Quantification of short term interactions between soil and fungi

• Main Author: Pajor, Radoslaw
• Other Authors: Otten, Wilfred
• Published: Abertay University 2012
• Subjects: 631.4
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.650818

This thesis evaluates protocols to visualise and quantify short-term interactions between soil-borne fungi and soil. The quantification captures interactions between the ubiquitous soil saprotroph and plant pathogen Rhizoctonia solani, and a sandy loam soil, over a period of five days. The literature review provides evidence of mutual interactions between soil and fungi and highlights the lack of understanding about processes occurring at short time scales, which are crucial for modelling the complexity of soil environment. The first part of the thesis merges X-ray microtomography, image analysis and laboratory measurements to investigate the impact of short term incubation of fungi on soil water retention and soil structure at macro (whole microcosm) and micro (individual aggregate) scales. Part Two quantifies the effect of experimental variables such as aggregate-size and soil bulk-density on key descriptors of the soil pore network. Finally, a fungal growth model was used to quantify to what extent soil structure mediated by bulk-density affected fungal growth dynamics. The experimental work showed that despite high fungal biomass content there was no effect of fungal colonisation on soil structure and hydraulic properties after short-term incubation. However, it was possible to alter the geometry of soil pore space and thus influence fungal growth dynamics. This was achieved by manipulating the initial conditions of re-packed soil microcosms through variation of aggregate size and bulk density. The experimental work showed that despite high fungal biomass content there was no effect of fungal colonisation on soil structure and hydraulic properties after short-term incubation. However, it was possible to alter the geometry of soil pore space and thus influence fungal growth dynamics. This was achieved by manipulating the initial conditions of re-packed soil microcosms through variation of aggregate size and bulk density.