Traditional Ecological Knowledge and Conservation of Miombo Woodlands in the Lubumbashi Charcoal Production Basin (Haut-Katanga, DR Congo)

1. Introduction

The need to preserve tropical forests has become clear in recent decades. Not only are they exceptional reservoirs of biodiversity [1], but they also play a crucial role in sequestering atmospheric carbon [2]. In addition to their ecological function, these forests fulfill indispensable social and cultural roles for local and Indigenous communities. They enable the survival of over 1.6 billion people worldwide, both rural and urban, through the ecosystem services they provide [3,4]. These ecosystem services include the provision of timber, wood energy and various non-timber forest products (NTFPs) [5].

In sub-Saharan Africa, these forests are under increasing anthropogenic pressure, exacerbated by rapid population growth in the context of extreme poverty, as well as rapid and generally unplanned urbanization. These dynamics are leading to unprecedented deforestation and degradation of these forest ecosystems [6,7]. Consequently, statistics relating to this deforestation are alarming. Indeed, in 2010, forests accounted for more than 675 million hectares, or around 23% of the African continent's surface area [8]. But this figure has dropped to less than 636 million hectares (21%) in 2020 [9]. The situation is particularly critical in the Congo Basin, which lost almost 100 million hectares of forest between 2010 and 2020 [10,11]. In the Democratic Republic of Congo (DRC), the annual deforestation rate rose from 0.4% between 2000 and 2010 [12] to 0.61% between 2010 and 2020 [2]. With this rate of deforestation, the DRC's forest area had already fallen from 250 million hectares in 2010 to just 117 million hectares in 2020 [2,12]. If no corrective measures are taken, a forest loss of almost 22% is anticipated by 2050 [2].

The south-east of the DRC is particularly hard hit, especially in the area where miombo woodlands—a forest formation dominated by species of the genera Brachystegia, Julbernardia and Isoberlinia—is the most dominant vegetation unit [13]. Indeed, between 2000 and 2010, miombo woodlands covered 23,220,000 hectares, representing almost 11% of the Zambezi region, but this coverage has declined considerably, from over 70% of Katangan territory in 2000 to around 43% in 2010 [14]. This deforestation trend is particularly marked in the Bassin de Production du Charbon de Bois de Lubumbashi (BPCBL), where the deforestation rate is more than six times higher than the national average, reaching 1.51% [15]. This deforestation is exacerbated by difficult socio-economic conditions, which make rural and urban populations highly dependent on forest resources, notably through shifting agriculture and wood-energy production [16,17]. In addition, the growing demand for wood energy in urban areas, supported by galloping demographics and inadequate electricity supply in large conurbations, is contributing to the increased degradation of BPCBL forests [15]. This affects the miombo woodlands’ rich biodiversity, characterized by a high rate of endemism, and threatens the livelihoods of the rural and urban populations that depend on it [18,19,20].

In response to deforestation and forest degradation, forest ecosystem restoration appears to be the main solution. Restoration refers to all practices aimed at re-establishing the ecological functionality of degraded habitats, thereby improving the living conditions of local populations. [21,22]. This restoration includes the production of seedlings of native or exotic forest species in nurseries, or the facilitation of natural regeneration in the habitats concerned [21,23], thus ensuring the continued provision of essential ecosystem services [24]. Nevertheless, to ensure the success of these initiatives, the integration of traditional ecological knowledge and practices (TEK) is necessary. TEK is defined as a set of culturally transmitted knowledge, practices, beliefs and taboos that evolve and play a central role in the sustainable management of ecosystems by local populations [25,26,27,28,29]. To this end, these TEK strengthen forest restoration through a fine-tuned understanding of local ecosystems, sustainable practices, and key species, while promoting community engagement in forest restoration processes and adaptation to environmental change [30]. The cultural and spiritual anchoring of these TEK guarantees responsible and sustainable management of restored forests [31]. As a result, since the 1992 United Nations Conference on Environment and Development, TEK has been recognized as a complement to modern scientific knowledge in approaches to ecosystem management and biodiversity conservation [32]. They now inspire forest policy through new management models, combining ecological conservation with the socio-economic needs of local populations [28].

