欢迎访问林业科学,今天是

林业科学 ›› 2010, Vol. 46 ›› Issue (11): 89-94.doi: 10.11707/j.1001-7488.20101112

• 论文 • 上一篇    下一篇

湘西南石漠化地区4种植被恢复模式早期林分燃烧性

邓湘雯1唐林琴1田大伦1周雄2刘豪健2 向志勇1   

  1. 1.中南林业科技大学南方林业生态应用技术国家工程实验室长沙 410004; 2.湖南省邵阳县林业局邵阳 422100
  • 收稿日期:2009-06-10 修回日期:2009-09-27 出版日期:2010-11-25 发布日期:2010-11-25

Combustibility of Four Young Vegetation Restoration Stands in the Rocky Desertification Area in the Southwest Region of Hunan Province

Deng Xiangwen1Tang Linqin1Tian Dalun1Zhou Xiong2Liu Haojian2Xiang Zhiyong1   

  1. 1.Central South University of Forestry and TechnologyNational Engineering Laboratory for Applied Technology of Forestry & Ecology in South ChinaChangsha 410004;2.Forestry Bureau of Shaoyang County of Hunan ProvinceShaoyang 422100
  • Received:2009-06-10 Revised:2009-09-27 Online:2010-11-25 Published:2010-11-25

摘要:

通过测定与分析林分有效可燃物负荷量、析水速率、燃烧热值和能量现存量等,对湘西南石漠化地区4种植被恢复模式(湿地松纯林PEPF、侧柏纯林POPF、湿地松+枫香混交林PLMF、枫香+侧柏混交林LPMF)早期林分燃烧性进行研究。结果表明: 湘西南石漠化生态系统植被恢复早期,主要有效可燃物(EF)为白茅、马鞭草和一些灌木; 且林分的有效可燃物负荷量(EFL),都比较大,为5.16~9.89 t·hm-2,其中,侧柏纯林最大,为9.89 t·hm-2。在湖南省高火险季节(秋冬季),EF的相对含水率为17.8%~42.6%,侧柏纯林中的白茅和凋落物的含水率小,水分逸出时间短,析水速率快,燃烧性较强; 湿地松+枫香混交林中的EF平均相对含水率最大,水分逸出时间最长,燃烧性相对较差。主要EF的燃烧热值为11.7~20.8 kJ·g-1; 除凋落物外,同种EF在不同植被恢复模式中的燃烧热值没有显著差异; 林分中EF燃烧热值的加权平均值相差很小,为17.37~18.03 kJ·g-1,不能作为林分燃烧性差异的判定因子。EF总能量现存量大小排序为: 侧柏纯林>湿地松纯林>湿地松+枫香混交林>枫香+侧柏混交林,侧柏纯林为176.69×106 kJ·hm-2,枫香+侧柏混交林为92.73×106 kJ·hm-2。这些林分EF燃烧特点表明,湘西南石漠化地区4种植被恢复模式早期林分燃烧性都较高,其中,纯林燃烧性大于混交林。因此,建议选择混交林进行石漠化生态系统植被恢复,并加强林地清理,尤其是草本植物,以减少EF的积累,降低林分的燃烧性。

关键词: 邵阳县, 石漠化, 有效可燃物, 可燃物负荷量, 燃烧热值

Abstract:

The forest combustibility played a decisive role in forest fire prevention, and could have a great impact on the success of vegetation restoration in the rocky desertification area. In order to study the combustibility of the young vegetation restoration stands in the rocky desertification area, four patterns of vegetation restoration stands were chosen in the rocky desertification area in the Southwest region of Hunan Province, and they were Pinus elliottii pure forest (PEPF), Platycladus orientalis pure forest (POPF), Pinus elliottii and Liquidambar formosana mixed forest (PLMF), Liquidambar formosana and Platycladus orientalismixed forest (LPMF). The efficient fuel loading (EFL), relative moist content (RMC), dehydration rate, gross caloric value (GCV), and the efficient fuel energy were measured and analyzed in sample plots. The results showed: 1) The main fuel types were Imperata cylindrica, Verbena officinalis, and some shrubs in the young vegetation restoration stands in the rocky desertification area. 2) The EFL of the 4 patterns of vegetation restoration stands were all high, between 5.16 and 9.89 t·hm-2, and the POPF had the highest EFL which was 9.89 t·hm-2. 3) RMC was lower in the fire risk season (autumn and winter in Hunan province), between 17.8%-42.6%, with lowest in the litter and I. cylindrica in POPF. The POPF had the lowest average RMC and the most rapid dehydration rate among the 4 patterns of stands, and hence the greatest combustibility, whereas the PLMF was opposite, with the highest RMC and the smallest combustibility. 4) The GCV of the major fuel types was between 11.7-20.8 kJ·g-1 in the 4 stand patterns. Through analysis of variance we found that there was no significant difference in GCV of the same fuel type in different stand patterns, except for the litters. And there was no significant difference of the weighted average GCV in the 4 different stand patterns, which value were between 17.37-18.03 kJ·g-1. 5) The order from high to low of the efficient fuel energy was: POPF, PEPF, PLMF, LPMF. The highest efficient fuel energy was 176.69×106 kJ·hm-2 in POPF, and the lowest was 92.73×106 kJ·hm-2 in LPMF. 6) From these features of the young stands we can see that the forests of the 4 patterns all had great combustibility, and the pure forest had a higher combustibility than the mixed forest. Therefore, for the purpose of forest fire protection, we should choose mixed forests instead of pure forests, and it is necessary to clean the forest in time and reduce the EFL, during the process of vegetation restoration in the rocky desertification area.

Key words: Shaoyang county, rocky desertification, efficient fuel, fuel loading, gross caloric value