李莲芳, 王慷林, 段安安, 李卫冲, 郑树宏, 龚建斌. VDT法疏伐云南松人工林胸径及其断面积结构的动态变化研究[J]. 西南林业大学学报, 2017, 37(5): 1-8. DOI: 10.11929/j.issn.2095-1914.2017.05.001
引用本文: 李莲芳, 王慷林, 段安安, 李卫冲, 郑树宏, 龚建斌. VDT法疏伐云南松人工林胸径及其断面积结构的动态变化研究[J]. 西南林业大学学报, 2017, 37(5): 1-8. DOI: 10.11929/j.issn.2095-1914.2017.05.001
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Lianfang Li, Kanglin Wang, Anan Duan, Weichong Li, Shuhong Zheng, Jianbin Gong. Structural Dynamic Changes of the Diameter at Breast Height and Basal Area in a VID Thinned Pinus yunnanensis Plantation[J]. Journal of Southwest Forestry University, 2017, 37(5): 1-8. DOI: 10.11929/j.issn.2095-1914.2017.05.001
Citation: Lianfang Li, Kanglin Wang, Anan Duan, Weichong Li, Shuhong Zheng, Jianbin Gong. Structural Dynamic Changes of the Diameter at Breast Height and Basal Area in a VID Thinned Pinus yunnanensis Plantation[J]. Journal of Southwest Forestry University, 2017, 37(5): 1-8. DOI: 10.11929/j.issn.2095-1914.2017.05.001
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VDT法疏伐云南松人工林胸径及其断面积结构的动态变化研究

Structural Dynamic Changes of the Diameter at Breast Height and Basal Area in a VID Thinned Pinus yunnanensis Plantation

    摘要
  • 摘要: 为了解中林龄阶段(25年生)疏伐对云南松人工林胸径及其断面积结构的动态影响，在昆明宜良禄丰村林场徐家山林区，采用可变密度疏伐法对直播造林后未开展任何抚育、密度分别为7 311、3 660、4 612、3 045株/hm2的4块云南松人工林样地进行疏伐，疏伐强度分别为0.0% (对照)、25.8%、31.5%、27.7%。以2 cm为径阶，分析疏伐前后及疏伐5 a后林木径阶、胸高断面积结构及其重要值的动态变化。结果表明，疏伐前，6~8 cm林木是林分的主要径阶构成，但胸高断面积却以6~12 cm径阶为优势，4块样地林分≤ 6~16 cm径阶分别占总断面积的77.5%、70.4%、74.6%、72.1%；疏伐后，除比例变化外，6~12 cm径阶仍然是构成断面积的主要径阶(样地2~4的分别占总断面积的73.9%、73.7%、69.3%)；疏伐5 a后，构成林分胸高断面积的林木前移为8~14 cm径阶，而且12、14 cm径阶的林木均有较大比例的增加，在样地1~4中分别达总株数的23.5%、21.5%、24.4%、32.8%；疏伐样地2~4的总断面积从疏伐后的13.86、28.31、24.26 m2/hm2增加至疏伐后5 a时的24.02、36.43、26.33 m2/hm2，而自然稀疏的样地1则从39.21 m2/hm2降低至29.07 m2/hm2；疏伐林分(样地2~4)的胸高总断面积较疏伐后分别增加73.3%、28.7%、8.5%，同期对照林分(样地1)的却降低25.8%。随着疏伐后林木的生长，林分重要值的主要构成也向更大径阶方向移动。

     

    Abstract: In order to understand the dynamic effects of thinned Pinus yunnanensis plantation on diameter at breast height (DBH) and their basal area (BA) structures for being thinned at middle aged stage (25-year-old), the method of variable-density thinning (VDT) was employed to be thinned 4 sampling plots (SPs) of P.yunnanensis plantation with densities of 7 311, 3 660, 4 612, and 3 045 stem/hm2 of the species, respectively, which never implemented any tending approaches after established stand by seeding method at Xujiashan Forest Zone in Lufengcun Forestry Centre, Yiliang County, Kunming. The thinning intensities were 0.0% (ck), 25.8%, 31.5% and 27.7% for abovementioned SPs. Dynamic changes of DBH, BA and their important value (Ⅳ) of stand trees were analyzed based on 2 cm acted as one DBH grade for the period of before stand thinned, after moment and for 5 years thinned. The results showed that the 6 and 8 cm were dominant DBH grade of standing-stocks, however, the 6-12 cm grade was dominaant BA with 77.5%, 70.4%, 74.6% and 72.1% of total BA for the 4 SPs, respectively, before stand thinned. After the forest thinned, excepting the proportion varied, the 6-12 cm grade structured primary the BA (which were 73.9%, 73.7%, and 69.3% of total Bas for the SP 2-4, respectively) also. After thinned for 5 years, stand trees composed of the BA was forward to 8-14 cm DBH grade, and there were great proportion increment of the 12 and 14 grade trees with 23.5%, 21.5%, 24.4% and 32.8% of those two DBH grade in total stand trees, respectively. Moreover, the total BA of the SP 2-4 were from 13.86, 28.31 and 24.24 m2/hm2 after thinned moment increased to 24.02, 36.43 and 26.33 m2/hm2 after 5 years thinned, while which of natural thinning SP 1 was from 39.21, 26.33 m2 decreased to 29.07, 26.33 m2 at the same period with the SP 2-4. Simultaneously, the total BA of the SP 2-4 increased by 73.3%, 28.7% and 8.5% respectively after thinning, the control stand (SP 1) decreased by 25.8%. Stand tree IVs of dominant structures also moved forward to bigger DBH grade orientation with tree growth after stand thinned.

     

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