Studies of these TEK in Africa show that they promote biodiversity conservation through orally transmitted taboos and beliefs. They protect ecosystems, regulate access to resources and maintain natural habitats [33,34,35,36], including in the miombo woodlands ecoregion [37,38,39]. Moreover, data on their effectiveness and an analysis of interactions with modern dynamics (urbanization, population growth) are often lacking. Yet these dynamics, like population growth, influence TEK implementation by increasing pressure on forest resources [40]. This would lead to the overexploitation of forest resources while limiting the observance of traditional practices, and weakening their transmission to younger generations [28]. Nevertheless, in the Lubumbashi region, research into TEK remains limited. The work of Refs. [41,42] addresses the importance of plant species in daily life and the farming system but does not explore the contribution of integrating these TEK in miombo woodlands management. This study fills these gaps by demonstrating the positive impact of these TEK in miombo woodlands conservation and management, particularly in reforested forest habitats. It documents these endangered practices and proposes their integration into environmental management policies, combining traditional knowledge and scientific expertise for sustainable forest management. The integration of traditional ecological knowledge and practices would promote sustainable management of residual miombo woodland patches and participatory restoration in the BPCBL.

This study aims to identify and describe traditional ecological knowledge and practices relating to biodiversity conservation and the sustainable management of miombo woodlands. It hypothesizes that (i) the endogenous knowledge of local indigenous communities in the Lubumbashi region abounds in TEK, such as sacred sites and trees, which would play a crucial role in forest restoration and sustainable management of miombo woodlands. These practices are transmitted orally within family councils, reinforcing respect for the prohibitions and beliefs associated with natural resource conservation. (ii) These practices are more likely to be applied in villages with small populations and limited forest resources, mainly by women, the elderly, and the less educated, due to their regular contact with the forest and the selective nature of their activities such as charcoal production, art carving and NTFP collection.

2. Materials and Methods

2.1. Study Area

The present study was conducted in the BPCBL in southeastern DRC (Figure 1), a region characterized by a Cw-type climate according to Köppen's classification.

This climate is marked by a dry season extending from May to September, a rainy season from November to March, and two transition periods in April and October [43,44]. The BPCBL, located at an altitude of between 1,200 and 1,300 m, receives annual rainfall of between 1,200 and 1,270 mm [13]. The mean annual temperature, which stood at around 20°C at the end of the XXth century [41], has risen significantly since the beginning of the XXI(st) century [45]. The predominant vegetation unit at the beginning of the 20th century in this region was miombo woodlands, generally established on ferralsols [46]. Today, however, this forest ecosystem is fragmented, a phenomenon attributable mainly to shifting agriculture, charcoal production, and increasing urbanization [15,16,47,48]. The local population, estimated at over 3 million [49], continues to rely heavily on natural resources. School enrolment remains low, with less than 50% of the population having access to formal education [17]. Main subsistence activities include shifting agriculture, firewood production (dendro-energy), illegal timber exploitation, small-scale informal trade, and artisanal mining [16,50].

2.2. Methods

2.2.1. Site Selection, Sampling, and Data Collection

The present study was carried out from November 20th, 2023, to January 20th, 2024, in the villages of Maksem, Mwawa, Nsela, and Texas, located in the rural area of Lubumbashi. These villages were selected because of their intense anthropogenic activities, mainly agriculture and charcoal production, their accessibility in all seasons, and their high connectivity to other satellite villages [17]. To verify the knowledge and application of TEK, these four villages were grouped according to the availability of forest resources (Figure 1), as well as the number of inhabitants (Table 1). This grouping assumes that villages with available forest resources and low population numbers will increasingly implement TEK due to the high availability of forest resources, enabling these inhabitants to remain selective in meeting daily needs. Forest resources are limited and the population is high in Maksem and Texas, compared with Mwawa and Nsela.

To gather information on traditional knowledge and practices relating to the conservation of forest resources, focus groups were organized in each village, following the methodology of [51]. These focus groups made up of 8 to 12 people, mainly the traditional chiefs and notables of each village (Table 1), collected data on the existence of sacred sites, sacred woody species, and associated beliefs and practices. Participation in these focus groups depended on local community members' mastery of TEK, particularly among the indigenous population. The aim was to determine the role of this traditional knowledge in biodiversity conservation and forest management.

Focus group data were validated by individual interviews with 200 local community members, i.e., 50 people per village. This number of respondents was chosen due to the lack of official statistics on the distribution of local communities, allowing a representative sampling of the different populations within these 4 villages. Nevertheless, this number of respondents is higher than that (40 respondents) recommended for social science studies [52]. The snowball method facilitated the identification of Indigenous local community members concerned by the present study, given the heterogeneity of origin (indigenous and non-indigenous) of the population of these four villages [53,54].

