Postgraduate Profiles

Benjamin Moreira Grez

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Thesis: Below-ground restoration on post-mining substrate. Taxonomic and funtional diversity as key factors for a complete land restoration.

As part of their environmental obligations, mining companies within WA are obligated to restore extraction sites. This is usually a costly and labor-consuming step, but compulsory in order to release the environmental bond. Current restoration strategies focus upon the ecology and restoration of aboveground biological components (i.e. 60-80% of pre-existing plant taxa), with little attention to key microbial ecology factors acting belowground within the soil which are fundamental to bring about plant growth. This vast reservoir of microbial diversity is a principal factor contributing to nutrient cycling, decomposition and, thus, overall soil heath and productivity, but the mechanisms that encompass the microbially mediated side of land restoration have been poorly studied in post-mining substrates during ecological restoration.

Whilst new technologies, such as next-generation DNA sequencing, secondary ion mass spectrometry and stable isotope probing are being used to determine soil microbial ecology and its impact upon aboveground productivity, almost no attempt has been made to understand the complex microbial succession within restoration scenarios. This work will address the complex matrix effect concerning microbes with soil structure, nutrient and seeds to understand the ecological laws at this fine scale and the microbial functionality (required microbial diversity and functional gene content) required to bring about successful aboveground productivity. This will give us the knowledge base to ascertain the microbial ecological dynamics in harsh substrates, their evolution and ultimately improve the current restoration yield, thus allowing a significant reduction in infrastructure and costs necessary for this task.

Why my research is important

Whilst legal requirements focus on aboveground components, there is still a pressing need to understand how belowground diversity influences plant growth and establishment in restoration scenarios since all terrestrial ecosystems involve a synergy between above and belowground components that work in tandem, to shape the overall ecosystem functioning. Elucidation of factors that influence belowground functions in rehabilitation scenario would ultimately allow assessment of likely barriers to plant growth and survival