Chin J Plant Ecol ›› 2008, Vol. 32 ›› Issue (6): 1285-1293.DOI: 10.3773/j.issn.1005-264x.2008.06.009

• Original article • Previous Articles     Next Articles

CHANGES IN BELOWGROUND CARBON ALLOCATION IN A CHINESE FIR CHRONOSEQUENCE IN FUJIAN PROVINCE, CHINA

CHEN Guang-Shui, YANG Yu-Sheng(), GAO Ren, XIE Jin-Sheng, YANG Zhi-Jie, MAO Yan-Ling   

  1. Key Laboratory of SubtropicalResources and Environments of Fujian Province, School of Geographical Sciences, Fujian Normal University, Fuzhou 350007, China
  • Received:2008-07-11 Accepted:2008-09-05 Online:2008-07-11 Published:2008-11-30
  • Contact: YANG Yu-Sheng

Abstract:

Aims Total belowground carbon allocation represents an important carbon flux in forest ecosystems and is closely related to carbon sequestration. Knowledge of how it changes with stand age in forest plantations is essential for carbon accounting and carbon management. Our primary objective is to elucidate changes in total belowground carbon allocation in a Chinese fir (Cunninghamia lanceolata) chronosequence.

Methods We selected an age sequence of 7 (young), 16 (middle-age), 21 (pre-mature), 41 (mature) and 88 year (old-growth) Chinese fir plantations with similar site conditions in Nanping, Fujian. Fine root production was determined by sequential soil coring, root respiration by trenching, current annual increment of tree biomass by allometric equations and annual litterfall by litter traps.

Important findings Annual fine root production (Pfr) was relatively high and statistically similar prior to the middle-age stage, but decreased in the following stages. The ratio of Pfr/litterfall decreased with stand age. Root respiration, which was linearly correlated to living fine root biomass, was lower in old-growth forest than in other forests. Total belowground carbon allocation (TBCA) was higher in middle-age and pre-mature forests than in young and mature forests and was lowest in old-growth forest. The ratio of aboveground net primary production to TBCA was higher in middle-age, pre-mature and mature forests than in young and old-growth forests. Root carbon use efficiency decreased with stand age.

Key words: Chinese fir, chronosequence, total belowground carbon allocation, fine root production, root respiration