In addition, individual interviews were conducted using a semi-structured questionnaire [55], using the Kobotoolbox application version v2023.2.4. This approach made it possible to focus responses on specific themes defined in the questionnaire [56]. In addition to the information gathered during the focus groups, socio-demographic data such as age, gender, level of education, and professional activities of the respondents were collected to correlate them with the TEK responses. For age, participants were grouped into three categories: young (18-35 years), adult (36-60 years) and elderly (≥61 years) [57]. For educational level, participants were classified into four groups: uneducated, primary level, secondary level, and university level.

During these individual interviews, data on knowledge concerning sacred sites and woody species, traditional biodiversity conservation practices, and the modes and circumstances of TEK transmission were collected [37]. The identification of woody species, mentioned under their vernacular names by the respondents, was carried out using existing floras (Flora of Zambia, Flora of Zimbabwe, Worldflora), specialist literature, and various identification guides [41,58,59,60]. Field trips, in the presence of some of the respondents, enabled us to identify woody species cited in vernacular languages by the local communities, but not listed in existing books.

2.2.2. Data Analysis

To assess the importance of traditional knowledge and the influence of associated beliefs and prohibitions, the citation frequency (C_f) of sacred sites and trees was determined using the ethnobotanyR package in R software version 4.3.2. This analysis was also extended to biodiversity conservation practices, modes and circumstances of transmission of traditional knowledge, and the role of ceremonials in forest management. The frequency of citation assumes that elements considered sacred are those that appear most often during interviews [61]. This frequency is calculated according to the following relationship (equation 1):

$$C_f={\displaystyle \frac{S}{N}}\times 100$$

(1)

where: S is the number of people citing the site or species, and N is the total number of people interviewed. When Fc tends towards 0, the site/species is weakly known as sacred, and when Fc tends towards 100, the site/species is strongly known as sacred.

To examine the association between the qualitative variables relating to Traditional Ecological Knowledge and Practices and the two village groups, Fisher's exact test with a risk of error of less than 5% was used. This non-parametric test is an alternative to the Chi-square test of association, particularly suitable when a cell in the contingency table has theoretical values below 5, one of the limiting conditions for applying the Chi-square test [62,63]. In addition, Fisher's exact test was also used to analyze the association between these variables and elements of the socio-demographic profile of the people surveyed.

Finally, to highlight the similarities between the possession of knowledge and its practical application according to the two groups of villages mentioned above, the Jaccard index (J; equation 2; [64]) was calculated using Past version 4.05 software.

$$J={\displaystyle \frac{a}{a+b+c}}$$

(2)

where a: represents the number of knowledge or practices common to both village categories, while b and c designate those specific to each category respectively.

3. Results

3.1. Traditional Knowledge, Transmission and the Role of Ceremonials in Biodiversity Conservation and Miombo Woodlands Management

3.1.1. Traditional Ecological Knowledge and Practices Related to Biodiversity Conservation and Miombo Woodlands Management

Over ¾ of those surveyed indicated that cemeteries, associated with the resting place of ancestors, are the most widely recognized sacred sites in rural Lubumbashi, particularly in villages with limited forest resources and high population numbers. In addition, cemeteries and river springs appear to be common sacred sites in both categories of villages studied. A greater diversity of sacred sites is noted particularly in villages with more abundant forest resources and a low number of inhabitants present, compared to villages with limited forest resources and a high number of inhabitants. The taboos associated with these sacred sites mainly take the form of prohibitions on tree-cutting, access to sacred sites, and bushfires. However, observance of these beliefs and prohibitions is generally low, particularly in villages with limited forest resources and high population numbers, except for cemeteries (Table 2). These results underline the cultural importance of cemeteries in Lubumbashi's rural communities, particularly in villages with limited forest resources and high population numbers. They also indicate that, although beliefs and prohibitions relating to sacred sites are often neglected, cemeteries benefit from more rigorous protection. This suggests a need to strengthen the preservation of sacred sites in resource-limited areas to support local cultural practices.

