塔里木河上游灰胡杨种群生活史特征与空间分布格局  

Life history characteristics and spatial distribution of Populus pruinosa population at the upper reaches of Tarim River

作　　者：韩路[1,2] 席琳乔[3] 王家强[1] 王海珍[1] 宇振荣[2] 

机构地区：[1]塔里木大学植物科学学院,新疆阿拉尔843300 [2]中国农业大学资源与环境学院,北京100193 [3]塔里木大学动物科学学院,新疆阿拉尔843300

出　　处：《生态学报》2013年第19期6181-6190,共10页Acta Ecologica Sinica

基　　金：国家自然科学基金资助项目(31060066);973前期研究专项资助(2012CB426507;2011CB411909)

摘　　要：灰胡杨是荒漠地区特有的珍稀渐危植物,主要分布在塔里木河流域,是塔里木荒漠生态系统的关键种之一。在塔里木河上游选择具有代表性群落设立5 hm2研究样地,应用相邻格子法进行每木调查,从年龄结构、生命表特征、存活曲线、生存分析以及种群不同发育阶段个体空间分布格局等方面研究了灰胡杨种群生活史动态特征与空间分布规律。结果表明:塔里木河上游灰胡杨种群结构整体上呈钟型,幼树个体较少,成年个体较多,属暂时稳定型种群;不同生境种群结构不同,随河流走向种群结构由稳定型转为衰退型。种群存活曲线趋于DeeveyⅡ,生存率呈单调下降趋势,中期(Ⅵ—Ⅸ)降幅较高;危险率呈上升趋势,于Ⅸ龄级出现危险率与死亡率、消失率高峰,生命期望单调下降,反映种群生存力下降的趋势。灰胡杨种群空间分布格局总体上为聚集分布,因生境不同空间格局发生变化,这是种群适应环境压力及与环境协同进化的结果;种群空间格局随发育进程而变化,从幼龄到中、大龄,种群分布格局的聚集强度减弱并逐渐转变为随机分布,这是种内竞争强度变化的结果。环境因子与种群分布多度的相关与逐步回归分析表明地下水位是影响种群分布的主要因素。可见,塔里木河上游灰胡杨种群结构与空间分布格局随生境和时间发生变化,环境因素和生物因素是影响灰胡杨种群生态特征的两个主要原因。Populus pruinosa Schrenk, a rare and vulnerable plant in arid deserts occurring mainly in the Tarim River Basin, is a key species of the Tarim desert ecosystem. The existence and development of desert riparian forest has controlled the structure and function of the desert ecosystem and eased sustainable development in the region. Since the 1950s, people used soil and water resources in the upper reaches of the Tarim River in an unsustainable manner, resulting in poor forest growth and death of many areas of forest. This directly endangered the sustainable development of the oasis＇ agricultural system and disturbed the ecological balance in this area. We studied the life history characteristics and spatial distribution patterns of P. pruinosa populations in the upper reaches of the Tarim River, Xinjiang, China, to determine the ecological characteristics of P. pruinosa populations and to learn how biological and environmental factors affect population the distribution and dynamics. The current trends in development of the P. pruinosa forest was studied, with the goal of ensuring the wise use （conservation） and protection （preservation） of this precious tree species in the Tarim River Basin. The survey area was located in the upper reaches of Tarim River （4025＇-4110＇N, 8010＇-8436＇E）. Five 1.0 hm2 plots were established and divided into 100 subplots. Diameter at breast height （DBH） of all trees DBH 〉 2.5 cm, regeneration-sized trees of P. pruinosa and shrubs as well as herbs were identified and measured using a contiguous grid quadrate method. We determined the life table, age structure and survivorship curve of P. pruinosa populations to analyze population structure and dynamics. We divided trees into four groups based on twelve DBH size classes to analyze spatial pattern dynamics for different age classes using field data. The results showed that the age structure of P. pruinosa populations had a bell shape with a low percentage of younger and healthy adult trees, which indicated the po

关 键 词：塔里木河上游 灰胡杨 种群结构 生活史 空间分布格局 

分 类 号：Q948[生物学—植物学]