Effects of 11 Years of CO2 Enrichment on Root Biomass and Spatial Distribution in a Florida Scrub-Oak Ecosystem

<p>A Florida (USA) scrub-oak ecosystem was exposed to elevated atmospheric CO₂ in open-top chambers from 1996-2007. Minirhizotrons and ground-penetrating radar (GPR) were used to measure fine root (< 2 mm diameter) and coarse root (> 5 mm diameter) biomass, respectively. After 11 years of CO₂ enrichment, there was a trend of greater total root biomass under elevated CO₂. Fine root biomass exhibited a pattern of recovery and steady state throughout the study, with significant CO₂ stimulation observed only after disturbance. Greater root biomass under elevated CO₂during recovery periods could result in greater carbon inputs belowground, alteration of the soil carbon cycle, and faster ecosystem recovery. At the end of the study, a greater proportion of fine root biomass was found deeper in the soil in plots exposed to elevated CO₂. The shift of biomass deeper in the soil and pattern of recovery and steady state suggest a limit on the soils' capacity to support fine roots. The dominant plants were not limited by water or nutrients, indicating that root responses to CO₂ enrichment were likely constrained by soil resource space.</p>

Name thesis:degree_name

Doctor of Philosophy (PhD)

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Biological Sciences

Year dc:date.available

2011

Author dc:creator

• Schroeder, Rachel Eilenfield

Contributors dc:contributor

• Frank P. Day
• Rebecca D. Bray
• G. Richard Whittecar

• Biomass
• Carbon dioxide
• Ground penetrating radar
• Minirhizotrons
• Root
• Ecology and Evolutionary Biology
• Environmental Sciences

Statement dc:rights

• <p>In Copyright. URI: <a href="http://rightsstatements.org/vocab/InC/1.0/">http://rightsstatements.org/vocab/InC/1.0/</a> This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s).</p>

Identifier

9781124973111

OAI identifier oai:identifier

oai:digitalcommons.odu.edu:biology_etds-1079