IMPACT OF SEED EXPOSURE TO PLANT MATERIAL ON PLANT GROWTH AND DEVELOPMENT ON REMEDIATED ARID LANDS 1

Remediation of land following surface mining requires the re- establishment of critical soil, plant, and microbial interactions on which the long- term sustainability of the site hinges. Current surface mine remediation practices may utilize topsoil with or without shredded plant material to overlay spoil. We evaluated whether the presence of such plant material may affect initial plant fitness and thus plant establishment. Tests were carried out in a greenhouse under controlled, replicated conditions common during early stages of remediation. Responses to seed exposure to plant material were species dependent. Plant growth parameters were linked to properties associated with the seed hull and seed surface and to functions associated with shredded plant material added to topsoil. Confirming the nature of these properties, hypothesized as microbial in origin, will be important for understanding factors critical to reclamation and management of disturbed sites, where native biological functions have been suppressed or fragmented. In degraded arid environments, such functions may govern micro-scale interactions that influence macro-scale processes. Additional Keywords: land remediation, surface mine, plant fitness, non-specific inoculation