The role of agricultural intensification in modulating ecosystem properties of embedded subtropical wetlands

Natural wetlands are unique ecosystems that offer substantial services to the surrounding landscape, are host to immense biodiversity, and are the largest global emitters of biogenic methane to the atmosphere. The unique nature of wetland ecosystems cater to an extensive diversity of microorganisms – essential regulators of biogeochemical and ecosystem-level processes including the production of methane. However, wetlands reside at the lowest elevational point in a landscape making them particularly vulnerable to inputs from the surrounding area. This is especially problematic for wetlands embedded in agricultural systems where surrounding management practices may indirectly impact wetland function and sustainability, including the relative influences on methane emission. The impact of surrounding management intensity on methane emissions from embedded wetlands is uncertain, in part because most studies on this subject focus on temperature and high latitude regions where agriculture is lacking. As humans continue to reduce global biodiversity through agricultural expansion and intensification, it remains unclear the degree this trend will impact wetland microbial populations. This thesis examines how management of the surrounding agricultural landscape, including intensity and/or grazing, influences net methane emissions and microbial populations from embedded, seasonal subtropical wetlands. This research further determined key mechanisms by which management decisions at the landscape scale modulate CH4 emissions from embedded wetlands. The goals of this research were to: 1) quantify the effects of surrounding agriculture on net CH4 emissions from embedded wetlands, 2) assess the impact management intensity has on the diversity and composition of wetland microbial populations, and 3) examine the relationship between ecosystem and microbial functionality with particular emphasis on methanogenic microorganisms. The findings presented here show that agricultural management strategies to optimize cattle production have significant and holistic impacts on functions important for CH4 production and the microbial diversity of embedded wetlands. Wetlands, but also tropical and subtropical regions in general, are largely underrepresented in literature, and the context of these results reflect the importance of expanding consideration of these regions regarding the impacts of agriculture on local ecosystems.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Plant Biology

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2020

Author dc:creator

• Delucia, Nicholas J.

Contributors dc:contributor

• Bernacchi, Carl J
• Gomez-Casanovas, Nuria
• Ainsworth, Elizabeth A
• Yang, Wendy H

• Plant Biology
• Wetlands
• Subtropics: Subtropical
• Florida
• Methane
• CH4
• green house gases
• GHG

Statement dc:rights

• Copyright 2020 Nicholas Delucia

Language dc:language

en

Handle dc:identifier

http://hdl.handle.net/2142/108013

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/108013