| 摘要: |
| 了解台湾桤木(Alnus formosana)在岩溶石山的生长表现以及根瘤生物量的特征,对石山植被的恢复与重建具有重要意义。该文采用典型样地调查方法对岩溶石山4.5年生台湾桤木与速生乡土树种任豆(Zenia insignis)、顶果木(Acrocarpus fraxinifolius)进行了调查研究,并用方差分析方法进行统计和评价。结果表明:台湾桤木平均胸径、树高、材积和冠幅分别为8.39 cm、7.72 m、0.0271 m3和3.18 m,均大于任豆和顶果木,且差异达到极显著水平; 台湾桤木冠长达6.01 m,分别比任豆和顶果木增加106.53%和70.25%; 台湾桤木在岩溶石山表现出速生的特性。对台湾桤木样株的根瘤生长状况进行深入调查分析发现,台湾桤木根瘤生物量平均每株达52.77 g,根瘤在水平方向分布从树干基部至树冠投影范围均有生长,离树干50 cm与离树干50～100 cm范围的根瘤生物量相近,离树干100 cm至树冠投影范围的根瘤生物量最多,三个地段的根瘤分别占整株根瘤生物量的15.7%、16.9%、67.4%; 大根瘤(直径≥1 cm)在离树干100 cm至树冠投影范围分布最多; 根瘤在垂直方向主要分布在0～20 cm土层,20～40 cm土层少有根瘤出现; 台湾桤木在岩溶石山表现出良好的结瘤固氮特性。该研究结果可为台湾桤木在岩溶石山的推广发展提供科学依据。 |
| 关键词: 台湾桤木, 任豆, 顶果木, 生长量, 根瘤,岩溶石山 |
| DOI：10.11931/guihaia.gxzw201903006 |
| 分类号:Q948.1 |
| 文章编号:1000-3142(2020)06-0776-06 |
| Fund project:广西科技攻关项目(桂科AB16380127,桂科2016AB12032); 中央财政林业科技推广示范项目(2013TG10)[Supported by the Key Science and Technology Program of Guangxi(AB16380127, 2016AB12032); Central Financial Forestry Science and Technology Promotion Demonstration Project(2013TG10)]。 |
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| Growth and nodule biomass characteristics of Alnus formosana in karst mountains |
|
HOU Yuanrui1,2,3, HUANG Xiaorong1, OU Zhiyang1, PANG Shilong1, SHEN Wenhui1*
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1. Guangxi Forestry Research Institute, Nanning 530002, China;2. Key Laboratory of Central South Fast-growing Timber
Cultivation of Forestry Ministry of China, Nanning 530002, China;3. Guangxi Key Laboratory of Superior
Timber Trees Resource Cultivation, Nanning 530002, China
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| Abstract: |
| Understanding the growth and nodule biomass characteristics of Alnus formosana on karst mountains is very important for vegetation restoration. Typical sample methods were used to investigate 4.5 year old populations of Alnus formosana, Zenia insignis and Acrocarpus fraxinifolius. The results were as follows: On average, Alnus formosana had DBH 8.39 cm, height 7.72 m, volume 0.027 1 m3and crown width 3.18 m, significantly higher than those of Zenia insignis and Acrocarpus fraxinifolius(P<0.01). Mean crown width of A. formosana was up to 6.01 m, 106.53% or 70.25% more than that of Zenia insignis or Acrocarpus fraxinifolius. Alnus formosana proved to be a fast-growing species on karst mountain. The root nodule growth of A. formosana was analyzed and its mean nodule biomass was 52.77 g per tree. The nodules dispersed within the range of crown projection around tree trunk. Nodule biomass at place < 50 cm from tree trunk was similar to that 50 cm to 100 cm away from the tree trunk, and the outer circle( >100 cm from tree trunk to outer bound of crown projection)contained the most nodule biomass. The three segments on average contained 15.7%, 16.9% and 67.4% of the total nodule biomass, respectively, and large nodules(diameter ≥ 1 cm)always distributed in the outer circles. For nodule vertical distribution, they mainly dispersed in 0-20 cm soil layer, and few nodules occured in 20-40 cm soil layer. A. formosana showed good nodulation and nitrogen fixation characteristics on karst mountain. This result provides scientific basis for recommending A. formosana afforestation in karst mountains. |
| Key words: Alnus formosana, Zenia insignis, Acrocarpus fraxinifolius, growth increment, root nodule, karst mountain |
