Assessing current environmental conditions and climate change influences on Syngonanthus nitens (Bong.) Ruhland: an endemic species and economic resource for extractive communities as globally important agricultural heritage systems

Capim dourado, also known as sedinha, refers to the everlasting flower Syngonanthus nitens (Bong.) Ruhland (Eriocaulaceae), prized for its use in crafting and as a significant income source for communities in Minas Gerais, Bahia, and Tocantins, Brazil. This plant is also utilized in the creation of highly valued jewelry and accessories on the global market. This study aims to ascertain the thermal and humidity thresholds of S. nitens while mapping and predicting its current and future distribution. Initially, distribution data was gathered through a literature review, supplemented by biological temperature and humidity data collected from the Quilombola Raiz Community in Minas Gerais and a germination experiment conducted at the Integrated Multi-User Research Laboratory of the Jequitinhonha and Mucuri Valleys (LIPEMVALE). Climate Index (CLIMEX) parameters were defined using biological information and occurrence locations. The optimal temperature range for S. nitens development is between 18 and 24 °C, with minimum and maximum thresholds of 5 °C and 40 °C respectively. Ninety-two occurrence records were found, all situated in South America, aligning with high climate suitability regions as per the model predictions. Future projections for 2050 and 2100 indicate a decrease in areas suitable for S. nitens. These findings provide crucial insights for decision-making, necessitating measures such as widespread monitoring, collaborative conservation efforts, and the establishment of sustainable use zoning to manage S. nitens effectively.