Evidence of old carbon used to grow new fine roots in a tropical forest

TitleEvidence of old carbon used to grow new fine roots in a tropical forest
Publication TypeJournal Article
Year of Publication2009
AuthorsVargas, R., Trumbore S. E., & Allen M. F.
JournalNew Phytologist
Date Published2009
Type of ArticleArticle
ISBN Number0028-646X
Accession NumberWOS:000265229400015
Keywords1705; below-ground; biomass; branch order; carbon reserves; defoliation; dynamics; ecosystem; fine roots; hardwood forest; hurricane; impacts; Keck / AMS Lab; longleaf pine forest; minirhizotron; radiocarbon; Research; rhizosphere; soil respiration; turnover

In this study, we explore how a hurricane disturbance influenced carbon allocation for the production of new fine roots. Before and after a hurricane, we measured the age of carbon (time since fixation from the atmosphere) in fine root structural tissues using natural abundance radiocarbon ((14)C) measured by accelerator mass spectrometry. Roots were sampled from five seasonally dry tropical forests ranging in age from 6 yr to a mature forest. Structural carbon in combined live + dead roots picked from soil cores sampled 1 month before the hurricane had mean ages ranging from 4 to 11 yr, whereas live roots alone had ages of 1-2 yr. Structural carbon in new live fine roots produced over a period lasting from 3 wk before the hurricane to 2 months after the event had mean ages of between 2 and 10 yr. Contrary to expectations, our results showed that plants allocate long-lived storage carbon pools to the production of new fine roots after canopy defoliation and root mortality. The age of the carbon allocated for new roots increased with forest age and forest above-ground biomass, suggesting an adaptation of plants to survive and recover from severe disturbances. New Phytologist (2009) 182: 710-718doi: 10.1111/j.1469-8137.2009.02789.x.

Alternate JournalNew Phytol.
ESS Associations
Research Area: 
Biogeochemical Cycles
Research Lab: 
Keck / AMS Lab