Changes to the natural environment may affect cultural practices and heritage values.
Aboriginal people who use plants for bushfoods, medicines and other purposes often observe ‘stranger plants’ before botanists and others. These weeds can have significant impacts on species that are important to Aboriginal families. In central Australia, the bush onion (Cyperus bulbosus) or yalka (in the Western Aranda language) is one species that has been reduced by invasive buffel grass (Cenchrus ciliaris) and couch grass (Cynodon dactylon).
Yalka is one of the most valuable bushfood species in the region. Its small edible tubers were readily collected in large quantities. The tubers were prepared in various ways—raw, roasted in ashes to eat, or ground to a paste to feed to children and old people. Yalka was also one of the few plants that could be stored. Yalka continues to be favoured by desert people.
River corridors and wetlands were prime habitat for yalka. In central Australia, buffel and couch grasses now dominate these habitats. In displacing yalka, they reduce both food security and intergenerational learning opportunities for Aboriginal people. This is of deep concern to families who see bushfoods as integral to cultural identity and heritage.
Western Aranda people view buffel grass as an ‘unwelcome stranger’ (CSIRO 2012). Its presence is blamed for the disappearance of productive yalka patches that have been harvested for generations. Families can no longer take children and young people to visit and harvest from these locations.
Older Western Aranda people, concerned with yalka being displaced by buffel grass, sought the assistance of the Tjuwanpa Rangers, an award-winning ranger group based at Ntaria (Hermannsburg) in central Australia. They are the longest established of the Central Land Council’s ranger groups. The rangers revitalised an area known for its yalka by reducing buffel grass. This provided opportunities for teaching children, and keeping practice and knowledge strong.
Despite the detrimental impacts of buffel grass on the intergenerational transmission of traditional knowledge, and scientific recognition of its negative impact on biodiversity, ecosystem processes and fire regimes, buffel grass is only listed as a weed in South Australia (Grice et al. 2012, DEWNR 2015).
Source: Josie Douglas, Senior Policy Officer, Central Land Council