Effects of Successive Rotation Regimes on Carbon Stocks in Eucalyptus Plantations in Subtropical China Measured over a Full Rotation

PLoS One. 2015 Jul 17;10(7):e0132858. doi: 10.1371/journal.pone.0132858. eCollection 2015.

Abstract

Plantations play an important role in carbon sequestration and the global carbon cycle. However, there is a dilemma in that most plantations are managed on short rotations, and the carbon sequestration capacities of these short-rotation plantations remain understudied. Eucalyptus has been widely planted in the tropics and subtropics due to its rapid growth, high adaptability, and large economic return. Eucalyptus plantations are primarily planted in successive rotations with a short rotation length of 6~8 years. In order to estimate the carbon-stock potential of eucalyptus plantations over successive rotations, we chose a first rotation (FR) and a second rotation (SR) stand and monitored the carbon stock dynamics over a full rotation from 1998 to 2005. Our results showed that carbon stock in eucalyptus trees (TC) did not significantly differ between rotations, while understory vegetation (UC) and soil organic matter (SOC) stored less carbon in the SR (1.01 vs. 2.76 Mg.ha(-1) and 70.68 vs. 81.08 Mg. ha(-1), respectively) and forest floor carbon (FFC) conversely stored more (2.80 vs. 2.34 Mg. ha(-1)). The lower UC and SOC stocks in the SR stand resulted in 1.13 times lower overall ecosystem carbon stock. Mineral soils and overstory trees were the two dominant carbon pools in eucalyptus plantations, accounting for 73.77%~75.06% and 20.50%~22.39%, respectively, of the ecosystem carbon pool. However, the relative contribution (to the ecosystem pool) of FFC stocks increased 1.38 times and that of UC decreased 2.30 times in the SR versus FR stand. These carbon pool changes over successive rotations were attributed to intensive successive rotation regimes of eucalyptus plantations. Our eight year study suggests that for the sustainable development of short-rotation plantations, a sound silvicultural strategy is required to achieve the best combination of high wood yield and carbon stock potential.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Agriculture*
  • Analysis of Variance
  • Carbon / analysis*
  • China
  • Ecosystem
  • Eucalyptus / chemistry*
  • Forests
  • Minerals / chemistry
  • Rotation*
  • Soil / chemistry
  • Trees
  • Tropical Climate*

Substances

  • Minerals
  • Soil
  • Carbon

Grants and funding

This study was funded by the Chinese National Natural Science Foundation (31460121), the Chinese Postdoctoral Science Foundation (2014M552286), the Ministry of Science and Technology (2012BAD22B01), the Chairman Foundation of Guangxi Zhuang Autonomous Region (11166-01), the Natural Science Foundation of Guangxi Zhuang Autonomous Region (1123014 and 11199001) and the Forestry Bureau of Guangxi Zhuang Autonomous Region.