【作者】 刘中亮；

【导师】 万福绪；

【作者基本信息】 南京林业大学 ， 水土保持与荒漠化防治， 2011， 博士

【摘要】 本文通过对盱眙火山岩山地中处于不同演替阶段的典型植物群落进行结构调查和空间结构分析,并以二年生实生树种黄连木(Pistacia chinensis)、黄檀(Dalbergia hupeana)、朴树(Celtis sinesis)、麻栎(Quercus acutissima)、湿地松(Pinus elliotii)5个主要建群种为研究对象,研究了其抗旱机理,主要研究结论如下：1、乔木层α多样性指数呈稳定上升趋势,灌木层、草本层在湿地松群落和朴树+侧柏群落都偏低,整个群落的多样性指数在朴树+黄连木群落达最大。群落的演替规律呈现为：针叶纯林阶段—→针叶林为主的针阔混交林阶段—→针阔混交林阶段—→阔叶混交林阶段。2、林分空间分析结果表明,林分物种多样性丰富,乔木层共出现14个树种,径级结构分布连续,群落垂直结构特征明显,可分为3个林层,林分平均混交度为0.516,处于强度混交状态；林分平均角尺度为0.465,属于均匀分布；林分平均大小比数为0.454,即有45.4%的林木处于优势状态；林分平均开敞度为0.296,林木生长空间略有不足。栓皮栎、麻栎和侧柏种群优势度明显,群落暂时处于相对稳定状态,但侧柏缺少更新个体,群落最终将演替为落叶阔叶混交林。3、对野外调查筛选出5个主要优势树种黄连木、黄檀、朴树、麻栎、湿地松,进行干旱模拟试验。在干旱胁迫下,气孔导度与Chla含量变化呈现出显著下降的趋势；从整体上可以看出抗旱性强的树种与渗透调节能力相关的脯氨酸、可溶性糖的含量呈现出上升的趋势,大多数树种在重度和中度胁迫的末期则呈现出了显著下降的趋势;抗旱性强的树种在胁迫的初期SOD呈现出显著的上升趋势,随着胁迫时间延长,抗旱性较弱的树种最先呈现出了下降的趋势。4、轻度干旱胁迫下,湿地松的叶片超微结构未受损伤；麻栎线粒体无明显变化,叶绿体有扩张现象；黄连木与黄檀线粒体外膜有降解现象,叶绿体膨胀；朴树线粒体与叶绿体受损明显。重度胁迫下,湿地松、麻栎的线粒体内部出现降解,叶绿体受损；黄连木与黄檀出现质壁分离,叶绿体与线粒体受到严重损伤；朴树细胞内部受损最严重。5、综合5种树种的成活率和外部形态,用隶属函数法对多个评价指标和各树种的抗旱性以及生理适应性进行评价,各树种抗旱能力从高到低的排序为：湿地松>麻栎>黄连木>黄檀>朴树。更多还原

【Abstract】 The typical plant communities in different succession phases were analysised in Volcanics Mountains of Xuyi, Jiangsu. The 2 years old young trees of 5 species (Pistacia chinensis Dalbergia hupeana、Celtis sinesis、Quercus acutissima. Pinus elliotii) were chosen as the experimental materials in order to reveal the drought tolerance mechanism.5 conclusions were drawn as follow:1、The species diversity of mixed forest was rich, there were 14 stocks in tree layer, the DBH structure of community was continuous, and the vertical structure of stand might be divided into 3 layers. The communities were in the highly mixed statement under intensity distribution, and the growth space for the trees was insufficient slightly. The dominant tree species was 45.4% in total. The a diversity index of the tree layer steady uptrend, and was higher than the shrub and herb layers in the Celtis sinesis Pers.+ Biota orientalis communities. And the top value appeared in the Celtis sinesis Pers.+ Pistacia chinensis Bunge communies. The succession underwent 4 steps:coniferous forest→mixed broadleaf-conifer forest (dominated by coniferous forest)→mixed broadleaf-conifer forest→mixed broadleaf forest.2、The species diversity of mixed forest was rich, there were 14 stocks in tree layer, the DBH structure of community was continuous, and the vertical structure of stand might be divided into 3 layers. The average mingling of the stand was 0.516, showed that the mixed degree of the forest is high. The angle index was 0.465, indicated that the tree position in this stand was uniform distribution. The neighborhood comparison was 0.454, and there were 45.4% trees in the stand being dominant. The average opening degree was 0.296, displayed the growth space of most trees in the forest was slightly less than sufficient. Q.variabilis, Q.acutissima and P.orientalis population are dominant now, and the community is being in a relatively stable state. But P.orientalis lack of updated individual, so when all of P.orientalis died, the stand will become deciduous broad leaved mixed forest.3、In drought stress, stomatal conductance and variation in content Chla shows significantly trend; from the whole can be seen that the praline and soluble sugar in the tree species of strong drought resistance shows ascendant trend, and most species in severe and moderate stress were present at the end of a significantly trend; SOD of strong drought resistance tree species in initial stress shows significant uptrend. With prolonged drought stress, weaker species first revealed a downward trend.4、Five species of the ultrastructure of mesophyll cells also had change:in normal moisture conditions, the mesophyll cell organelles structure was complete. Under slight drought stress, Pinus elliotii leaves ultrastructure were not hurt. There was no obvious change of quercus acutissima Carruth. mitochondrial, and expand phenomenon to the chloroplast. Degradation phenomenons were observed at the Pistacia chinensis Bunge and Dalbergia hupeana Hance mitochondrial membrane and chloroplast were swelling. Celtis sinesis Pers. mitochondria and chloroplasts were damaged obviously. Under severe stress, there were internal possibilities of degradation of Quercus acutissima Carruth. and Pinus elliotii mitochondrial, and chloroplast were damaged. Pistacia chinensis Bunge and Dalbergia hupeana Hance appeard qualitative wall separation, and chloroplast and mitochondrial badly damaged. The Celtis sinesis Pers. cells. were damaged most seriously.5. Compositing five species survival rate and external shape, with the method of multiple subordinate function of each species evaluation indexes of drought resistance and evaluate the physiological adaptive drought resistance, the sequence of the 5 trees from high to low in the resistance of drought stress was Pinus elliotii>Quercus acutissima Carruth.>Pistacia chinensis Bunge>Dalbergia hupeana Hance>Celtis sinesis Pers.更多还原