【作者】 王金凤；

【导师】 温远光；

【作者基本信息】 广西大学 ， 生态学， 2004， 硕士

【摘要】 酸雨分布范围广，危害严重，已成为世界十大环境问题之一。本文以定点监测与对比研究相结合的方法，通过在酸雨重污染区(柳州长塘)和轻污染区(柳州三门江森林公园)马尾松林分设立对比研究样地，对试验区的降水化学特征、马尾松针叶显微结构、生理特性及不同器官化学元素含量等方面进行了研究，并就增施石灰的作用和效果进行了试验性探讨，研究结果表明： (1)因大量燃烧高硫煤，向大气中排放了大量的二氧化硫，柳州是一个盆地，逆温频率高，不利于二氧化硫的扩散，高温、高湿又有利于二氧化硫的转化，加上土质呈酸性，大气中碱性物质少，使该区成为强酸性降雨区。 (2)在观察马尾松针叶显微结构中发现，由于受到酸雨的长期冲刷，试验区马尾松针叶的角质层厚度明显变薄，尤其以长塘酸雨重污染区更甚，长塘平均(G+B，下同)为1.43μm，三门江平均为1.73μm，长塘比三门江小20.98％，和正常的马尾松针叶的角质层厚度(2-2.5μm)相比，分别减少28.50％-42.80％和13.50％-38.80％。针叶横切面短轴长和长轴长，长塘的(短轴527.9μm和长轴807.8μm)比三门江的(短轴581.8μm和长轴900.1μm)分别短53.9μm和92.2μm，明显小于正常针叶(短轴800μm和长轴1200μm)，酸雨使马尾松针叶变得细小。长塘和三门江马尾松针叶的气孔密度分别为123.5num／mm~2和143.1 num／mm~2，重污染区比轻污染区减少13.70％；两试验区针叶的气孔密度比清洁区正常马尾松针叶的气孔密度(180num／mm~2)都小。因此，酸雨会降低针叶的气孔密度。观测还表明，两个地点马尾松针叶的气孔开度存在明显的季节差异，表现为夏季＞秋季＞春季＞冬季，这与降水的pH季节变化相一致，表明冬、春季的强酸性降雨抑制气孔开度。 (3)酸雨对马尾松针叶的生理特性也有明显的影响。首先，酸雨使细胞膜透性增大，从试验区来看，重污染区长塘马尾松针叶细胞膜透性比轻污染区高25.3％-149.19％；在同一试验区，受害较重的针叶细胞膜透性也比受害轻的针叶高广西大学硕士学位论文摘要2.66十9.77%(长塘)和0.67十5.77%(三门江)。其次，酸雨降低针叶的叶绿素含量，重污染区比轻污染区的针叶叶绿素含量低50.70十64.62%，同一试验区，受害重的针叶比受害轻的针叶低7.67%一16.30%(长塘)和6.25%一9.35%(三门江):并改变叶绿素a和叶绿素b的结构比。第三，酸雨使细胞的总糖含量降低，过氧化物酶活性增大，多酚氧化酶活性减小。 (4)酸雨对马尾松器官元素含量的影响，随不同器官和不同元素而不同。除个别器官或个别元素外，三门江马尾松器官的营养元素含量高于长塘，尤以N元素显著，其中三门江马尾松树皮中N含量高出长塘将近一半。除Ca，Mg以枝条含量最多，木材含量最少以外，其余元素一般呈现针叶>树皮、枝条>木材不同分布趋势。 (5)施石灰对马尾松针叶的影响，在解剖结构方面，首先，施石灰可增加针叶的角质层厚度(平均增加0.07阳)，长和长轴长分别增加与对照相比平均增加13.38阳和20.促进针叶生长，使马尾松针叶横切面的短轴07腼。其次，施石灰可提高针叶的气孔密度，2.3 num/mfn，。其次，大体上，施石灰针叶中N、P和Ca的含量增加，分别比对照增加1、6%，18.7%，9.15%(以春季为例，下同)，施石灰针叶中S含量下降，比对照减小6.4%。在生理特性方面，大体上，施过石灰的马尾松针叶的膜透性、叶绿素含量、过氧化物酶含量要小于对照的，分别减小26.4%，5.03%，10.8%。经过施石灰处理的马尾松针叶多酚氧化酶含量明显大于对照 (8 .9%)。 (6)马尾松属于酸雨敏感型，受到酸雨危害后，常导致马尾松林衰亡，主要以其角质层薄，再生能力弱等生长特点所决定。但其气孔密度低、针叶细小以及旱生化趋势是对污染环境长期适应的结果。更多还原

