艾丁湖盐角草种群动态生命表及其对温度变化的响应  

Dynamic life table and response to temperature change of Salicornia europaeain Ayding Lake

作　　者：王锋[1] 黄俊华[1] 杨文英[2] 包灵[1] 仲亚婷 刘灿[1] 

机构地区：[1]新疆农业大学林学与园艺学院,新疆乌鲁木齐830052 [2]新疆农业大学林业研究所,新疆乌鲁木齐830052

出　　处：《草业科学》2017年第5期1064-1071,共8页Pratacultural Science

基　　金：国家自然科学基金项目(31260040)

摘　　要：艾丁湖地处亚洲中部极端干旱区,夏季酷热,地势闭塞,环境条件独特。本研究在该地区选择3个具有不同水分特征和盐角草(Salicornia europaea)种群特征的样地(A样地:地形偏高,4月之后地表无积水,盐角草密度相对较低;B样地:位于地表径流覆盖范围内,地表长期有积水,种群密度相对中等;C样地:地表早期有积水,种群密度相对最大,盖度最高)进行调查,根据盐角草的生长情况,从3月至10月每月调查1~2次,共10次,每次统计样方内盐角草的株数。利用动态生命表以及相关性分析的方法来研究该地区盐角草种群变化及其与环境温度之间的关系。结果表明,艾丁湖盐角草种群密度在5月前基本呈增长状态,5月末至6月由于温度升高、水分下降和营养物质减少引发了种群自疏,出现第1次死亡率高峰期;7月至8月,A、B两个种群出现第2次死亡率高峰期,主要原因是连续长达34d的40℃以上的极端高温;9月A种群出现第3次死亡率高峰期,主要原因可能是高温以及高温加速土壤水分蒸发引起的土壤返盐、水分丧失,从而导致的高温胁迫和盐胁迫。相关性分析表明,A、B种群死亡率与高温显著相关(P<0.05)。C种群仅有一次死亡率高峰期,且与温度相关不显著(P>0.05),与A、B种群差异较大的原因可能是由于C样地水分条件好、种群密度高缓解了高温的胁迫作用。A、B两个种群存活曲线属于Deevy-Ⅲ型,即初期死亡率较高,9月之后趋于稳定;C种群属于Deevey-Ⅱ型存活曲线,呈对角线型,即各个龄级存活率基本一致。Ayding Lake, located in the extreme arid region in Middle Asia, has a unique environment condition. Occluded terrain leads to high temperatures in summer. Currently, no studies have shown how this area is af- fected by Salicornia europaea. In this study, 3 sample plots with different water and population characteristics were selected and named plots A, B, and C. Plot A was a high terrain, with no water on the surface after April and low plant density. The surface of plot B was covered with water for a long period, and it had moderate plant density. The surface of plot C was covered with water during the early months of the year, and it had the highest plant density. We set 3 quadrats of 0.5 m×0.5 m in each plot. Each quadrat was investigated 1-2 times a month, and the plant density was counted 10 times. By using dynamic life table and correlation analysis, we studied the relationship between population change and temperature. The results showed that S. europaea ulations grew before May. In all plots, the high mortality period for S. europaea populations was from M June because of self-thinning triggered by increase in temperature and reductions in moisture andnutrients. pop- ay to S. europaea populations of plots A and B showed a second high mortality period from July to August because of the extreme temperature of 43 ℃ for 43 days. The S. europaea population in plot A showed a third high mor- tality period in September because of high temperature and salt stresses caused by evaporation of soil moisture resulting in increased salt concentration. The plant mortality noted in plots A and B was significantly correlated with temperature. S. europaea population in plot C had only one period of high mortality, but this was not sig- nificantly correlated with temperature. This is because compared to plots A and B, plot C had more moisture and higher plant population density, which can relieve the stress of high temperature. The survival curves of plant populations in plots A and B belong to Deevey type Ⅲ, which sho

关 键 词：种群动态 高温胁迫 盐胁迫 存活曲线 极端环境 

分 类 号：Q948.1[生物学—植物学]