Effects of thinning intensity on diversity of undergrowth vegetation and regeneration in artifical spruce forest

• Yan-yan QIN, 
• Bin JIANG, 
• Xiu-wen CAO, 
• Yi-ming FENG, 
• Dan-chun LI, 
• Meng-meng YANG, 
• Mei XIANG, 
• Rong CHEN, 
• Bo LI, 
• Zong-quan CHE