【Abstract】 Acid rain is widely distributed and seriously endangers land and aquatic ecosystem. Acid rain has become one of the top-ten environmental questions in the world. This paper combined the on-spot inspection and contrasted research to investigate the chemical characteristic of rainfall?anatomy and physiology of needle leaf?the content of chemical elements of different organs through the contrasted plots in seriously polluted area (Changtang) and lightly polluted area (Sanmenjiang) in Liuzhou . The effects of liming were also experimental researched. The results of study showed:(1)SO2 is ejected to the atmosphere because of burning a lot of coal with high sulphur content and Liouzhou is a basin with a high frequency of adverse thermal layer. All these prevent the diffusion of SO2. High temperature and moisture accelerate the transform of SO2. Soil acidification and low content of alkalescence substance in atmosphere make Liouzhou a high acidity rainfall area.(2)In the course of observing the anatomy of needle leaf, I found that the cuticle thickness obviously got thinner in the experimental area especially in Changtang. Compared with the cuticle thickness of normal needle leaf (2-2.5μm), the average cuticle thickness of Changtang (G+B) and Sanmenjiang were separately 1.43 μm and 1.73μm and they were lessened about 28.50%-42.80% and 13.50%-38.80% respectively. Changtang’s (the stub axle 527.9μm and the major axis 807.8μm) were 53.9μm and 92.2μm shorter than Sanmenjiang’s (the stub axle 581.8μm and the major axis 900.1μm). The stub axle and the major axis length of need leaf were obviously shorter than normal needle leaf (the stub axle 800μm and the major axis 1200μm) and needleleaf got shorter by acid rain. The stomatal density of Changtang and Sanmenjiang were 123.5 num/mm2 and 143.1 num/mm2. The stomatal density in seriously polluted area was lessened about 13.70% compared with that in the lightly polluted area. The stomatal density was shorter in two experimental areas than that in clear area (180 num/mm2). Hence, acid rain could reduce the stomatal density of needle leaf. The observation still showed that there was seasonal variation in stomatal apertura. It turned out to be that summer >autumn >spring> winter, which was consistent with the seasonal pH variation of acid rain. It showed that high acidity in winter and spring could restrain stomatal apertura.(3)Acid rain had obvious impact on the physiology of needle leaf. First, Cell membrane permeability was added by acid rain. The cell membrane permeability in Changtang was 25.3%-149.19% higher than that in Sanmenjiang. We could also see the cell membrane permeability of seriously damaged leaf were 2.66%-9.77% (Changtang) and 0.67%-5.77%(Sanmenjiang) higher than that of lightly damaged leaf. Second, the content of chlorophyll of needle leaf in seriously damaged area was 50.70%-64.62% lower than that of lightly damaged area. In the same experimental area, heavily damaged needle leaf were 7.67%-16.30%(Changtang) and 6.25%-9.35%(Sanmenjiang) lower than lightly damaged needle leaf. Acid rain still influenced the structural ratio of chlorophyll a and b. Third, acid rain made total sugar content reduced, the activity of peroxidase increased and the activity of PPO reduced.(4)The effect of acid rain on content of chemical elements of different organs was different with different organs and different elements. Except some exceptional organs and elements, the nutrient element content of different organs of Pinus massioniana in Sanmenjiang were higher than that in Changtang, especially for N, the content of N in over-bark pole in Sanmenjiang was almost twice as much as that in Changtang. Except Ca, Mg which had biggest content in branch least content in timber, other elements appeared the regularity: the needle leaf>over-bark pole, branch > the bark.(5)The effects of liming on needle leaf were as follows: First was on the anatomy of needle leaf. Liming could increase the cuticle thickness (average increase was 0.07um) and accelerated the growth of needle更多还原