Ethnobotanical study on factors influencing plant composition and traditional knowledge in homegardens of Laifeng Tujia ethnic communities, the hinterland of the Wuling mountain area, central China.

Background: A homegarden is a conventional small-scale agricultural ecosystem dominated predominantly by humans. Homegarden plants, which are plants with specific functionalities that are either cultivated or consciously preserved within the homegarden, are the most critical elements of the homegarden and are capable of providing a multitude of products and services. Recognized as one of China's biodiversity hotspots, the Wuling mountain area has long been inhabited by multiple ethnic groups, each of which has accumulated a wealth of traditional knowledge. This study focuses on the Tujia ethnic communities in Laifeng County, situated in the hinterland of the Wuling mountain area, with the primary objective of collecting, documenting, and organizing local homegarden plants, their functions, and the associated traditional knowledge, and exploring the factors influencing their composition and diversity.

Methods: From May 2023 to August 2024, field surveys were conducted in Laifeng County, Enshi Tujia and Miao Autonomous Prefecture, Hubei Province, China. Semi-structured interviews and participatory observation were used to gather information on homegarden plants with informed consent. To analyze and evaluate homegarden plants, we employed the relative frequency of citation (RFC) and Jaccard index (J) for quantitative analysis. Additionally, the factors influencing the composition of homegarden plants were investigated using redundancy analysis (RDA).

Results: This study documented a total of 414 species of homegarden plants from 114 families. These plants are primarily sourced from market purchases (158), spontaneous species (107), wild introductions (103), neighborhood sharing (59), and self-preservation (36). Homegarden plants serve multiple functions, including ornamental (201), medicinal (189), edible (165), traded (95), timber (34), forage (28), and other functions (11). There are 24 homegarden plants with an RFC greater than 0.5, indicating their high importance, including Allium fistulosum, Raphanus sativus, and Brassica rapa var. chinensis. The Jaccard index results suggest the highest degree of similarity between the homegarden plants in Geleche Town and Dahe Town. The RDA results established that knowledge of herbal medicine and homegarden area are two significant factors impacting the composition and diversity of homegarden plants, with the average age of the household resident population also exerting an influence.

Conclusions: This study reveals the composition, source diversity, and functional diversity of homegarden plants within the Laifeng Tujia ethnic community, along with the influencing factors. These homegarden plants play an integral role in sustaining the balance of the homegarden ecosystem and supporting the daily lives of local residents. The management of homegarden plants by the Laifeng Tujia ethnic community carries traditional agricultural knowledge and wisdom. Emphasis should be placed on bolstering the understanding, protection, and transmission of traditional knowledge and culture related to homegardens, which play a vital role in safeguarding local agricultural biodiversity and fostering sustainable development.