Partitioning of belowground C in young sugar maple forest

Autor: Timothy J. Fahey, Guoliang Wang, Peter M. Groffman, Ruth E. Sherman, Joseph B. Yavitt
Rok vydání: 2012
Předmět:
Zdroj: Plant and Soil. 367:379-389
ISSN: 1573-5036
0032-079X
DOI: 10.1007/s11104-012-1459-1
Popis: Trees allocate a high proportion of assimilated carbon belowground, but the partitioning of that C among ecosystem components is poorly understood thereby limiting our ability to predict responses of forest C dynamics to global change drivers. We labeled sugar maple saplings in natural forest with a pulse of photosynthetic 13C in late summer and traced the pulse over the following 3 years. We quantified the fate of belowground carbon by measuring 13C enrichment of roots, rhizosphere soil, soil respiration, soil aggregates and microbial biomass. The pulse of 13C contributed strongly to root and rhizosphere respiration for over a year, and respiration comprised about 75 % of total belowground C allocation (TBCA) in the first year. We estimate that rhizosphere carbon flux (RCF) during the dormant season comprises at least 6 % of TBCA. After 3 years, 3.8 % of the C allocated belowground was recovered in soil organic matter, mostly in water-stable aggregates. A pulse of carbon allocated belowground in temperate forest supplies root respiration, root growth and RCF throughout the following year and a small proportion becomes stabilized in soil aggregates.
Databáze: OpenAIRE
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