Abstract
Mine reclamation and closure plans have historically focused on returning disturbed lands to a vegetative community, often without consideration of the pre-existing natural vegetation, resulting in sites dominated by non-native agronomic species. Once established, agronomic grass communities often dominate, restricting native species, and enter a stable state with little successional advancement. Regulatory standards, local community engagement and mines operating on Indigenous territories have now shifted their closure objectives towards community-engaged closure which places more value on ecosystem function and native biodiversity. Large scale disturbances, notably fire, have historically structured grasslands both naturally and through Indigenous cultural use, and can alter successional trajectory. We tested the effects of prescribed burning in a 24-year old mine-reclaimed, agronomic-dominated closed tailings storage facility as a means of shifting an agronomic community to a native grassland. Our objectives were to test the effects of prescribed burning in the field and in a controlled greenhouse experiment to assess: a) if prescribed fire can transition low diversity agronomic driven communities to a native plant community ; b) the role fire severity plays in the vegetative community under mesocosm conditions; c) plant biodiversity. Semi-structured interviews were also completed to assess: d) what level of involvement, and what role the Nlaka’pamux peoples had in the field portion of the prescribed fire project. Fire severity was modified within the greenhouse trial at three levels (high, moderate, low) and held constant (moderate) in the field. Fire severity adjustments were made via modifying the fuel load and time of burning per treatment. Plant community composition shifted as a result of the burning treatment. Greater effects were found in the greenhouse trial, likely due to better control of the burn, such that native species colonization was observed. Our experiment provides a novel approach in mine reclamation.