Calcium carbonate biomineralisation in plant roots and the rhizosphere: processes, products and the fossil record

Kosir, Adrijan 2022. Calcium carbonate biomineralisation in plant roots and the rhizosphere: processes, products and the fossil record. PhD Thesis, Cardiff University. Item availability restricted.

Preview	PDF - Accepted Post-Print Version Download (66MB) | Preview
	PDF (Cardiff University Electronic Publication Form) - Supplemental Material Restricted to Repository staff only Download (109kB)

Abstract

The primary aim of the thesis was to examine calcification processes in roots of terrestrial plants and to apply these mechanisms to the study of calcified roots in the fossil record. The central idea is a hypothesis that fine roots of vascular plants, i.e. the part of the root system responsible for water and nutrient uptake, play a central role in carbonate formation and diagenesis in near surface terrestrial vadose settings, particularly in certain types of calcretes. Introductory literature review chapter, providing an overview of geobiology of calcium carbonate in the plant root–soil system, presents the concepts of fine roots, the rhizosphere and related biomineralisation processes in soils. Chapter Two re-examines root-related carbonate micromorphology of some classical Quaternary calcrete localities on the Bahamian islands and re-evaluates the rhizogenic calcrete model. Chapter Three documents immense carbonate biomineralisation products from modern soil environments, forming through intracellular calcification of root cortex, hypothetically linked with proton extrusion as an effective nutrient acquisition mechanism. Calcified roots have been studied in present-day calcareous soils of the Province of Alicante, SE Spain. Intracellular CaCO3 precipitation in plant roots is discussed in terms of biomineralisation processes, ecophysiology, and its geological significance. Chapter Four presents results of DNA identification of calcifying plants, based on DNA extracted from organic tissues preserved in modern intracellularly calcified roots. Chapter Five deals with Microcodium, a problematic biogenic calcite feature of calcretes and palaeosols. The major part is focused on morphological and ultrastructural analysis and stable isotope analysis of Microcodium material from Cretaceous and Palaeogene of south-central Europe and Quaternary of the Caribbean, its comparison with modern intracellularly calcified roots, and discusses the arguments opposing the rhizogenic interpretations, using recently published works as a discourse framework. Final section re-evaluates existing models of root calcification processes and products and propose directions of future research.

Item Type:	Thesis (PhD)
Date Type:	Completion
Status:	Unpublished
Schools:	Earth and Environmental Sciences
Date of First Compliant Deposit:	13 October 2022
Last Modified:	06 Jan 2024 02:34
URI:	https://orca.cardiff.ac.uk/id/eprint/153353

Actions (repository staff only)

Edit Item