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研究报告目录 |
云南热带、亚热带次生林部分优势种的能量分配格局 |
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| 出 版 社：硕士研究生毕业论文 |
| 发表时间：2006.06. |
| 台 站：
哀牢山亚热带森林生态系统研究站
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| 作 者：乔秀娟 |
| 点 击 率：13985 |
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| 关 键 字：能量,热值,优势物种,次生演替,西双版纳,哀牢山 |
| 摘 要：本文对西双版纳和哀牢山次生植物群落优势树种的热值进行了研究。在西双版纳选取4种群落类型（山黄麻群落、白楸群落、中平树群落和思茅崖豆群落）进行了群落调查，群落的年龄分别为2年、4年、6年、大于15年。每群落类型中建立3个20 m×20 m样地，根据群落学调查结果得到优势树种。在哀牢山，根据以往研究确定次生优势树种5种。按叶、枝、干、根四部分分别取样，磨粉烘干后用SDCM-IIIa氧弹式量热仪进行热值测定。本项研究还选取部分代表性树种的叶片进行营养物质含量的测定。结果表明：
1、随着林龄增加，群落物种丰富度和生物多样性指数均增加。表明随着群落的成熟，需要增加生物多样性来建造更为复杂的结构。为了更好的增加能量的耗散，生态系统发展更复杂的结构，产生更多能量流动的渠道，增加循环能力，发展更好的生物多样性。
2、西双版纳4种群落各优势树种的平均干重热值分别为19182.11、19474.81、19551.38 和19445.95 J•g-1。总体来讲，热值随着群落年龄的增加而增加。增长的原因应该是群落光能利用效率的增加。思茅崖豆群落的热值稍有降低，我们认为是因为这个群落样地处在阴坡，不能接受到像其他三个群落那样在阳坡的充足光照。
3、西双版纳所研究全部物种的叶、枝、干、根的平均热值分别为20133.34、19371.96、19475.32和19227.31 J•g-1，存在着叶＞干＞枝＞根的规律；哀牢山先锋树种平均热值分别为21614.07、20715.44、20162.52及19870.19 J•g-1，存在着叶＞枝＞干＞根的规律。
4、西双版纳先锋树种的热值明显低于顶极树种。我们推测，在群落演替初期，生态系统增加能量耗散的主要方式是通过生物量的增加；而当结构建成，生物量增加到一定程度，已经没有足够增长空间的时候，生态系统将会改变能量储存方式，主要通过单位质量固定能量的增加，也就是热值的增加，来耗散能量。山黄麻群落中叶片的热值非常低，低于根的热值水平，我们认为是短命树种将能量更多地投资于繁殖的原因。
5、哀牢山先锋树种热值高于顶极树种，推测其原因可能为群落循环周期
长，萌生现象明显，以及采样时间的稍有不同产生的差异。具体原因有待进一
步研究。
6、哀牢山干季植物的热值略高于雨季热值。我们认为，在干季先锋植物受环境条件限制，生物量生长缓慢，而单位质量的热值却较高；雨季来临，植物生长迅速，生物量的增长加快，但是单位质量的能量含量却因植物的快速生长而下降，故干季热值稍高于雨季。
7、哀牢山先锋群落热值显著高于西双版纳先锋群落热值，原因是在高纬度、高海拔地区，植物需要合成更多的高能物质用以抵御寒冷。
8、西双版纳先锋树种的蛋白质含量显著高于顶极树种，而顶极树种的粗纤维含量显著高于先锋树种的粗纤维含量；哀牢山顶极树种的粗纤维含量显著高于先锋树种的粗纤维含量。哀牢山树种脂肪和淀粉含量极显著高于西双版纳树种。
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| 关 键 字(英文)：energy, caloric value, dominant species, secondary succession, Xishuangbanna, the Ailao Mountains |
| 摘 要(英文)：Succession is a hotspot of ecology all the times, and energy plays an essential role in life activity. The objective of this study is to determine the allocation pattern of caloric values in some dominant species of the secondary forests that were evolved from deforestation of local tropical rain forests in Xishuangbanna and subtropical forests on the Ailao Mountains, Southwest China.
The four communities in Xishuangbanna were Trema orientalis forest, Mallotus paniculatus forest, Macaranga denticulata forest and Millettia leptobotrya forest, which were 2-, 4-, 6- and > 15 years old respectively. Three plots of 20 m 20 m were established in each of the 4 forest types, in which species names, DBH of all trees whose diameters were over 3 cm were measured. Caloric values of 17 dominant tree species were observed. In the Ailao Mountains, we sampled 5 pioneer trees based on the data from previous investigates. Five sample trees comprised of one small, three intermediate and one large-sized tree were investigated for each dominant species. The sampled parts included foliages, branches, stems and roots. The caloric values of three replications for each sample part were measured with SDCM-IIIa oxygen bomb calorimeter, with error under100 J • g-1. Differences were tested by the t - Test. The results show that:
1. Total number of species and species richness increased with forest ages. With the mature of communities, there should be more species diversity to abet energy dissipation.
2. The mean caloric values of T. orientalis forest, M. paniculatus forest, M. denticulata forest and M. leptobotrya forest were 19182.11, 19474.81, 19551.38 and 19445.95 J•g-1 respectively. When the biomass of the community is low, the ecosystem increases the accumulation of energy though biomass growth, so the caloric values of the pioneer trees are low. But as the organic structures build up, the ecosystem augments the fixation efficiency of the energy, and then the caloric values are enhanced.
3. The caloric values of the climax tree species in Xishuangbanna were greater than those of the pioneer. However, the differences between foliages were significant, and the differences between branches, stems, roots and the average were not significant.
4. The caloric values of different parts were ranked as: foliage > stem or branch > root at the average level, although Trema orientalis, Vitex quinata, Aporusa yunnanensis showed lower caloric value in foliage.
5. The caloric values of pioneer species in the Ailao Mountains were higher than the climax, the reason need more investigates.
6. The caloric values of pioneer species in rainy season in the Ailao Mountains were lower than those in dry season. Biomass increased slowly in dry season, so caloric values were higher; Plants grew fast in rainy season, and caloric value decreased.
7. The caloric values of pioneer species in the Ailao Mountains were higher than those in Xishuangbnana.
8. Protein content of pioneer trees in Xishuangbanna was significantly higher than that of the climax trees, and the cellulose content of pioneer trees was significant lower than that of the climax trees. In the Ailao Mountains, the cellulose content of pioneer trees was significant lower than that of the climax trees. The contents of fat and cellulose were significantly higher in the Ailao Mountains than in Xishuangbanna.
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 乔秀娟毕业论文定稿.doc |
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