Ethnoweaving in Sumba Island, Indonesia: Ethnobotanical knowledge and use of natural dye plants

Abstract

Background: Traditional weaving on Sumba Island, Indonesia, represents an important cultural heritage closely linked with the use of natural dyes obtained from local plants. The limited ethnobotanical data of the natural dye plants, their uses, and their supply sustainability pose a high risk to both cultural preservation and forest-based livelihoods.

Methods: Semi-structured interviews, participant observations, and plant identification were used to gather ethnobotanical data. 122 informants from six Sumba weaving communities participated in the study. Relative Frequency of Citation (RFC), Informant Consensus Factor (ICF), and a simplified Functional Redundancy Index (FRI) were used to analyze the data regarding cultural importance, knowledge standardization, and substitution flexibility.

Results: 21 plant species from 14 families were identified and categorized into six functional dye categories. All informants mentioned Indigofera tinctoria L. (blue), Morinda citrifolia L. (red), and Symplocos fasciculata Zoll. (mordant) (RFC=1.00), according to RFC analysis. All three species were found to be fundamental. Informant consensus was consistently high across all categories (ICF>0.982), indicating standardized knowledge transmission. However, functional redundancy values were consistently low (FRI<0.023), indicating concentration of use on few key species and limited culturally recognized substitution.

Conclusions: Sumba's ethnoweaving is a plant-based cultural production system that suggests potential vulnerability due to the limited alternative species but stable due to the presence of key species. The vulnerability is further increased by overexploitation, land conversion, and pressure from synthetic dyes. By integrating a comprehensive ethnobotanical inventory and quantitative structural analysis, the study provides an analytical framework for the sustainability of weaving traditions on Sumba Island and in similar areas.

Keywords: Ethnobotany; Ethnoweaving, Natural dyes; Indigofera tinctoria; Morinda citrifolia; Symplocos fasciculata