zone. Consequently, the forest is encroaching upon residential areas.

The sustainability index analysis for the legal-institutional dimension stands at 69.61 percent. Although this is lower than the environmental dimension, it still reflects a strong sustainability status when compared to the multidimensional outcomes. Overall, the legal and institutional dimensions appear robust. Nevertheless, as explained in leverage factors in Table 2, there is an undeniable loss or alteration in traditional social organization, customary norms, and traditional rules regarding the use and management of resources. Leverage attributes needing attention include the status of the local community within the organizational structure of the Wain River protected forest, particularly concerning their role in managing the forest buffer zone and their associated rights and obligations. Similarly, the government must demonstrate commitment and firmness in regulating the use of community forest permits through protected forest land rules to prevent easy land use conversion. This is significant given the decline of traditional regulations and belief systems (Belian) among indigenous communities historically responsible for protecting the forest.

The sustainability index analysis for the technology-infrastructure dimension is 67.38 percent. Compared to the multidimensional outcomes, this dimension displays a weak sustainability status. There is a loss of traditional access to natural resources. Two crucial factors influencing this weakness are the government’s low commitment to providing infrastructure and facilities and the lack of suitable technology applications. Currently, the efforts in infrastructure preparation are suboptimal and do not meet the local community’s needs. Therefore, the community should be aided with technology to enhance the value of the Wain River protected forest and receive training in sustainable environmental practices that do not harm the environment but add value to the local economy, aligning with proven local wisdom in nature conservation.