山东海岸沙地主要防风固沙树种对风和风沙流危害的耐受力及其适应机制

Large area of coastal sand land distributes in long coastal zone, China. Most plants are difficult to survive except for a few kinds of psammophytes in the area because of frequency gale and strong wind-blow sand activity. But so far, it is rarely reported on how the wind and wind-blow sand damage to the coastal sand land plants and what adaptation mechanism are involved in those plants adapting to wind and wind-blow sand. Based on 4 tree species of windbreak and fixation sand trees grown in coastal sand area of Jiaodong Peninsula of Shandong Province, tolerance threshold and their adaptation mechanisms for several tree species of windbreak and fixation sand to damage of gale and strong wind-blow sand in coastal sand land will be studied in this project by using field portable wind tunnel and sand wind tunnel. The project main contents include that 1) study on the tolerance threshold of the several plants continuous blowing of gale and strong wind-blow sand and its critical characteristics of dying, to explore its mechanism of death under the stress of the gale and strong wind-blow sand; 2) Study on plant configuration, stem and leaf morphology, height, crown cover, growth and development rhythm of the several species under stress of different time gale and strong wind-blow sand to explore their ecological adaptation strategy to wind and wind-blow sand stress; 3) Study on leaf temperature, leaf water content, photosynthetic rate, epidermal anatomy, MDA content, membrane permeability, protective enzyme, osmotic adjustment substances contents, under stress of different time gale and strong wind-blow sand to explore their physiological adaptation mechanism to wind and wind blow sand stress and relationship between difference in capacity of those plants resistance to wind sand stress and its adaptability in ecology and physiology. The results of this study can not only promote the development of plant stress physiology and ecology, but also provide theoretical guidance for the restoration and reconstruction of coastal sandy vegetation in northern China.

在我国漫长的海岸地区分布着大片滨海沙地。由于大风频发，风沙流活动强烈，除少数沙生植物外，一般植物难以生存。但迄今为止，关于大风及其风沙流吹袭对植物的危害及其适应机制研究还鲜有报道。本项目以胶东半岛滨海沙地4种防风固沙树种为对象，通过野外风洞吹袭试验，研究其不同植物耐受大风及其风沙流持续吹袭的能力及其临界死亡特征，探索大风及其风沙流胁迫下其致死机制；研究不同时间大风及其风沙流胁迫下其植株构型、株高、生长节律、生物量等生物学特征变化，分析其对大风及其风沙流胁迫的生态适应对策；研究不同时间大风及其风沙流胁迫下其叶面温度、含水量、光合作用、丙二醛含量、膜透性、保护酶活性和渗透调节物质含量等生理指标变化，分析其对大风及其风沙流胁迫的生理响应，探讨其抗风沙胁迫能力的差异与其生理生态适应能力的关系。其研究成果不仅可拓展植物逆境生理生态学研究的新领域，还可为我国北方滨海沙地植被恢复重建提供理论指导。

海岸地区大风频发所引发的风沙流不仅污染大气环境、限制植物分布、侵袭农田、破坏海岸景观。建立海岸防护林带在维护海岸生态环境和经济发展有重要作用。而揭示海岸防风植物抗风蚀的适应生理机理将有助于筛选和培育抗风植物，为此我们申请了该项目。项目研究了海岸防风植物抗强风吹袭耐受阈，并集中研究了不同时间和强度净风和风沙流吹袭，及反复强净风和风沙流吹袭下，黑松和紫穗槐幼株叶片含水量、膜透性、MDA含量、渗透调节物、抗氧化酶活力等抗逆生理指标的变化。结果表明：1.黑松、紫穗槐、柽柳、单叶蔓荆在经历持续强风沙流（18m/s)吹袭后，尽管其生存策略不同但在第二年春季均繁茂生长，不存在抗风耐受阈值。并且在自然状况下，黑松和紫穗槐抗逆生理指标存在差异，黑松可溶糖含量和SOD活力较紫穗槐高111.5%和28.2%。紫穗槐MDA和脯氨酸含量、CAT和POD活力较黑松高93.3%、78.6&、118.8%、6.5倍，2.黑松在低速净风吹袭下，叶片各项抗逆生理指标变化较小，而在风沙流处理抗逆生理指标增高。同风速吹袭下，风沙流处理叶片MDA含量、SOD和CAT活力较净风处理高 52.6%、11.5%、26.4%。黑松针叶较强的抗脱水力和渗透调节及抗氧化能力在抗风生长中起重要生理保护作用。3.随着净风和风沙流吹袭风速的增加，紫穗槐叶片RWC下降与质膜透性和MDA含量增高成明显负相关。在大风（18m/s)净风和风沙流吹袭40min时，其叶片含水量下降不仅伴随着可溶性糖和脯氨酸含量增加，还伴随着MDA含量、CAT、SOD、POD活力增高。研究表明，渗透调节物和抗氧化酶通过维护水分平衡和氧自由基代谢平衡而在其抗风中起重要的生理保护作用。4.在重复强净风（18M/s)和风沙流吹袭中，紫穗槐和黑松在风吹处理中叶片MDA、可溶性糖、脯氨酸含量和CAT活力增高，在恢复期伴随叶片MDA下降，黑松维持较高的SOD活力，而紫穗槐叶片维持较高的CAT和POD活力。科属不同的两树种不仅抗风形态和生理调控机理不同，而且自愈修复机理也不同。项目实施期间，发表论文9篇，其中国内核心期刊收录5篇；培养硕士研究生1名。全面完成各项任务指标。