青藏高原纬度梯度下紫花针茅种子大小适应性的初步研究 毕业论文.doc

西南林业大学 本科毕业（设计）论文 （2011届） 题目:青藏高原纬度梯度下紫花针茅种子大小适应性的初步研究 教学院系 环境科学与工程学院 专 业 环境科学 学生姓名 指导教师 评 阅 人 2011年5月10日 青藏高原纬度梯度下紫花针茅种子大小适应性的初步研究 摘要：紫花针茅（Stipa purpurea）是青藏高原上一种分布较为广泛、对恶劣环境抵抗能力较强、适应性较高的植物。但由于近年来环境状况日趋恶劣、气候变暖等因素其生长受到了较大的影响。为了了解紫花针茅对水热等环境条件的适应，本文通过对紫花针茅种子随景观变化以及紫花针茅与各指标间的权衡关系进行研究。结果表明：①种子直径随着纬度的增加而增加，说明大种子在水热条件较差时有较好的适应性；芒长随着纬度的增加而增加，说明芒长的增加有利于种子的传播及能促进种子的萌发；第二节间直径随着纬度的增加而增加，说明第二节间直径长得越健壮越有利于穗的生长。穗长随着海拔的升高而减小，说明海拔较高的区域较低矮的穗有更强的适应性；种子数量随着海拔的升高而减小，说明高海拔区环境恶劣植株生长状况而导致差结实率低。种子各指标与经度的变化均无关系。②种子直径随着第二节间直径的增大而增大，种子总重量随种子直径的增加而增大；外稃长、芒长、内稃长、种子总重量随着种子长的增加而增加。 关键词：青藏高原；紫花针茅；种子大小；芒长 Qinghai-Tibet Plateau latitudinal gradient Stipa purpurea a preliminary study of seed size adaptation Diao Kaiyou (College of Environmental Science and Engineering, Southwest Forestry University, Kunming 650224, China) Abstract: Stipa purpurea is a distribution on the Qinghai-Tibet Plateau is more widespread, strong resistance to harsh environments, adaptability higher plants. However, due to deteriorating environmental conditions in recent years, the growth factors such as climate change has been seriously affected. In order to understand in this case Stipa purpurea grandis adaptation, namely the Stipa purpurea grandis species to habitat choice, seed propagation and reproductive rule. This article through to Stipa purpurea grandis seeds with landscape changes and Stipa purpurea grandis and the relationship between each index research and analysis. The results showed that: ① The seed diameter increases with latitude, indicating that large seeds in hot water when the less the better adaptability; Mountain long as the latitude increases, indicating that the increase is conducive to long-Mount seeds transmission and can promote seed germination; II between the diameter increases with latitude, section II looks more robust between the diameter of t