Determining the role of plant-soil-microbial relationships in forest ecosystem function and biogeochemistry

Edwards, Joseph Douglas

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https://hdl.handle.net/2142/115459 Copy

Description

Title

Determining the role of plant-soil-microbial relationships in forest ecosystem function and biogeochemistry

Author(s)

Edwards, Joseph Douglas

Issue Date

2022-04-21

Director of Research (if dissertation) or Advisor (if thesis)

Yang, Wendy H

Doctoral Committee Chair(s)

Yang, Wendy H

Committee Member(s)

• Yannarell, Anthony C
• Dalling, James
• Davis, Adam

Department of Study

School of Integrative Biology

Discipline

Ecol, Evol, Conservation Biol

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

Ph.D.

Degree Level

Dissertation

Keyword(s)

• Microbial ecology
• biogeochemistry
• plant-microbial interactions
• forests
• ecosystem ecology
• invasive species
• DNA sequencing
• stable isotopes
• soil organic matter
• nitrogen deposition
• mycorrhizal fungi

Abstract

Plant-soil-microbial relationships are an essential component of ecosystem function; however, they remain critically underexplored relative to aboveground aspects of ecosystems. In my dissertation, I seek to better understand how interactions among plants, microbial communities, and their environment drive surrounding soil microbiome composition and biogeochemical processes in forests. This work integrates important global change factors like invasive species and increased anthropogenic nutrient deposition while taking a global perspective, spanning temperate and tropical ecosystems. In my first and second chapters, I show how the invasive species Alliaria petiolata (garlic mustard) has a dynamic relationship with soil microbial communities and nitrogen cycling processes over space and time. In my third chapter, I provide evidence for the important role fungal communities play in acquiring nitrogen from soil organic matter in a montane rainforest of Panama, and how this function is diminished under elevated nitrogen deposition. Finally, a focal component of my research is how the diversity of mycorrhizal relationships between plants and fungi influences their impact on ecosystems. I explore this in-depth in my last chapter, presenting a study investigating how ectomycorrhizal tree species and fungal communities differ in their associated effects on important ecosystem traits like soil organic matter dynamics and extracellular enzyme activities. Overall, my dissertation supports the inclusion of microbial communities as critical independent players in ecological phenomena, promoting the use of microbially-explicit paradigms and models in informing conservation decision-making and predicting ecosystem response to global change. My dissertation shows that the nature of plant-soil-microbial relationships is highly context-dependent, varying based on environmental conditions, temporal factors, and species diversity.

Graduation Semester

2022-05

Type of Resource

Thesis

Copyright and License Information

Copyright 2022 Joseph Edwards

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