Vegetation Succession Rule Andregeneration Stratigies in Disturbed Karst Area,Northwest Guangxi
Vegetation Succession Rule Andregeneration Stratigies in Disturbed Karst Area,Northwest Guangxi
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发表时间：
2008
影响因子：
2.5
通讯作者：
Ouyang Ziwen
中科院分区：
文献类型：
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作者：
Ouyang Ziwen
通过实地调查和查阅文献资料，研究了桂西北岩溶扰动区环境保护后自然恢复22年的植被演替和生物多样性变化。本研究以木伦自然保护区顶极群落为对照，采用干扰理论和群落分析方法。调查结果表明，桂西北岩溶区共有维管植物91科206属241种，仅占木伦自然保护区种类的26.6%。这表明岩溶扰动区物种多样性丧失严重。植被生长类型主要有6种，分别为：枯落物、石漠化疏草、草地、草灌、灌木、藤灌、乔灌。在自然恢复后，群落平均高度为0.49 ~ 15.56 m，密度为468.50 ~ 0.31株/ha 2，总盖度呈高（0.85）、低（0.50）、高（0.90）、高（0.80）的趋势。群落生物量随高度的增加而增加，在7.74 ~ 131.42 t/ha ~ 2之间变化，草本生物量占总生物量的比例随高度的增加而降低。物种多样性和Shannon-Wiener指数逐渐增加，分别从14增加到46和从0.89增加到4.13。群落生态优势度在演替中期由0.10下降到0.16，变化相对较小，演替初期为0.28，演替末期为0.23。均衡原则正好相反。与顶极群落相比，最大高度、生物量和多样性指数分别降低了10.82 m、42.02 t/hm 2和0.29。针对干扰区植被恢复缓慢的现象，探讨了干扰区的形成机制及其对植被的影响。同时，提出了桂西北岩溶大扰动区植被过度退化的3条自然与人为相结合的恢复途径。
The vegetation succession and biodiversity changes in 22 years' natural restoration after environmental protection were studied in disturbed karst area in northwest Guangxi, via the spot investigation and referred literatures in this paper. Taken climax community in Mulun Natural Reserve as contrast, disturbance theory and community analysis methods were adopted in this study. The investigation showed that there were about 241 species of vascular plant, which belong to 91 families and 206 genera in karst area in the northwest of Guangxi with only 26.6% of species in Mulun Natural Reserve. It indicated that species diversity lost severely in disturbed karst area. There were six vegetation growth forms in the sere, sparse grass of rocky desertification, grassland, grass-shrub, shrub, vine-shrub, tree-shrub. In the sere except the stage with sparse grass of rocky desertification, the average community height ranged from 0.49 m to 15.56 m while density from 468.50 plants per ha2 to 0.31 plants per ha2, and whole coverage was in the trend of higher (0.85), low (0.50), highest (0.90) and high (0.80) after natural restoration. The community biomass varied from 7.74 tons per ha2 to 131.42 tons per ha2 with the +community height increasing and the percentage of the grass biomass to the whole community biomass decreasing. The species diversity and Shannon-Wiener's index increased gradually, from 14 to 46 and from 0.89 to 4.13, respectively. Ecological dominance in the middle stages of the succession lowered from 0.10 to 0.16 with comparative less variations, whereas 0.28 in the beginning and 0.23 in the ending. The reverse was true to the rule of evenness. Compared to the climax community, the largest height, biomass and diversity index reduced by 10.82 m, 42.02 tons per hm2 and 0.29, respectively. According to slow vegetation restoration in disturbed area, the authors discussed the formation mechanism of disturbed area and the effects on vegetation. Meanwhile, the authors put forward three approaches with combination of nature and human being to vegetation recovery, which would be suitable in exceeding degradation in great karst disturbed area in northwest Guangxi.