Dioscorea divaricata Blanco: a cultural keystone species of the Magbukún Ayta of Kanawan, Morong, Philippines

Dioscorea divaricata (Dioscoreaceae) is a wild yam locally known as buloy in the Magbukún Ayta community of Morong, Bataan, Philippines. Using key informant interviews, participant-observation and semi-structured interviews, the traditional ecological knowledge of the Aytas concerning buloy was documented. Buloy was then shown to be a cultural keystone species of the community. Knowledge distribution and transmission were also studied through multiple regressions, revealing that age was the most predictive factor of knowledge regarding buloy. Harvesting practice, as well as Magbukún language use, was shown to decline with younger generations. Principal component analysis suggested an intimacy gradient running from exposure to knowledge then practice, with practice having the highest intimacy. An intimacy gradient was then developed consisting of multiple gradients of increasing intimacy. The intimacy matrix may be a potential tool for assessing the perpetuation of any relationship between people and plants, wherein higher intimacy would suggest a higher persistence potential.