Ethnobotanical surveys carried out in both village categories identified a total of 30 sacred woody species (23 in villages with limited forest resources and high population density; 27 in villages with available forest resources and low density (VRFD & HF), divided into 29 genera (24 in VRFMD & HE; 27 in VRFD & HF) and 18 families (15 in VRFMD & HE; 15 in VRFD & HF), with a predominance of Fabaceae. Among these species, Afzelia quanzensis, Entandrophragma delevoyi, Ficus spp., Parinari curatellifolia, Sterculia quinqueloba, and Strychnos cocculoides are the most widely recognized by respondents, due to their associations with ancestor and spirit beliefs. In addition, species such as Diplorhynchus condylocarpon and Bobgunnia madagascariensis are considered sacred in both types of villages, with around 1/8 and over a quarter of species cited respectively in villages with limited forest resources and high numbers of inhabitants, and villages with abundant forest resources and low numbers of inhabitants. However, implementation of the beliefs and prohibitions associated with these species remains low in villages, particularly in those with limited forest resources and high population numbers. This is particularly noticeable for species such as Afzelia quanzensis, Entandrophragma delevoyi, Ficus spp. and Sterculia quinqueloba, which are otherwise rare in forest ecosystems (Table 3). The,se results show that, although many woody species are recognized as sacred, the implementation of associated prohibitions is often insufficient, especially in villages with limited forest resources and high population numbers. This highlights an urgent need to strengthen conservation practices to protect these culturally crucial species, particularly those that are rare.

In addition, ecological practices for biodiversity conservation and forest management, traditionally known to local communities, include small-scale farming, intercropping (allowing 2 to 3 crops to be grown on the same plot), the prohibition of cutting trees in sacred places, long fallow/rotation periods, and the use of dead wood instead of charcoal. These practices were reported by ¾ of respondents in both village categories. It should be noted that knowledge of these ecological practices is almost equivalent to the two categories of villages located in the rural area of Lubumbashi. Regarding the actual application of these practices, it is observed that intercropping and the ban on cutting trees in sacred places are implemented by more than 65% of respondents in villages with limited forest resources and a high number of inhabitants, whereas these practices concern only around 26% of respondents in villages with abundant forest resources and a low number of inhabitants. Other practices, such as the gradual exploitation of forest areas (19%), long fallow/rotation periods (13%), and the use of dead wood instead of charcoal (12%), are most applied in villages with abundant forest resources and low population numbers (Table 4)

In addition, certain long-standing practices such as the standing abandonment of large or sacred trees and long fallow/rotation periods, which were once essential for biodiversity conservation and forest management, have evolved. They have been transformed into standing abandonment of rare and sacred medicinal trees and shorter fallow/rotation periods. Implementation of these modified practices varies from 8% to 20% in villages with limited forest resources and high population numbers, compared with 4% to 16% in villages with abundant forest resources with low population numbers. addition, concession fencing, a more recent innovation, is particularly observed in villages with abundant forest resources and low population numbers (Table 4). These results indicate that traditional ecological practices of forest conservation and management are more widely applied in villages with abundant forest resources and low population density. However, the evolution and reduction of certain long-standing practices, such as long fallow periods, point to a need to revise and strengthen sustainable management strategies, particularly in villages with limited forest resources and high population numbers.

3.1.2. Circumstances of Knowledge Transmission and the Role of Ceremonial in Biodiversity Conservation and Forest Management

The main means of transmitting traditional ecological knowledge and practices are songs (53%); fables, tales & stories (23%), and proverbs (12%) in both village categories. Specifically, riddles, riddles and skits were particularly cited in villages with abundant forest resources and few inhabitants. In addition, this knowledge and practice is particularly transmitted during family councils, bereavements and weddings (Table 5). These results underline the fact that this traditional knowledge is transmitted especially during family councils, mourning, and weddings, underscoring the importance of social contexts in the preservation of ecological practices.

In the traditions of the tribes of rural Lubumbashi, certain ceremonials take place specifically under the forest canopy. These ceremonials mainly include the burial of a dead relative (79%), the enthronement of a new village chief (10%), and prayers to the gods (12%). Specifically, the burial of a dead relative and the enthronement of a new customary chief are particularly singled out in villages with limited forest resources and large numbers of inhabitants. On the other hand, ceremonials such as exorcism and prayers to the gods are most common in villages with abundant forest resources and numbers of inhabitants (Table 6). These results show a distinct distribution of these practices according to forest resources and village population. This underlines the importance of ecological and demographic contexts in the practice of certain ceremonials.

