Populus euphratica Oliv. is widely distributed along the Tarim River. Maintaining stability of P. euphratica population is important to local development. This study explored the static life table, survivorship curves...Populus euphratica Oliv. is widely distributed along the Tarim River. Maintaining stability of P. euphratica population is important to local development. This study explored the static life table, survivorship curves and four function curves (survival rate, cumulative mortality rate, mortality density, and hazard rate), and development index of P. euphratica population in the middle reaches of Tarim River. The results indicated that the age structure of P. euphratica population belonged to positive pyramidal type, which meant young age-class individuals occupied most populations. The number ofⅠ-Ⅱage classes accounted for 66.2% of whole population, and this indicated that there were abundant subsequent seedlings resources to support the growth of P. euphratica population in the middle reaches of Tarim River. The survivorship curve of P. euphratica belonged to the Deevey Ⅲ (concave-type) and the development index was 47.72%. Four function curves revealed that the individuals of P. euphratica sharply decreased at the initial stage and then leveled off at the late stage of survival curve. Time sequence prediction models predicted that the number of midlife individuals would increase in future 10, 20, 30 years, and P. euphratica population grew steadily as a result of rich saplings.展开更多
通过对中国唯一银砂槐（Ammodendron bi folium）分布区——新疆伊犁河谷地塔克尔莫乎尔沙漠狭窄区域的样地调查和数据统计分析，绘制了银砂槐自然种群的径级结构图，编制了种群的特定时间生命表，分析了存活曲线、死亡率曲线和寿命期...通过对中国唯一银砂槐（Ammodendron bi folium）分布区——新疆伊犁河谷地塔克尔莫乎尔沙漠狭窄区域的样地调查和数据统计分析，绘制了银砂槐自然种群的径级结构图，编制了种群的特定时间生命表，分析了存活曲线、死亡率曲线和寿命期望等重要参数，并运用时间序列模型预测种群数量动态。结果表明：（1）研究区内银砂槐种群结构中小径级个体较多，即I～Ⅲ径级占70．4％，Ⅳ～Ⅶ径级占27．62％，Ⅷ～X径级仅占1．98％，种群整体结构属于增长型，但I径级个体数少于Ⅱ径级，种群的自然更新相对较差。（2）静态生命表分析结果表明，随着径级的增加银砂槐种群死亡率大致为上升趋势，且种群内基径超过3．5cm（Ⅷ径级）的银砂槐数量迅速下降，即研究区内银砂槐基径越接近Ⅷ径级就越接近其生理寿命。（3）研究区内银砂槐的存活曲线基本接近DeeveyⅢ型，但I径级存活数低于Ⅱ径级，Ⅱ径级后存活数量迅速下降，说明该种群幼苗补充量较少，自然更新受阻。（4）时间序列分析表明，随着时间推移，种群未来会呈现老龄个体增加的趋势。研究认为，新疆伊犁河谷地的银砂槐种群的生长发育主要受限于其自身的生物学特性和种内竞争，其种群的长期稳定维持较为困难，现有植株及生境斑块的妥善保护和适当的人工辅助措施是该区银砂槐种群恢复的关键。展开更多
基金the National Science and Technology Support Program Projects (2009BAC54B04) for financing this research
文摘Populus euphratica Oliv. is widely distributed along the Tarim River. Maintaining stability of P. euphratica population is important to local development. This study explored the static life table, survivorship curves and four function curves (survival rate, cumulative mortality rate, mortality density, and hazard rate), and development index of P. euphratica population in the middle reaches of Tarim River. The results indicated that the age structure of P. euphratica population belonged to positive pyramidal type, which meant young age-class individuals occupied most populations. The number ofⅠ-Ⅱage classes accounted for 66.2% of whole population, and this indicated that there were abundant subsequent seedlings resources to support the growth of P. euphratica population in the middle reaches of Tarim River. The survivorship curve of P. euphratica belonged to the Deevey Ⅲ (concave-type) and the development index was 47.72%. Four function curves revealed that the individuals of P. euphratica sharply decreased at the initial stage and then leveled off at the late stage of survival curve. Time sequence prediction models predicted that the number of midlife individuals would increase in future 10, 20, 30 years, and P. euphratica population grew steadily as a result of rich saplings.
文摘通过对中国唯一银砂槐（Ammodendron bi folium）分布区——新疆伊犁河谷地塔克尔莫乎尔沙漠狭窄区域的样地调查和数据统计分析，绘制了银砂槐自然种群的径级结构图，编制了种群的特定时间生命表，分析了存活曲线、死亡率曲线和寿命期望等重要参数，并运用时间序列模型预测种群数量动态。结果表明：（1）研究区内银砂槐种群结构中小径级个体较多，即I～Ⅲ径级占70．4％，Ⅳ～Ⅶ径级占27．62％，Ⅷ～X径级仅占1．98％，种群整体结构属于增长型，但I径级个体数少于Ⅱ径级，种群的自然更新相对较差。（2）静态生命表分析结果表明，随着径级的增加银砂槐种群死亡率大致为上升趋势，且种群内基径超过3．5cm（Ⅷ径级）的银砂槐数量迅速下降，即研究区内银砂槐基径越接近Ⅷ径级就越接近其生理寿命。（3）研究区内银砂槐的存活曲线基本接近DeeveyⅢ型，但I径级存活数低于Ⅱ径级，Ⅱ径级后存活数量迅速下降，说明该种群幼苗补充量较少，自然更新受阻。（4）时间序列分析表明，随着时间推移，种群未来会呈现老龄个体增加的趋势。研究认为，新疆伊犁河谷地的银砂槐种群的生长发育主要受限于其自身的生物学特性和种内竞争，其种群的长期稳定维持较为困难，现有植株及生境斑块的妥善保护和适当的人工辅助措施是该区银砂槐种群恢复的关键。
