生态学报2017，Vol.37Issue(8)：2763-2769,7.DOI:10.5846/stxb201409281913
甘肃省民勤连古城自然保护区沙木蓼种群的结构与动态
Structure and dynamics of Atraphaxis bracteata populations in Minqin Liangucheng Nature Reserve, Gansu
摘要
Abstract
The Minqin Liangucheng Nature Reserve has different types of habitats and vegetations of Atraphaxis bracteata populations.In this study,three types of habitats,i.e.,the low denuded hills covered by gravel (habitat I),tilted alluvial fans with small aeolian sand dunes (habitat Ⅱ),and tilted alluvial fans without aeolian sand dunes (habitat Ⅲ),were selected to compare the development status,age structure,static life curve,and distribution pattern of A.bracteata populations at this reserve to reveal their succession dynamics,assess their ecological value,and provide the scientific knowledge for their rational management and sustainable usage.We found that (1) the population densities of young,mature,and old seedlings of A.bracteata were the highest at habitat I,followed by those at habitats Ⅱ and Ⅲ.However,there were no significant differences in the average height,average crown width,and new shoot growth among the same age groups at the three population habitats.(2) The seedlings of all ages dominated position at the three habitats and played a vital role on the propagation of A.bracteata.The age structures of young and mature populations at habitats Ⅰ and Ⅲ showed continuous growth curves,but that of the old population showed a single growth curve,suggesting that A.bracteata populations at these habitats were developing.The age structures of young and mature populations at habitat Ⅱ showed continuous stable growth curves,but that of old population showed a single stable curve,indicating that A.bracteata populations at this habitat were stable.(3) The lx,dx,and qx curves of seedlings and young and mature populations at the three habitats showed similar change trends.These curves showed decreasing trends from seedling age stage to young age stage,and then stabilized in the young and mature age stages,whereas the curves of old age grade were significantly different,and the populations overlapped between habitats Ⅲ and Ⅰ.This suggested that seedlings and older A.bracteata populations showed peak mortality,and there was a general pattern of growth at the earlier stage,which stabilized at the middle stage and then decreased at the later stage.(4) The distribution patterns of seedlings and young and mature populations were clump,whereas those for old populations were Poisson.The results indicated that the A.bracteata populations at the three habitats propagated vigorously and showed relatively optimal structure.The environmental difference among the three habitats only had significant impacts on soil seed bank,seed germination,and seedling preservation,but not on population development.These findings suggested that A.bracteata has strong adaptability and dominance in desert areas and can be restored and reconstructed.关键词
沙木蓼/年龄结构/静态生命曲线/种群动态Key words
Atraphaxis bracteata/age structure/static life curve/population dynamics引用本文复制引用
刘世增,李昌龙,纪永福,胡生新,李得禄,唐卫东,柴成武..甘肃省民勤连古城自然保护区沙木蓼种群的结构与动态[J].生态学报,2017,37(8):2763-2769,7.基金项目
甘肃省创新群体资助项目(145RJIA335) （145RJIA335）
甘肃省创新团队资助项目(1207TTCA002) （1207TTCA002）