3.2. Association Between TEK-Elements Variables of the Socio-Demographic Profile and Similarity of Biodiversity Conservation and Miombo Woodlands Management Practices

The application of biodiversity conservation and forest management practices in rural Lubumbashi is strongly influenced by socio-demographic factors such as gender, age, level of education and main occupation of the individuals surveyed. In particular, the application of intercropping and short rotation practices is strongly influenced by the gender and educational level of local community members. In addition, the implementation of most practices is age-dependent, except for stump-free farming practices, selective cutting, the ban on cutting trees in sacred places, and long fallow/rotation periods. However, the practices of leaving rare and sacred medicinal trees standing, intercropping, and prohibiting the cutting of trees in sacred places are particularly influenced by the types of main activities of the respondents. These observations underline the fact that the socio-demographic characteristics of members of the population play a decisive role in the application of biodiversity conservation and forest management practices (Table 7). More specifically, practices such as selective cutting, use of dead wood, leaving rare and sacred medicinal trees standing, long fallow/rotation periods, stump-free agriculture, progressive logging, and defending concessions are mainly adopted by women, the elderly, uneducated individuals or those with a primary level of education, whose main occupations include charcoal production, art carving and NTFP collection. Conversely, practices such as short fallow periods, intercropping, and the ban on cutting down trees in sacred places are more common among men, young people, and adults with secondary education, who are mainly involved in farming and logging for timber.

As regards the comparison between beliefs and prohibitions relating to sacred sites and their application, a total similarity of 100% was observed in both categories of villages. However, similarities in the application of taboos relating to sacred sites show a notable disparity, with a correspondence of only 40% between villages with limited forest resources and a high number of inhabitants and those with abundant forest resources and a low number of inhabitants.

Jaccard's index reveals a similarity of 21.74% between quotations of sacred woody species and the application of corresponding beliefs and prohibitions, in villages with limited forest resources and a high number of inhabitants. This compares with 42.31% in villages with abundant forest resources and few inhabitants. Furthermore, the application of taboos relating to sacred trees shows a similarity of 41.67% between the two categories of villages studied.

As far as biodiversity conservation and forest management practices are concerned, Jaccard's index shows a 50% similarity between citations of these practices and their implementation in villages with limited forest resources and a high number of inhabitants, compared with 61.54% in villages with abundant forest resources and a low number of inhabitants. Overall, the implementation of these practices was 70% similar between the two categories of villages. These results suggest that, although beliefs and prohibitions relating to sacred sites and trees are recognized in both types of villages, their implementation varies considerably according to the availability of forest resources and population in the village areas. Furthermore, the implementation of biodiversity conservation and forest management practices is more consistent in villages with abundant forest resources and small populations, indicating a better integration of these ecological practices in these contexts.

4. Discussion

4.1. Traditional Ecological Knowledge and Practices, Transmission and Role of Ceremonials in Biodiversity Conservation and Miombo Woodlands Management

The depletion of forest resources in the Lubumbashi Charcoal Production Basin is having a direct impact on the livelihoods of local riverside communities, which are largely dependent on the productivity of miombo [65]. In response to this situation, various mechanisms for restoring forest cover and managing residual patches of miombo woodlands have been put in place in this region of southeastern DRC, notably through reforestation initiatives. However, these efforts are struggling to gain the support of local populations, largely due to the lack of integration of traditional ecological knowledge and practices into these mechanisms [17].

The results of the ethnoecological survey conducted as part of the present study reveal the existence of a range of traditional knowledge and practices for biodiversity conservation and miombo woodlands management. This knowledge has significant socio-cultural and spiritual values and plays a crucial role in maintaining forest ecosystems [66]. The beliefs and prohibitions associated with these TEK contribute to the preservation of forest resources and forest resilience [67,68]. These observations are consistent with the results of previous studies in Africa [28,69] and specifically in the miombo woodlands ecoregion [36,70]. The integration of TEK into the processes of vegetation cover restoration and miombo woodlands management could, to this end, represent a significant opportunity to encourage local communities to actively participate in these initiatives and take ownership of the processes [17].

On the other hand, the scarcity of forest resources, coupled with unfavorable economic conditions, increases anthropic pressure on these resources, thus compromising the forest restoration and management mechanisms put in place [17,22]. The data collected also shows that local communities in villages with abundant forest resources and a smaller population have a higher number of TEK than those in villages with limited resources and a large population (Table 2, Table 3 and Table 4). This disparity can be explained by the fact that villages with abundant forest resources and low population numbers retain and apply traditions to a greater extent due to the high availability of resources, in contrast to villages faced with limited resources and high population numbers. Previous studies in Zambia have revealed that the scarcity of forest resources and population growth leads to a decrease in the importance attached to traditional knowledge, resulting in an erosion of this knowledge and practices [40,71]. The results of this study concur with the observations of Ref. [40] in Zambia, who showed that the scarcity of forest resources, coupled with rapid population growth, leads to a gradual erosion of TEK, as local populations turn away from traditional practices in the face of increased economic and ecological pressures.

