Biodiversity and ecosystem function in the bird's nest fern

Donald, Julian David

Abstract

Understanding the relationship between the biodiversity and functioning of an ecosystem is a key component of ecological studies. Given the importance of soil as the basis for life on earth, understanding this relationship across the multiple trophic levels of the brown food web is vital. The thesis begins by trialling methods of soil analysis at the Eden Project, determining the relationship between microbial communities, their contribution to decomposition and the physical conditions of the soil which they inhabit. The thesis goes on to use the bird’s nest fern as a natural microcosm to explore patterns in soil biodiversity and functioning. Using a canopy simulation tool at the Eden Project, microbial community functioning was characterised using a method tracing the isotopic enrichment of microorganisms during decomposition. At Eden, the role of the physical conditions experienced by suspended soils in determining microbial community composition was demonstrated, before this finding was confirmed with suspended soil samples collected from the Nouragues reserve in French Guiana. In order to explore the multi-trophic relationship between microbial functioning and invertebrate biodiversity, a largescale experiment was performed at Danum Valley in Malaysian Borneo. Bird’s nest fern microcosms were prepared to manipulate levels of invertebrate diversity and access to isotopically enriched organic matter. Tracing the enrichment of organic matter over time demonstrated that increasing invertebrate diversity resulted in increased rates of decomposition within the soil body. Subsequent analysis of microbial enrichment demonstrated the interacting effect of invertebrate biodiversity on microbial functioning. Increases in invertebrate species stimulated microorganisms to decompose organic matter and assimilate released carbon into their cell walls at higher rates. By characterising microbial community composition, and quantifying their contributions to the decomposition under simulated reductions in invertebrate diversity, this thesis supports the view that the loss of biodiversity will have negative effects on the functioning of ecosystems.

• Thesis Type: Thesis
• Publicly Available Date: Jun 7, 2019
• Peer Reviewed: Not Peer Reviewed
• Public URL: https://uwe-repository.worktribe.com/output/866762
• Award Date: Jun 11, 2018