Diameter Growth, Biological Rotation Age and Biomass of Chinese Fir in Burning and Clearing Site Preparations in Subtropical China

• Main Authors: Hua Zhou, Shengwang Meng, Qijing Liu
• Format: Article
• Language: English
• Published: MDPI AG 2016-08-01
• Series: Forests
• Subjects: biomass; Chinese fir; rotation age; site preparation; subtropical forests
• Online Access: http://www.mdpi.com/1999-4907/7/8/177

Sustained forest management of Cunninghamia lanceolata (Chinese fir) plantations in subtropical China is restricted by the limited availability of quantitative data. This study combines inventory data and tree-ring analysis of Chinese fir from natural and plantation forests that were subjected to controlled burning or brush clearing site preparations. Inter-annual variation of Chinese fir tree-ring widths were measured for the controlled burning, brush clearing and natural forest sites. The mean annual diametric growth of Chinese fir was 0.56 cm·year−1 for the natural forest, 0.80 cm·year−1 for the brush clearing site and 1.10 cm·year−1 for the controlled burning site. The time needed to reach the minimum cutting/logging diameter of 15 cm was 14 years in the controlled burning site, 19 years in the brush clearing site and >40 years in the natural forest. The biological rotation ages for the burning, cutting and natural forest sites were 15, 26 and >100 years, respectively. The total aboveground biomasses for the burning and clearing sites were 269.8 t·ha−1 and 252 t·ha−1, respectively. These results suggest that the current 25-year cutting cycle greatly underestimates the growth rate of Chinese fir plantations.