The study was conducted in the Ziama Biosphere Reserve (ZBR), located in southeastern Guinea between 8˚03'N and 8˚32'N latitude and 9˚08'W and 9˚32'W longitude. The reserve covers an area of approximately 119,019 ha and is surrounded by five Rural Communes comprising a total of 35 villages [22]. According to the General Population and Housing Census (RGPH, 2014), the area has a population of 73,175 inhabitants, corresponding to a population density of 18.9 inhabitants/km².

The climate of the ZBR is humid tropical, characterized by high annual rainfall averaging approximately 2700 mm and mean annual temperatures ranging from 17.7˚C to 30.4˚C (Figure 1). The vegetation is stratified into two main layers: a lower layer dominated by plant communities characterized by Parinari excelsa Sabine [23], and an upper montane layer dominated by Triplochiton scleroxylon K. Schum [24].

Figure 1.Location map of the Ziama Biosphere Reserve.

Data were collected through a socioeconomic survey conducted among populations aged 20 years and above in three villages located around the reserve: Bôo, Baimani, and Lazawou. Structured and semi-structured interviews were used to gather information from respondents. Before data collection, meetings were held with local authorities in each village to explain the objectives of the study and obtain community consent. Subsequently, households recognized as being involved in the exploitation of non-timber forest products (NTFPs) were identified [25].

Structured and semi-structured questionnaires were then administered to heads of households identified as users of plant-based NTFPs within the ZBR [26]. In total, 110 household heads, primarily farmers, were interviewed. The questionnaire covered respondents’ sociodemographic characteristics (sex, age, level of education, and number of dependents) as well as information on priority NTFPs exploited, including local product names, selling prices, and the allocation of income generated from these products [27]. All plant-based NTFPs mentioned in local languages were recorded and subsequently translated into French to facilitate identification and analysis [28].

Survey data were compiled, coded, and analyzed using Microsoft Word and Excel 2013. Scientific identification of plant species was carried out using reference floras of tropical Africa [29], relevant botanical literature [30], and herbarium collections from the University of N’Zérékoré and the Institute of Agronomic Research of Guinea (IRAG) in Sérédou.

The production value is equal to the price of NTFPs (P) multiplied by the quantity of products collected (xf). That is: VP = Pxf

The total production cost consists of the labor cost (Lf) for collecting forest products [31][32], that is: CT = Lfw with w = unit labor cost.

Lf = βxf

where β is the time required to collect one unit of NTFP xf, hence

CT = βxfw.

The income from NTFPs is written as: Revpfnl = Pxf – βxfw.

Spatial data processing and cartographic representation of the study area were performed using QGIS version 2.10 (Pisa).

3.1.1. Gender Distribution

A total of 110 respondents from villages surrounding the Ziama Biosphere Reserve were surveyed. Men accounted for 63.64% of respondents, while women represented 36.36% (Figure 2).

The predominance of men among respondents reflects their greater involvement in the harvesting of plant-based non-timber forest products (NTFPs), an activity that often requires long-distance travel and physical effort for transporting harvested materials. In addition, men are generally household heads and bear primary responsibility for household subsistence. Women, who were less represented, mainly collect NTFPs located closer to villages and that are more easily accessible.

Figure 2.Distribution of respondents by gender.

3.1.2. Age Structure of Respondents

Respondents ranged in age from 20 to 70 years. The most represented age group was 40 - 50 years (44%), followed by 30 - 40 years (33%). Individuals aged 60 - 70 years were the least represented, accounting for only 4% of respondents (Figure 3).

Figure 3.Distribution of respondents by age group.

The predominance of respondents aged 30 - 50 years indicates that economically active adults are the main actors involved in the exploitation of plant-based NTFPs. This age group generally possesses extensive knowledge of forest resources and their locations within the reserve.

3.1.3. Educational Level of Respondents

The educational level of respondents was generally low. Half of the respondents (50%) had no formal education, while the remaining 50% had attended school to varying degrees. Among those with formal education, 27.27% had completed primary education, 10.91% secondary education, and 11.82% university education (Figure 4).

Figure 4.Distribution of respondents by educational level.

The high proportion of respondents without formal education reflects the predominance of farming and hunting activities in the area, as well as school dropout rates linked to socioeconomic constraints. Respondents with secondary and university education were mainly students who engaged in NTFP exploitation seasonally to meet financial needs.

3.1.4. Household Dependency Burden

Most respondents (43.64%) reported being responsible for households of 5 - 10 dependents. This was followed by 26.36% of respondents with 10 - 15 dependents, while 11.82% supported between 15 and 20 individuals (Figure 5).

Figure 5.Household dependency burden of respondents.

These results indicate that most respondents support large households, which increases reliance on forest resources as a primary means of subsistence and income generation.

The survey identified a total of eight plant-based NTFP species exploited across the studied villages. Eremospatha macrocarpa (G. Mann & H. Wendl.) was the most frequently cited species (35%), followed by Laccosperma secundiflorum (P. Beauv.) Kuntze (22%) and Piper guineense Schumach. & Thonn. (16%). Beilschmiedia mannii (Meisn.) Benth. & Hook. f. was the least cited species (5%). All respondents (100%) acknowledged the economic importance of these plant-based NTFPs (Table 1).

Table 1.Uses of priority plant-based NTFPs identified by local populations.

Overall, plant-based NTFPs play a critical role in local livelihoods. Six species (44%) were reported to be used for both food and medicinal purposes, while all eight species were used for economic purposes and income generation.

3.2.1. Economic Value of Priority Plant-Based NTFPs

Plant-based NTFPs constitute an important source of income for local communities. The plant parts commercialized include stems, fruits, and seeds, which are sold either in bundles or by weight. Among the identified species, Eremospatha macrocarpa exhibited the highest annual economic value, ranging from 5,000,000 to 10,000,000 GNF (approximately 303,250 - 606,500 FCFA). Laccosperma secundiflorum generated an estimated annual income of 4,000,000 - 8,000,000 GNF (252,500 - 505,000 FCFA), while Piper guineense generated 3,000,000 - 7,000,000 GNF (200,000 - 451,500 FCFA). In contrast, Beilschmiedia mannii showed a lower economic value, with annual income ranging from 200,000 to 500,000 GNF (13,000 - 33,250 FCFA) (Table 2).

Table 2.Estimated annual economic value of priority plant-based NTFPs.

Three species—Eremospatha macrocarpa, Laccosperma scandensflorum (P. Beauv.) Kuntze, and Piper guineense—were identified as the most economically significant for local communities, largely due to their high demand in urban markets.

3.2.2. Allocation of Income from Plant-Based NTFPs

Income derived from the exploitation of plant-based NTFPs was allocated to several household needs (Figure 6). Food accounted for the largest share (40.00%), followed by children’s education (26.36%), healthcare (18.18%), and clothing (15.45%).

Figure 6.Allocation of income derived from plant-based NTFPs.

These findings demonstrate that income generated from NTFPs plays a central role in ensuring household food security, access to education, healthcare, and basic living requirements.