However, the durability of TEK, such as sacred sites, also depends on several factors such as geography, hydrography, and the distribution of miombo woodlands variants in the study area. The transmission of TEK, mainly orally through songs and stories (Table 5), remains a common practice in Africa, not least because of the low rate of school enrolment and the virtual non-existence of written documentation on the subject [71,72,73]. This mode of transmission, although adapted to poorly educated populations [37] such as those in rural Lubumbashi, leads to a modification or even alteration of knowledge over time, leading to the loss or appearance of new knowledge and practices [36].

These results corroborate studies carried out in Zambia, showing that stories, songs, and proverbs are predominant modes of TEK transmission [36,37,74]. In addition, TEK are often transmitted during family councils, mourning ceremonies, and weddings (Table 5), as well as during ceremonials such as burials performed exclusively in the forest (Table 6). These events, being frequent and bring together many members of the community, offer ideal opportunities for the transmission of TEK. The results corroborate the work of Ref. [37] in Zambia, who emphasize the importance of these ceremonials in the transmission of traditional knowledge, as well as in biodiversity conservation and forest management.

4.2. Association Between TEK and Similarity of Implementation of Biodiversity Conservation Practices and Miombo Woodlands Management

Local communities in villages characterized by limited forest resources and a high number of inhabitants apply TEK less effectively than those in villages with available forest resources and a low number of inhabitants. This situation is attributable to the scarcity of forest resources and population growth, which encourage communities to modify or abandon TEK, thus compromising the sustainable management of forest resources [67,75]. Previous studies in Zambia have shown that the scarcity of forest resources, combined with growing economic needs, is leading to a decline in respect for traditional beliefs and prohibitions when exploiting forest resources to meet daily needs [40]. In addition, high population density significantly reduces the usable area for everyone, increasing anthropogenic pressure on already limited forest resources [76]. This increased pressure contributes to TEK deletion or partial adaptation to cope with resource scarcity, particularly in villages with high population numbers. These observations are in line with the findings of Ref. [28], who points out that TEK evolve over generations and are adapted to environmental changes.

On the other hand, in villages where forest resources are available and the population is small, biodiversity conservation and sustainable forest management practices are mainly implemented by women, who are elderly, poorly educated, and whose main activities include charcoal production, art carving, and the collection of non-timber forest products (Table 7). This predominance of women in the implementation of practices can be explained by their central role in Africa, and particularly in the study area, in the education and transmission of cultural knowledge, including TEK. By passing on this knowledge to the younger generations, they integrate it into everyday practices, thereby contributing to their sustainability. Research in Venezuela also shows that women are more respectful of traditional beliefs and prohibitions than men [77]. Furthermore, the application of TEK increases with age. Older people apply these forest conservation and management practices more assiduously because of their experience, their role as custodians of culture, and their lesser exposure to modernity, which reinforces their perception of the relevance of this knowledge [78,79]. It should also be noted that the transmission of these TEK begins at an early age in the Lubumbashi region.

In addition, people with low levels of education are also more likely to apply TEK. Indeed, activities related to the management of forest areas are often dominated by individuals with a low level of education, due to the lack of alternatives in the labor market and the absence of required skills [17]. Finally, charcoal producers, sculptors, and NTFP collectors are more likely to apply TEK than farmers. Agriculture, whether intensive or slash-and-burn, requires deforestation to avoid competition between natural trees and crops, which contrasts with other activities with selective exploitation of forest resources [6,80,81,82]. These findings corroborate those of Ref. [83] in the Yangambi Biosphere Reserve, who show that forest conservation and management practices are mainly linked to sacred tree prohibitions, agricultural practices, and respect for sacred sites.

