Mycorrhizal Fungi-- Quantifying fungal inputs to mineral weathering and soil carbon stocks in humid to semiarid landscapes
EMSL Project ID
49710
Abstract
Mycorrhizae, the symbiotic relationships between plant roots and fungi, are the primary suppliers of growth-limiting nutrients to plants and the main transporters of carbon from plants to soils. Mycorrhizal fungi associate with >80% of terrestrial plants, promoting plant productivity through inorganic nutrient acquisition from soil minerals and contributing to ecosystem level soil carbon storage through biomass production. Climatic and edaphic controls on mycorrhizae activity are poorly understood despite the importance of mycorrhizal fungi in soil carbon fluxes, ecosystem productivity, and mineral weathering. The current work integrates bioclimatic (desert-conifer forest) and topographic (summit-drainage) factors into a cross-scale examination of mycorrhizal contributions to mineral weathering and soil carbon stocks. This proposal will address the global challenge of climate change by advancing our understanding of how climate, topography, and mineral composition drive fungal weathering mechanisms and mycorrhizal biomass production in semiarid and humid ecosystems. An in-soil approach was developed and deployed in the water-limited ecosystems of the Catalina Critical Zone Observatory (CZO), Arizona and the wet, humid environments of the Calhoun CZO, South Carolina. Ground rock materials (250-53µm; basalt, granite, quartz sand) were sealed into fine and coarse mesh bags that were then buried in surface soils during 2015. The proposed work aims to: 1) differentiate between the initial stages of chemical and fungal-driven weathering features in ground rock retrieved from fine and coarse mesh bags, 2) test the hypothesis that mycorrhizal fungi act as bio-sensors that selectively dissolve minerals containing growth-limiting nutrients, and 3) quantify fungal growth across contrasting climates and landscape positions. The aims of the study would be accomplished using helium ion microscopy and environmental scanning electron microscopy in conjunction with EMSL. Expected outcomes of this research include stronger mechanistic interpretations of mycorrhizal inputs to soil carbon stocks and mineral weathering in humid to semiarid ecosystems-- an imperative task for advancing global carbon and nutrient cycling models where the activities of mycorrhizal fungi are poorly represented.
Project Details
Project type
Limited Scope
Start Date
2017-02-06
End Date
2017-04-06
Status
Closed
Released Data Link
Team
Principal Investigator
Related Publications
Lybrand R.A., J.C. Austin, J. Fedenko, R.E. Gallery, E.C. Rooney, P. Schroeder, and D.G. Zaharescu, et al. 2019. "A coupled microscopy approach to assess the nano-landscape of weathering." Scientific Reports 9, no. 1:Article Number 5377. PNNL-SA-142858. doi:10.1038/s41598-019-41357-0