However, the implementation of conservation and forest management practices is influenced by other factors, such as the amount of forest space available to an individual. TEK-integrated forest management requires not only recognition of this traditional knowledge but also adequate access to the resources needed for its application. The decrease in forest area available to an individual limits his or her ability to maintain and transmit TEK [76,84]. Furthermore, the application of these TEK in Africa is also influenced by cultural changes, such as formal education, modernization, and above all Western and Asian religions [36]. Indeed, formal education and modernization stemming from colonization have contributed to the marginalization of traditional knowledge in Africa, inculcating Western values that are largely incompatible with local cultures [36,85]. Furthermore, studies carried out in Nigeria, Ghana, and Botswana have shown that local communities adopting Western and Asian religions now reject the application of these TEK, considering them inferior, demonic, and fetishistic [86,87,88].

4.3. Involvement in Contributing to the Sustainable Management and Restoration of Miombo Woodlands

TEK have considerable cultural and spiritual values, but their application is under constant threat from modernization and the shrinking of miombo woodland areas. This situation contributes not only to deforestation and forest degradation, but also to the erosion of the cultural and spiritual values of local communities. To remedy this problem, it is essential to promote the popularization of TEK within local communities. An effective approach for this popularization could include educational programs facilitating the empirical learning of TEK [89]. However, the low school enrolment rate in rural Lubumbashi is a significant obstacle to the application of this method. To overcome this obstacle, it is crucial to foster intergenerational exchanges of knowledge between grandparents, parents, and younger generations, as well as to organize various socio-cultural awareness-raising activities to facilitate the transfer of these TEK [36]. Furthermore, universities should collaborate with the Congolese government to systematically collect and document (including digitizing) the various forms of TEK, to prevent their erosion and preserve this knowledge for current and future generations [90,91]. This documentation is essential to prevent the loss of this traditional knowledge over time.

In addition, there is a need for conservation and sustainable management programs for miombo woodland remnants, as well as forest restoration initiatives through reforestation and assisted natural regeneration [21,92]. These programs should focus on sacred sites (such as cemeteries, river springs, and the habitats of ancestors and deities), using sacred woody species such as Afzelia quanzensis, Entandrophragma delevoyi and Sterculia quinqueloba, whose associated beliefs and prohibitions are respected by local communities [93]. This approach would not only help restore forest ecosystems but also revitalize the cultural and religious practices associated with these places [93,94]. In addition, taking these TEK into account in the forest restoration mechanism would encourage the involvement of local communities and ownership of these forest management and restoration mechanisms, which is crucial to ensuring their long-term success [17].

Finally, these results suggest that the integration of TEK into forest policy requires the creation of a local participatory framework, involving both local communities and decision-makers. This participatory framework could facilitate the identification of relevant TEK and their application at the local scale, their integration into forest management plans, and reforestation or assisted natural regeneration initiatives [95,96]. In addition, incorporating the sacred woody species identified in this study, such as Afzelia quanzensis and Sterculia quinqueloba, into reforestation initiatives could strengthen community commitment while respecting local beliefs.

The present study was carried out on a limited number of villages and respondents. In addition, the cultural variability of different tribes in the Lubumbashi region was underestimated, limiting the generalizability of the results obtained.

5. Conclusions

This study aimed to identify and describe TEK relating to biodiversity conservation and miombo woodlands management, through interviews (group and individual) carried out in two categories of villages differentiated by the availability of forest resources and their population. The results show that most respondents are aware of sacred sites and woody species, including their beliefs and prohibitions. In addition, biodiversity conservation and miombo woodlands management practices include small-scale farming, intercropping, the prohibition of cutting trees in sacred sites, long rotation periods and the use of dead wood. Certain ceremonials, such as burials of the dead, take place only in the forests, encouraging people to leave certain forest patches untouched. TEK are more rigorously applied in villages with abundant forest resources and smaller populations, enabling daily needs to be met while respecting local beliefs and prohibitions. These TEK are particularly observed by women, the elderly and the less educated, involved in charcoal production, art carving and the collection of non-timber forest products.

The present study was carried out on a limited sample of villages and participants. Furthermore, the cultural diversity of the different tribes in the Lubumbashi region was not sufficiently considered, which limits the possibility of generalizing the results obtained. Nevertheless, this study demonstrates the existence of TEK in the Lubumbashi region and their potential to contribute to the sustainable management and restoration of miombo woodlands. The DRC's national forest policy must include concrete strategies for the integration of TEK. This could involve setting up local forest management committees, legally protecting sacred sites and species, and prioritizing TEK in reforestation initiatives. In addition, the documentation and digitization of this traditional knowledge by scientists is essential to ensure its transmission and preservation.